// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Drawing;
using System.Drawing.Imaging;
using Microsoft.DotNet.RemoteExecutor;
using Moq;
using WinForms.Common.Tests;
using Xunit;
using static Interop;

namespace System.Windows.Forms.Tests
{
    using Point = System.Drawing.Point;
    using Size = System.Drawing.Size;

    public class TabPageTests : IClassFixture<ThreadExceptionFixture>
    {
        [WinFormsFact]
        public void TabPage_Ctor_Default()
        {
            using var control = new SubTabPage();
            Assert.Null(control.AccessibleDefaultActionDescription);
            Assert.Null(control.AccessibleDescription);
            Assert.Null(control.AccessibleName);
            Assert.Equal(AccessibleRole.Default, control.AccessibleRole);
            Assert.False(control.AllowDrop);
            Assert.Equal(AnchorStyles.Top | AnchorStyles.Left, control.Anchor);
            Assert.False(control.AutoScroll);
            Assert.Equal(Size.Empty, control.AutoScrollMargin);
            Assert.Equal(Size.Empty, control.AutoScrollMinSize);
            Assert.Equal(Point.Empty, control.AutoScrollPosition);
            Assert.False(control.AutoSize);
            Assert.Equal(AutoSizeMode.GrowOnly, control.AutoSizeMode);
            Assert.Equal(Control.DefaultBackColor, control.BackColor);
            Assert.Null(control.BackgroundImage);
            Assert.Equal(ImageLayout.Tile, control.BackgroundImageLayout);
            Assert.Null(control.BindingContext);
            Assert.Equal(BorderStyle.None, control.BorderStyle);
            Assert.Equal(100, control.Bottom);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.Bounds);
            Assert.True(control.CanEnableIme);
            Assert.False(control.CanFocus);
            Assert.True(control.CanRaiseEvents);
            Assert.False(control.CanSelect);
            Assert.False(control.Capture);
            Assert.True(control.CausesValidation);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.ClientRectangle);
            Assert.Equal(new Size(200, 100), control.ClientSize);
            Assert.Null(control.Container);
            Assert.False(control.ContainsFocus);
            Assert.True(control.CausesValidation);
            Assert.Empty(control.Controls);
            Assert.Same(control.Controls, control.Controls);
            Assert.IsType<TabPage.TabPageControlCollection>(control.Controls);
            Assert.False(control.Created);
            Assert.Same(Cursors.Default, control.Cursor);
            Assert.Same(Cursors.Default, control.DefaultCursor);
            Assert.Equal(ImeMode.Inherit, control.DefaultImeMode);
            Assert.Equal(new Padding(3), control.DefaultMargin);
            Assert.Equal(Size.Empty, control.DefaultMaximumSize);
            Assert.Equal(Size.Empty, control.DefaultMinimumSize);
            Assert.Equal(Padding.Empty, control.DefaultPadding);
            Assert.Equal(new Size(200, 100), control.DefaultSize);
            Assert.False(control.DesignMode);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.DisplayRectangle);
            Assert.Equal(DockStyle.None, control.Dock);
            Assert.NotNull(control.DockPadding);
            Assert.Same(control.DockPadding, control.DockPadding);
            Assert.Equal(0, control.DockPadding.Top);
            Assert.Equal(0, control.DockPadding.Bottom);
            Assert.Equal(0, control.DockPadding.Left);
            Assert.Equal(0, control.DockPadding.Right);
            Assert.False(control.DoubleBuffered);
            Assert.True(control.Enabled);
            Assert.NotNull(control.Events);
            Assert.Same(control.Events, control.Events);
            Assert.False(control.Focused);
            Assert.Equal(Control.DefaultFont, control.Font);
            Assert.Equal(control.Font.Height, control.FontHeight);
            Assert.Equal(Control.DefaultForeColor, control.ForeColor);
            Assert.False(control.HasChildren);
            Assert.Equal(100, control.Height);
            Assert.NotNull(control.HorizontalScroll);
            Assert.Same(control.HorizontalScroll, control.HorizontalScroll);
            Assert.False(control.HScroll);
            Assert.Equal(ImeMode.NoControl, control.ImeMode);
            Assert.Equal(ImeMode.NoControl, control.ImeModeBase);
            Assert.False(control.IsAccessible);
            Assert.False(control.IsMirrored);
            Assert.NotNull(control.LayoutEngine);
            Assert.Same(control.LayoutEngine, control.LayoutEngine);
            Assert.Equal(0, control.Left);
            Assert.Equal(Point.Empty, control.Location);
            Assert.Equal(new Padding(3), control.Margin);
            Assert.Equal(Size.Empty, control.MaximumSize);
            Assert.Equal(Size.Empty, control.MinimumSize);
            Assert.Equal(Padding.Empty, control.Padding);
            Assert.Null(control.Parent);
            Assert.Equal(Size.Empty, control.PreferredSize);
            Assert.Equal("Microsoft\u00AE .NET", control.ProductName);
            Assert.False(control.RecreatingHandle);
            Assert.Null(control.Region);
            Assert.False(control.ResizeRedraw);
            Assert.Equal(200, control.Right);
            Assert.Equal(RightToLeft.No, control.RightToLeft);
            Assert.True(control.ShowFocusCues);
            Assert.True(control.ShowKeyboardCues);
            Assert.Null(control.Site);
            Assert.Equal(new Size(200, 100), control.Size);
            Assert.Equal(0, control.TabIndex);
            Assert.False(control.TabStop);
            Assert.Empty(control.Text);
            Assert.Equal(0, control.Top);
            Assert.Null(control.TopLevelControl);
            Assert.False(control.UseVisualStyleBackColor);
            Assert.False(control.UseWaitCursor);
            Assert.True(control.Visible);
            Assert.NotNull(control.VerticalScroll);
            Assert.Same(control.VerticalScroll, control.VerticalScroll);
            Assert.False(control.VScroll);
            Assert.Equal(200, control.Width);

            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringNormalizedTheoryData))]
        public void TabPage_Ctor_String(string text, string expectedText)
        {
            using var control = new SubTabPage(text);
            Assert.Null(control.AccessibleDefaultActionDescription);
            Assert.Null(control.AccessibleDescription);
            Assert.Null(control.AccessibleName);
            Assert.Equal(AccessibleRole.Default, control.AccessibleRole);
            Assert.False(control.AllowDrop);
            Assert.Equal(AnchorStyles.Top | AnchorStyles.Left, control.Anchor);
            Assert.False(control.AutoScroll);
            Assert.Equal(Size.Empty, control.AutoScrollMargin);
            Assert.Equal(Size.Empty, control.AutoScrollMinSize);
            Assert.Equal(Point.Empty, control.AutoScrollPosition);
            Assert.False(control.AutoSize);
            Assert.Equal(AutoSizeMode.GrowOnly, control.AutoSizeMode);
            Assert.Equal(Control.DefaultBackColor, control.BackColor);
            Assert.Null(control.BackgroundImage);
            Assert.Equal(ImageLayout.Tile, control.BackgroundImageLayout);
            Assert.Null(control.BindingContext);
            Assert.Equal(BorderStyle.None, control.BorderStyle);
            Assert.Equal(100, control.Bottom);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.Bounds);
            Assert.True(control.CanEnableIme);
            Assert.False(control.CanFocus);
            Assert.True(control.CanRaiseEvents);
            Assert.False(control.CanSelect);
            Assert.False(control.Capture);
            Assert.True(control.CausesValidation);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.ClientRectangle);
            Assert.Equal(new Size(200, 100), control.ClientSize);
            Assert.Null(control.Container);
            Assert.False(control.ContainsFocus);
            Assert.True(control.CausesValidation);
            Assert.Empty(control.Controls);
            Assert.Same(control.Controls, control.Controls);
            Assert.IsType<TabPage.TabPageControlCollection>(control.Controls);
            Assert.False(control.Created);
            Assert.Same(Cursors.Default, control.Cursor);
            Assert.Same(Cursors.Default, control.DefaultCursor);
            Assert.Equal(ImeMode.Inherit, control.DefaultImeMode);
            Assert.Equal(new Padding(3), control.DefaultMargin);
            Assert.Equal(Size.Empty, control.DefaultMaximumSize);
            Assert.Equal(Size.Empty, control.DefaultMinimumSize);
            Assert.Equal(Padding.Empty, control.DefaultPadding);
            Assert.Equal(new Size(200, 100), control.DefaultSize);
            Assert.False(control.DesignMode);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.DisplayRectangle);
            Assert.Equal(DockStyle.None, control.Dock);
            Assert.NotNull(control.DockPadding);
            Assert.Same(control.DockPadding, control.DockPadding);
            Assert.Equal(0, control.DockPadding.Top);
            Assert.Equal(0, control.DockPadding.Bottom);
            Assert.Equal(0, control.DockPadding.Left);
            Assert.Equal(0, control.DockPadding.Right);
            Assert.False(control.DoubleBuffered);
            Assert.True(control.Enabled);
            Assert.NotNull(control.Events);
            Assert.Same(control.Events, control.Events);
            Assert.False(control.Focused);
            Assert.Equal(Control.DefaultFont, control.Font);
            Assert.Equal(control.Font.Height, control.FontHeight);
            Assert.Equal(Control.DefaultForeColor, control.ForeColor);
            Assert.False(control.HasChildren);
            Assert.Equal(100, control.Height);
            Assert.NotNull(control.HorizontalScroll);
            Assert.Same(control.HorizontalScroll, control.HorizontalScroll);
            Assert.False(control.HScroll);
            Assert.Equal(ImeMode.NoControl, control.ImeMode);
            Assert.Equal(ImeMode.NoControl, control.ImeModeBase);
            Assert.False(control.IsAccessible);
            Assert.False(control.IsMirrored);
            Assert.NotNull(control.LayoutEngine);
            Assert.Same(control.LayoutEngine, control.LayoutEngine);
            Assert.Equal(0, control.Left);
            Assert.Equal(Point.Empty, control.Location);
            Assert.Equal(new Padding(3), control.Margin);
            Assert.Equal(Size.Empty, control.MaximumSize);
            Assert.Equal(Size.Empty, control.MinimumSize);
            Assert.Equal(Padding.Empty, control.Padding);
            Assert.Null(control.Parent);
            Assert.Equal(Size.Empty, control.PreferredSize);
            Assert.Equal("Microsoft\u00AE .NET", control.ProductName);
            Assert.False(control.RecreatingHandle);
            Assert.Null(control.Region);
            Assert.False(control.ResizeRedraw);
            Assert.Equal(200, control.Right);
            Assert.Equal(RightToLeft.No, control.RightToLeft);
            Assert.True(control.ShowFocusCues);
            Assert.True(control.ShowKeyboardCues);
            Assert.Null(control.Site);
            Assert.Equal(new Size(200, 100), control.Size);
            Assert.Equal(0, control.TabIndex);
            Assert.False(control.TabStop);
            Assert.Equal(expectedText, control.Text);
            Assert.Equal(0, control.Top);
            Assert.Null(control.TopLevelControl);
            Assert.False(control.UseVisualStyleBackColor);
            Assert.False(control.UseWaitCursor);
            Assert.True(control.Visible);
            Assert.NotNull(control.VerticalScroll);
            Assert.Same(control.VerticalScroll, control.VerticalScroll);
            Assert.False(control.VScroll);
            Assert.Equal(200, control.Width);

            Assert.False(control.IsHandleCreated);
        }

        [WinFormsFact]
        public void TabPage_CreateParams_GetDefault_ReturnsExpected()
        {
            using var control = new SubTabPage();
            CreateParams createParams = control.CreateParams;
            Assert.Null(createParams.Caption);
            Assert.Null(createParams.ClassName);
            Assert.Equal(0x8, createParams.ClassStyle);
            Assert.Equal(0x10000, createParams.ExStyle);
            Assert.Equal(100, createParams.Height);
            Assert.Equal(IntPtr.Zero, createParams.Parent);
            Assert.Null(createParams.Param);
            Assert.Equal(0x56000000, createParams.Style);
            Assert.Equal(200, createParams.Width);
            Assert.Equal(0, createParams.X);
            Assert.Equal(0, createParams.Y);
            Assert.Same(createParams, control.CreateParams);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [MemberData(nameof(ControlTests.Anchor_Set_TestData), MemberType = typeof(ControlTests))]
        public void TabPage_Anchor_Set_GetReturnsExpected(AnchorStyles value, AnchorStyles expected)
        {
            using var control = new TabPage
            {
                Anchor = value
            };
            Assert.Equal(expected, control.Anchor);
            Assert.Equal(DockStyle.None, control.Dock);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.Anchor = value;
            Assert.Equal(expected, control.Anchor);
            Assert.Equal(DockStyle.None, control.Dock);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [MemberData(nameof(ControlTests.Anchor_Set_TestData), MemberType = typeof(ControlTests))]
        public void TabPage_Anchor_SetWithOldValue_GetReturnsExpected(AnchorStyles value, AnchorStyles expected)
        {
            using var control = new TabPage
            {
                Anchor = AnchorStyles.Left
            };

            control.Anchor = value;
            Assert.Equal(expected, control.Anchor);
            Assert.Equal(DockStyle.None, control.Dock);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.Anchor = value;
            Assert.Equal(expected, control.Anchor);
            Assert.Equal(DockStyle.None, control.Dock);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [MemberData(nameof(ControlTests.Anchor_SetWithDock_TestData), MemberType = typeof(ControlTests))]
        public void TabPage_Anchor_SetWithDock_GetReturnsExpected(DockStyle dock, AnchorStyles value, AnchorStyles expectedAnchor, DockStyle expectedDock)
        {
            using var control = new TabPage
            {
                Dock = dock
            };

            control.Anchor = value;
            Assert.Equal(expectedAnchor, control.Anchor);
            Assert.Equal(expectedDock, control.Dock);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.Anchor = value;
            Assert.Equal(expectedAnchor, control.Anchor);
            Assert.Equal(expectedDock, control.Dock);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBoolTheoryData))]
        public void TabPage_AutoSize_Set_GetReturnsExpected(bool value)
        {
            using var control = new TabPage();
            int layoutCallCount = 0;
            control.Layout += (sender, e) => layoutCallCount++;

            control.AutoSize = value;
            Assert.Equal(value, control.AutoSize);
            Assert.Equal(0, layoutCallCount);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.AutoSize = value;
            Assert.Equal(value, control.AutoSize);
            Assert.Equal(0, layoutCallCount);
            Assert.False(control.IsHandleCreated);

            // Set different.
            control.AutoSize = !value;
            Assert.Equal(!value, control.AutoSize);
            Assert.Equal(0, layoutCallCount);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsFact]
        public void TabPage_AutoSize_SetWithHandler_CallsAutoSizeChanged()
        {
            using var control = new TabPage
            {
                AutoSize = true
            };
            int callCount = 0;
            EventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                callCount++;
            };
            control.AutoSizeChanged += handler;

            // Set different.
            control.AutoSize = false;
            Assert.False(control.AutoSize);
            Assert.Equal(1, callCount);

            // Set same.
            control.AutoSize = false;
            Assert.False(control.AutoSize);
            Assert.Equal(1, callCount);

            // Set different.
            control.AutoSize = true;
            Assert.True(control.AutoSize);
            Assert.Equal(2, callCount);

            // Remove handler.
            control.AutoSizeChanged -= handler;
            control.AutoSize = false;
            Assert.False(control.AutoSize);
            Assert.Equal(2, callCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetEnumTypeTheoryData), typeof(AutoSizeMode))]
        [CommonMemberData(nameof(CommonTestHelper.GetEnumTypeTheoryDataInvalid), typeof(AutoSizeMode))]
        public void TabPage_AutoSizeMode_Set_GetReturnsExpected(AutoSizeMode value)
        {
            using var control = new SubTabPage();
            int layoutCallCount = 0;
            control.Layout += (sender, e) => layoutCallCount++;

            control.AutoSizeMode = value;
            Assert.Equal(AutoSizeMode.GrowOnly, control.AutoSizeMode);
            Assert.Equal(AutoSizeMode.GrowOnly, control.GetAutoSizeMode());
            Assert.False(control.IsHandleCreated);
            Assert.Equal(0, layoutCallCount);

            // Set same.
            control.AutoSizeMode = value;
            Assert.Equal(AutoSizeMode.GrowOnly, control.AutoSizeMode);
            Assert.Equal(AutoSizeMode.GrowOnly, control.GetAutoSizeMode());
            Assert.False(control.IsHandleCreated);
            Assert.Equal(0, layoutCallCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetEnumTypeTheoryData), typeof(AutoSizeMode))]
        [CommonMemberData(nameof(CommonTestHelper.GetEnumTypeTheoryDataInvalid), typeof(AutoSizeMode))]
        public void TabPage_AutoSizeMode_SetWithParent_GetReturnsExpected(AutoSizeMode value)
        {
            using var parent = new TabControl();
            using var control = new SubTabPage
            {
                Parent = parent
            };
            int layoutCallCount = 0;
            control.Layout += (sender, e) => layoutCallCount++;
            int parentLayoutCallCount = 0;
            parent.Layout += (sender, e) => parentLayoutCallCount++;

            control.AutoSizeMode = value;
            Assert.Equal(AutoSizeMode.GrowOnly, control.AutoSizeMode);
            Assert.Equal(AutoSizeMode.GrowOnly, control.GetAutoSizeMode());
            Assert.False(control.IsHandleCreated);
            Assert.Equal(0, layoutCallCount);
            Assert.False(parent.IsHandleCreated);
            Assert.Equal(0, parentLayoutCallCount);

            // Set same.
            control.AutoSizeMode = value;
            Assert.Equal(AutoSizeMode.GrowOnly, control.AutoSizeMode);
            Assert.Equal(AutoSizeMode.GrowOnly, control.GetAutoSizeMode());
            Assert.False(control.IsHandleCreated);
            Assert.Equal(0, layoutCallCount);
            Assert.False(parent.IsHandleCreated);
            Assert.Equal(0, parentLayoutCallCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetEnumTypeTheoryData), typeof(AutoSizeMode))]
        [CommonMemberData(nameof(CommonTestHelper.GetEnumTypeTheoryDataInvalid), typeof(AutoSizeMode))]
        public void TabPage_AutoSizeMode_SetWithHandle_GetReturnsExpected(AutoSizeMode value)
        {
            using var control = new SubTabPage();
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            control.AutoSizeMode = value;
            Assert.Equal(AutoSizeMode.GrowOnly, control.AutoSizeMode);
            Assert.Equal(AutoSizeMode.GrowOnly, control.GetAutoSizeMode());
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set same.
            control.AutoSizeMode = value;
            Assert.Equal(AutoSizeMode.GrowOnly, control.AutoSizeMode);
            Assert.Equal(AutoSizeMode.GrowOnly, control.GetAutoSizeMode());
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetEnumTypeTheoryData), typeof(AutoSizeMode))]
        [CommonMemberData(nameof(CommonTestHelper.GetEnumTypeTheoryDataInvalid), typeof(AutoSizeMode))]
        public void TabPage_AutoSizeMode_SetWithHandleWithParent_GetReturnsExpected(AutoSizeMode value)
        {
            using var parent = new TabControl();
            using var control = new SubTabPage
            {
                Parent = parent
            };
            Assert.NotEqual(IntPtr.Zero, parent.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;
            int layoutCallCount = 0;
            control.Layout += (sender, e) => layoutCallCount++;
            int parentInvalidatedCallCount = 0;
            parent.Invalidated += (sender, e) => parentInvalidatedCallCount++;
            int parentStyleChangedCallCount = 0;
            parent.StyleChanged += (sender, e) => parentStyleChangedCallCount++;
            int parentCreatedCallCount = 0;
            parent.HandleCreated += (sender, e) => parentCreatedCallCount++;
            int parentLayoutCallCount = 0;
            parent.Layout += (sender, e) => parentLayoutCallCount++;

            control.AutoSizeMode = value;
            Assert.Equal(AutoSizeMode.GrowOnly, control.AutoSizeMode);
            Assert.Equal(AutoSizeMode.GrowOnly, control.GetAutoSizeMode());
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.Equal(0, layoutCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);
            Assert.Equal(0, parentLayoutCallCount);

            // Set same.
            control.AutoSizeMode = value;
            Assert.Equal(AutoSizeMode.GrowOnly, control.AutoSizeMode);
            Assert.Equal(AutoSizeMode.GrowOnly, control.GetAutoSizeMode());
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.Equal(0, layoutCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);
            Assert.Equal(0, parentLayoutCallCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBoolTheoryData))]
        public static void TabPage_BackColor_Get_ReturnsExpected(bool useVisualStyleBackColor)
        {
            using var control = new TabPage
            {
                UseVisualStyleBackColor = useVisualStyleBackColor
            };
            Assert.Equal(Control.DefaultBackColor, control.BackColor);
        }

        [WinFormsTheory(Skip = "Crash with AbandonedMutexException. See: https://github.com/dotnet/arcade/issues/5325")]
        [CommonMemberData(nameof(CommonTestHelper.GetBoolTheoryData))]
        public static void TabPage_BackColor_GetVisualStyles_ReturnsExpected(bool useVisualStyleBackColorParam)
        {
            // Run this from another thread as we call Application.EnableVisualStyles.
            RemoteExecutor.Invoke((useVisualStyleBackColorString) =>
            {
                bool useVisualStyleBackColor = bool.Parse(useVisualStyleBackColorString);

                Application.EnableVisualStyles();

                using var control = new TabPage
                {
                    UseVisualStyleBackColor = useVisualStyleBackColor
                };
                Assert.Equal(Control.DefaultBackColor, control.BackColor);
            }, useVisualStyleBackColorParam.ToString()).Dispose();
        }

        [WinFormsTheory]
        [InlineData(true, TabAppearance.Buttons)]
        [InlineData(true, TabAppearance.FlatButtons)]
        // Has different behaviour with VisualStyles on, see: TabPage_BackColor_TabAppearance_Normal_GetWithParent_ReturnsExpected
        // [InlineData(true, TabAppearance.Normal)]
        [InlineData(false, TabAppearance.Buttons)]
        [InlineData(false, TabAppearance.FlatButtons)]
        [InlineData(false, TabAppearance.Normal)]
        public static void TabPage_BackColor_GetWithParent_ReturnsExpected(bool useVisualStyleBackColor, TabAppearance parentAppearance)
        {
            if (Application.UseVisualStyles)
            {
                return;
            }

            using var parent = new TabControl
            {
                Appearance = parentAppearance
            };
            using var control = new TabPage
            {
                UseVisualStyleBackColor = useVisualStyleBackColor,
                Parent = parent
            };

            Assert.Equal(Control.DefaultBackColor, control.BackColor);
        }

        [WinFormsFact]
        public static void TabPage_BackColor_TabAppearance_Normal_GetWithParent_ReturnsExpected()
        {
            using var parent = new TabControl
            {
                Appearance = TabAppearance.Normal
            };
            using var control = new TabPage
            {
                UseVisualStyleBackColor = true,
                Parent = parent
            };

            if (Application.UseVisualStyles)
            {
                Assert.Equal(Color.Transparent, control.BackColor);
            }
            else
            {
                Assert.Equal(Control.DefaultBackColor, control.BackColor);
            }
        }

        public static IEnumerable<object[]> BackColor_GetVisualStylesWithParent_TestData()
        {
            yield return new object[] { true, TabAppearance.Buttons, Control.DefaultBackColor };
            yield return new object[] { true, TabAppearance.FlatButtons, Control.DefaultBackColor };
            yield return new object[] { true, TabAppearance.Normal, Color.Transparent };
            yield return new object[] { false, TabAppearance.Buttons, Control.DefaultBackColor };
            yield return new object[] { false, TabAppearance.FlatButtons, Control.DefaultBackColor };
            yield return new object[] { false, TabAppearance.Normal, Control.DefaultBackColor };
        }

        [WinFormsTheory(Skip = "Crash with AbandonedMutexException. See: https://github.com/dotnet/arcade/issues/5325")]
        [MemberData(nameof(BackColor_GetVisualStylesWithParent_TestData))]
        public static void TabPage_BackColor_GetVisualStylesWithParent_ReturnsExpected(bool useVisualStyleBackColorParam, TabAppearance parentAppearanceParam, Color expectedParam)
        {
            // Run this from another thread as we call Application.EnableVisualStyles.
            RemoteExecutor.Invoke((useVisualStyleBackColorString, parentAppearanceString, expectedString) =>
            {
                bool useVisualStyleBackColor = bool.Parse(useVisualStyleBackColorString);
                TabAppearance parentAppearance = (TabAppearance)Enum.Parse(typeof(TabAppearance), parentAppearanceString);
                Color expected = Color.FromArgb(int.Parse(expectedString));

                Application.EnableVisualStyles();

                using var parent = new TabControl
                {
                    Appearance = parentAppearance
                };
                using var control = new TabPage
                {
                    UseVisualStyleBackColor = useVisualStyleBackColor,
                    Parent = parent
                };
                Assert.Equal(expected.ToArgb(), control.BackColor.ToArgb());
            }, useVisualStyleBackColorParam.ToString(), parentAppearanceParam.ToString(), expectedParam.ToArgb().ToString()).Dispose();
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBackColorTheoryData))]
        public void TabPage_BackColor_Set_GetReturnsExpected(Color value, Color expected)
        {
            using var control = new TabPage
            {
                BackColor = value
            };
            Assert.Equal(expected, control.BackColor);
            Assert.False(control.UseVisualStyleBackColor);

            // Set same.
            control.BackColor = value;
            Assert.Equal(expected, control.BackColor);
            Assert.False(control.UseVisualStyleBackColor);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBackColorTheoryData))]
        public void TabPage_BackColor_SetWithUseVisualStyleBackColor_GetReturnsExpected(Color value, Color expected)
        {
            using var control = new TabPage
            {
                UseVisualStyleBackColor = true,
                BackColor = value
            };
            Assert.Equal(expected, control.BackColor);
            Assert.False(control.UseVisualStyleBackColor);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.BackColor = value;
            Assert.Equal(expected, control.BackColor);
            Assert.False(control.UseVisualStyleBackColor);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBackColorTheoryData))]
        public void TabPage_BackColor_SetDesignMode_GetReturnsExpected(Color value, Color expected)
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.GetService(typeof(IDictionaryService)))
                .Returns(null);
            mockSite
                .Setup(s => s.GetService(typeof(IExtenderListService)))
                .Returns(null);
            mockSite
                .Setup(s => s.GetService(typeof(IComponentChangeService)))
                .Returns(null);
            mockSite
                .Setup(s => s.GetService(typeof(ITypeDescriptorFilterService)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var control = new TabPage
            {
                Site = mockSite.Object,
                BackColor = value
            };
            Assert.Equal(expected, control.BackColor);
            Assert.False(control.UseVisualStyleBackColor);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.BackColor = value;
            Assert.Equal(expected, control.BackColor);
            Assert.False(control.UseVisualStyleBackColor);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBackColorTheoryData))]
        public void TabPage_BackColor_SetDesignModeWithUseVisualStyleBackColor_GetReturnsExpected(Color value, Color expected)
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.GetService(typeof(IDictionaryService)))
                .Returns(null);
            mockSite
                .Setup(s => s.GetService(typeof(IExtenderListService)))
                .Returns(null);
            mockSite
                .Setup(s => s.GetService(typeof(IComponentChangeService)))
                .Returns(null);
            mockSite
                .Setup(s => s.GetService(typeof(ITypeDescriptorFilterService)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var control = new TabPage
            {
                Site = mockSite.Object,
                UseVisualStyleBackColor = true,
                BackColor = value
            };
            Assert.Equal(expected, control.BackColor);
            Assert.Equal(value.IsEmpty, control.UseVisualStyleBackColor);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.BackColor = value;
            Assert.Equal(expected, control.BackColor);
            Assert.Equal(value.IsEmpty, control.UseVisualStyleBackColor);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBackColorTheoryData))]
        public void TabPage_BackColor_SetDesignModeWithInvalidDescriptor_GetReturnsExpected(Color value, Color expected)
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.GetService(typeof(IDictionaryService)))
                .Returns(null);
            mockSite
                .Setup(s => s.GetService(typeof(IExtenderListService)))
                .Returns(null);
            mockSite
                .Setup(s => s.GetService(typeof(IComponentChangeService)))
                .Returns(null);
            mockSite
                .Setup(s => s.GetService(typeof(ITypeDescriptorFilterService)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var control = new TabPage
            {
                Site = mockSite.Object,
                UseVisualStyleBackColor = true,
            };
            var mockCustomTypeDescriptor = new Mock<ICustomTypeDescriptor>(MockBehavior.Strict);
            mockCustomTypeDescriptor
                .Setup(d => d.GetProperties())
                .Returns(PropertyDescriptorCollection.Empty);
            var mockProvider = new Mock<TypeDescriptionProvider>(MockBehavior.Strict);
            mockProvider
                .Setup(p => p.GetCache(control))
                .CallBase();
            mockProvider
                .Setup(p => p.GetExtendedTypeDescriptor(control))
                .CallBase();
            mockProvider
                .Setup(p => p.GetTypeDescriptor(typeof(TabPage), control))
                .Returns(mockCustomTypeDescriptor.Object);
            TypeDescriptor.AddProvider(mockProvider.Object, control);

            control.BackColor = value;
            Assert.Equal(expected, control.BackColor);
            Assert.True(control.UseVisualStyleBackColor);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.BackColor = value;
            Assert.Equal(expected, control.BackColor);
            Assert.True(control.UseVisualStyleBackColor);
            Assert.False(control.IsHandleCreated);
        }

        public static IEnumerable<object[]> BackColor_SetWithHandle_TestData()
        {
            yield return new object[] { Color.Red, Color.Red, 1 };
            yield return new object[] { Color.Empty, Control.DefaultBackColor, 0 };
        }

        [WinFormsTheory]
        [MemberData(nameof(BackColor_SetWithHandle_TestData))]
        public void TabPage_BackColor_SetWithHandle_GetReturnsExpected(Color value, Color expected, int expectedInvalidatedCallCount)
        {
            using var control = new TabPage();
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            control.BackColor = value;
            Assert.Equal(expected, control.BackColor);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidatedCallCount, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set same.
            control.BackColor = value;
            Assert.Equal(expected, control.BackColor);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidatedCallCount, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        [WinFormsFact]
        public void TabPage_BackColor_SetWithHandler_CallsBackColorChanged()
        {
            using var control = new TabPage();
            int callCount = 0;
            EventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                callCount++;
            };
            control.BackColorChanged += handler;

            // Set different.
            control.BackColor = Color.Red;
            Assert.Equal(Color.Red, control.BackColor);
            Assert.Equal(1, callCount);

            // Set same.
            control.BackColor = Color.Red;
            Assert.Equal(Color.Red, control.BackColor);
            Assert.Equal(1, callCount);

            // Set different.
            control.BackColor = Color.Empty;
            Assert.Equal(Control.DefaultBackColor, control.BackColor);
            Assert.Equal(2, callCount);

            // Remove handler.
            control.BackColorChanged -= handler;
            control.BackColor = Color.Red;
            Assert.Equal(Color.Red, control.BackColor);
            Assert.Equal(2, callCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetEnumTypeTheoryData), typeof(DockStyle))]
        public void TabPage_Dock_Set_GetReturnsExpected(DockStyle value)
        {
            using var control = new TabPage
            {
                Dock = value
            };
            Assert.Equal(value, control.Dock);
            Assert.Equal(AnchorStyles.Top | AnchorStyles.Left, control.Anchor);

            // Set same.
            control.Dock = value;
            Assert.Equal(value, control.Dock);
            Assert.Equal(AnchorStyles.Top | AnchorStyles.Left, control.Anchor);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetEnumTypeTheoryData), typeof(DockStyle))]
        public void TabPage_Dock_SetWithOldValue_GetReturnsExpected(DockStyle value)
        {
            using var control = new TabPage
            {
                Dock = DockStyle.Top
            };

            control.Dock = value;
            Assert.Equal(value, control.Dock);
            Assert.Equal(AnchorStyles.Top | AnchorStyles.Left, control.Anchor);

            // Set same.
            control.Dock = value;
            Assert.Equal(value, control.Dock);
            Assert.Equal(AnchorStyles.Top | AnchorStyles.Left, control.Anchor);
        }

        [WinFormsTheory]
        [MemberData(nameof(ControlTests.Dock_SetWithAnchor_TestData), MemberType = typeof(ControlTests))]
        public void TabPage_Dock_SetWithAnchor_GetReturnsExpected(AnchorStyles anchor, DockStyle value, AnchorStyles expectedAnchor)
        {
            using var control = new TabPage
            {
                Anchor = anchor
            };

            control.Dock = value;
            Assert.Equal(value, control.Dock);
            Assert.Equal(expectedAnchor, control.Anchor);

            // Set same.
            control.Dock = value;
            Assert.Equal(value, control.Dock);
            Assert.Equal(expectedAnchor, control.Anchor);
        }

        [WinFormsFact]
        public void TabPage_Dock_SetWithHandler_CallsDockChanged()
        {
            using var control = new TabPage
            {
                Dock = DockStyle.None
            };
            int callCount = 0;
            EventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                callCount++;
            };
            control.DockChanged += handler;

            // Set different.
            control.Dock = DockStyle.Top;
            Assert.Equal(DockStyle.Top, control.Dock);
            Assert.Equal(1, callCount);

            // Set same.
            control.Dock = DockStyle.Top;
            Assert.Equal(DockStyle.Top, control.Dock);
            Assert.Equal(1, callCount);

            // Set different.
            control.Dock = DockStyle.Left;
            Assert.Equal(DockStyle.Left, control.Dock);
            Assert.Equal(2, callCount);

            // Remove handler.
            control.DockChanged -= handler;
            control.Dock = DockStyle.Top;
            Assert.Equal(DockStyle.Top, control.Dock);
            Assert.Equal(2, callCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetEnumTypeTheoryDataInvalid), typeof(DockStyle))]
        public void TabPage_Dock_SetInvalid_ThrowsInvalidEnumArgumentException(DockStyle value)
        {
            using var control = new TabPage();
            Assert.Throws<InvalidEnumArgumentException>("value", () => control.Dock = value);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBoolTheoryData))]
        public void TabPage_Enabled_Set_GetReturnsExpected(bool value)
        {
            using var control = new TabPage
            {
                Enabled = value
            };
            Assert.Equal(value, control.Enabled);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.Enabled = value;
            Assert.Equal(value, control.Enabled);
            Assert.False(control.IsHandleCreated);

            // Set different.
            control.Enabled = !value;
            Assert.Equal(!value, control.Enabled);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [InlineData(true, false, 1, 2)]
        [InlineData(true, true, 0, 1)]
        [InlineData(false, false, 0, 0)]
        [InlineData(false, true, 0, 0)]
        public void TabPage_Enabled_SetWithHandle_GetReturnsExpected(bool userPaint, bool value, int expectedInvalidateCallCount1, int expectedInvalidateCallCount2)
        {
            using var control = new SubTabPage();
            control.SetStyle(ControlStyles.UserPaint, userPaint);
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;
            Assert.Equal(userPaint, control.GetStyle(ControlStyles.UserPaint));

            control.Enabled = value;
            Assert.Equal(value, control.Enabled);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidateCallCount1, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set same.
            control.Enabled = value;
            Assert.Equal(value, control.Enabled);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidateCallCount1, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set different.
            control.Enabled = !value;
            Assert.Equal(!value, control.Enabled);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidateCallCount2, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        [WinFormsFact]
        public void TabPage_Enabled_SetWithHandler_CallsEnabledChanged()
        {
            using var control = new TabPage
            {
                Enabled = true
            };
            int callCount = 0;
            EventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                callCount++;
            };
            control.EnabledChanged += handler;

            // Set different.
            control.Enabled = false;
            Assert.False(control.Enabled);
            Assert.Equal(1, callCount);

            // Set same.
            control.Enabled = false;
            Assert.False(control.Enabled);
            Assert.Equal(1, callCount);

            // Set different.
            control.Enabled = true;
            Assert.True(control.Enabled);
            Assert.Equal(2, callCount);

            // Remove handler.
            control.EnabledChanged -= handler;
            control.Enabled = false;
            Assert.False(control.Enabled);
            Assert.Equal(2, callCount);
        }

        [WinFormsTheory]
        [InlineData(-1)]
        [InlineData(0)]
        [InlineData(1)]
        public void TabPage_ImageIndex_Set_GetReturnsExpected(int value)
        {
            using var control = new TabPage
            {
                ImageIndex = value
            };
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.True(control.Visible);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.ImageIndex = value;
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.True(control.Visible);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [InlineData(-1)]
        [InlineData(0)]
        [InlineData(1)]
        public void TabPage_ImageIndex_SetWithParent_GetReturnsExpected(int value)
        {
            using var parent = new TabControl();
            using var control = new TabPage
            {
                Parent = parent,
                ImageIndex = value
            };
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.False(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);

            // Set same.
            control.ImageIndex = value;
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.False(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);
        }

        [WinFormsTheory]
        [InlineData(-1)]
        [InlineData(0)]
        [InlineData(1)]
        public void TabPage_ImageIndex_SetWithDesignModeParent_GetReturnsExpected(int value)
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var parent = new TabControl
            {
                Site = mockSite.Object
            };
            using var control = new TabPage
            {
                Parent = parent,
                ImageIndex = value
            };
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.False(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);

            // Set same.
            control.ImageIndex = value;
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.False(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);
        }

        [WinFormsTheory]
        [InlineData(-1)]
        [InlineData(0)]
        [InlineData(1)]
        public void TabPage_ImageIndex_SetWithImageKey_GetReturnsExpected(int value)
        {
            using var control = new TabPage
            {
                ImageKey = "imageKey",
                ImageIndex = value
            };
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.True(control.Visible);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.ImageIndex = value;
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.True(control.Visible);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [InlineData(-1)]
        [InlineData(0)]
        [InlineData(1)]
        public void TabPage_ImageIndex_SetWithHandle_GetReturnsExpected(int value)
        {
            using var control = new TabPage();
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            control.ImageIndex = value;
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set same.
            control.ImageIndex = value;
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        [WinFormsTheory]
        [InlineData(-1)]
        [InlineData(0)]
        [InlineData(1)]
        public void TabPage_ImageIndex_SetWithParentWithHandle_GetReturnsExpected(int value)
        {
            using var parent = new TabControl();
            using var control = new TabPage
            {
                Parent = parent
            };
            Assert.NotEqual(IntPtr.Zero, parent.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;
            int parentInvalidatedCallCount = 0;
            parent.Invalidated += (sender, e) => parentInvalidatedCallCount++;
            int parentStyleChangedCallCount = 0;
            parent.StyleChanged += (sender, e) => parentStyleChangedCallCount++;
            int parentCreatedCallCount = 0;
            parent.HandleCreated += (sender, e) => parentCreatedCallCount++;

            control.ImageIndex = value;
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(1, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);

            // Set same.
            control.ImageIndex = value;
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(2, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);
        }

        [WinFormsTheory]
        [InlineData(-1)]
        [InlineData(0)]
        [InlineData(1)]
        public void TabPage_ImageIndex_SetWithDesignModeParentWithHandle_GetReturnsExpected(int value)
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var parent = new TabControl
            {
                Site = mockSite.Object
            };
            using var control = new TabPage
            {
                Parent = parent
            };
            Assert.NotEqual(IntPtr.Zero, parent.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;
            int parentInvalidatedCallCount = 0;
            parent.Invalidated += (sender, e) => parentInvalidatedCallCount++;
            int parentStyleChangedCallCount = 0;
            parent.StyleChanged += (sender, e) => parentStyleChangedCallCount++;
            int parentCreatedCallCount = 0;
            parent.HandleCreated += (sender, e) => parentCreatedCallCount++;

            control.ImageIndex = value;
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(1, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);

            // Set same.
            control.ImageIndex = value;
            Assert.Equal(value, control.ImageIndex);
            Assert.Empty(control.ImageKey);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(2, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);
        }

        [WinFormsTheory]
        [InlineData(-1)]
        [InlineData(0)]
        [InlineData(1)]
        public unsafe void TabPageCollection_ImageIndex_SetGetItemsWithHandle_Success(int imageIndex)
        {
            using var owner = new TabControl();
            using var page1 = new TabPage();
            using var page2 = new TabPage
            {
                Text = "Text",
                ImageIndex = 1
            };
            using var page3 = new NullTextTabPage();
            owner.TabPages.Add(page1);
            owner.TabPages.Add(page2);
            owner.TabPages.Add(page3);
            Assert.NotEqual(IntPtr.Zero, owner.Handle);

            page2.ImageIndex = imageIndex;
            Assert.Equal((IntPtr)3, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMCOUNT, IntPtr.Zero, IntPtr.Zero));

            char* buffer = stackalloc char[256];
            ComCtl32.TCITEMW item = default;
            item.cchTextMax = int.MaxValue;
            item.pszText = buffer;
            item.dwStateMask = (ComCtl32.TCIS)uint.MaxValue;
            item.mask = (ComCtl32.TCIF)uint.MaxValue;

            // Get item 0.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)0, ref item));
            Assert.Equal(ComCtl32.TCIS.BUTTONPRESSED, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);

            // Get item 1.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)1, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Equal("Text", new string(item.pszText));
            Assert.Equal(imageIndex, item.iImage);

            // Get item 2.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)2, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);
        }

        [WinFormsTheory]
        [InlineData(-1)]
        [InlineData(0)]
        [InlineData(1)]
        public unsafe void TabPageCollection_ImageIndex_SetGetItemsWithHandleDesignMode_Success(int imageIndex)
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var owner = new TabControl
            {
                Site = mockSite.Object
            };
            using var page1 = new TabPage();
            using var page2 = new TabPage
            {
                Text = "Text",
                ImageIndex = 1
            };
            using var page3 = new NullTextTabPage();
            owner.TabPages.Add(page1);
            owner.TabPages.Add(page2);
            owner.TabPages.Add(page3);
            Assert.NotEqual(IntPtr.Zero, owner.Handle);

            page2.ImageIndex = imageIndex;
            Assert.Equal((IntPtr)3, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMCOUNT, IntPtr.Zero, IntPtr.Zero));

            char* buffer = stackalloc char[256];
            ComCtl32.TCITEMW item = default;
            item.cchTextMax = int.MaxValue;
            item.pszText = buffer;
            item.dwStateMask = (ComCtl32.TCIS)uint.MaxValue;
            item.mask = (ComCtl32.TCIF)uint.MaxValue;

            // Get item 0.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)0, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);

            // Get item 1.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)1, ref item));
            Assert.Equal(ComCtl32.TCIS.BUTTONPRESSED, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Equal("Text", new string(item.pszText));
            Assert.Equal(imageIndex, item.iImage);

            // Get item 2.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)2, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);
        }

        [WinFormsFact]
        public void TabPage_ImageIndex_SetInvalidValue_ThrowsArgumentOutOfRangeException()
        {
            using var control = new TabPage();
            Assert.Throws<ArgumentOutOfRangeException>("value", () => control.ImageIndex = -2);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringTheoryData))]
        public void TabPage_ImageKey_Set_GetReturnsExpected(string value)
        {
            using var control = new TabPage
            {
                ImageKey = value
            };
            Assert.Equal(-1, control.ImageIndex);
            Assert.Equal(value, control.ImageKey);
            Assert.True(control.Visible);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.ImageKey = value;
            Assert.Equal(-1, control.ImageIndex);
            Assert.Equal(value, control.ImageKey);
            Assert.True(control.Visible);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringTheoryData))]
        public void TabPage_ImageKey_SetWithParent_GetReturnsExpected(string value)
        {
            using var parent = new TabControl();
            using var control = new TabPage
            {
                ImageKey = value
            };
            Assert.Equal(-1, control.ImageIndex);
            Assert.Equal(value, control.ImageKey);
            Assert.True(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);

            // Set same.
            control.ImageKey = value;
            Assert.Equal(-1, control.ImageIndex);
            Assert.Equal(value, control.ImageKey);
            Assert.True(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringTheoryData))]
        public void TabPage_ImageKey_SetWithDesignModeParent_GetReturnsExpected(string value)
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var parent = new TabControl
            {
                Site = mockSite.Object
            };
            using var control = new TabPage
            {
                ImageKey = value
            };
            Assert.Equal(-1, control.ImageIndex);
            Assert.Equal(value, control.ImageKey);
            Assert.True(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);

            // Set same.
            control.ImageKey = value;
            Assert.Equal(-1, control.ImageIndex);
            Assert.Equal(value, control.ImageKey);
            Assert.True(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringTheoryData))]
        public void TabPage_ImageKey_SetWithImageIndex_GetReturnsExpected(string value)
        {
            using var control = new TabPage
            {
                ImageIndex = 1,
                ImageKey = value
            };
            Assert.Equal(-1, control.ImageIndex);
            Assert.True(control.Visible);
            Assert.Equal(value, control.ImageKey);

            // Set same.
            control.ImageKey = value;
            Assert.Equal(-1, control.ImageIndex);
            Assert.True(control.Visible);
            Assert.Equal(value, control.ImageKey);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringTheoryData))]
        public void TabPage_ImageKey_SetWithHandle_GetReturnsExpected(string value)
        {
            using var control = new TabPage();
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            control.ImageKey = value;
            Assert.Equal(-1, control.ImageIndex);
            Assert.Equal(value, control.ImageKey);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set same.
            control.ImageKey = value;
            Assert.Equal(-1, control.ImageIndex);
            Assert.Equal(value, control.ImageKey);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringTheoryData))]
        public void TabPage_ImageKey_SetWithHandleWithParent_GetReturnsExpected(string value)
        {
            using var parent = new TabControl();
            using var control = new TabPage
            {
                Parent = parent
            };
            Assert.NotEqual(IntPtr.Zero, parent.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;
            int parentInvalidatedCallCount = 0;
            parent.Invalidated += (sender, e) => parentInvalidatedCallCount++;
            int parentStyleChangedCallCount = 0;
            parent.StyleChanged += (sender, e) => parentStyleChangedCallCount++;
            int parentCreatedCallCount = 0;
            parent.HandleCreated += (sender, e) => parentCreatedCallCount++;

            control.ImageKey = value;
            Assert.Equal(-1, control.ImageIndex);
            Assert.Equal(value, control.ImageKey);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(1, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);

            // Set same.
            control.ImageKey = value;
            Assert.Equal(-1, control.ImageIndex);
            Assert.Equal(value, control.ImageKey);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(2, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringTheoryData))]
        public void TabPage_ImageKey_SetWithDesignModeParentWithHandle_GetReturnsExpected(string value)
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var parent = new TabControl
            {
                Site = mockSite.Object
            };
            using var control = new TabPage
            {
                Parent = parent
            };
            Assert.NotEqual(IntPtr.Zero, parent.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;
            int parentInvalidatedCallCount = 0;
            parent.Invalidated += (sender, e) => parentInvalidatedCallCount++;
            int parentStyleChangedCallCount = 0;
            parent.StyleChanged += (sender, e) => parentStyleChangedCallCount++;
            int parentCreatedCallCount = 0;
            parent.HandleCreated += (sender, e) => parentCreatedCallCount++;

            control.ImageKey = value;
            Assert.Equal(-1, control.ImageIndex);
            Assert.Equal(value, control.ImageKey);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(1, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);

            // Set same.
            control.ImageKey = value;
            Assert.Equal(-1, control.ImageIndex);
            Assert.Equal(value, control.ImageKey);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(2, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);
        }

        [WinFormsFact]
        public unsafe void TabPageCollection_ImageKey_SetGetItemsWithHandle_Success()
        {
            using var owner = new TabControl();
            using var page1 = new TabPage();
            using var page2 = new TabPage
            {
                Text = "Text",
                ImageIndex = 1
            };
            using var page3 = new NullTextTabPage();
            owner.TabPages.Add(page1);
            owner.TabPages.Add(page2);
            owner.TabPages.Add(page3);
            Assert.NotEqual(IntPtr.Zero, owner.Handle);

            page2.ImageKey = "ImageKey";
            Assert.Equal((IntPtr)3, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMCOUNT, IntPtr.Zero, IntPtr.Zero));

            char* buffer = stackalloc char[256];
            ComCtl32.TCITEMW item = default;
            item.cchTextMax = int.MaxValue;
            item.pszText = buffer;
            item.dwStateMask = (ComCtl32.TCIS)uint.MaxValue;
            item.mask = (ComCtl32.TCIF)uint.MaxValue;

            // Get item 0.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)0, ref item));
            Assert.Equal(ComCtl32.TCIS.BUTTONPRESSED, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);

            // Get item 1.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)1, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Equal("Text", new string(item.pszText));
            Assert.Equal(-1, item.iImage);

            // Get item 2.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)2, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);
        }

        [WinFormsFact]
        public unsafe void TabPageCollection_ImageKey_SetGetItemsWithHandleDesignMode_Success()
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var owner = new TabControl
            {
                Site = mockSite.Object
            };
            using var page1 = new TabPage();
            using var page2 = new TabPage
            {
                Text = "Text",
                ImageIndex = 1
            };
            using var page3 = new NullTextTabPage();
            owner.TabPages.Add(page1);
            owner.TabPages.Add(page2);
            owner.TabPages.Add(page3);
            Assert.NotEqual(IntPtr.Zero, owner.Handle);

            page2.ImageKey = "ImageKey";
            Assert.Equal((IntPtr)3, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMCOUNT, IntPtr.Zero, IntPtr.Zero));

            char* buffer = stackalloc char[256];
            ComCtl32.TCITEMW item = default;
            item.cchTextMax = int.MaxValue;
            item.pszText = buffer;
            item.dwStateMask = (ComCtl32.TCIS)uint.MaxValue;
            item.mask = (ComCtl32.TCIF)uint.MaxValue;

            // Get item 0.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)0, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);

            // Get item 1.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)1, ref item));
            Assert.Equal(ComCtl32.TCIS.BUTTONPRESSED, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Equal("Text", new string(item.pszText));
            Assert.Equal(-1, item.iImage);

            // Get item 2.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)2, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);
        }

        public static IEnumerable<object[]> Location_Set_TestData()
        {
            yield return new object[] { new Point(0, 0), 0 };
            yield return new object[] { new Point(-1, -2), 1 };
            yield return new object[] { new Point(1, 0), 1 };
            yield return new object[] { new Point(0, 2), 1 };
            yield return new object[] { new Point(1, 2), 1 };
        }

        [WinFormsTheory]
        [MemberData(nameof(Location_Set_TestData))]
        public void TabPage_Location_Set_GetReturnsExpected(Point value, int expectedLocationChangedCallCount)
        {
            using var control = new TabPage();
            int moveCallCount = 0;
            int locationChangedCallCount = 0;
            int layoutCallCount = 0;
            int resizeCallCount = 0;
            int sizeChangedCallCount = 0;
            int clientSizeChangedCallCount = 0;
            control.Move += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(locationChangedCallCount, moveCallCount);
                moveCallCount++;
            };
            control.LocationChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(moveCallCount - 1, locationChangedCallCount);
                locationChangedCallCount++;
            };
            control.Layout += (sender, e) => layoutCallCount++;
            control.Resize += (sender, e) => resizeCallCount++;
            control.SizeChanged += (sender, e) => sizeChangedCallCount++;
            control.ClientSizeChanged += (sender, e) => clientSizeChangedCallCount++;

            control.Location = value;
            Assert.Equal(new Size(200, 100), control.ClientSize);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.ClientRectangle);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.DisplayRectangle);
            Assert.Equal(new Size(200, 100), control.Size);
            Assert.Equal(value.X, control.Left);
            Assert.Equal(value.X + 200, control.Right);
            Assert.Equal(value, control.Location);
            Assert.Equal(value.Y, control.Top);
            Assert.Equal(value.Y + 100, control.Bottom);
            Assert.Equal(200, control.Width);
            Assert.Equal(100, control.Height);
            Assert.Equal(new Rectangle(value.X, value.Y, 200, 100), control.Bounds);
            Assert.Equal(expectedLocationChangedCallCount, moveCallCount);
            Assert.Equal(expectedLocationChangedCallCount, locationChangedCallCount);
            Assert.Equal(0, layoutCallCount);
            Assert.Equal(0, resizeCallCount);
            Assert.Equal(0, sizeChangedCallCount);
            Assert.Equal(0, clientSizeChangedCallCount);
            Assert.False(control.IsHandleCreated);

            // Call again.
            control.Location = value;
            Assert.Equal(new Size(200, 100), control.ClientSize);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.ClientRectangle);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.DisplayRectangle);
            Assert.Equal(new Size(200, 100), control.Size);
            Assert.Equal(value.X, control.Left);
            Assert.Equal(value.X + 200, control.Right);
            Assert.Equal(value, control.Location);
            Assert.Equal(value.Y, control.Top);
            Assert.Equal(value.Y + 100, control.Bottom);
            Assert.Equal(200, control.Width);
            Assert.Equal(100, control.Height);
            Assert.Equal(new Rectangle(value.X, value.Y, 200, 100), control.Bounds);
            Assert.Equal(expectedLocationChangedCallCount, moveCallCount);
            Assert.Equal(expectedLocationChangedCallCount, locationChangedCallCount);
            Assert.Equal(0, layoutCallCount);
            Assert.Equal(0, resizeCallCount);
            Assert.Equal(0, sizeChangedCallCount);
            Assert.Equal(0, clientSizeChangedCallCount);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [MemberData(nameof(Location_Set_TestData))]
        public void TabPage_Location_SetWithParent_GetReturnsExpected(Point value, int expectedLocationChangedCallCount)
        {
            using var parent = new TabControl();
            using var control = new SubTabPage
            {
                Parent = parent
            };
            int layoutCallCount = 0;
            int moveCallCount = 0;
            int locationChangedCallCount = 0;
            int resizeCallCount = 0;
            int sizeChangedCallCount = 0;
            int clientSizeChangedCallCount = 0;
            int parentLayoutCallCount = 0;
            control.Move += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(locationChangedCallCount, moveCallCount);
                moveCallCount++;
            };
            control.LocationChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(moveCallCount - 1, locationChangedCallCount);
                locationChangedCallCount++;
            };
            control.Layout += (sender, e) => layoutCallCount++;
            control.Resize += (sender, e) => resizeCallCount++;
            control.SizeChanged += (sender, e) => sizeChangedCallCount++;
            control.ClientSizeChanged += (sender, e) => clientSizeChangedCallCount++;
            void parentHandler(object sender, LayoutEventArgs e)
            {
                Assert.Same(parent, sender);
                Assert.Same(control, e.AffectedControl);
                Assert.Equal("Bounds", e.AffectedProperty);
                parentLayoutCallCount++;
            }

            parent.Layout += parentHandler;

            try
            {
                control.Location = value;
                Assert.Equal(new Size(200, 100), control.ClientSize);
                Assert.Equal(new Rectangle(0, 0, 200, 100), control.ClientRectangle);
                Assert.Equal(new Rectangle(0, 0, 200, 100), control.DisplayRectangle);
                Assert.Equal(new Size(200, 100), control.Size);
                Assert.Equal(value.X, control.Left);
                Assert.Equal(value.X + 200, control.Right);
                Assert.Equal(value, control.Location);
                Assert.Equal(value.Y, control.Top);
                Assert.Equal(value.Y + 100, control.Bottom);
                Assert.Equal(200, control.Width);
                Assert.Equal(100, control.Height);
                Assert.Equal(new Rectangle(value.X, value.Y, 200, 100), control.Bounds);
                Assert.Equal(expectedLocationChangedCallCount, moveCallCount);
                Assert.Equal(expectedLocationChangedCallCount, locationChangedCallCount);
                Assert.Equal(0, layoutCallCount);
                Assert.Equal(0, resizeCallCount);
                Assert.Equal(0, sizeChangedCallCount);
                Assert.Equal(0, clientSizeChangedCallCount);
                Assert.Equal(expectedLocationChangedCallCount, parentLayoutCallCount);
                Assert.False(control.IsHandleCreated);

                // Call again.
                control.Location = value;
                Assert.Equal(new Size(200, 100), control.ClientSize);
                Assert.Equal(new Rectangle(0, 0, 200, 100), control.ClientRectangle);
                Assert.Equal(new Rectangle(0, 0, 200, 100), control.DisplayRectangle);
                Assert.Equal(new Size(200, 100), control.Size);
                Assert.Equal(value.X, control.Left);
                Assert.Equal(value.X + 200, control.Right);
                Assert.Equal(value, control.Location);
                Assert.Equal(value.Y, control.Top);
                Assert.Equal(value.Y + 100, control.Bottom);
                Assert.Equal(200, control.Width);
                Assert.Equal(100, control.Height);
                Assert.Equal(new Rectangle(value.X, value.Y, 200, 100), control.Bounds);
                Assert.Equal(expectedLocationChangedCallCount, moveCallCount);
                Assert.Equal(expectedLocationChangedCallCount, locationChangedCallCount);
                Assert.Equal(0, layoutCallCount);
                Assert.Equal(0, resizeCallCount);
                Assert.Equal(0, sizeChangedCallCount);
                Assert.Equal(0, clientSizeChangedCallCount);
                Assert.Equal(expectedLocationChangedCallCount, parentLayoutCallCount);
                Assert.False(control.IsHandleCreated);
            }
            finally
            {
                parent.Layout -= parentHandler;
            }
        }

        public static IEnumerable<object[]> Location_SetWithHandle_TestData()
        {
            foreach (bool resizeRedraw in new bool[] { true, false })
            {
                yield return new object[] { resizeRedraw, new Point(0, 0), 0 };
                yield return new object[] { resizeRedraw, new Point(-1, -2), 1 };
                yield return new object[] { resizeRedraw, new Point(1, 0), 1 };
                yield return new object[] { resizeRedraw, new Point(0, 2), 1 };
                yield return new object[] { resizeRedraw, new Point(1, 2), 1 };
            }
        }

        [WinFormsTheory]
        [MemberData(nameof(Location_SetWithHandle_TestData))]
        public void TabPage_Location_SetWithHandle_GetReturnsExpected(bool resizeRedraw, Point value, int expectedLocationChangedCallCount)
        {
            using var control = new SubTabPage();
            control.SetStyle(ControlStyles.ResizeRedraw, resizeRedraw);
            int moveCallCount = 0;
            int locationChangedCallCount = 0;
            int layoutCallCount = 0;
            int resizeCallCount = 0;
            int sizeChangedCallCount = 0;
            int clientSizeChangedCallCount = 0;
            control.Move += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(locationChangedCallCount, moveCallCount);
                moveCallCount++;
            };
            control.LocationChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(moveCallCount - 1, locationChangedCallCount);
                locationChangedCallCount++;
            };
            control.Layout += (sender, e) => layoutCallCount++;
            control.Resize += (sender, e) => resizeCallCount++;
            control.SizeChanged += (sender, e) => sizeChangedCallCount++;
            control.ClientSizeChanged += (sender, e) => clientSizeChangedCallCount++;
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            control.Location = value;
            Assert.Equal(new Size(200, 100), control.ClientSize);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.ClientRectangle);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.DisplayRectangle);
            Assert.Equal(new Size(200, 100), control.Size);
            Assert.Equal(value.X, control.Left);
            Assert.Equal(value.X + 200, control.Right);
            Assert.Equal(value, control.Location);
            Assert.Equal(value.Y, control.Top);
            Assert.Equal(value.Y + 100, control.Bottom);
            Assert.Equal(200, control.Width);
            Assert.Equal(100, control.Height);
            Assert.Equal(new Rectangle(value.X, value.Y, 200, 100), control.Bounds);
            Assert.Equal(expectedLocationChangedCallCount, moveCallCount);
            Assert.Equal(expectedLocationChangedCallCount, locationChangedCallCount);
            Assert.Equal(0, layoutCallCount);
            Assert.Equal(0, resizeCallCount);
            Assert.Equal(0, sizeChangedCallCount);
            Assert.Equal(0, clientSizeChangedCallCount);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Call again.
            control.Location = value;
            Assert.Equal(new Size(200, 100), control.ClientSize);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.ClientRectangle);
            Assert.Equal(new Rectangle(0, 0, 200, 100), control.DisplayRectangle);
            Assert.Equal(new Size(200, 100), control.Size);
            Assert.Equal(value.X, control.Left);
            Assert.Equal(value.X + 200, control.Right);
            Assert.Equal(value, control.Location);
            Assert.Equal(value.Y, control.Top);
            Assert.Equal(value.Y + 100, control.Bottom);
            Assert.Equal(200, control.Width);
            Assert.Equal(100, control.Height);
            Assert.Equal(new Rectangle(value.X, value.Y, 200, 100), control.Bounds);
            Assert.Equal(expectedLocationChangedCallCount, moveCallCount);
            Assert.Equal(expectedLocationChangedCallCount, locationChangedCallCount);
            Assert.Equal(0, layoutCallCount);
            Assert.Equal(0, resizeCallCount);
            Assert.Equal(0, sizeChangedCallCount);
            Assert.Equal(0, clientSizeChangedCallCount);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        public static IEnumerable<object[]> Location_SetWithParentWithHandle_TestData()
        {
            foreach (bool resizeRedraw in new bool[] { true, false })
            {
                yield return new object[] { resizeRedraw, new Point(0, 0) };
                yield return new object[] { resizeRedraw, new Point(-1, -2) };
                yield return new object[] { resizeRedraw, new Point(1, 0) };
                yield return new object[] { resizeRedraw, new Point(0, 2) };
                yield return new object[] { resizeRedraw, new Point(1, 2) };
            }
        }

        [WinFormsTheory]
        [MemberData(nameof(Location_SetWithParentWithHandle_TestData))]
        public void TabPage_Location_SetWithParentWithHandle_GetReturnsExpected(bool resizeRedraw, Point value)
        {
            using var parent = new TabControl();
            using var control = new SubTabPage
            {
                Parent = parent
            };
            control.SetStyle(ControlStyles.ResizeRedraw, resizeRedraw);
            Assert.NotEqual(IntPtr.Zero, parent.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;
            int parentInvalidatedCallCount = 0;
            parent.Invalidated += (sender, e) => parentInvalidatedCallCount++;
            int parentStyleChangedCallCount = 0;
            parent.StyleChanged += (sender, e) => parentStyleChangedCallCount++;
            int parentCreatedCallCount = 0;
            parent.HandleCreated += (sender, e) => parentCreatedCallCount++;
            Rectangle expected = parent.DisplayRectangle;

            int moveCallCount = 0;
            int locationChangedCallCount = 0;
            int layoutCallCount = 0;
            int resizeCallCount = 0;
            int sizeChangedCallCount = 0;
            int clientSizeChangedCallCount = 0;
            int parentLayoutCallCount = 0;
            control.Move += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(locationChangedCallCount, moveCallCount);
                moveCallCount++;
            };
            control.LocationChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(moveCallCount - 1, locationChangedCallCount);
                locationChangedCallCount++;
            };
            control.Layout += (sender, e) => layoutCallCount++;
            control.Resize += (sender, e) => resizeCallCount++;
            control.SizeChanged += (sender, e) => sizeChangedCallCount++;
            control.ClientSizeChanged += (sender, e) => clientSizeChangedCallCount++;
            void parentHandler(object sender, LayoutEventArgs e)
            {
                Assert.Same(parent, sender);
                Assert.Same(control, e.AffectedControl);
                Assert.Equal("Bounds", e.AffectedProperty);
                parentLayoutCallCount++;
            }

            parent.Layout += parentHandler;

            try
            {
                control.Location = value;
                Assert.Equal(expected.Size, control.ClientSize);
                Assert.Equal(new Rectangle(0, 0, expected.Width, expected.Height), control.ClientRectangle);
                Assert.Equal(new Rectangle(0, 0, expected.Width, expected.Height), control.DisplayRectangle);
                Assert.Equal(expected.Size, control.Size);
                Assert.Equal(expected.X, control.Left);
                Assert.Equal(expected.X + expected.Width, control.Right);
                Assert.Equal(expected.Location, control.Location);
                Assert.Equal(expected.Y, control.Top);
                Assert.Equal(expected.Y + expected.Height, control.Bottom);
                Assert.Equal(expected.Width, control.Width);
                Assert.Equal(expected.Height, control.Height);
                Assert.Equal(expected, control.Bounds);
                Assert.Equal(0, moveCallCount);
                Assert.Equal(0, locationChangedCallCount);
                Assert.Equal(0, layoutCallCount);
                Assert.Equal(1, parentLayoutCallCount);
                Assert.Equal(0, resizeCallCount);
                Assert.Equal(0, sizeChangedCallCount);
                Assert.Equal(0, clientSizeChangedCallCount);
                Assert.True(control.IsHandleCreated);
                Assert.Equal(0, invalidatedCallCount);
                Assert.Equal(0, styleChangedCallCount);
                Assert.Equal(0, createdCallCount);
                Assert.True(parent.IsHandleCreated);
                Assert.Equal(0, parentInvalidatedCallCount);
                Assert.Equal(0, parentStyleChangedCallCount);
                Assert.Equal(0, parentCreatedCallCount);

                // Call again.
                control.Location = value;
                Assert.Equal(expected.Size, control.ClientSize);
                Assert.Equal(new Rectangle(0, 0, expected.Width, expected.Height), control.ClientRectangle);
                Assert.Equal(new Rectangle(0, 0, expected.Width, expected.Height), control.DisplayRectangle);
                Assert.Equal(expected.Size, control.Size);
                Assert.Equal(expected.X, control.Left);
                Assert.Equal(expected.X + expected.Width, control.Right);
                Assert.Equal(expected.Location, control.Location);
                Assert.Equal(expected.Y, control.Top);
                Assert.Equal(expected.Y + expected.Height, control.Bottom);
                Assert.Equal(expected.Width, control.Width);
                Assert.Equal(expected.Height, control.Height);
                Assert.Equal(expected, control.Bounds);
                Assert.Equal(0, moveCallCount);
                Assert.Equal(0, locationChangedCallCount);
                Assert.Equal(0, layoutCallCount);
                Assert.Equal(2, parentLayoutCallCount);
                Assert.Equal(0, resizeCallCount);
                Assert.Equal(0, sizeChangedCallCount);
                Assert.Equal(0, clientSizeChangedCallCount);
                Assert.True(control.IsHandleCreated);
                Assert.Equal(0, invalidatedCallCount);
                Assert.Equal(0, styleChangedCallCount);
                Assert.Equal(0, createdCallCount);
                Assert.True(parent.IsHandleCreated);
                Assert.Equal(0, parentInvalidatedCallCount);
                Assert.Equal(0, parentStyleChangedCallCount);
                Assert.Equal(0, parentCreatedCallCount);
            }
            finally
            {
                parent.Layout -= parentHandler;
            }
        }

        [WinFormsTheory]
        [InlineData(true, 1)]
        [InlineData(false, 0)]
        public void TabPage_Location_SetWithHandleWithTransparentBackColor_DoesNotCallInvalidate(bool supportsTransparentBackgroundColor, int expectedInvalidatedCallCount)
        {
            using var control = new SubTabPage();
            control.SetStyle(ControlStyles.SupportsTransparentBackColor, true);
            control.BackColor = Color.FromArgb(254, 255, 255, 255);
            control.SetStyle(ControlStyles.SupportsTransparentBackColor, supportsTransparentBackgroundColor);

            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;

            // Set different.
            control.Location = new Point(1, 2);
            Assert.Equal(new Point(1, 2), control.Location);
            Assert.Equal(expectedInvalidatedCallCount, invalidatedCallCount);

            // Set same.
            control.Location = new Point(1, 2);
            Assert.Equal(new Point(1, 2), control.Location);
            Assert.Equal(expectedInvalidatedCallCount, invalidatedCallCount);

            // Set different.
            control.Location = new Point(2, 3);
            Assert.Equal(new Point(2, 3), control.Location);
            Assert.Equal(expectedInvalidatedCallCount * 2, invalidatedCallCount);
        }

        [WinFormsFact]
        public void TabPage_Location_SetWithHandler_CallsLocationChanged()
        {
            using var control = new TabPage();
            int locationChangedCallCount = 0;
            EventHandler locationChangedHandler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                locationChangedCallCount++;
            };
            control.LocationChanged += locationChangedHandler;
            int moveCallCount = 0;
            EventHandler moveHandler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                moveCallCount++;
            };
            control.Move += moveHandler;

            // Set different.
            control.Location = new Point(1, 2);
            Assert.Equal(new Point(1, 2), control.Location);
            Assert.Equal(1, locationChangedCallCount);
            Assert.Equal(1, moveCallCount);

            // Set same.
            control.Location = new Point(1, 2);
            Assert.Equal(new Point(1, 2), control.Location);
            Assert.Equal(1, locationChangedCallCount);
            Assert.Equal(1, moveCallCount);

            // Set different x.
            control.Location = new Point(2, 2);
            Assert.Equal(new Point(2, 2), control.Location);
            Assert.Equal(2, locationChangedCallCount);
            Assert.Equal(2, moveCallCount);

            // Set different y.
            control.Location = new Point(2, 3);
            Assert.Equal(new Point(2, 3), control.Location);
            Assert.Equal(3, locationChangedCallCount);
            Assert.Equal(3, moveCallCount);

            // Remove handler.
            control.LocationChanged -= locationChangedHandler;
            control.Move -= moveHandler;
            control.Location = new Point(1, 2);
            Assert.Equal(new Point(1, 2), control.Location);
            Assert.Equal(3, locationChangedCallCount);
            Assert.Equal(3, moveCallCount);
        }

        [WinFormsFact]
        public void TabPage_Location_ResetValue_Success()
        {
            PropertyDescriptor property = TypeDescriptor.GetProperties(typeof(TabPage))[nameof(TabPage.Location)];
            using var control = new TabPage();
            Assert.False(property.CanResetValue(control));

            control.Location = new Point(1, 0);
            Assert.Equal(new Point(1, 0), control.Location);
            Assert.False(property.CanResetValue(control));

            control.Location = new Point(0, 1);
            Assert.Equal(new Point(0, 1), control.Location);
            Assert.False(property.CanResetValue(control));

            control.Location = new Point(1, 2);
            Assert.Equal(new Point(1, 2), control.Location);
            Assert.False(property.CanResetValue(control));

            property.ResetValue(control);
            Assert.Equal(new Point(1, 2), control.Location);
            Assert.False(property.CanResetValue(control));

            control.Location = Point.Empty;
            Assert.Equal(Point.Empty, control.Location);
            Assert.False(property.CanResetValue(control));
        }

        [WinFormsFact]
        public void TabPage_Location_ShouldSerializeValue_Success()
        {
            PropertyDescriptor property = TypeDescriptor.GetProperties(typeof(TabPage))[nameof(TabPage.Location)];
            using var control = new TabPage();
            Assert.False(property.ShouldSerializeValue(control));

            control.Location = new Point(1, 0);
            Assert.Equal(new Point(1, 0), control.Location);
            Assert.True(property.ShouldSerializeValue(control));

            control.Location = new Point(0, 1);
            Assert.Equal(new Point(0, 1), control.Location);
            Assert.True(property.ShouldSerializeValue(control));

            control.Location = new Point(1, 2);
            Assert.Equal(new Point(1, 2), control.Location);
            Assert.True(property.ShouldSerializeValue(control));

            property.ResetValue(control);
            Assert.Equal(new Point(1, 2), control.Location);
            Assert.True(property.ShouldSerializeValue(control));

            control.Location = Point.Empty;
            Assert.Equal(Point.Empty, control.Location);
            Assert.False(property.ShouldSerializeValue(control));
        }

        [WinFormsTheory]
        [MemberData(nameof(ControlTests.MaximumSize_Set_TestData), MemberType = typeof(ControlTests))]
        public void TabPage_MaximumSize_Set_GetReturnsExpected(Size value)
        {
            using var control = new TabPage
            {
                Size = Size.Empty
            };
            int layoutCallCount = 0;
            control.Layout += (sender, e) => layoutCallCount++;

            control.MaximumSize = value;
            Assert.Equal(value, control.MaximumSize);
            Assert.Equal(Size.Empty, control.Size);
            Assert.Equal(0, layoutCallCount);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.MaximumSize = value;
            Assert.Equal(value, control.MaximumSize);
            Assert.Equal(Size.Empty, control.Size);
            Assert.Equal(0, layoutCallCount);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [MemberData(nameof(ControlTests.MinimumSize_Set_TestData), MemberType = typeof(ControlTests))]
        public void TabPage_MinimumSize_Set_GetReturnsExpected(Size value, Size expectedSize, int expectedLayoutCallCount)
        {
            using var control = new TabPage
            {
                Size = Size.Empty
            };
            int layoutCallCount = 0;
            control.Layout += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(control, e.AffectedControl);
                Assert.Equal("Bounds", e.AffectedProperty);
                layoutCallCount++;
            };

            control.MinimumSize = value;
            Assert.Equal(value, control.MinimumSize);
            Assert.Equal(expectedSize, control.Size);
            Assert.Equal(expectedLayoutCallCount, layoutCallCount);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.MinimumSize = value;
            Assert.Equal(value, control.MinimumSize);
            Assert.Equal(expectedSize, control.Size);
            Assert.Equal(expectedLayoutCallCount, layoutCallCount);
            Assert.False(control.IsHandleCreated);
        }

        public static IEnumerable<object[]> Parent_Set_TestData()
        {
            yield return new object[] { null };
            yield return new object[] { new TabControl() };
        }

        [WinFormsTheory]
        [MemberData(nameof(Parent_Set_TestData))]
        public void TabPage_Parent_Set_GetReturnsExpected(Control value)
        {
            using var control = new TabPage
            {
                Parent = value
            };
            Assert.Same(value, control.Parent);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.Parent = value;
            Assert.Same(value, control.Parent);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [MemberData(nameof(Parent_Set_TestData))]
        public void TabPage_Parent_SetWithNonNullOldParent_GetReturnsExpected(Control value)
        {
            using var oldParent = new TabControl();
            using var control = new TabPage
            {
                Parent = oldParent
            };

            control.Parent = value;
            Assert.Same(value, control.Parent);
            Assert.Empty(oldParent.Controls);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.Parent = value;
            Assert.Same(value, control.Parent);
            Assert.Empty(oldParent.Controls);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsFact]
        public void TabPage_Parent_SetNonNull_AddsToControls()
        {
            using var parent = new TabControl();
            using var control = new TabPage
            {
                Parent = parent
            };
            Assert.Same(parent, control.Parent);
            Assert.Same(control, Assert.Single(parent.Controls));
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.Parent = parent;
            Assert.Same(parent, control.Parent);
            Assert.Same(control, Assert.Single(parent.Controls));
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [MemberData(nameof(Parent_Set_TestData))]
        public void TabPage_Parent_SetWithHandle_GetReturnsExpected(Control value)
        {
            using var control = new TabPage();
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            control.Parent = value;
            Assert.Same(value, control.Parent);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set same.
            control.Parent = value;
            Assert.Same(value, control.Parent);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        [WinFormsFact]
        public void TabPage_Parent_SetWithHandler_CallsParentChanged()
        {
            using var parent = new TabControl();
            using var control = new TabPage();
            int callCount = 0;
            EventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                callCount++;
            };
            control.ParentChanged += handler;

            // Set different.
            control.Parent = parent;
            Assert.Same(parent, control.Parent);
            Assert.Equal(1, callCount);

            // Set same.
            control.Parent = parent;
            Assert.Same(parent, control.Parent);
            Assert.Equal(1, callCount);

            // Set null.
            control.Parent = null;
            Assert.Null(control.Parent);
            Assert.Equal(2, callCount);

            // Remove handler.
            control.ParentChanged -= handler;
            control.Parent = parent;
            Assert.Same(parent, control.Parent);
            Assert.Equal(2, callCount);
        }

        [WinFormsFact]
        public void TabPage_Parent_SetSame_ThrowsArgumentException()
        {
            using var control = new TabPage();
            Assert.Throws<ArgumentException>(null, () => control.Parent = control);
            Assert.Null(control.Parent);
        }

        [WinFormsFact]
        public void TabPage_Parent_SetNonTabControl_ThrowsArgumentException()
        {
            using var parent = new Control();
            using var control = new TabPage();
            Assert.Throws<ArgumentException>(null, () => control.Parent = parent);
            Assert.Null(control.Parent);
        }

        [WinFormsTheory]
        [InlineData(0)]
        [InlineData(1)]
        [InlineData(2)]
        public void TabPage_TabIndex_Set_GetReturnsExpected(int value)
        {
            using var control = new TabPage
            {
                TabIndex = value
            };
            Assert.Equal(value, control.TabIndex);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.TabIndex = value;
            Assert.Equal(value, control.TabIndex);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsFact]
        public void TabPage_TabIndex_SetWithHandler_CallsTabIndexChanged()
        {
            using var control = new TabPage
            {
                TabIndex = 0
            };
            int callCount = 0;
            EventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                callCount++;
            };
            control.TabIndexChanged += handler;

            // Set different.
            control.TabIndex = 1;
            Assert.Equal(1, control.TabIndex);
            Assert.Equal(1, callCount);

            // Set same.
            control.TabIndex = 1;
            Assert.Equal(1, control.TabIndex);
            Assert.Equal(1, callCount);

            // Set different.
            control.TabIndex = 2;
            Assert.Equal(2, control.TabIndex);
            Assert.Equal(2, callCount);

            // Remove handler.
            control.TabIndexChanged -= handler;
            control.TabIndex = 1;
            Assert.Equal(1, control.TabIndex);
            Assert.Equal(2, callCount);
        }

        [WinFormsFact]
        public void TabPage_TabIndex_SetNegative_CallsArgumentOutOfRangeException()
        {
            using var control = new TabPage();
            Assert.Throws<ArgumentOutOfRangeException>("value", () => control.TabIndex = -1);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBoolTheoryData))]
        public void TabPage_TabStop_Set_GetReturnsExpected(bool value)
        {
            using var control = new TabPage
            {
                TabStop = value
            };
            Assert.Equal(value, control.TabStop);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.TabStop = value;
            Assert.Equal(value, control.TabStop);
            Assert.False(control.IsHandleCreated);

            // Set different.
            control.TabStop = value;
            Assert.Equal(value, control.TabStop);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBoolTheoryData))]
        public void TabPage_TabStop_SetWithHandle_GetReturnsExpected(bool value)
        {
            using var control = new TabPage();
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            control.TabStop = value;
            Assert.Equal(value, control.TabStop);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set same.
            control.TabStop = value;
            Assert.Equal(value, control.TabStop);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set different.
            control.TabStop = value;
            Assert.Equal(value, control.TabStop);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        [WinFormsFact]
        public void TabPage_TabStop_SetWithHandler_CallsTabStopChanged()
        {
            using var control = new TabPage
            {
                TabStop = true
            };
            int callCount = 0;
            EventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                callCount++;
            };
            control.TabStopChanged += handler;

            // Set different.
            control.TabStop = false;
            Assert.False(control.TabStop);
            Assert.Equal(1, callCount);

            // Set same.
            control.TabStop = false;
            Assert.False(control.TabStop);
            Assert.Equal(1, callCount);

            // Set different.
            control.TabStop = true;
            Assert.True(control.TabStop);
            Assert.Equal(2, callCount);

            // Remove handler.
            control.TabStopChanged -= handler;
            control.TabStop = false;
            Assert.False(control.TabStop);
            Assert.Equal(2, callCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringNormalizedTheoryData))]
        public void TabPage_Text_Set_GetReturnsExpected(string value, string expected)
        {
            using var control = new TabPage
            {
                Text = value
            };
            Assert.Equal(expected, control.Text);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.Text = value;
            Assert.Equal(expected, control.Text);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringNormalizedTheoryData))]
        public void TabPage_Text_SetWithParent_GetReturnsExpected(string value, string expected)
        {
            using var parent = new TabControl();
            using var control = new TabPage
            {
                Parent = parent,
                Text = value
            };
            Assert.Equal(expected, control.Text);
            Assert.False(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);

            // Set same.
            control.Text = value;
            Assert.Equal(expected, control.Text);
            Assert.False(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringNormalizedTheoryData))]
        public void TabPage_Text_SetWithDesignModeParent_GetReturnsExpected(string value, string expected)
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var parent = new TabControl
            {
                Site = mockSite.Object
            };
            using var control = new TabPage
            {
                Parent = parent,
                Text = value
            };
            Assert.Equal(expected, control.Text);
            Assert.False(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);

            // Set same.
            control.Text = value;
            Assert.Equal(expected, control.Text);
            Assert.False(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringNormalizedTheoryData))]
        public void TabPage_Text_SetWithHandle_GetReturnsExpected(string value, string expected)
        {
            using var control = new TabPage();
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            control.Text = value;
            Assert.Equal(expected, control.Text);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set same.
            control.Text = value;
            Assert.Equal(expected, control.Text);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringNormalizedTheoryData))]
        public void TabPage_Text_SetWithParentWithHandle_GetReturnsExpected(string value, string expected)
        {
            using var parent = new TabControl();
            using var control = new TabPage
            {
                Parent = parent
            };
            Assert.NotEqual(IntPtr.Zero, parent.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;
            int parentInvalidatedCallCount = 0;
            parent.Invalidated += (sender, e) => parentInvalidatedCallCount++;
            int parentStyleChangedCallCount = 0;
            parent.StyleChanged += (sender, e) => parentStyleChangedCallCount++;
            int parentCreatedCallCount = 0;
            parent.HandleCreated += (sender, e) => parentCreatedCallCount++;

            control.Text = value;
            Assert.Equal(expected, control.Text);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(1, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);

            // Set same.
            control.Text = value;
            Assert.Equal(expected, control.Text);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(2, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringNormalizedTheoryData))]
        public void TabPage_Text_SetWithDesignModeParentWithHandle_GetReturnsExpected(string value, string expected)
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var parent = new TabControl
            {
                Site = mockSite.Object
            };
            using var control = new TabPage
            {
                Parent = parent
            };
            Assert.NotEqual(IntPtr.Zero, parent.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;
            int parentInvalidatedCallCount = 0;
            parent.Invalidated += (sender, e) => parentInvalidatedCallCount++;
            int parentStyleChangedCallCount = 0;
            parent.StyleChanged += (sender, e) => parentStyleChangedCallCount++;
            int parentCreatedCallCount = 0;
            parent.HandleCreated += (sender, e) => parentCreatedCallCount++;

            control.Text = value;
            Assert.Equal(expected, control.Text);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(1, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);

            // Set same.
            control.Text = value;
            Assert.Equal(expected, control.Text);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(2, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);
        }

        [WinFormsTheory]
        [InlineData("Text", "Text")]
        [InlineData("&&Text", "&&Text")]
        [InlineData("&", "&&")]
        [InlineData("&Text", "&&Text")]
        public unsafe void TabPageCollection_Text_SetGetItemsWithHandle_Success(string text, string expectedText)
        {
            using var owner = new TabControl();
            using var page1 = new TabPage();
            using var page2 = new TabPage
            {
                ImageIndex = 1
            };
            using var page3 = new NullTextTabPage();
            owner.TabPages.Add(page1);
            owner.TabPages.Add(page2);
            owner.TabPages.Add(page3);
            Assert.NotEqual(IntPtr.Zero, owner.Handle);

            page2.Text = text;
            Assert.Equal((IntPtr)3, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMCOUNT, IntPtr.Zero, IntPtr.Zero));

            char* buffer = stackalloc char[256];
            ComCtl32.TCITEMW item = default;
            item.cchTextMax = int.MaxValue;
            item.pszText = buffer;
            item.dwStateMask = (ComCtl32.TCIS)uint.MaxValue;
            item.mask = (ComCtl32.TCIF)uint.MaxValue;

            // Get item 0.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)0, ref item));
            Assert.Equal(ComCtl32.TCIS.BUTTONPRESSED, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);

            // Get item 1.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)1, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Equal(expectedText, new string(item.pszText));
            Assert.Equal(1, item.iImage);

            // Get item 2.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)2, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);
        }

        [WinFormsTheory]
        [InlineData("Text", "Text")]
        [InlineData("&&Text", "&&Text")]
        [InlineData("&", "&&")]
        [InlineData("&Text", "&&Text")]
        public unsafe void TabPageCollection_Text_SetGetItemsWithHandleDesignMode_Success(string text, string expectedText)
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var owner = new TabControl
            {
                Site = mockSite.Object
            };
            using var page1 = new TabPage();
            using var page2 = new TabPage
            {
                ImageIndex = 1
            };
            using var page3 = new NullTextTabPage();
            owner.TabPages.Add(page1);
            owner.TabPages.Add(page2);
            owner.TabPages.Add(page3);
            Assert.NotEqual(IntPtr.Zero, owner.Handle);

            page2.Text = text;
            Assert.Equal((IntPtr)3, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMCOUNT, IntPtr.Zero, IntPtr.Zero));

            char* buffer = stackalloc char[256];
            ComCtl32.TCITEMW item = default;
            item.cchTextMax = int.MaxValue;
            item.pszText = buffer;
            item.dwStateMask = (ComCtl32.TCIS)uint.MaxValue;
            item.mask = (ComCtl32.TCIF)uint.MaxValue;

            // Get item 0.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)0, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);

            // Get item 1.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)1, ref item));
            Assert.Equal(ComCtl32.TCIS.BUTTONPRESSED, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Equal(expectedText, new string(item.pszText));
            Assert.Equal(1, item.iImage);

            // Get item 2.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)2, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);
        }

        [WinFormsFact]
        public void TabPage_Text_SetWithHandler_CallsTextChanged()
        {
            using var control = new TabPage();
            int callCount = 0;
            EventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Equal(EventArgs.Empty, e);
                callCount++;
            };
            control.TextChanged += handler;

            // Set different.
            control.Text = "text";
            Assert.Equal("text", control.Text);
            Assert.Equal(1, callCount);

            // Set same.
            control.Text = "text";
            Assert.Equal("text", control.Text);
            Assert.Equal(1, callCount);

            // Set different.
            control.Text = null;
            Assert.Empty(control.Text);
            Assert.Equal(2, callCount);

            // Remove handler.
            control.TextChanged -= handler;
            control.Text = "text";
            Assert.Equal("text", control.Text);
            Assert.Equal(2, callCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringNormalizedTheoryData))]
        public void TabPage_ToolTipText_Set_GetReturnsExpected(string value, string expected)
        {
            using var control = new TabPage
            {
                ToolTipText = value
            };
            Assert.Equal(expected, control.ToolTipText);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.ToolTipText = value;
            Assert.Equal(expected, control.ToolTipText);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringNormalizedTheoryData))]
        public void TabPage_ToolTipText_SetWithParent_GetReturnsExpected(string value, string expected)
        {
            using var parent = new TabControl();
            using var control = new TabPage
            {
                Parent = parent,
                ToolTipText = value
            };
            Assert.Equal(expected, control.ToolTipText);
            Assert.False(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);

            // Set same.
            control.ToolTipText = value;
            Assert.Equal(expected, control.ToolTipText);
            Assert.False(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringNormalizedTheoryData))]
        public void TabPage_ToolTipText_SetWithDesignModeParent_GetReturnsExpected(string value, string expected)
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var parent = new TabControl
            {
                Site = mockSite.Object
            };
            using var control = new TabPage
            {
                Parent = parent,
                ToolTipText = value
            };
            Assert.Equal(expected, control.ToolTipText);
            Assert.False(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);

            // Set same.
            control.ToolTipText = value;
            Assert.Equal(expected, control.ToolTipText);
            Assert.False(control.Visible);
            Assert.False(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetStringNormalizedTheoryData))]
        public void TabPage_ToolTipText_SetWithHandle_GetReturnsExpected(string value, string expected)
        {
            using var control = new TabPage();
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            control.ToolTipText = value;
            Assert.Equal(expected, control.ToolTipText);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set same.
            control.ToolTipText = value;
            Assert.Equal(expected, control.ToolTipText);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        [WinFormsTheory]
        [InlineData(null, "", 0)]
        [InlineData("", "", 0)]
        [InlineData("text", "text", 1)]
        public void TabPage_ToolTipText_SetWithParentWithHandle_GetReturnsExpected(string value, string expected, int expectedInvalidateCallCount)
        {
            using var parent = new TabControl();
            using var control = new TabPage
            {
                Parent = parent
            };
            Assert.NotEqual(IntPtr.Zero, parent.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;
            int parentInvalidatedCallCount = 0;
            parent.Invalidated += (sender, e) => parentInvalidatedCallCount++;
            int parentStyleChangedCallCount = 0;
            parent.StyleChanged += (sender, e) => parentStyleChangedCallCount++;
            int parentCreatedCallCount = 0;
            parent.HandleCreated += (sender, e) => parentCreatedCallCount++;

            control.ToolTipText = value;
            Assert.Equal(expected, control.ToolTipText);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidateCallCount, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);

            // Set same.
            control.ToolTipText = value;
            Assert.Equal(expected, control.ToolTipText);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidateCallCount, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);
        }

        [WinFormsTheory]
        [InlineData(null, "", 0)]
        [InlineData("", "", 0)]
        [InlineData("text", "text", 1)]
        public void TabPage_ToolTipText_SetWithDesignModeParentWithHandle_GetReturnsExpected(string value, string expected, int expectedInvalidateCallCount)
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var parent = new TabControl
            {
                Site = mockSite.Object
            };
            using var control = new TabPage
            {
                Parent = parent
            };
            Assert.NotEqual(IntPtr.Zero, parent.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;
            int parentInvalidatedCallCount = 0;
            parent.Invalidated += (sender, e) => parentInvalidatedCallCount++;
            int parentStyleChangedCallCount = 0;
            parent.StyleChanged += (sender, e) => parentStyleChangedCallCount++;
            int parentCreatedCallCount = 0;
            parent.HandleCreated += (sender, e) => parentCreatedCallCount++;

            control.ToolTipText = value;
            Assert.Equal(expected, control.ToolTipText);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidateCallCount, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);

            // Set same.
            control.ToolTipText = value;
            Assert.Equal(expected, control.ToolTipText);
            Assert.True(control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidateCallCount, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);
        }

        [WinFormsFact]
        public unsafe void TabPageCollection_ToolTipText_SetGetItemsWithHandle_Success()
        {
            using var owner = new TabControl();
            using var page1 = new TabPage();
            using var page2 = new TabPage
            {
                Text = "Text",
                ImageIndex = 1
            };
            using var page3 = new NullTextTabPage();
            owner.TabPages.Add(page1);
            owner.TabPages.Add(page2);
            owner.TabPages.Add(page3);
            Assert.NotEqual(IntPtr.Zero, owner.Handle);

            page2.ToolTipText = "ToolTipText";
            Assert.Equal((IntPtr)3, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMCOUNT, IntPtr.Zero, IntPtr.Zero));

            char* buffer = stackalloc char[256];
            ComCtl32.TCITEMW item = default;
            item.cchTextMax = int.MaxValue;
            item.pszText = buffer;
            item.dwStateMask = (ComCtl32.TCIS)uint.MaxValue;
            item.mask = (ComCtl32.TCIF)uint.MaxValue;

            // Get item 0.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)0, ref item));
            Assert.Equal(ComCtl32.TCIS.BUTTONPRESSED, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);

            // Get item 1.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)1, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Equal("Text", new string(item.pszText));
            Assert.Equal(1, item.iImage);

            // Get item 2.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)2, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);
        }

        [WinFormsFact]
        public unsafe void TabPageCollection_ToolTipText_SetGetItemsWithHandleDesignMode_Success()
        {
            var mockSite = new Mock<ISite>(MockBehavior.Strict);
            mockSite
                .Setup(s => s.GetService(typeof(AmbientProperties)))
                .Returns(null);
            mockSite
                .Setup(s => s.DesignMode)
                .Returns(true);
            mockSite
                .Setup(s => s.Container)
                .Returns((IContainer)null);
            using var owner = new TabControl
            {
                Site = mockSite.Object
            };
            using var page1 = new TabPage();
            using var page2 = new TabPage
            {
                Text = "Text",
                ImageIndex = 1
            };
            using var page3 = new NullTextTabPage();
            owner.TabPages.Add(page1);
            owner.TabPages.Add(page2);
            owner.TabPages.Add(page3);
            Assert.NotEqual(IntPtr.Zero, owner.Handle);

            page2.ToolTipText = "ToolTipText";
            Assert.Equal((IntPtr)3, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMCOUNT, IntPtr.Zero, IntPtr.Zero));

            char* buffer = stackalloc char[256];
            ComCtl32.TCITEMW item = default;
            item.cchTextMax = int.MaxValue;
            item.pszText = buffer;
            item.dwStateMask = (ComCtl32.TCIS)uint.MaxValue;
            item.mask = (ComCtl32.TCIF)uint.MaxValue;

            // Get item 0.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)0, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);

            // Get item 1.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)1, ref item));
            Assert.Equal(ComCtl32.TCIS.BUTTONPRESSED, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Equal("Text", new string(item.pszText));
            Assert.Equal(1, item.iImage);

            // Get item 2.
            Assert.Equal((IntPtr)1, User32.SendMessageW(owner.Handle, (User32.WM)ComCtl32.TCM.GETITEMW, (IntPtr)2, ref item));
            Assert.Equal((ComCtl32.TCIS)0, item.dwState);
            Assert.Equal(IntPtr.Zero, item.lParam);
            Assert.Equal(int.MaxValue, item.cchTextMax);
            Assert.Empty(new string(item.pszText));
            Assert.Equal(-1, item.iImage);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBoolTheoryData))]
        public void TabPage_UseVisualStyleBackColor_Set_GetReturnsExpected(bool value)
        {
            using var control = new TabPage
            {
                UseVisualStyleBackColor = value
            };
            Assert.Equal(value, control.UseVisualStyleBackColor);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.UseVisualStyleBackColor = value;
            Assert.Equal(value, control.UseVisualStyleBackColor);
            Assert.False(control.IsHandleCreated);

            // Set different.
            control.UseVisualStyleBackColor = !value;
            Assert.Equal(!value, control.UseVisualStyleBackColor);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [InlineData(true, 1)]
        [InlineData(false, 0)]
        public void TabPage_UseVisualStyleBackColor_SetWithHandle_GetReturnsExpected(bool value, int expectedInvalidatedCallCount)
        {
            using var control = new TabPage();
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            control.UseVisualStyleBackColor = value;
            Assert.Equal(value, control.UseVisualStyleBackColor);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidatedCallCount, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set same.
            control.UseVisualStyleBackColor = value;
            Assert.Equal(value, control.UseVisualStyleBackColor);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidatedCallCount, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set different.
            control.UseVisualStyleBackColor = !value;
            Assert.Equal(!value, control.UseVisualStyleBackColor);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidatedCallCount + 1, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBoolTheoryData))]
        public void TabPage_Visible_Set_GetReturnsExpected(bool value)
        {
            using var control = new TabPage
            {
                Visible = value
            };
            Assert.Equal(value, control.Visible);
            Assert.False(control.IsHandleCreated);

            // Set same.
            control.Visible = value;
            Assert.Equal(value, control.Visible);
            Assert.False(control.IsHandleCreated);

            // Set different.
            control.Visible = !value;
            Assert.Equal(!value, control.Visible);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBoolTheoryData))]
        public void TabPage_Visible_SetWithParent_GetReturnsExpected(bool value)
        {
            using var parent = new TabControl();
            using var control = new TabPage
            {
                Parent = parent,
                Visible = value
            };
            Assert.Equal(value, control.Visible);
            Assert.Equal(value, control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);

            // Set same.
            control.Visible = value;
            Assert.Equal(value, control.Visible);
            Assert.Equal(value, control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);

            // Set different.
            control.Visible = !value;
            Assert.Equal(!value, control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.False(parent.IsHandleCreated);
        }

        public static IEnumerable<object[]> Visible_SetWithHandle_TestData()
        {
            foreach (bool userPaint in new bool[] { true, false })
            {
                yield return new object[] { userPaint, true };
                yield return new object[] { userPaint, false };
            }
        }

        [WinFormsTheory]
        [MemberData(nameof(Visible_SetWithHandle_TestData))]
        public void TabPage_Visible_SetWithHandle_GetReturnsExpected(bool userPaint, bool value)
        {
            using var control = new SubTabPage();
            control.SetStyle(ControlStyles.UserPaint, userPaint);
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            control.Visible = value;
            Assert.Equal(value, control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set same.
            control.Visible = value;
            Assert.Equal(value, control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Set different.
            control.Visible = !value;
            Assert.Equal(!value, control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetBoolTheoryData))]
        public void TabPage_Visible_SetWithParentWithHandle_GetReturnsExpected(bool value)
        {
            using var parent = new TabControl();
            using var control = new TabPage
            {
                Parent = parent
            };
            Assert.NotEqual(IntPtr.Zero, parent.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;
            int parentInvalidatedCallCount = 0;
            parent.Invalidated += (sender, e) => parentInvalidatedCallCount++;
            int parentStyleChangedCallCount = 0;
            parent.StyleChanged += (sender, e) => parentStyleChangedCallCount++;
            int parentCreatedCallCount = 0;
            parent.HandleCreated += (sender, e) => parentCreatedCallCount++;

            control.Visible = value;
            Assert.Equal(value, control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);

            // Set same.
            control.Visible = value;
            Assert.Equal(value, control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);

            // Set different.
            control.Visible = !value;
            Assert.Equal(!value, control.Visible);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
            Assert.True(parent.IsHandleCreated);
            Assert.Equal(0, parentInvalidatedCallCount);
            Assert.Equal(0, parentStyleChangedCallCount);
            Assert.Equal(0, parentCreatedCallCount);
        }

        [WinFormsFact]
        public void TabPage_Visible_SetWithHandler_CallsVisibleChanged()
        {
            using var control = new TabPage
            {
                Visible = true
            };
            int callCount = 0;
            EventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                callCount++;
            };
            control.VisibleChanged += handler;

            // Set different.
            control.Visible = false;
            Assert.False(control.Visible);
            Assert.Equal(1, callCount);

            // Set same.
            control.Visible = false;
            Assert.False(control.Visible);
            Assert.Equal(1, callCount);

            // Set different.
            control.Visible = true;
            Assert.True(control.Visible);
            Assert.Equal(2, callCount);

            // Remove handler.
            control.VisibleChanged -= handler;
            control.Visible = false;
            Assert.False(control.Visible);
            Assert.Equal(2, callCount);
        }

        [WinFormsFact]
        public void TabPage_CreateControlsInstance_Invoke_ReturnsExpected()
        {
            using var control = new SubTabPage();
            Control.ControlCollection controls = Assert.IsType<TabPage.TabPageControlCollection>(control.CreateControlsInstance());
            Assert.Empty(controls);
            Assert.Same(control, controls.Owner);
            Assert.False(controls.IsReadOnly);
            Assert.NotSame(controls, control.CreateControlsInstance());
        }

        [WinFormsFact]
        public void TabPage_GetAutoSizeMode_Invoke_ReturnsExpected()
        {
            using var control = new SubTabPage();
            Assert.Equal(AutoSizeMode.GrowOnly, control.GetAutoSizeMode());
        }

        [WinFormsTheory]
        [InlineData(0, true)]
        [InlineData(SubTabPage.ScrollStateAutoScrolling, false)]
        [InlineData(SubTabPage.ScrollStateFullDrag, false)]
        [InlineData(SubTabPage.ScrollStateHScrollVisible, false)]
        [InlineData(SubTabPage.ScrollStateUserHasScrolled, false)]
        [InlineData(SubTabPage.ScrollStateVScrollVisible, false)]
        [InlineData(int.MaxValue, false)]
        [InlineData((-1), false)]
        public void TabPage_GetScrollState_Invoke_ReturnsExpected(int bit, bool expected)
        {
            using var control = new SubTabPage();
            Assert.Equal(expected, control.GetScrollState(bit));
        }

        [WinFormsTheory]
        [InlineData(ControlStyles.ContainerControl, true)]
        [InlineData(ControlStyles.UserPaint, true)]
        [InlineData(ControlStyles.Opaque, false)]
        [InlineData(ControlStyles.ResizeRedraw, false)]
        [InlineData(ControlStyles.FixedWidth, false)]
        [InlineData(ControlStyles.FixedHeight, false)]
        [InlineData(ControlStyles.StandardClick, true)]
        [InlineData(ControlStyles.Selectable, false)]
        [InlineData(ControlStyles.UserMouse, false)]
        [InlineData(ControlStyles.SupportsTransparentBackColor, true)]
        [InlineData(ControlStyles.StandardDoubleClick, true)]
        [InlineData(ControlStyles.AllPaintingInWmPaint, false)]
        [InlineData(ControlStyles.CacheText, true)]
        [InlineData(ControlStyles.EnableNotifyMessage, false)]
        [InlineData(ControlStyles.DoubleBuffer, false)]
        [InlineData(ControlStyles.OptimizedDoubleBuffer, false)]
        [InlineData(ControlStyles.UseTextForAccessibility, true)]
        [InlineData((ControlStyles)0, true)]
        [InlineData((ControlStyles)int.MaxValue, false)]
        [InlineData((ControlStyles)(-1), false)]
        public void TabPage_GetStyle_Invoke_ReturnsExpected(ControlStyles flag, bool expected)
        {
            using var control = new SubTabPage();
            Assert.Equal(expected, control.GetStyle(flag));

            // Call again to test caching.
            Assert.Equal(expected, control.GetStyle(flag));
        }

        [WinFormsFact]
        public void TabPage_GetTopLevel_Invoke_ReturnsExpected()
        {
            using var control = new SubTabPage();
            Assert.False(control.GetTopLevel());
        }

        [WinFormsFact]
        public void TabPage_GetTabPageOfComponent_InvokeTabPageInHierachy_ReturnsExpected()
        {
            using var grandparent = new TabPage();
            using var parent = new Control
            {
                Parent = grandparent
            };
            using var control = new Control
            {
                Parent = parent
            };
            Assert.Same(grandparent, TabPage.GetTabPageOfComponent(control));
            Assert.Same(grandparent, TabPage.GetTabPageOfComponent(parent));
            Assert.Same(grandparent, TabPage.GetTabPageOfComponent(grandparent));
        }

        [WinFormsFact]
        public void TabPage_GetTabPageOfComponent_InvokeNoTabPageInHierachy_ReturnsNull()
        {
            using var grandparent = new Control();
            using var parent = new Control
            {
                Parent = grandparent
            };
            using var control = new Control
            {
                Parent = parent
            };
            Assert.Null(TabPage.GetTabPageOfComponent(control));
            Assert.Null(TabPage.GetTabPageOfComponent(parent));
            Assert.Null(TabPage.GetTabPageOfComponent(grandparent));
        }

        [WinFormsTheory]
        [InlineData(null)]
        [InlineData("NotAControl")]
        public void TabPage_GetTabPageOfComponent_InvokeInvalidControl_ReturnsNull(object comp)
        {
            Assert.Null(TabPage.GetTabPageOfComponent(comp));
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetEventArgsTheoryData))]
        public void TabPage_OnEnter_Invoke_DoesNotCallEnter(EventArgs eventArgs)
        {
            using var control = new SubTabPage();
            int callCount = 0;
            EventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(eventArgs, e);
                callCount++;
            };

            // Call with handler.
            control.Enter += handler;
            control.OnEnter(eventArgs);
            Assert.Equal(0, callCount);

            // Remove handler.
            control.Enter -= handler;
            control.OnEnter(eventArgs);
            Assert.Equal(0, callCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetEventArgsTheoryData))]
        public void TabPage_OnEnter_InvokeWithParent_DoesNotCallEnter(EventArgs eventArgs)
        {
            using var parent = new TabControl();
            using var control = new SubTabPage
            {
                Parent = parent
            };
            int callCount = 0;
            EventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(eventArgs, e);
                callCount++;
            };

            // Call with handler.
            control.Enter += handler;
            control.OnEnter(eventArgs);
            Assert.Equal(0, callCount);

            // Remove handler.
            control.Enter -= handler;
            control.OnEnter(eventArgs);
            Assert.Equal(0, callCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetEventArgsTheoryData))]
        public void TabPage_OnLeave_Invoke_DoesNotCallLeave(EventArgs eventArgs)
        {
            using var control = new SubTabPage();
            int callCount = 0;
            EventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(eventArgs, e);
                callCount++;
            };

            // Call with handler.
            control.Leave += handler;
            control.OnLeave(eventArgs);
            Assert.Equal(0, callCount);

            // Remove handler.
            control.Leave -= handler;
            control.OnLeave(eventArgs);
            Assert.Equal(0, callCount);
        }

        [WinFormsTheory]
        [CommonMemberData(nameof(CommonTestHelper.GetEventArgsTheoryData))]
        public void TabPage_OnLeave_InvokeWithParent_DoesNotCallLeave(EventArgs eventArgs)
        {
            using var parent = new TabControl();
            using var control = new SubTabPage
            {
                Parent = parent
            };
            int callCount = 0;
            EventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(eventArgs, e);
                callCount++;
            };

            // Call with handler.
            control.Leave += handler;
            control.OnLeave(eventArgs);
            Assert.Equal(0, callCount);

            // Remove handler.
            control.Leave -= handler;
            control.OnLeave(eventArgs);
            Assert.Equal(0, callCount);
        }

        public static IEnumerable<object[]> OnPaintBackground_TestData()
        {
            foreach (Image backgroundImage in new Image[] { null, new Bitmap(10, 10, PixelFormat.Format32bppRgb), new Bitmap(10, 10, PixelFormat.Format32bppArgb) })
            {
                foreach (ImageLayout backgroundImageLayout in Enum.GetValues(typeof(ImageLayout)))
                {
                    yield return new object[] { true, Color.Empty, backgroundImage, backgroundImageLayout };
                    yield return new object[] { true, Color.Red, backgroundImage, backgroundImageLayout };
                    yield return new object[] { true, Color.FromArgb(100, 50, 100, 150), backgroundImage, backgroundImageLayout };
                    yield return new object[] { true, Color.FromArgb(0, 50, 100, 150), backgroundImage, backgroundImageLayout };
                    yield return new object[] { false, Color.Empty, backgroundImage, backgroundImageLayout };
                    yield return new object[] { false, Color.Red, backgroundImage, backgroundImageLayout };
                }
            }
        }

        [WinFormsTheory]
        [MemberData(nameof(OnPaintBackground_TestData))]
        public void TabPage_OnPaintBackground_Invoke_Success(bool supportsTransparentBackColor, Color backColor, Image backgroundImage, ImageLayout backgroundImageLayout)
        {
            using var image = new Bitmap(10, 10);
            using Graphics graphics = Graphics.FromImage(image);
            var eventArgs = new PaintEventArgs(graphics, new Rectangle(1, 2, 3, 4));

            using var control = new SubTabPage();
            control.SetStyle(ControlStyles.SupportsTransparentBackColor, supportsTransparentBackColor);
            control.BackColor = backColor;
            control.BackgroundImage = backgroundImage;
            control.BackgroundImageLayout = backgroundImageLayout;
            int callCount = 0;
            PaintEventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(eventArgs, e);
                callCount++;
            };

            // Call with handler.
            control.Paint += handler;
            control.OnPaintBackground(eventArgs);
            Assert.Equal(0, callCount);
            Assert.False(control.IsHandleCreated);

            // Remove handler.
            control.Paint -= handler;
            control.OnPaintBackground(eventArgs);
            Assert.Equal(0, callCount);
            Assert.False(control.IsHandleCreated);
        }

        public static IEnumerable<object[]> OnPaintBackground_WithParent_TestData()
        {
            foreach (TabAppearance appearance in Enum.GetValues(typeof(TabAppearance)))
            {
                foreach (bool useVisualStyleBackColor in new bool[] { true, false })
                {
                    foreach (Image backgroundImage in new Image[] { null, new Bitmap(10, 10, PixelFormat.Format32bppRgb) })
                    {
                        foreach (ImageLayout backgroundImageLayout in Enum.GetValues(typeof(ImageLayout)))
                        {
                            yield return new object[] { appearance, useVisualStyleBackColor, true, Color.Empty, backgroundImage, backgroundImageLayout, 0 };
                            yield return new object[] { appearance, useVisualStyleBackColor, true, Color.Red, backgroundImage, backgroundImageLayout, 0 };
                            yield return new object[] { appearance, useVisualStyleBackColor, true, Color.FromArgb(100, 50, 100, 150), backgroundImage, backgroundImageLayout, 1 };
                            yield return new object[] { appearance, useVisualStyleBackColor, true, Color.FromArgb(0, 50, 100, 150), backgroundImage, backgroundImageLayout, 1 };
                            yield return new object[] { appearance, useVisualStyleBackColor, false, Color.Empty, backgroundImage, backgroundImageLayout, 0 };
                            yield return new object[] { appearance, useVisualStyleBackColor, false, Color.Red, backgroundImage, backgroundImageLayout, 0 };
                        }
                    }

                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.Empty, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.None, 0 };
                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.Red, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.None, 0 };
                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.FromArgb(100, 50, 100, 150), new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.None, 1 };
                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.FromArgb(0, 50, 100, 150), new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.None, 1 };
                    yield return new object[] { appearance, useVisualStyleBackColor, false, Color.Empty, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.None, 0 };
                    yield return new object[] { appearance, useVisualStyleBackColor, false, Color.Red, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.None, 0 };

                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.Empty, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.Tile, 1 };
                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.Red, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.Tile, 1 };
                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.FromArgb(100, 50, 100, 150), new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.Tile, 2 };
                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.FromArgb(0, 50, 100, 150), new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.Tile, 2 };
                    yield return new object[] { appearance, useVisualStyleBackColor, false, Color.Empty, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.Tile, 1 };
                    yield return new object[] { appearance, useVisualStyleBackColor, false, Color.Red, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.Tile, 1 };
                }
            }
        }

        [WinFormsTheory]
        [MemberData(nameof(OnPaintBackground_WithParent_TestData))]
        public void TabPage_OnPaintBackground_InvokeWithParent_CallsPaint(TabAppearance appearance, bool useVisualStyleBackColor, bool supportsTransparentBackColor, Color backColor, Image backgroundImage, ImageLayout backgroundImageLayout, int expectedPaintCallCount)
        {
            using var image = new Bitmap(10, 10);
            using Graphics graphics = Graphics.FromImage(image);
            var eventArgs = new PaintEventArgs(graphics, new Rectangle(1, 2, 3, 4));

            using var parent = new TabControl
            {
                Bounds = new Rectangle(1, 2, 30, 40),
                Appearance = appearance
            };
            using var control = new SubTabPage
            {
                Bounds = new Rectangle(1, 2, 10, 20),
                Parent = parent,
                UseVisualStyleBackColor = useVisualStyleBackColor
            };
            control.SetStyle(ControlStyles.SupportsTransparentBackColor, supportsTransparentBackColor);
            control.BackColor = backColor;
            control.BackgroundImage = backgroundImage;
            control.BackgroundImageLayout = backgroundImageLayout;
            int callCount = 0;
            PaintEventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(eventArgs, e);
                callCount++;
            };
            int parentCallCount = 0;
            PaintEventHandler parentHandler = (sender, e) =>
            {
                Assert.Same(parent, sender);
                Assert.NotSame(graphics, e.Graphics);
                Assert.Equal(new Rectangle(1, 2, 0, 0), e.ClipRectangle);
                parentCallCount++;
            };

            // Call with handler.
            control.Paint += handler;
            parent.Paint += parentHandler;
            control.OnPaintBackground(eventArgs);
            Assert.Equal(0, callCount);
            Assert.Equal(expectedPaintCallCount, parentCallCount);
            Assert.False(control.IsHandleCreated);

            // Remove handler.
            control.Paint -= handler;
            parent.Paint -= parentHandler;
            control.OnPaintBackground(eventArgs);
            Assert.Equal(0, callCount);
            Assert.Equal(expectedPaintCallCount, parentCallCount);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [MemberData(nameof(OnPaintBackground_TestData))]
        public void TabPage_OnPaintBackground_InvokeWithHandle_Success(bool supportsTransparentBackColor, Color backColor, Image backgroundImage, ImageLayout backgroundImageLayout)
        {
            using var image = new Bitmap(10, 10);
            using Graphics graphics = Graphics.FromImage(image);
            var eventArgs = new PaintEventArgs(graphics, new Rectangle(1, 2, 3, 4));

            using var control = new SubTabPage();
            control.SetStyle(ControlStyles.SupportsTransparentBackColor, supportsTransparentBackColor);
            control.BackColor = backColor;
            control.BackgroundImage = backgroundImage;
            control.BackgroundImageLayout = backgroundImageLayout;
            int callCount = 0;
            PaintEventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(eventArgs, e);
                callCount++;
            };
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            // Call with handler.
            control.Paint += handler;
            control.OnPaintBackground(eventArgs);
            Assert.Equal(0, callCount);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Remove handler.
            control.Paint -= handler;
            control.OnPaintBackground(eventArgs);
            Assert.Equal(0, callCount);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        public static IEnumerable<object[]> OnPaintBackground_WithParentWithHandle_TestData()
        {
            foreach (TabAppearance appearance in Enum.GetValues(typeof(TabAppearance)))
            {
                foreach (bool useVisualStyleBackColor in new bool[] { true, false })
                {
                    foreach (Image backgroundImage in new Image[] { null, new Bitmap(10, 10, PixelFormat.Format32bppRgb) })
                    {
                        foreach (ImageLayout backgroundImageLayout in Enum.GetValues(typeof(ImageLayout)))
                        {
                            yield return new object[] { appearance, useVisualStyleBackColor, true, Color.Empty, backgroundImage, backgroundImageLayout, 0 };
                            yield return new object[] { appearance, useVisualStyleBackColor, true, Color.Red, backgroundImage, backgroundImageLayout, 0 };
                            yield return new object[] { appearance, useVisualStyleBackColor, true, Color.FromArgb(100, 50, 100, 150), backgroundImage, backgroundImageLayout, 1 };
                            yield return new object[] { appearance, useVisualStyleBackColor, true, Color.FromArgb(0, 50, 100, 150), backgroundImage, backgroundImageLayout, 1 };
                            yield return new object[] { appearance, useVisualStyleBackColor, false, Color.Empty, backgroundImage, backgroundImageLayout, 0 };
                            yield return new object[] { appearance, useVisualStyleBackColor, false, Color.Red, backgroundImage, backgroundImageLayout, 0 };
                        }
                    }

                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.Empty, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.None, 0 };
                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.Red, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.None, 0 };
                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.FromArgb(100, 50, 100, 150), new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.None, 1 };
                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.FromArgb(0, 50, 100, 150), new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.None, 1 };
                    yield return new object[] { appearance, useVisualStyleBackColor, false, Color.Empty, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.None, 0 };
                    yield return new object[] { appearance, useVisualStyleBackColor, false, Color.Red, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.None, 0 };

                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.Empty, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.Tile, 1 };
                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.Red, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.Tile, 1 };
                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.FromArgb(100, 50, 100, 150), new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.Tile, 2 };
                    yield return new object[] { appearance, useVisualStyleBackColor, true, Color.FromArgb(0, 50, 100, 150), new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.Tile, 2 };
                    yield return new object[] { appearance, useVisualStyleBackColor, false, Color.Empty, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.Tile, 1 };
                    yield return new object[] { appearance, useVisualStyleBackColor, false, Color.Red, new Bitmap(10, 10, PixelFormat.Format32bppArgb), ImageLayout.Tile, 1 };
                }
            }
        }

        [WinFormsTheory]
        [MemberData(nameof(OnPaintBackground_WithParentWithHandle_TestData))]
        public void TabPage_OnPaintBackground_InvokeWithParentWithHandle_CallsPaint(TabAppearance appearance, bool useVisualStyleBackColor, bool supportsTransparentBackColor, Color backColor, Image backgroundImage, ImageLayout backgroundImageLayout, int expectedPaintCallCount)
        {
            using var image = new Bitmap(10, 10);
            using Graphics graphics = Graphics.FromImage(image);
            var eventArgs = new PaintEventArgs(graphics, new Rectangle(1, 2, 3, 4));

            using var parent = new TabControl
            {
                Bounds = new Rectangle(1, 2, 30, 40),
                Appearance = appearance,
            };
            using var control = new SubTabPage
            {
                Bounds = new Rectangle(1, 2, 10, 20),
                Parent = parent,
                UseVisualStyleBackColor = useVisualStyleBackColor
            };
            control.SetStyle(ControlStyles.SupportsTransparentBackColor, supportsTransparentBackColor);
            control.BackColor = backColor;
            control.BackgroundImage = backgroundImage;
            control.BackgroundImageLayout = backgroundImageLayout;
            int callCount = 0;
            PaintEventHandler handler = (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(eventArgs, e);
                callCount++;
            };
            int parentCallCount = 0;
            PaintEventHandler parentHandler = (sender, e) =>
            {
                Assert.Same(parent, sender);
                Assert.NotSame(graphics, e.Graphics);
                Assert.Equal(parent.DisplayRectangle, e.ClipRectangle);
                parentCallCount++;
            };
            Assert.NotEqual(IntPtr.Zero, parent.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            // Call with handler.
            control.Paint += handler;
            parent.Paint += parentHandler;
            control.OnPaintBackground(eventArgs);
            Assert.Equal(0, callCount);
            Assert.Equal(expectedPaintCallCount, parentCallCount);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Remove handler.
            control.Paint -= handler;
            parent.Paint -= parentHandler;
            control.OnPaintBackground(eventArgs);
            Assert.Equal(0, callCount);
            Assert.Equal(expectedPaintCallCount, parentCallCount);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(0, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        [WinFormsFact]
        public void TabPage_OnPaintBackground_NullEventArgs_ThrowsArgumentNullException()
        {
            using var control = new SubTabPage();
            Assert.Throws<ArgumentNullException>(() => control.OnPaintBackground(null));
        }

        public static IEnumerable<object[]> SetBoundsCore_TestData()
        {
            foreach (BoundsSpecified specified in Enum.GetValues(typeof(BoundsSpecified)))
            {
                yield return new object[] { 0, 0, 0, 0, specified, 0 };
                yield return new object[] { -1, -2, -3, -4, specified, 1 };
                yield return new object[] { 1, 0, 0, 0, specified, 1 };
                yield return new object[] { 0, 2, 0, 0, specified, 1 };
                yield return new object[] { 1, 2, 0, 0, specified, 1 };
                yield return new object[] { 0, 0, 1, 0, specified, 0 };
                yield return new object[] { 0, 0, 0, 2, specified, 0 };
                yield return new object[] { 0, 0, 1, 2, specified, 0 };
                yield return new object[] { 1, 2, 30, 40, specified, 1 };
            }
        }

        [WinFormsTheory]
        [MemberData(nameof(SetBoundsCore_TestData))]
        public void TabPage_SetBoundsCore_Invoke_Success(int x, int y, int width, int height, BoundsSpecified specified, int expectedLocationChangedCallCount)
        {
            using var control = new SubTabPage();
            int moveCallCount = 0;
            int locationChangedCallCount = 0;
            int layoutCallCount = 0;
            int resizeCallCount = 0;
            int sizeChangedCallCount = 0;
            int clientSizeChangedCallCount = 0;
            control.Move += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(locationChangedCallCount, moveCallCount);
                Assert.Equal(layoutCallCount, moveCallCount);
                Assert.Equal(resizeCallCount, moveCallCount);
                Assert.Equal(sizeChangedCallCount, moveCallCount);
                Assert.Equal(clientSizeChangedCallCount, moveCallCount);
                moveCallCount++;
            };
            control.LocationChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(moveCallCount - 1, locationChangedCallCount);
                Assert.Equal(layoutCallCount, locationChangedCallCount);
                Assert.Equal(resizeCallCount, locationChangedCallCount);
                Assert.Equal(sizeChangedCallCount, locationChangedCallCount);
                Assert.Equal(clientSizeChangedCallCount, locationChangedCallCount);
                locationChangedCallCount++;
            };
            control.Layout += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(control, e.AffectedControl);
                Assert.Equal("Bounds", e.AffectedProperty);
                Assert.Equal(resizeCallCount, layoutCallCount);
                Assert.Equal(sizeChangedCallCount, layoutCallCount);
                Assert.Equal(clientSizeChangedCallCount, layoutCallCount);
                layoutCallCount++;
            };
            control.Resize += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(layoutCallCount - 1, resizeCallCount);
                Assert.Equal(sizeChangedCallCount, resizeCallCount);
                Assert.Equal(clientSizeChangedCallCount, resizeCallCount);
                resizeCallCount++;
            };
            control.SizeChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(resizeCallCount - 1, sizeChangedCallCount);
                Assert.Equal(layoutCallCount - 1, sizeChangedCallCount);
                Assert.Equal(clientSizeChangedCallCount, sizeChangedCallCount);
                sizeChangedCallCount++;
            };
            control.ClientSizeChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(resizeCallCount - 1, clientSizeChangedCallCount);
                Assert.Equal(layoutCallCount - 1, clientSizeChangedCallCount);
                Assert.Equal(sizeChangedCallCount - 1, clientSizeChangedCallCount);
                clientSizeChangedCallCount++;
            };

            control.SetBoundsCore(x, y, width, height, specified);
            Assert.Equal(new Size(width, height), control.ClientSize);
            Assert.Equal(new Rectangle(0, 0, width, height), control.ClientRectangle);
            Assert.Equal(new Rectangle(0, 0, width, height), control.DisplayRectangle);
            Assert.Equal(new Size(width, height), control.Size);
            Assert.Equal(x, control.Left);
            Assert.Equal(x + width, control.Right);
            Assert.Equal(y, control.Top);
            Assert.Equal(y + height, control.Bottom);
            Assert.Equal(width, control.Width);
            Assert.Equal(height, control.Height);
            Assert.Equal(new Rectangle(x, y, width, height), control.Bounds);
            Assert.Equal(expectedLocationChangedCallCount, moveCallCount);
            Assert.Equal(expectedLocationChangedCallCount, locationChangedCallCount);
            Assert.Equal(1, layoutCallCount);
            Assert.Equal(1, resizeCallCount);
            Assert.Equal(1, sizeChangedCallCount);
            Assert.Equal(1, clientSizeChangedCallCount);
            Assert.False(control.IsHandleCreated);

            // Call again.
            control.SetBoundsCore(x, y, width, height, specified);
            Assert.Equal(new Size(width, height), control.ClientSize);
            Assert.Equal(new Rectangle(0, 0, width, height), control.ClientRectangle);
            Assert.Equal(new Rectangle(0, 0, width, height), control.DisplayRectangle);
            Assert.Equal(new Size(width, height), control.Size);
            Assert.Equal(x, control.Left);
            Assert.Equal(x + width, control.Right);
            Assert.Equal(y, control.Top);
            Assert.Equal(y + height, control.Bottom);
            Assert.Equal(width, control.Width);
            Assert.Equal(height, control.Height);
            Assert.Equal(new Rectangle(x, y, width, height), control.Bounds);
            Assert.Equal(expectedLocationChangedCallCount, moveCallCount);
            Assert.Equal(expectedLocationChangedCallCount, locationChangedCallCount);
            Assert.Equal(1, layoutCallCount);
            Assert.Equal(1, resizeCallCount);
            Assert.Equal(1, sizeChangedCallCount);
            Assert.Equal(1, clientSizeChangedCallCount);
            Assert.False(control.IsHandleCreated);
        }

        [WinFormsTheory]
        [MemberData(nameof(SetBoundsCore_TestData))]
        public void TabPage_SetBoundsCore_InvokeWithParent_Success(int x, int y, int width, int height, BoundsSpecified specified, int expectedLocationChangedCallCount)
        {
            using var parent = new TabControl();
            using var control = new SubTabPage
            {
                Parent = parent
            };
            int moveCallCount = 0;
            int locationChangedCallCount = 0;
            int layoutCallCount = 0;
            int resizeCallCount = 0;
            int sizeChangedCallCount = 0;
            int clientSizeChangedCallCount = 0;
            int parentLayoutCallCount = 0;
            control.Move += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(locationChangedCallCount, moveCallCount);
                Assert.Equal(layoutCallCount, moveCallCount);
                Assert.Equal(resizeCallCount, moveCallCount);
                Assert.Equal(sizeChangedCallCount, moveCallCount);
                Assert.Equal(clientSizeChangedCallCount, moveCallCount);
                moveCallCount++;
            };
            control.LocationChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(moveCallCount - 1, locationChangedCallCount);
                Assert.Equal(layoutCallCount, locationChangedCallCount);
                Assert.Equal(resizeCallCount, locationChangedCallCount);
                Assert.Equal(sizeChangedCallCount, locationChangedCallCount);
                Assert.Equal(clientSizeChangedCallCount, locationChangedCallCount);
                locationChangedCallCount++;
            };
            control.Layout += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(control, e.AffectedControl);
                Assert.Equal("Bounds", e.AffectedProperty);
                Assert.Equal(resizeCallCount, layoutCallCount);
                Assert.Equal(sizeChangedCallCount, layoutCallCount);
                Assert.Equal(clientSizeChangedCallCount, layoutCallCount);
                Assert.Equal(parentLayoutCallCount, layoutCallCount);
                layoutCallCount++;
            };
            control.Resize += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(layoutCallCount - 1, resizeCallCount);
                Assert.Equal(sizeChangedCallCount, resizeCallCount);
                Assert.Equal(clientSizeChangedCallCount, resizeCallCount);
                Assert.Equal(parentLayoutCallCount, resizeCallCount);
                resizeCallCount++;
            };
            control.SizeChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(resizeCallCount - 1, sizeChangedCallCount);
                Assert.Equal(layoutCallCount - 1, sizeChangedCallCount);
                Assert.Equal(clientSizeChangedCallCount, sizeChangedCallCount);
                Assert.Equal(parentLayoutCallCount, sizeChangedCallCount);
                sizeChangedCallCount++;
            };
            control.ClientSizeChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(resizeCallCount - 1, clientSizeChangedCallCount);
                Assert.Equal(layoutCallCount - 1, clientSizeChangedCallCount);
                Assert.Equal(sizeChangedCallCount - 1, clientSizeChangedCallCount);
                Assert.Equal(parentLayoutCallCount, clientSizeChangedCallCount);
                clientSizeChangedCallCount++;
            };
            void parentHandler(object sender, LayoutEventArgs e)
            {
                Assert.Same(parent, sender);
                Assert.Same(control, e.AffectedControl);
                Assert.Equal("Bounds", e.AffectedProperty);
                Assert.Equal(resizeCallCount - 1, parentLayoutCallCount);
                Assert.Equal(layoutCallCount - 1, parentLayoutCallCount);
                Assert.Equal(sizeChangedCallCount - 1, parentLayoutCallCount);
                Assert.Equal(clientSizeChangedCallCount - 1, parentLayoutCallCount);
                parentLayoutCallCount++;
            }

            parent.Layout += parentHandler;

            try
            {
                control.SetBoundsCore(x, y, width, height, specified);
                Assert.Equal(new Size(width, height), control.ClientSize);
                Assert.Equal(new Rectangle(0, 0, width, height), control.ClientRectangle);
                Assert.Equal(new Rectangle(0, 0, width, height), control.DisplayRectangle);
                Assert.Equal(new Size(width, height), control.Size);
                Assert.Equal(x, control.Left);
                Assert.Equal(x + width, control.Right);
                Assert.Equal(y, control.Top);
                Assert.Equal(y + height, control.Bottom);
                Assert.Equal(width, control.Width);
                Assert.Equal(height, control.Height);
                Assert.Equal(new Rectangle(x, y, width, height), control.Bounds);
                Assert.Equal(expectedLocationChangedCallCount, moveCallCount);
                Assert.Equal(expectedLocationChangedCallCount, locationChangedCallCount);
                Assert.Equal(1, layoutCallCount);
                Assert.Equal(1, resizeCallCount);
                Assert.Equal(1, sizeChangedCallCount);
                Assert.Equal(1, clientSizeChangedCallCount);
                Assert.Equal(1, parentLayoutCallCount);
                Assert.False(control.IsHandleCreated);

                // Call again.
                control.SetBoundsCore(x, y, width, height, specified);
                Assert.Equal(new Size(width, height), control.ClientSize);
                Assert.Equal(new Rectangle(0, 0, width, height), control.ClientRectangle);
                Assert.Equal(new Rectangle(0, 0, width, height), control.DisplayRectangle);
                Assert.Equal(new Size(width, height), control.Size);
                Assert.Equal(x, control.Left);
                Assert.Equal(x + width, control.Right);
                Assert.Equal(y, control.Top);
                Assert.Equal(y + height, control.Bottom);
                Assert.Equal(width, control.Width);
                Assert.Equal(height, control.Height);
                Assert.Equal(new Rectangle(x, y, width, height), control.Bounds);
                Assert.Equal(expectedLocationChangedCallCount, moveCallCount);
                Assert.Equal(expectedLocationChangedCallCount, locationChangedCallCount);
                Assert.Equal(1, layoutCallCount);
                Assert.Equal(1, resizeCallCount);
                Assert.Equal(1, sizeChangedCallCount);
                Assert.Equal(1, clientSizeChangedCallCount);
                Assert.Equal(1, parentLayoutCallCount);
                Assert.False(control.IsHandleCreated);
            }
            finally
            {
                parent.Layout -= parentHandler;
            }
        }

        public static IEnumerable<object[]> SetBoundsCore_WithHandle_TestData()
        {
            foreach (BoundsSpecified specified in Enum.GetValues(typeof(BoundsSpecified)))
            {
                yield return new object[] { true, 0, 0, 0, 0, specified, 0, 0, 0, 1 };
                yield return new object[] { true, -1, -2, -3, -4, specified, 0, 0, 1, 1 };
                yield return new object[] { true, 1, 0, 0, 0, specified, 0, 0, 1, 1 };
                yield return new object[] { true, 0, 2, 0, 0, specified, 0, 0, 1, 1 };
                yield return new object[] { true, 1, 2, 0, 0, specified, 0, 0, 1, 1 };
                yield return new object[] { true, 0, 0, 1, 0, specified, 1, 0, 0, 1 };
                yield return new object[] { true, 0, 0, 0, 2, specified, 0, 2, 0, 1 };
                yield return new object[] { true, 0, 0, 1, 2, specified, 1, 2, 0, 1 };
                yield return new object[] { true, 1, 2, 30, 40, specified, 30, 40, 1, 1 };

                yield return new object[] { false, 0, 0, 0, 0, specified, 0, 0, 0, 0 };
                yield return new object[] { false, -1, -2, -3, -4, specified, 0, 0, 1, 0 };
                yield return new object[] { false, 1, 0, 0, 0, specified, 0, 0, 1, 0 };
                yield return new object[] { false, 0, 2, 0, 0, specified, 0, 0, 1, 0 };
                yield return new object[] { false, 1, 2, 0, 0, specified, 0, 0, 1, 0 };
                yield return new object[] { false, 0, 0, 1, 0, specified, 1, 0, 0, 0 };
                yield return new object[] { false, 0, 0, 0, 2, specified, 0, 2, 0, 0 };
                yield return new object[] { false, 0, 0, 1, 2, specified, 1, 2, 0, 0 };
                yield return new object[] { false, 1, 2, 30, 40, specified, 30, 40, 1, 0 };
            }
        }

        [WinFormsTheory]
        [MemberData(nameof(SetBoundsCore_WithHandle_TestData))]
        public void TabPage_SetBoundsCore_InvokeWithHandle_Success(bool resizeRedraw, int x, int y, int width, int height, BoundsSpecified specified, int expectedWidth, int expectedHeight, int expectedLocationChangedCallCount, int expectedInvalidatedCallCount)
        {
            using var control = new SubTabPage();
            control.SetStyle(ControlStyles.ResizeRedraw, resizeRedraw);
            Assert.NotEqual(IntPtr.Zero, control.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;

            int moveCallCount = 0;
            int locationChangedCallCount = 0;
            int layoutCallCount = 0;
            int resizeCallCount = 0;
            int sizeChangedCallCount = 0;
            int clientSizeChangedCallCount = 0;
            control.Move += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(locationChangedCallCount, moveCallCount);
                Assert.Equal(layoutCallCount, moveCallCount);
                Assert.Equal(resizeCallCount, moveCallCount);
                Assert.Equal(sizeChangedCallCount, moveCallCount);
                Assert.Equal(clientSizeChangedCallCount, moveCallCount);
                moveCallCount++;
            };
            control.LocationChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(moveCallCount - 1, locationChangedCallCount);
                Assert.Equal(layoutCallCount, locationChangedCallCount);
                Assert.Equal(resizeCallCount, locationChangedCallCount);
                Assert.Equal(sizeChangedCallCount, locationChangedCallCount);
                Assert.Equal(clientSizeChangedCallCount, locationChangedCallCount);
                locationChangedCallCount++;
            };
            control.Layout += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(control, e.AffectedControl);
                Assert.Equal("Bounds", e.AffectedProperty);
                Assert.Equal(resizeCallCount, layoutCallCount);
                Assert.Equal(sizeChangedCallCount, layoutCallCount);
                Assert.Equal(clientSizeChangedCallCount, layoutCallCount);
                layoutCallCount++;
            };
            control.Resize += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(layoutCallCount - 1, resizeCallCount);
                Assert.Equal(sizeChangedCallCount, resizeCallCount);
                Assert.Equal(clientSizeChangedCallCount, resizeCallCount);
                resizeCallCount++;
            };
            control.SizeChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(resizeCallCount - 1, sizeChangedCallCount);
                Assert.Equal(layoutCallCount - 1, sizeChangedCallCount);
                Assert.Equal(clientSizeChangedCallCount, sizeChangedCallCount);
                sizeChangedCallCount++;
            };
            control.ClientSizeChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(resizeCallCount - 1, clientSizeChangedCallCount);
                Assert.Equal(layoutCallCount - 1, clientSizeChangedCallCount);
                Assert.Equal(sizeChangedCallCount - 1, clientSizeChangedCallCount);
                clientSizeChangedCallCount++;
            };

            control.SetBoundsCore(x, y, width, height, specified);
            Assert.Equal(new Size(expectedWidth, expectedHeight), control.ClientSize);
            Assert.Equal(new Rectangle(0, 0, expectedWidth, expectedHeight), control.ClientRectangle);
            Assert.Equal(new Rectangle(0, 0, expectedWidth, expectedHeight), control.DisplayRectangle);
            Assert.Equal(new Size(expectedWidth, expectedHeight), control.Size);
            Assert.Equal(x, control.Left);
            Assert.Equal(x + expectedWidth, control.Right);
            Assert.Equal(y, control.Top);
            Assert.Equal(y + expectedHeight, control.Bottom);
            Assert.Equal(expectedWidth, control.Width);
            Assert.Equal(expectedHeight, control.Height);
            Assert.Equal(new Rectangle(x, y, expectedWidth, expectedHeight), control.Bounds);
            Assert.Equal(expectedLocationChangedCallCount, moveCallCount);
            Assert.Equal(expectedLocationChangedCallCount, locationChangedCallCount);
            Assert.Equal(1, layoutCallCount);
            Assert.Equal(1, resizeCallCount);
            Assert.Equal(1, sizeChangedCallCount);
            Assert.Equal(1, clientSizeChangedCallCount);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidatedCallCount, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);

            // Call again.
            control.SetBoundsCore(x, y, width, height, specified);
            Assert.Equal(new Size(expectedWidth, expectedHeight), control.ClientSize);
            Assert.Equal(new Rectangle(0, 0, expectedWidth, expectedHeight), control.ClientRectangle);
            Assert.Equal(new Rectangle(0, 0, expectedWidth, expectedHeight), control.DisplayRectangle);
            Assert.Equal(new Size(expectedWidth, expectedHeight), control.Size);
            Assert.Equal(x, control.Left);
            Assert.Equal(x + expectedWidth, control.Right);
            Assert.Equal(y, control.Top);
            Assert.Equal(y + expectedHeight, control.Bottom);
            Assert.Equal(expectedWidth, control.Width);
            Assert.Equal(expectedHeight, control.Height);
            Assert.Equal(new Rectangle(x, y, expectedWidth, expectedHeight), control.Bounds);
            Assert.Equal(expectedLocationChangedCallCount, moveCallCount);
            Assert.Equal(expectedLocationChangedCallCount, locationChangedCallCount);
            Assert.Equal(1, layoutCallCount);
            Assert.Equal(1, resizeCallCount);
            Assert.Equal(1, sizeChangedCallCount);
            Assert.Equal(1, clientSizeChangedCallCount);
            Assert.True(control.IsHandleCreated);
            Assert.Equal(expectedInvalidatedCallCount, invalidatedCallCount);
            Assert.Equal(0, styleChangedCallCount);
            Assert.Equal(0, createdCallCount);
        }

        public static IEnumerable<object[]> SetBoundsCore_WithParentWithHandle_TestData()
        {
            foreach (BoundsSpecified specified in Enum.GetValues(typeof(BoundsSpecified)))
            {
                foreach (bool resizeRedraw in new bool[] { true, false })
                {
                    yield return new object[] { resizeRedraw, 0, 0, 0, 0, specified };
                    yield return new object[] { resizeRedraw, -1, -2, -3, -4, specified };
                    yield return new object[] { resizeRedraw, 1, 0, 0, 0, specified };
                    yield return new object[] { resizeRedraw, 0, 2, 0, 0, specified };
                    yield return new object[] { resizeRedraw, 1, 2, 0, 0, specified };
                    yield return new object[] { resizeRedraw, 0, 0, 1, 0, specified };
                    yield return new object[] { resizeRedraw, 0, 0, 0, 2, specified };
                    yield return new object[] { resizeRedraw, 0, 0, 1, 2, specified };
                    yield return new object[] { resizeRedraw, 1, 2, 30, 40, specified };
                }
            }
        }

        [WinFormsTheory]
        [MemberData(nameof(SetBoundsCore_WithParentWithHandle_TestData))]
        public void TabPage_SetBoundsCore_InvokeWithParentWithHandle_Success(bool resizeRedraw, int x, int y, int width, int height, BoundsSpecified specified)
        {
            using var parent = new TabControl();
            using var control = new SubTabPage
            {
                Parent = parent
            };
            control.SetStyle(ControlStyles.ResizeRedraw, resizeRedraw);
            Assert.NotEqual(IntPtr.Zero, parent.Handle);
            int invalidatedCallCount = 0;
            control.Invalidated += (sender, e) => invalidatedCallCount++;
            int styleChangedCallCount = 0;
            control.StyleChanged += (sender, e) => styleChangedCallCount++;
            int createdCallCount = 0;
            control.HandleCreated += (sender, e) => createdCallCount++;
            int parentInvalidatedCallCount = 0;
            parent.Invalidated += (sender, e) => parentInvalidatedCallCount++;
            int parentStyleChangedCallCount = 0;
            parent.StyleChanged += (sender, e) => parentStyleChangedCallCount++;
            int parentCreatedCallCount = 0;
            parent.HandleCreated += (sender, e) => parentCreatedCallCount++;
            Rectangle expected = parent.DisplayRectangle;

            int moveCallCount = 0;
            int locationChangedCallCount = 0;
            int layoutCallCount = 0;
            int resizeCallCount = 0;
            int sizeChangedCallCount = 0;
            int clientSizeChangedCallCount = 0;
            int parentLayoutCallCount = 0;
            control.Move += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(locationChangedCallCount, moveCallCount);
                Assert.Equal(layoutCallCount, moveCallCount);
                Assert.Equal(resizeCallCount, moveCallCount);
                Assert.Equal(sizeChangedCallCount, moveCallCount);
                Assert.Equal(clientSizeChangedCallCount, moveCallCount);
                moveCallCount++;
            };
            control.LocationChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(moveCallCount - 1, locationChangedCallCount);
                Assert.Equal(layoutCallCount, locationChangedCallCount);
                Assert.Equal(resizeCallCount, locationChangedCallCount);
                Assert.Equal(sizeChangedCallCount, locationChangedCallCount);
                Assert.Equal(clientSizeChangedCallCount, locationChangedCallCount);
                locationChangedCallCount++;
            };
            control.Layout += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(control, e.AffectedControl);
                Assert.Equal("Bounds", e.AffectedProperty);
                Assert.Equal(resizeCallCount, layoutCallCount);
                Assert.Equal(sizeChangedCallCount, layoutCallCount);
                Assert.Equal(clientSizeChangedCallCount, layoutCallCount);
                Assert.Equal(parentLayoutCallCount, layoutCallCount);
                layoutCallCount++;
            };
            control.Resize += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(layoutCallCount - 1, resizeCallCount);
                Assert.Equal(sizeChangedCallCount, resizeCallCount);
                Assert.Equal(clientSizeChangedCallCount, resizeCallCount);
                Assert.Equal(parentLayoutCallCount, resizeCallCount);
                resizeCallCount++;
            };
            control.SizeChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(resizeCallCount - 1, sizeChangedCallCount);
                Assert.Equal(layoutCallCount - 1, sizeChangedCallCount);
                Assert.Equal(clientSizeChangedCallCount, sizeChangedCallCount);
                Assert.Equal(parentLayoutCallCount, sizeChangedCallCount);
                sizeChangedCallCount++;
            };
            control.ClientSizeChanged += (sender, e) =>
            {
                Assert.Same(control, sender);
                Assert.Same(EventArgs.Empty, e);
                Assert.Equal(resizeCallCount - 1, clientSizeChangedCallCount);
                Assert.Equal(layoutCallCount - 1, clientSizeChangedCallCount);
                Assert.Equal(sizeChangedCallCount - 1, clientSizeChangedCallCount);
                Assert.Equal(parentLayoutCallCount, clientSizeChangedCallCount);
                clientSizeChangedCallCount++;
            };
            void parentHandler(object sender, LayoutEventArgs e)
            {
                Assert.Same(parent, sender);
                Assert.Same(control, e.AffectedControl);
                Assert.Equal("Bounds", e.AffectedProperty);
                Assert.Equal(resizeCallCount - 1, parentLayoutCallCount);
                Assert.Equal(layoutCallCount - 1, parentLayoutCallCount);
                Assert.Equal(sizeChangedCallCount - 1, parentLayoutCallCount);
                Assert.Equal(clientSizeChangedCallCount - 1, parentLayoutCallCount);
                parentLayoutCallCount++;
            }

            parent.Layout += parentHandler;

            try
            {
                control.SetBoundsCore(x, y, width, height, specified);
                Assert.Equal(expected.Size, control.ClientSize);
                Assert.Equal(new Rectangle(0, 0, expected.Width, expected.Height), control.ClientRectangle);
                Assert.Equal(new Rectangle(0, 0, expected.Width, expected.Height), control.DisplayRectangle);
                Assert.Equal(expected.Size, control.Size);
                Assert.Equal(expected.X, control.Left);
                Assert.Equal(expected.X + expected.Width, control.Right);
                Assert.Equal(expected.Location, control.Location);
                Assert.Equal(expected.Y, control.Top);
                Assert.Equal(expected.Y + expected.Height, control.Bottom);
                Assert.Equal(expected.Width, control.Width);
                Assert.Equal(expected.Height, control.Height);
                Assert.Equal(expected, control.Bounds);
                Assert.Equal(0, moveCallCount);
                Assert.Equal(0, locationChangedCallCount);
                Assert.Equal(0, layoutCallCount);
                Assert.Equal(0, parentLayoutCallCount);
                Assert.Equal(0, resizeCallCount);
                Assert.Equal(0, sizeChangedCallCount);
                Assert.Equal(0, clientSizeChangedCallCount);
                Assert.True(control.IsHandleCreated);
                Assert.Equal(0, invalidatedCallCount);
                Assert.Equal(0, styleChangedCallCount);
                Assert.Equal(0, createdCallCount);
                Assert.True(parent.IsHandleCreated);
                Assert.Equal(0, parentInvalidatedCallCount);
                Assert.Equal(0, parentStyleChangedCallCount);
                Assert.Equal(0, parentCreatedCallCount);

                // Call again.
                control.SetBoundsCore(x, y, width, height, specified);
                Assert.Equal(expected.Size, control.ClientSize);
                Assert.Equal(new Rectangle(0, 0, expected.Width, expected.Height), control.ClientRectangle);
                Assert.Equal(new Rectangle(0, 0, expected.Width, expected.Height), control.DisplayRectangle);
                Assert.Equal(expected.Size, control.Size);
                Assert.Equal(expected.X, control.Left);
                Assert.Equal(expected.X + expected.Width, control.Right);
                Assert.Equal(expected.Location, control.Location);
                Assert.Equal(expected.Y, control.Top);
                Assert.Equal(expected.Y + expected.Height, control.Bottom);
                Assert.Equal(expected.Width, control.Width);
                Assert.Equal(expected.Height, control.Height);
                Assert.Equal(expected, control.Bounds);
                Assert.Equal(0, moveCallCount);
                Assert.Equal(0, locationChangedCallCount);
                Assert.Equal(0, layoutCallCount);
                Assert.Equal(0, parentLayoutCallCount);
                Assert.Equal(0, resizeCallCount);
                Assert.Equal(0, sizeChangedCallCount);
                Assert.Equal(0, clientSizeChangedCallCount);
                Assert.True(control.IsHandleCreated);
                Assert.Equal(0, invalidatedCallCount);
                Assert.Equal(0, styleChangedCallCount);
                Assert.Equal(0, createdCallCount);
                Assert.True(parent.IsHandleCreated);
                Assert.Equal(0, parentInvalidatedCallCount);
                Assert.Equal(0, parentStyleChangedCallCount);
                Assert.Equal(0, parentCreatedCallCount);
            }
            finally
            {
                parent.Layout -= parentHandler;
            }
        }

        [WinFormsFact]
        public void TabPage_ToString_Invoke_ReturnsExpected()
        {
            using var control = new TabPage();
            Assert.Equal("TabPage: {}", control.ToString());
        }

        [WinFormsFact]
        public void TabPage_ToString_InvokeWithText_ReturnsExpected()
        {
            using var control = new TabPage("text");
            Assert.Equal("TabPage: {text}", control.ToString());
        }

        [WinFormsFact]
        public void TabPage_ToString_InvokeWithNullText_ReturnsExpected()
        {
            using var control = new NullTextTabPage();
            Assert.Equal("TabPage: {}", control.ToString());
        }

        [WinFormsFact]
        public void TabPage_GetCaptionForTool_ReturnsToolTipText_IfToolTipTextIsSet()
        {
            using TabPage control = new TabPage();
            string text = "Some test text";
            control.ToolTipText = text;
            using ToolTip toolTip = new ToolTip();

            string actual = ((IKeyboardToolTip)control).GetCaptionForTool(toolTip);

            Assert.Equal(text, actual);
        }

        [WinFormsFact]
        public void TabPage_GetCaptionForTool_ReturnsExternalToolTipText_IfInternalsAreNotSet()
        {
            using TabPage control = new TabPage();
            using ToolTip toolTip = new ToolTip();
            control.CreateControl();

            Assert.NotEqual(IntPtr.Zero, toolTip.Handle); // A workaroung to create the tooltip native window Handle

            string text = "Some test text";
            toolTip.SetToolTip(control, text);

            string actual = ((IKeyboardToolTip)control).GetCaptionForTool(toolTip);

            Assert.Equal(text, actual);
        }

        [WinFormsFact]
        public void TabPage_GetCaptionForTool_ReturnsNull_IfNoToolTipIsSet()
        {
            using TabPage control = new TabPage();
            using ToolTip toolTip = new ToolTip();

            string actual = ((IKeyboardToolTip)control).GetCaptionForTool(toolTip);

            Assert.Null(actual);
        }

        [WinFormsFact]
        public void TabPage_GetNeighboringToolsRectangles_ReturnsEmptyCollection_IfPageDoesntHaveTabControl()
        {
            using TabPage control = new TabPage();

            IList<Rectangle> actual = ((IKeyboardToolTip)control).GetNeighboringToolsRectangles();

            Assert.Empty(actual);
        }

        [WinFormsTheory]
        [InlineData(0)]
        [InlineData(1)]
        [InlineData(2)]
        [InlineData(3)]
        [InlineData(4)]
        public void TabPage_GetNeighboringToolsRectangles_ReturnsCorrect(int index)
        {
            using TabControl tabControl = new TabControl();
            const int pagesCount = 5;

            for (int i = 0; i < pagesCount; i++)
            {
                tabControl.TabPages.Add(new TabPage());
            }

            TabPage testedTab = tabControl.TabPages[index];
            IList<Rectangle> neighborsRectangles = ((IKeyboardToolTip)testedTab).GetNeighboringToolsRectangles();

            Assert.NotEmpty(neighborsRectangles);

            if (index > 0) // has the left neighbor
            {
                Assert.True(neighborsRectangles.Contains(GetTabRect(index - 1))); // check the left neighbor

                for (int i = 0; i < index - 1; i++)
                {
                    Assert.False(neighborsRectangles.Contains(GetTabRect(i))); // check the rest lefts
                }
            }

            if (index < pagesCount - 1) // has the right neighbor
            {
                Assert.True(neighborsRectangles.Contains(GetTabRect(index + 1))); // check the right neighbor

                for (int i = index + 2; i < pagesCount; i++)
                {
                    Assert.False(neighborsRectangles.Contains(GetTabRect(i))); // check the rest rights
                }
            }

            Rectangle GetTabRect(int index)
                => tabControl.RectangleToScreen(tabControl.GetTabRect(index));
        }

        [WinFormsFact]
        public void TabPage_InternalToolTip_IsSet_IfNoExternalIsSet()
        {
            using TabPage control = new TabPage();
            string text = "Some test text";
            control.ToolTipText = text;

            ToolTip internalToolTip = control.TestAccessor().Dynamic._internalToolTip;
            string actual = internalToolTip.GetCaptionForTool(control);

            Assert.Equal(text, actual);
        }

        [WinFormsFact]
        public void TabPage_InternalToolTip_IsNotSet_IfExternalIsSet()
        {
            using TabPage control = new TabPage();
            using ToolTip toolTip = new ToolTip();
            string text = "Some test text";
            control.ToolTipText = text;
            control.CreateControl();

            Assert.NotEqual(IntPtr.Zero, toolTip.Handle); // A workaroung to create the tooltip native window Handle

            toolTip.SetToolTip(control, text);
            ToolTip internalToolTip = control.TestAccessor().Dynamic._internalToolTip;
            string actual = internalToolTip.GetCaptionForTool(control);

            Assert.Null(actual);
        }

        [WinFormsFact]
        public void TabPage_GetToolNativeScreenRectangle_ReturnsExpected()
        {
            using TabControl tabControl = new TabControl();
            using TabPage page = new TabPage();
            tabControl.TabPages.Add(page);

            Rectangle expected = tabControl.RectangleToScreen(tabControl.GetTabRect(0));
            Rectangle actual = page.GetToolNativeScreenRectangle();

            Assert.Equal(expected, actual);
        }

        [WinFormsFact]
        public void TabPage_GetToolNativeScreenRectangle_ReturnsEmpty_WithoutParent()
        {
            using TabPage control = new TabPage();

            Rectangle actual = control.GetToolNativeScreenRectangle();

            Assert.Equal(Rectangle.Empty, actual);
        }

        [WinFormsTheory]
        [InlineData(true, null)]
        [InlineData(false, "Some test text")]
        public void TabPage_SetToolTip_ManagesAssociatedToolTips_ForOneToolTipInstance(bool createToolTip, string expectedText)
        {
            using TabPage control = new TabPage();
            string text = "Some test text";
            control.ToolTipText = text;

            dynamic tabPageDynamic = control.TestAccessor().Dynamic;
            ToolTip internalToolTip = tabPageDynamic._internalToolTip;
            ToolTip externalToolTip = tabPageDynamic._externalToolTip;
            List<ToolTip> associatedToolTips = tabPageDynamic._associatedToolTips;
            string actualText = internalToolTip.GetCaptionForTool(control);

            Assert.Equal(text, actualText);
            Assert.Null(externalToolTip);
            Assert.Null(associatedToolTips);

            using ToolTip toolTip = createToolTip
                ? new ToolTip() // TabPage's SetToolTip will clear the internal toolTip because external one is set
                : null;  // TabPage's SetToolTip won't change states of fields and won't throw any exceptions

            control.SetToolTip(toolTip);

            externalToolTip = tabPageDynamic._externalToolTip;
            associatedToolTips = tabPageDynamic._associatedToolTips;
            actualText = internalToolTip.GetCaptionForTool(control);

            Assert.Equal(expectedText, actualText);
            Assert.Equal(toolTip, externalToolTip);
            Assert.Null(associatedToolTips);
        }

        [WinFormsFact]
        public void TabPage_SetToolTip_ManagesInternalAndAssociatedToolTips_ForTwoToolTipInstances()
        {
            using TabPage control = new TabPage();
            string text = "Some test text";
            control.ToolTipText = text;

            dynamic tabPageDynamic = control.TestAccessor().Dynamic;
            ToolTip internalToolTip = tabPageDynamic._internalToolTip;
            ToolTip externalToolTip = tabPageDynamic._externalToolTip;
            List<ToolTip> associatedToolTips = tabPageDynamic._associatedToolTips;
            string actualText = internalToolTip.GetCaptionForTool(control);

            Assert.Equal(text, actualText);
            Assert.Null(externalToolTip);
            Assert.Null(associatedToolTips);

            using ToolTip toolTip1 = new ToolTip();
            using ToolTip toolTip2 = new ToolTip();

            control.SetToolTip(toolTip1);
            control.SetToolTip(toolTip2);

            actualText = internalToolTip.GetCaptionForTool(control);
            externalToolTip = tabPageDynamic._externalToolTip;
            associatedToolTips = tabPageDynamic._associatedToolTips;

            Assert.Null(actualText);
            Assert.Equal(toolTip1, externalToolTip);
            Assert.Equal(2, associatedToolTips.Count);
            Assert.Equal(toolTip1, associatedToolTips[0]);
            Assert.Equal(toolTip2, associatedToolTips[1]);
        }

        [WinFormsTheory]
        [InlineData(true, true)]
        [InlineData(false, false)]
        public void TabPage_RemoveToolTip_ManagesAssociatedToolTips_ForOneToolTipInstance(bool createToolTip, bool setToolTip)
        {
            using TabPage control = new TabPage();
            string text = "Some test text";
            control.ToolTipText = text;

            dynamic tabPageDynamic = control.TestAccessor().Dynamic;
            ToolTip internalToolTip = tabPageDynamic._internalToolTip;
            ToolTip externalToolTip = tabPageDynamic._externalToolTip;

            using ToolTip toolTip = createToolTip
                ? new ToolTip() // TabPage's RemoveToolTip will clear the internal toolTip because external one is set
                : null;  // TabPage's RemoveToolTip won't change states of fields and won't throw any exceptions

            if (createToolTip && setToolTip)
            {
                // A simple workaround in the test to set expected states for fields
                control.SetToolTip(toolTip);
            }

            control.RemoveToolTip(toolTip);

            List<ToolTip> associatedToolTips = tabPageDynamic._associatedToolTips;
            string actualText = internalToolTip.GetCaptionForTool(control);

            Assert.Equal(text, actualText);
            Assert.Null(externalToolTip);
            Assert.Null(associatedToolTips);
        }

        [WinFormsFact]
        public void TabPage_RemoveToolTip_ManagesAssociatedToolTips_ForTwoToolTipInstances()
        {
            using TabPage control = new TabPage();
            string text = "Some test text";
            control.ToolTipText = text;

            dynamic tabPageDynamic = control.TestAccessor().Dynamic;
            ToolTip internalToolTip = tabPageDynamic._internalToolTip;

            using ToolTip toolTip1 = new ToolTip();
            using ToolTip toolTip2 = new ToolTip();

            // A simple workaround in the test to set expected states for fields
            control.SetToolTip(toolTip1);
            control.SetToolTip(toolTip2);

            control.RemoveToolTip(toolTip1);

            List<ToolTip> associatedToolTips = tabPageDynamic._associatedToolTips;
            ToolTip externalToolTip = tabPageDynamic._externalToolTip;

            Assert.Equal(toolTip2, externalToolTip);
            Assert.Null(associatedToolTips);
        }

        [WinFormsFact]
        public void TabPage_RemoveToolTip_ManagesAssociatedToolTips_ForThreeToolTipInstances()
        {
            using TabPage control = new TabPage();
            string text = "Some test text";
            control.ToolTipText = text;

            dynamic tabPageDynamic = control.TestAccessor().Dynamic;
            ToolTip internalToolTip = tabPageDynamic._internalToolTip;
            ToolTip externalToolTip = tabPageDynamic._externalToolTip;

            using ToolTip toolTip1 = new ToolTip();
            using ToolTip toolTip2 = new ToolTip();
            using ToolTip toolTip3 = new ToolTip();

            // A simple workaround in the test to set expected states for fields
            control.SetToolTip(toolTip1);
            control.SetToolTip(toolTip2);
            control.SetToolTip(toolTip3);

            control.RemoveToolTip(toolTip1);

            List<ToolTip> associatedToolTips = tabPageDynamic._associatedToolTips;

            Assert.Equal(2, associatedToolTips.Count);
            Assert.Equal(toolTip2, associatedToolTips[0]);
            Assert.Equal(toolTip3, associatedToolTips[1]);
        }

        private class NullTextTabPage : TabPage
        {
            public override string Text
            {
                get => null;
                set { }
            }
        }

        private class SubTabPage : TabPage
        {
            public new const int ScrollStateAutoScrolling = TabPage.ScrollStateAutoScrolling;

            public new const int ScrollStateHScrollVisible = TabPage.ScrollStateHScrollVisible;

            public new const int ScrollStateVScrollVisible = TabPage.ScrollStateVScrollVisible;

            public new const int ScrollStateUserHasScrolled = TabPage.ScrollStateUserHasScrolled;

            public new const int ScrollStateFullDrag = TabPage.ScrollStateFullDrag;

            public SubTabPage() : base()
            {
            }

            public SubTabPage(string text) : base(text)
            {
            }

            public new bool CanEnableIme => base.CanEnableIme;

            public new bool CanRaiseEvents => base.CanRaiseEvents;

            public new CreateParams CreateParams => base.CreateParams;

            public new Cursor DefaultCursor => base.DefaultCursor;

            public new ImeMode DefaultImeMode => base.DefaultImeMode;

            public new Padding DefaultMargin => base.DefaultMargin;

            public new Size DefaultMaximumSize => base.DefaultMaximumSize;

            public new Size DefaultMinimumSize => base.DefaultMinimumSize;

            public new Padding DefaultPadding => base.DefaultPadding;

            public new Size DefaultSize => base.DefaultSize;

            public new bool DesignMode => base.DesignMode;

            public new bool DoubleBuffered
            {
                get => base.DoubleBuffered;
                set => base.DoubleBuffered = value;
            }

            public new EventHandlerList Events => base.Events;

            public new int FontHeight
            {
                get => base.FontHeight;
                set => base.FontHeight = value;
            }

            public new ImeMode ImeModeBase
            {
                get => base.ImeModeBase;
                set => base.ImeModeBase = value;
            }

            public new bool HScroll
            {
                get => base.HScroll;
                set => base.HScroll = value;
            }

            public new bool ResizeRedraw
            {
                get => base.ResizeRedraw;
                set => base.ResizeRedraw = value;
            }

            public new bool ShowFocusCues => base.ShowFocusCues;

            public new bool ShowKeyboardCues => base.ShowKeyboardCues;

            public new bool VScroll
            {
                get => base.VScroll;
                set => base.VScroll = value;
            }

            public new ControlCollection CreateControlsInstance() => base.CreateControlsInstance();

            public new AutoSizeMode GetAutoSizeMode() => base.GetAutoSizeMode();

            public new bool GetScrollState(int bit) => base.GetScrollState(bit);

            public new bool GetStyle(ControlStyles flag) => base.GetStyle(flag);

            public new bool GetTopLevel() => base.GetTopLevel();

            public new void SetBoundsCore(int x, int y, int width, int height, BoundsSpecified specified) => base.SetBoundsCore(x, y, width, height, specified);

            public new void SetStyle(ControlStyles flag, bool value) => base.SetStyle(flag, value);

            public new void OnEnter(EventArgs e) => base.OnEnter(e);

            public new void OnLeave(EventArgs e) => base.OnLeave(e);

            public new void OnPaintBackground(PaintEventArgs e) => base.OnPaintBackground(e);
        }
    }
}
