// 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.

#nullable disable

using System.Collections.Specialized;
using System.ComponentModel;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Net;
using System.Runtime.InteropServices;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms.Layout;
using static Interop;

namespace System.Windows.Forms
{
    /// <summary>
    ///  Displays an image that can be a graphic from a bitmap, icon, or metafile, as well as from
    ///  an enhanced metafile, JPEG, or GIF files.
    /// </summary>
    [DefaultProperty(nameof(Image))]
    [DefaultBindingProperty(nameof(Image))]
    [Docking(DockingBehavior.Ask)]
    [Designer("System.Windows.Forms.Design.PictureBoxDesigner, " + AssemblyRef.SystemDesign)]
    [SRDescription(nameof(SR.DescriptionPictureBox))]
    public partial class PictureBox : Control, ISupportInitialize
    {
        /// <summary>
        ///  The type of border this control will have.
        /// </summary>
        private BorderStyle _borderStyle = BorderStyle.None;

        /// <summary>
        ///  The image being displayed.
        /// </summary>
        private Image _image;

        /// <summary>
        ///  Controls how the image is placed within our bounds, or how we are sized to fit said image.
        /// </summary>
        private PictureBoxSizeMode _sizeMode = PictureBoxSizeMode.Normal;

        private Size _savedSize;

        private bool _currentlyAnimating;

        // Instance members for asynchronous behavior
        private AsyncOperation _currentAsyncLoadOperation;

        private string _imageLocation;
        private Image _initialImage;
        private Image errorImage;
        private int _contentLength;
        private int _totalBytesRead;
        private MemoryStream _tempDownloadStream;
        private const int ReadBlockSize = 4096;
        private byte[] _readBuffer;
        private ImageInstallationType _imageInstallationType;
        private SendOrPostCallback _loadCompletedDelegate;
        private SendOrPostCallback _loadProgressDelegate;
        private bool _handleValid;
        private readonly object _internalSyncObject = new object();

        // These default images will be demand loaded.
        private Image _defaultInitialImage;
        private Image _defaultErrorImage;

        [ThreadStatic]
        private static Image t_defaultInitialImageForThread;

        [ThreadStatic]
        private static Image t_defaultErrorImageForThread;

        private static readonly object s_loadCompletedKey = new object();
        private static readonly object s_loadProgressChangedKey = new object();

        private const int AsyncOperationInProgressState = 0x00000001;
        private const int CancellationPendingState = 0x00000002;
        private const int UseDefaultInitialImageState = 0x00000004;
        private const int UseDefaultErrorImageState = 0x00000008;
        private const int WaitOnLoadState = 0x00000010;
        private const int NeedToLoadImageLocationState = 0x00000020;
        private const int InInitializationState = 0x00000040;

        // PERF: take all the bools and put them into a state variable
        private BitVector32 _pictureBoxState; // see PICTUREBOXSTATE_ consts above

        /// <summary>
        ///  http://msdn.microsoft.com/en-us/library/93z9ee4x(v=VS.100).aspx
        ///  if we load an image from a stream, we must keep the stream open for the lifetime of the Image
        /// </summary>
        private StreamReader _localImageStreamReader;
        private Stream _uriImageStream;

        /// <summary>
        ///  Creates a new picture with all default properties and no Image. The default PictureBox.SizeMode
        ///  will be PictureBoxSizeMode.NORMAL.
        /// </summary>
        public PictureBox()
        {
            // this class overrides GetPreferredSizeCore, let Control automatically cache the result
            SetExtendedState(ExtendedStates.UserPreferredSizeCache, true);

            _pictureBoxState = new BitVector32(UseDefaultErrorImageState | UseDefaultInitialImageState);

            SetStyle(ControlStyles.Opaque | ControlStyles.Selectable, false);
            SetStyle(ControlStyles.OptimizedDoubleBuffer | ControlStyles.SupportsTransparentBackColor, true);

            TabStop = false;
            _savedSize = Size;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public override bool AllowDrop
        {
            get => base.AllowDrop;
            set => base.AllowDrop = value;
        }

        /// <summary>
        ///  Indicates the border style for the control.
        /// </summary>
        [DefaultValue(BorderStyle.None)]
        [SRCategory(nameof(SR.CatAppearance))]
        [DispId((int)Ole32.DispatchID.BORDERSTYLE)]
        [SRDescription(nameof(SR.PictureBoxBorderStyleDescr))]
        public BorderStyle BorderStyle
        {
            get => _borderStyle;
            set
            {
                if (!ClientUtils.IsEnumValid(value, (int)value, (int)BorderStyle.None, (int)BorderStyle.Fixed3D))
                {
                    throw new InvalidEnumArgumentException(nameof(value), (int)value, typeof(BorderStyle));
                }

                if (_borderStyle != value)
                {
                    _borderStyle = value;
                    RecreateHandle();
                    AdjustSize();
                }
            }
        }

        /// <summary>
        ///  Try to build a URI, but if that fails, that means it's a relative path, and we treat it as
        ///  relative to the working directory (which is what GetFullPath uses).
        /// </summary>
        private Uri CalculateUri(string path)
        {
            try
            {
                return new Uri(path);
            }
            catch (UriFormatException)
            {
                // It's a relative pathname, get its full path as a file.
                path = Path.GetFullPath(path);
                return new Uri(path);
            }
        }

        [SRCategory(nameof(SR.CatAsynchronous))]
        [SRDescription(nameof(SR.PictureBoxCancelAsyncDescr))]
        public void CancelAsync()
        {
            _pictureBoxState[CancellationPendingState] = true;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new bool CausesValidation
        {
            get => base.CausesValidation;
            set => base.CausesValidation = value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new event EventHandler CausesValidationChanged
        {
            add => base.CausesValidationChanged += value;
            remove => base.CausesValidationChanged -= value;
        }

        /// <summary>
        ///  Returns the parameters needed to create the handle.
        /// </summary>
        protected override CreateParams CreateParams
        {
            get
            {
                CreateParams cp = base.CreateParams;

                switch (_borderStyle)
                {
                    case BorderStyle.Fixed3D:
                        cp.ExStyle |= (int)User32.WS_EX.CLIENTEDGE;
                        break;
                    case BorderStyle.FixedSingle:
                        cp.Style |= (int)User32.WS.BORDER;
                        break;
                }

                return cp;
            }
        }

        protected override ImeMode DefaultImeMode => ImeMode.Disable;

        /// <summary>
        ///  Deriving classes can override this to configure a default size for their control.
        ///  This is more efficient than setting the size in the control's constructor.
        /// </summary>
        protected override Size DefaultSize => new Size(100, 50);

        [SRCategory(nameof(SR.CatAsynchronous))]
        [Localizable(true)]
        [RefreshProperties(RefreshProperties.All)]
        [SRDescription(nameof(SR.PictureBoxErrorImageDescr))]
        public Image ErrorImage
        {
            get
            {
                // Strange pictureBoxState[PICTUREBOXSTATE_useDefaultErrorImage] approach used
                // here to avoid statically loading the default bitmaps from resources at
                // runtime when they're never used.
                if (errorImage is null && _pictureBoxState[UseDefaultErrorImageState])
                {
                    if (_defaultErrorImage is null)
                    {
                        // Can't share images across threads.
                        if (t_defaultErrorImageForThread is null)
                        {
                            t_defaultErrorImageForThread = DpiHelper.GetBitmapFromIcon(typeof(PictureBox), "ImageInError");
                        }

                        _defaultErrorImage = t_defaultErrorImageForThread;
                    }

                    errorImage = _defaultErrorImage;
                }

                return errorImage;
            }
            set
            {
                if (ErrorImage != value)
                {
                    _pictureBoxState[UseDefaultErrorImageState] = false;
                }

                errorImage = value;
            }
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public override Color ForeColor
        {
            get => base.ForeColor;
            set => base.ForeColor = value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new event EventHandler ForeColorChanged
        {
            add => base.ForeColorChanged += value;
            remove => base.ForeColorChanged -= value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public override Font Font
        {
            get => base.Font;
            set => base.Font = value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new event EventHandler FontChanged
        {
            add => base.FontChanged += value;
            remove => base.FontChanged -= value;
        }

        /// <summary>
        ///  Retrieves the Image that the <see cref='PictureBox'/> is currently displaying.
        /// </summary>
        [SRCategory(nameof(SR.CatAppearance))]
        [Localizable(true)]
        [Bindable(true)]
        [SRDescription(nameof(SR.PictureBoxImageDescr))]
        public Image Image
        {
            get => _image;
            set => InstallNewImage(value, ImageInstallationType.DirectlySpecified);
        }

        // The area occupied by the image
        [SRCategory(nameof(SR.CatAsynchronous))]
        [Localizable(true)]
        [DefaultValue(null)]
        [RefreshProperties(RefreshProperties.All)]
        [SRDescription(nameof(SR.PictureBoxImageLocationDescr))]
        public string ImageLocation
        {
            get => _imageLocation;
            set
            {
                // Reload even if value hasn't changed, since Image itself may have changed.
                _imageLocation = value;

                _pictureBoxState[NeedToLoadImageLocationState] = !string.IsNullOrEmpty(_imageLocation);

                // Reset main image if it hasn't been directly specified.
                if (string.IsNullOrEmpty(_imageLocation) && _imageInstallationType != ImageInstallationType.DirectlySpecified)
                {
                    InstallNewImage(null, ImageInstallationType.DirectlySpecified);
                }

                if (WaitOnLoad && !_pictureBoxState[InInitializationState] && !string.IsNullOrEmpty(_imageLocation))
                {
                    // Load immediately, so any error will occur synchronously
                    Load();
                }

                Invalidate();
            }
        }

        private Rectangle ImageRectangle => ImageRectangleFromSizeMode(_sizeMode);

        private Rectangle ImageRectangleFromSizeMode(PictureBoxSizeMode mode)
        {
            Rectangle result = LayoutUtils.DeflateRect(ClientRectangle, Padding);
            if (_image != null)
            {
                switch (mode)
                {
                    case PictureBoxSizeMode.Normal:
                    case PictureBoxSizeMode.AutoSize:
                        // Use image's size rather than client size.
                        result.Size = _image.Size;
                        break;

                    case PictureBoxSizeMode.StretchImage:
                        // Do nothing, was initialized to the available dimensions.
                        break;

                    case PictureBoxSizeMode.CenterImage:
                        // Center within the available space.
                        result.X += (result.Width - _image.Width) / 2;
                        result.Y += (result.Height - _image.Height) / 2;
                        result.Size = _image.Size;
                        break;

                    case PictureBoxSizeMode.Zoom:
                        Size imageSize = _image.Size;
                        float ratio = Math.Min((float)ClientRectangle.Width / (float)imageSize.Width, (float)ClientRectangle.Height / (float)imageSize.Height);
                        result.Width = (int)(imageSize.Width * ratio);
                        result.Height = (int)(imageSize.Height * ratio);
                        result.X = (ClientRectangle.Width - result.Width) / 2;
                        result.Y = (ClientRectangle.Height - result.Height) / 2;
                        break;

                    default:
                        Debug.Fail("Unsupported PictureBoxSizeMode value: " + mode);
                        break;
                }
            }

            return result;
        }

        [SRCategory(nameof(SR.CatAsynchronous))]
        [Localizable(true)]
        [RefreshProperties(RefreshProperties.All)]
        [SRDescription(nameof(SR.PictureBoxInitialImageDescr))]
        public Image InitialImage
        {
            get
            {
                // Strange pictureBoxState[PICTUREBOXSTATE_useDefaultInitialImage] approach
                // used here to avoid statically loading the default bitmaps from resources at
                // runtime when they're never used.
                if (_initialImage is null && _pictureBoxState[UseDefaultInitialImageState])
                {
                    if (_defaultInitialImage is null)
                    {
                        // Can't share images across threads.
                        if (t_defaultInitialImageForThread is null)
                        {
                            t_defaultInitialImageForThread = DpiHelper.GetBitmapFromIcon(typeof(PictureBox), "PictureBox.Loading");
                        }

                        _defaultInitialImage = t_defaultInitialImageForThread;
                    }

                    _initialImage = _defaultInitialImage;
                }

                return _initialImage;
            }
            set
            {
                if (InitialImage != value)
                {
                    _pictureBoxState[UseDefaultInitialImageState] = false;
                }

                _initialImage = value;
            }
        }

        private void InstallNewImage(Image value, ImageInstallationType installationType)
        {
            StopAnimate();
            _image = value;

            LayoutTransaction.DoLayoutIf(AutoSize, this, this, PropertyNames.Image);

            Animate();
            if (installationType != ImageInstallationType.ErrorOrInitial)
            {
                AdjustSize();
            }

            _imageInstallationType = installationType;

            Invalidate();
            CommonProperties.xClearPreferredSizeCache(this);
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new ImeMode ImeMode
        {
            get => base.ImeMode;
            set => base.ImeMode = value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new event EventHandler ImeModeChanged
        {
            add => base.ImeModeChanged += value;
            remove => base.ImeModeChanged -= value;
        }

        /// <summary>
        ///  Synchronous load
        /// </summary>
        [SRCategory(nameof(SR.CatAsynchronous))]
        [SRDescription(nameof(SR.PictureBoxLoad0Descr))]
        public void Load()
        {
            if (string.IsNullOrEmpty(_imageLocation))
            {
                throw new InvalidOperationException(SR.PictureBoxNoImageLocation);
            }

            // If the load and install fails, pictureBoxState[PICTUREBOXSTATE_needToLoadImageLocation] will be
            // false to prevent subsequent attempts.
            _pictureBoxState[NeedToLoadImageLocationState] = false;

            Image img;
            ImageInstallationType installType = ImageInstallationType.FromUrl;
            try
            {
                DisposeImageStream();

                Uri uri = CalculateUri(_imageLocation);
                if (uri.IsFile)
                {
                    _localImageStreamReader = new StreamReader(uri.LocalPath);
                    img = Image.FromStream(_localImageStreamReader.BaseStream);
                }
                else
                {
                    using (WebClient wc = new WebClient())
                    {
                        _uriImageStream = wc.OpenRead(uri.ToString());
                        img = Image.FromStream(_uriImageStream);
                    }
                }
            }
            catch
            {
                if (!DesignMode)
                {
                    throw;
                }
                else
                {
                    // In design mode, just replace with Error bitmap.
                    img = ErrorImage;
                    installType = ImageInstallationType.ErrorOrInitial;
                }
            }

            InstallNewImage(img, installType);
        }

        [SRCategory(nameof(SR.CatAsynchronous))]
        [SRDescription(nameof(SR.PictureBoxLoad1Descr))]
        public void Load(string url)
        {
            ImageLocation = url;
            Load();
        }

        [SRCategory(nameof(SR.CatAsynchronous))]
        [SRDescription(nameof(SR.PictureBoxLoadAsync0Descr))]
        public void LoadAsync()
        {
            if (string.IsNullOrEmpty(_imageLocation))
            {
                throw new InvalidOperationException(SR.PictureBoxNoImageLocation);
            }

            if (_pictureBoxState[AsyncOperationInProgressState])
            {
                // We shouldn't throw here: just return.
                return;
            }

            _pictureBoxState[AsyncOperationInProgressState] = true;

            if ((Image is null || (_imageInstallationType == ImageInstallationType.ErrorOrInitial)) && InitialImage != null)
            {
                InstallNewImage(InitialImage, ImageInstallationType.ErrorOrInitial);
            }

            _currentAsyncLoadOperation = AsyncOperationManager.CreateOperation(null);

            if (_loadCompletedDelegate is null)
            {
                _loadCompletedDelegate = new SendOrPostCallback(LoadCompletedDelegate);
                _loadProgressDelegate = new SendOrPostCallback(LoadProgressDelegate);
                _readBuffer = new byte[ReadBlockSize];
            }

            _pictureBoxState[NeedToLoadImageLocationState] = false;
            _pictureBoxState[CancellationPendingState] = false;
            _contentLength = -1;
            _tempDownloadStream = new MemoryStream();

            WebRequest req = WebRequest.Create(CalculateUri(_imageLocation));

            Task.Run(() =>
            {
                // Invoke BeginGetResponse on a threadpool thread, as it has unpredictable latency
                req.BeginGetResponse(new AsyncCallback(GetResponseCallback), req);
            });
        }

        private void PostCompleted(Exception error, bool cancelled)
        {
            AsyncOperation temp = _currentAsyncLoadOperation;
            _currentAsyncLoadOperation = null;
            if (temp != null)
            {
                temp.PostOperationCompleted(_loadCompletedDelegate, new AsyncCompletedEventArgs(error, cancelled, null));
            }
        }

        private void LoadCompletedDelegate(object arg)
        {
            AsyncCompletedEventArgs e = (AsyncCompletedEventArgs)arg;

            Image img = ErrorImage;
            ImageInstallationType installType = ImageInstallationType.ErrorOrInitial;
            if (!e.Cancelled && e.Error is null)
            {
                // successful completion
                try
                {
                    img = Image.FromStream(_tempDownloadStream);
                    installType = ImageInstallationType.FromUrl;
                }
                catch (Exception error)
                {
                    e = new AsyncCompletedEventArgs(error, false, null);
                }
            }

            // If cancelled, don't change the image
            if (!e.Cancelled)
            {
                InstallNewImage(img, installType);
            }

            _tempDownloadStream = null;
            _pictureBoxState[CancellationPendingState] = false;
            _pictureBoxState[AsyncOperationInProgressState] = false;
            OnLoadCompleted(e);
        }

        private void LoadProgressDelegate(object arg) => OnLoadProgressChanged((ProgressChangedEventArgs)arg);

        private void GetResponseCallback(IAsyncResult result)
        {
            if (_pictureBoxState[CancellationPendingState])
            {
                PostCompleted(null, true);
                return;
            }

            try
            {
                WebRequest req = (WebRequest)result.AsyncState;
                WebResponse webResponse = req.EndGetResponse(result);

                _contentLength = (int)webResponse.ContentLength;
                _totalBytesRead = 0;

                Stream responseStream = webResponse.GetResponseStream();

                // Continue on with asynchronous reading.
                responseStream.BeginRead(
                    _readBuffer,
                    0,
                    ReadBlockSize,
                    new AsyncCallback(ReadCallBack),
                    responseStream);
            }
            catch (Exception error)
            {
                // Since this is on a non-UI thread, we catch any exceptions and
                // pass them back as data to the UI-thread.
                PostCompleted(error, false);
            }
        }

        private void ReadCallBack(IAsyncResult result)
        {
            if (_pictureBoxState[CancellationPendingState])
            {
                PostCompleted(null, true);
                return;
            }

            Stream responseStream = (Stream)result.AsyncState;
            try
            {
                int bytesRead = responseStream.EndRead(result);

                if (bytesRead > 0)
                {
                    _totalBytesRead += bytesRead;
                    _tempDownloadStream.Write(_readBuffer, 0, bytesRead);

                    responseStream.BeginRead(
                        _readBuffer,
                        0,
                        ReadBlockSize,
                        new AsyncCallback(ReadCallBack),
                        responseStream);

                    // Report progress thus far, but only if we know total length.
                    if (_contentLength != -1)
                    {
                        int progress = (int)(100 * (((float)_totalBytesRead) / ((float)_contentLength)));
                        if (_currentAsyncLoadOperation != null)
                        {
                            _currentAsyncLoadOperation.Post(_loadProgressDelegate,
                                    new ProgressChangedEventArgs(progress, null));
                        }
                    }
                }
                else
                {
                    _tempDownloadStream.Seek(0, SeekOrigin.Begin);
                    if (_currentAsyncLoadOperation != null)
                    {
                        _currentAsyncLoadOperation.Post(_loadProgressDelegate,
                                    new ProgressChangedEventArgs(100, null));
                    }
                    PostCompleted(null, false);

                    // Do this so any exception that Close() throws will be
                    // dealt with ok.
                    Stream rs = responseStream;
                    responseStream = null;
                    rs.Close();
                }
            }
            catch (Exception error)
            {
                // Since this is on a non-UI thread, we catch any exceptions and
                // pass them back as data to the UI-thread.
                PostCompleted(error, false);
                responseStream?.Close();
            }
        }

        [SRCategory(nameof(SR.CatAsynchronous))]
        [SRDescription(nameof(SR.PictureBoxLoadAsync1Descr))]
        public void LoadAsync(string url)
        {
            ImageLocation = url;
            LoadAsync();
        }

        [SRCategory(nameof(SR.CatAsynchronous))]
        [SRDescription(nameof(SR.PictureBoxLoadCompletedDescr))]
        public event AsyncCompletedEventHandler LoadCompleted
        {
            add => Events.AddHandler(s_loadCompletedKey, value);
            remove => Events.RemoveHandler(s_loadCompletedKey, value);
        }

        [SRCategory(nameof(SR.CatAsynchronous))]
        [SRDescription(nameof(SR.PictureBoxLoadProgressChangedDescr))]
        public event ProgressChangedEventHandler LoadProgressChanged
        {
            add => Events.AddHandler(s_loadProgressChangedKey, value);
            remove => Events.RemoveHandler(s_loadProgressChangedKey, value);
        }

        private void ResetInitialImage()
        {
            _pictureBoxState[UseDefaultInitialImageState] = true;
            _initialImage = _defaultInitialImage;
        }

        private void ResetErrorImage()
        {
            _pictureBoxState[UseDefaultErrorImageState] = true;
            errorImage = _defaultErrorImage;
        }

        private void ResetImage()
        {
            InstallNewImage(null, ImageInstallationType.DirectlySpecified);
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public override RightToLeft RightToLeft
        {
            get => base.RightToLeft;
            set => base.RightToLeft = value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new event EventHandler RightToLeftChanged
        {
            add => base.RightToLeftChanged += value;
            remove => base.RightToLeftChanged -= value;
        }

        /// <summary>
        ///  Be sure not to re-serialized initial image if it's the default.
        /// </summary>
        private bool ShouldSerializeInitialImage()
        {
            return !_pictureBoxState[UseDefaultInitialImageState];
        }

        /// <summary>
        ///  Be sure not to re-serialized error image if it's the default.
        /// </summary>
        private bool ShouldSerializeErrorImage()
        {
            return !_pictureBoxState[UseDefaultErrorImageState];
        }

        /// <summary>
        ///  Be sure not to serialize image if it wasn't directly specified
        ///  through the Image property (e.g., if it's a download, or an initial
        ///  or error image)
        /// </summary>
        private bool ShouldSerializeImage()
        {
            return (_imageInstallationType == ImageInstallationType.DirectlySpecified) && (Image != null);
        }

        /// <summary>
        ///  Indicates how the image is displayed.
        /// </summary>
        [DefaultValue(PictureBoxSizeMode.Normal)]
        [SRCategory(nameof(SR.CatBehavior))]
        [Localizable(true)]
        [SRDescription(nameof(SR.PictureBoxSizeModeDescr))]
        [RefreshProperties(RefreshProperties.Repaint)]
        public PictureBoxSizeMode SizeMode
        {
            get => _sizeMode;
            set
            {
                if (!ClientUtils.IsEnumValid(value, (int)value, (int)PictureBoxSizeMode.Normal, (int)PictureBoxSizeMode.Zoom))
                {
                    throw new InvalidEnumArgumentException(nameof(value), (int)value, typeof(PictureBoxSizeMode));
                }

                if (_sizeMode != value)
                {
                    if (value == PictureBoxSizeMode.AutoSize)
                    {
                        AutoSize = true;
                        SetStyle(ControlStyles.FixedHeight | ControlStyles.FixedWidth, true);
                    }
                    if (value != PictureBoxSizeMode.AutoSize)
                    {
                        AutoSize = false;
                        SetStyle(ControlStyles.FixedHeight | ControlStyles.FixedWidth, false);
                        _savedSize = Size;
                    }

                    _sizeMode = value;
                    AdjustSize();
                    Invalidate();
                    OnSizeModeChanged(EventArgs.Empty);
                }
            }
        }

        private static readonly object EVENT_SIZEMODECHANGED = new object();

        [SRCategory(nameof(SR.CatPropertyChanged))]
        [SRDescription(nameof(SR.PictureBoxOnSizeModeChangedDescr))]
        public event EventHandler SizeModeChanged
        {
            add => Events.AddHandler(EVENT_SIZEMODECHANGED, value);

            remove => Events.RemoveHandler(EVENT_SIZEMODECHANGED, value);
        }

        internal override bool SupportsUiaProviders => true;

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new bool TabStop
        {
            get => base.TabStop;
            set => base.TabStop = value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new event EventHandler TabStopChanged
        {
            add => base.TabStopChanged += value;
            remove => base.TabStopChanged -= value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new int TabIndex
        {
            get => base.TabIndex;
            set => base.TabIndex = value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new event EventHandler TabIndexChanged
        {
            add => base.TabIndexChanged += value;
            remove => base.TabIndexChanged -= value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        [Bindable(false)]
        public override string Text
        {
            get => base.Text;
            set => base.Text = value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new event EventHandler TextChanged
        {
            add => base.TextChanged += value;
            remove => base.TextChanged -= value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new event EventHandler Enter
        {
            add => base.Enter += value;
            remove => base.Enter -= value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new event KeyEventHandler KeyUp
        {
            add => base.KeyUp += value;
            remove => base.KeyUp -= value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new event KeyEventHandler KeyDown
        {
            add => base.KeyDown += value;
            remove => base.KeyDown -= value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new event KeyPressEventHandler KeyPress
        {
            add => base.KeyPress += value;
            remove => base.KeyPress -= value;
        }

        [Browsable(false)]
        [EditorBrowsable(EditorBrowsableState.Never)]
        public new event EventHandler Leave
        {
            add => base.Leave += value;
            remove => base.Leave -= value;
        }

        /// <summary>
        ///  If the PictureBox has the SizeMode property set to AutoSize, this makes sure that the
        ///  picturebox is large enough to hold the image.
        /// </summary>
        private void AdjustSize()
        {
            if (_sizeMode == PictureBoxSizeMode.AutoSize)
            {
                Size = PreferredSize;
            }
            else
            {
                Size = _savedSize;
            }
        }

        private void Animate() => Animate(animate: !DesignMode && Visible && Enabled && ParentInternal != null);

        private void StopAnimate() => Animate(animate: false);

        private void Animate(bool animate)
        {
            if (animate != _currentlyAnimating)
            {
                if (animate)
                {
                    if (_image != null)
                    {
                        ImageAnimator.Animate(_image, new EventHandler(OnFrameChanged));
                        _currentlyAnimating = animate;
                    }
                }
                else
                {
                    if (_image != null)
                    {
                        ImageAnimator.StopAnimate(_image, new EventHandler(OnFrameChanged));
                        _currentlyAnimating = animate;
                    }
                }
            }
        }

        protected override AccessibleObject CreateAccessibilityInstance()
            => new PictureBoxAccessibleObject(this);

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                StopAnimate();
            }

            DisposeImageStream();
            base.Dispose(disposing);
        }

        private void DisposeImageStream()
        {
            if (_localImageStreamReader != null)
            {
                _localImageStreamReader.Dispose();
                _localImageStreamReader = null;
            }
            if (_uriImageStream != null)
            {
                _uriImageStream.Dispose();
                _localImageStreamReader = null;
            }
        }

        /// <summary>
        ///  Overriding this method allows us to get the caching and clamping the proposedSize/output to
        ///  MinimumSize / MaximumSize from GetPreferredSize for free.
        /// </summary>
        internal override Size GetPreferredSizeCore(Size proposedSize)
        {
            if (_image is null)
            {
                return CommonProperties.GetSpecifiedBounds(this).Size;
            }
            else
            {
                Size bordersAndPadding = SizeFromClientSize(Size.Empty) + Padding.Size;
                return _image.Size + bordersAndPadding;
            }
        }

        protected override void OnEnabledChanged(EventArgs e)
        {
            base.OnEnabledChanged(e);
            Animate();
        }

        private void OnFrameChanged(object o, EventArgs e)
        {
            if (Disposing || IsDisposed)
            {
                return;
            }

            // Handle should be created, before calling the BeginInvoke.
            if (InvokeRequired && IsHandleCreated)
            {
                lock (_internalSyncObject)
                {
                    if (_handleValid)
                    {
                        BeginInvoke(new EventHandler(OnFrameChanged), o, e);
                    }
                    return;
                }
            }

            Invalidate();
        }

        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected override void OnHandleDestroyed(EventArgs e)
        {
            lock (_internalSyncObject)
            {
                _handleValid = false;
            }

            base.OnHandleDestroyed(e);
        }

        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected override void OnHandleCreated(EventArgs e)
        {
            lock (_internalSyncObject)
            {
                _handleValid = true;
            }

            base.OnHandleCreated(e);
        }

        protected virtual void OnLoadCompleted(AsyncCompletedEventArgs e)
        {
            ((AsyncCompletedEventHandler)(Events[s_loadCompletedKey]))?.Invoke(this, e);
        }

        protected virtual void OnLoadProgressChanged(ProgressChangedEventArgs e)
        {
            ((ProgressChangedEventHandler)(Events[s_loadProgressChangedKey]))?.Invoke(this, e);
        }

        /// <summary>
        ///  Overridden onPaint to make sure that the image is painted correctly.
        /// </summary>
        protected override void OnPaint(PaintEventArgs pe)
        {
            if (_pictureBoxState[NeedToLoadImageLocationState])
            {
                try
                {
                    if (WaitOnLoad)
                    {
                        Load();
                    }
                    else
                    {
                        LoadAsync();
                    }
                }
                catch (Exception ex) when (!ClientUtils.IsCriticalException(ex))
                {
                    _image = ErrorImage;
                }
            }

            if (_image != null && pe != null)
            {
                Animate();
                ImageAnimator.UpdateFrames(Image);

                // Error and initial image are drawn centered, non-stretched.
                Rectangle drawingRect =
                    (_imageInstallationType == ImageInstallationType.ErrorOrInitial)
                    ? ImageRectangleFromSizeMode(PictureBoxSizeMode.CenterImage)
                    : ImageRectangle;

                pe.Graphics.DrawImage(_image, drawingRect);
            }

            // Windows draws the border for us (see CreateParams)
            base.OnPaint(pe);
        }

        protected override void OnVisibleChanged(EventArgs e)
        {
            base.OnVisibleChanged(e);
            Animate();
        }

        protected override void OnParentChanged(EventArgs e)
        {
            base.OnParentChanged(e);
            Animate();
        }

        /// <summary>
        ///  OnResize override to invalidate entire control in Stetch mode
        /// </summary>
        protected override void OnResize(EventArgs e)
        {
            base.OnResize(e);
            if (_sizeMode == PictureBoxSizeMode.Zoom || _sizeMode == PictureBoxSizeMode.StretchImage || _sizeMode == PictureBoxSizeMode.CenterImage || BackgroundImage != null)
            {
                Invalidate();
            }

            _savedSize = Size;
        }

        protected virtual void OnSizeModeChanged(EventArgs e)
        {
            if (Events[EVENT_SIZEMODECHANGED] is EventHandler eh)
            {
                eh(this, e);
            }
        }

        /// <summary>
        ///  Returns a string representation for this control.
        /// </summary>
        public override string ToString()
        {
            string s = base.ToString();
            return s + ", SizeMode: " + _sizeMode.ToString("G");
        }

        [SRCategory(nameof(SR.CatAsynchronous))]
        [Localizable(true)]
        [DefaultValue(false)]
        [SRDescription(nameof(SR.PictureBoxWaitOnLoadDescr))]
        public bool WaitOnLoad
        {
            get => _pictureBoxState[WaitOnLoadState];
            set => _pictureBoxState[WaitOnLoadState] = value;
        }

        void ISupportInitialize.BeginInit()
        {
            _pictureBoxState[InInitializationState] = true;
        }

        void ISupportInitialize.EndInit()
        {
            if (!_pictureBoxState[InInitializationState])
            {
                return;
            }

            // Need to do this in EndInit since there's no guarantee of the
            // order in which ImageLocation and WaitOnLoad will be set.
            if (ImageLocation != null && ImageLocation.Length != 0 && WaitOnLoad)
            {
                // Load when initialization completes, so any error will occur synchronously
                Load();
            }

            _pictureBoxState[InInitializationState] = false;
        }

        private enum ImageInstallationType
        {
            DirectlySpecified,
            ErrorOrInitial,
            FromUrl
        }
    }
}
