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Image and ImageButton

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This commit is contained in:
David H. Friedel Jr.
2026-01-16 04:49:21 +00:00
parent 81f7d9c90e
commit 71a37da1a4
4 changed files with 956 additions and 125 deletions
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15
Handlers/ImageButtonHandler.cs
View File

@@ -121,13 +121,13 @@ public partial class ImageButtonHandler : ViewHandler<IImageButton, SkiaImageBut
if (handler.PlatformView is null) return;
if (imageButton.StrokeColor is not null)
handler.PlatformView.StrokeColor = imageButton.StrokeColor.ToSKColor();
handler.PlatformView.StrokeColor = imageButton.StrokeColor;
}
public static void MapStrokeThickness(ImageButtonHandler handler, IImageButton imageButton)
{
if (handler.PlatformView is null) return;
handler.PlatformView.StrokeThickness = (float)imageButton.StrokeThickness;
handler.PlatformView.StrokeThickness = imageButton.StrokeThickness;
}
public static void MapCornerRadius(ImageButtonHandler handler, IImageButton imageButton)
@@ -139,12 +139,7 @@ public partial class ImageButtonHandler : ViewHandler<IImageButton, SkiaImageBut
public static void MapPadding(ImageButtonHandler handler, IImageButton imageButton)
{
if (handler.PlatformView is null) return;
var padding = imageButton.Padding;
handler.PlatformView.PaddingLeft = (float)padding.Left;
handler.PlatformView.PaddingTop = (float)padding.Top;
handler.PlatformView.PaddingRight = (float)padding.Right;
handler.PlatformView.PaddingBottom = (float)padding.Bottom;
handler.PlatformView.Padding = imageButton.Padding;
}
public static void MapBackground(ImageButtonHandler handler, IImageButton imageButton)
@@ -153,7 +148,7 @@ public partial class ImageButtonHandler : ViewHandler<IImageButton, SkiaImageBut
if (imageButton.Background is SolidPaint solidPaint && solidPaint.Color is not null)
{
handler.PlatformView.BackgroundColor = solidPaint.Color.ToSKColor();
handler.PlatformView.ImageBackgroundColor = solidPaint.Color;
}
}
@@ -163,7 +158,7 @@ public partial class ImageButtonHandler : ViewHandler<IImageButton, SkiaImageBut
if (imageButton is Microsoft.Maui.Controls.ImageButton imgBtn && imgBtn.BackgroundColor is not null)
{
handler.PlatformView.BackgroundColor = imgBtn.BackgroundColor.ToSKColor();
handler.PlatformView.ImageBackgroundColor = imgBtn.BackgroundColor;
}
}

2
Handlers/ImageHandler.cs
View File

@@ -114,7 +114,7 @@ public partial class ImageHandler : ViewHandler<IImage, SkiaImage>
if (image.Background is SolidPaint solidPaint && solidPaint.Color is not null)
{
handler.PlatformView.BackgroundColor = solidPaint.Color.ToSKColor();
handler.PlatformView.ImageBackgroundColor = solidPaint.Color;
}
}

745
Views/SkiaImage.cs
View File

@@ -2,25 +2,199 @@
// The .NET Foundation licenses this file to you under the MIT license.
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using System.Timers;
using Microsoft.Maui.Controls;
using Microsoft.Maui.Graphics;
using SkiaSharp;
using Svg.Skia;
namespace Microsoft.Maui.Platform;
/// <summary>
/// Skia-rendered image control with SVG support.
/// Skia-rendered image control with SVG support and GIF animation.
/// Full MAUI-compliant implementation.
/// </summary>
public class SkiaImage : SkiaView
{
#region Image Cache
/// <summary>
/// Static image cache for decoded bitmaps to avoid re-decoding.
/// Key is the file path or URI, value is the cached bitmap data.
/// </summary>
private static readonly ConcurrentDictionary<string, CachedImage> _imageCache = new();
private static readonly object _cacheLock = new();
private const int MaxCacheSize = 50; // Maximum number of cached images
private const long MaxCacheMemoryBytes = 100 * 1024 * 1024; // 100MB max cache
private class CachedImage
{
public SKBitmap? Bitmap { get; set; }
public List<AnimationFrame>? Frames { get; set; }
public bool IsAnimated { get; set; }
public DateTime LastAccessed { get; set; }
public long MemorySize { get; set; }
}
/// <summary>
/// Clears the image cache.
/// </summary>
public static void ClearCache()
{
lock (_cacheLock)
{
foreach (var cached in _imageCache.Values)
{
cached.Bitmap?.Dispose();
if (cached.Frames != null)
{
foreach (var frame in cached.Frames)
{
frame.Bitmap?.Dispose();
}
}
}
_imageCache.Clear();
}
}
private static void TrimCacheIfNeeded()
{
lock (_cacheLock)
{
if (_imageCache.Count <= MaxCacheSize)
return;
// Calculate total memory
long totalMemory = 0;
foreach (var cached in _imageCache.Values)
{
totalMemory += cached.MemorySize;
}
// If under memory limit and count limit, don't trim
if (totalMemory < MaxCacheMemoryBytes && _imageCache.Count <= MaxCacheSize)
return;
// Remove oldest entries until under limits
var sortedEntries = _imageCache.ToArray();
Array.Sort(sortedEntries, (a, b) => a.Value.LastAccessed.CompareTo(b.Value.LastAccessed));
int removeCount = Math.Max(1, _imageCache.Count - MaxCacheSize + 10);
for (int i = 0; i < removeCount && i < sortedEntries.Length; i++)
{
if (_imageCache.TryRemove(sortedEntries[i].Key, out var removed))
{
removed.Bitmap?.Dispose();
if (removed.Frames != null)
{
foreach (var frame in removed.Frames)
{
frame.Bitmap?.Dispose();
}
}
}
}
}
}
#endregion
#region Animation Support
private class AnimationFrame
{
public SKBitmap? Bitmap { get; set; }
public int Duration { get; set; } // Duration in milliseconds
}
private List<AnimationFrame>? _animationFrames;
private int _currentFrameIndex;
private System.Timers.Timer? _animationTimer;
private bool _isAnimatedImage;
#endregion
#region BindableProperties
/// <summary>
/// Bindable property for Aspect.
/// </summary>
public static readonly BindableProperty AspectProperty =
BindableProperty.Create(
nameof(Aspect),
typeof(Aspect),
typeof(SkiaImage),
Aspect.AspectFit,
BindingMode.TwoWay,
propertyChanged: (b, o, n) => ((SkiaImage)b).Invalidate());
/// <summary>
/// Bindable property for IsOpaque.
/// </summary>
public static readonly BindableProperty IsOpaqueProperty =
BindableProperty.Create(
nameof(IsOpaque),
typeof(bool),
typeof(SkiaImage),
false,
BindingMode.TwoWay,
propertyChanged: (b, o, n) => ((SkiaImage)b).Invalidate());
/// <summary>
/// Bindable property for IsAnimationPlaying.
/// </summary>
public static readonly BindableProperty IsAnimationPlayingProperty =
BindableProperty.Create(
nameof(IsAnimationPlaying),
typeof(bool),
typeof(SkiaImage),
false,
BindingMode.TwoWay,
propertyChanged: (b, o, n) => ((SkiaImage)b).OnIsAnimationPlayingChanged((bool)n));
/// <summary>
/// Bindable property for ImageBackgroundColor (MAUI Color for background).
/// </summary>
public static readonly BindableProperty ImageBackgroundColorProperty =
BindableProperty.Create(
nameof(ImageBackgroundColor),
typeof(Color),
typeof(SkiaImage),
Colors.Transparent,
BindingMode.TwoWay,
propertyChanged: (b, o, n) => ((SkiaImage)b).Invalidate());
#endregion
#region Color Conversion Helper
/// <summary>
/// Converts a MAUI Color to SkiaSharp SKColor.
/// </summary>
private static SKColor ToSKColor(Color color)
{
if (color == null) return SKColors.Transparent;
return new SKColor(
(byte)(color.Red * 255),
(byte)(color.Green * 255),
(byte)(color.Blue * 255),
(byte)(color.Alpha * 255));
}
#endregion
private SKBitmap? _bitmap;
private SKImage? _image;
private bool _isLoading;
private string? _currentFilePath;
private string? _cacheKey;
private bool _isSvg;
private CancellationTokenSource? _loadCts;
private readonly object _loadLock = new object();
@@ -34,7 +208,11 @@ public class SkiaImage : SkiaView
get => _bitmap;
set
{
_bitmap?.Dispose();
// Don't dispose if this is a cached bitmap
if (_bitmap != null && (_cacheKey == null || !_imageCache.ContainsKey(_cacheKey)))
{
_bitmap.Dispose();
}
_bitmap = value;
_image?.Dispose();
_image = value != null ? SKImage.FromBitmap(value) : null;
@@ -42,13 +220,48 @@ public class SkiaImage : SkiaView
}
}
public Aspect Aspect { get; set; }
/// <summary>
/// Gets or sets the aspect ratio scaling mode.
/// </summary>
public Aspect Aspect
{
get => (Aspect)GetValue(AspectProperty);
set => SetValue(AspectProperty, value);
}
public bool IsOpaque { get; set; }
/// <summary>
/// Gets or sets whether the image is opaque.
/// </summary>
public bool IsOpaque
{
get => (bool)GetValue(IsOpaqueProperty);
set => SetValue(IsOpaqueProperty, value);
}
/// <summary>
/// Gets whether the image is currently loading.
/// </summary>
public bool IsLoading => _isLoading;
public bool IsAnimationPlaying { get; set; }
/// <summary>
/// Gets or sets whether animation is playing (for GIF support).
/// When set to true, animated GIFs will play their animation.
/// When set to false, the first frame is displayed.
/// </summary>
public bool IsAnimationPlaying
{
get => (bool)GetValue(IsAnimationPlayingProperty);
set => SetValue(IsAnimationPlayingProperty, value);
}
/// <summary>
/// Gets or sets the image background color (MAUI Color type).
/// </summary>
public Color ImageBackgroundColor
{
get => (Color)GetValue(ImageBackgroundColorProperty);
set => SetValue(ImageBackgroundColorProperty, value);
}
public new double WidthRequest
{
@@ -73,6 +286,78 @@ public class SkiaImage : SkiaView
public event EventHandler? ImageLoaded;
public event EventHandler<ImageLoadingErrorEventArgs>? ImageLoadingError;
private void OnIsAnimationPlayingChanged(bool isPlaying)
{
if (_isAnimatedImage && _animationFrames != null && _animationFrames.Count > 1)
{
if (isPlaying)
{
StartAnimation();
}
else
{
StopAnimation();
}
}
}
private void StartAnimation()
{
if (_animationFrames == null || _animationFrames.Count <= 1)
return;
StopAnimation();
var frame = _animationFrames[_currentFrameIndex];
int duration = frame.Duration > 0 ? frame.Duration : 100; // Default 100ms if not specified
_animationTimer = new System.Timers.Timer(duration);
_animationTimer.Elapsed += OnAnimationTimerElapsed;
_animationTimer.AutoReset = false;
_animationTimer.Start();
}
private void StopAnimation()
{
if (_animationTimer != null)
{
_animationTimer.Stop();
_animationTimer.Elapsed -= OnAnimationTimerElapsed;
_animationTimer.Dispose();
_animationTimer = null;
}
}
private void OnAnimationTimerElapsed(object? sender, ElapsedEventArgs e)
{
if (_animationFrames == null || _animationFrames.Count <= 1 || !IsAnimationPlaying)
return;
// Move to next frame
_currentFrameIndex = (_currentFrameIndex + 1) % _animationFrames.Count;
// Update the displayed image
var frame = _animationFrames[_currentFrameIndex];
if (frame.Bitmap != null)
{
_image?.Dispose();
_image = SKImage.FromBitmap(frame.Bitmap);
Invalidate();
}
// Schedule next frame
if (IsAnimationPlaying)
{
int duration = frame.Duration > 0 ? frame.Duration : 100;
_animationTimer?.Stop();
if (_animationTimer != null)
{
_animationTimer.Interval = duration;
_animationTimer.Start();
}
}
}
private void ScheduleSvgReloadIfNeeded()
{
if (_isSvg && !string.IsNullOrEmpty(_currentFilePath))
@@ -95,7 +380,6 @@ public class SkiaImage : SkiaView
_pendingSvgReload = false;
if (!string.IsNullOrEmpty(_currentFilePath) && WidthRequest > 0.0 && HeightRequest > 0.0)
{
Console.WriteLine($"[SkiaImage] Reloading SVG at {WidthRequest}x{HeightRequest} (was {_svgLoadedWidth}x{_svgLoadedHeight})");
await LoadSvgAtSizeAsync(_currentFilePath, WidthRequest, HeightRequest);
}
}
@@ -103,11 +387,12 @@ public class SkiaImage : SkiaView
protected override void OnDraw(SKCanvas canvas, SKRect bounds)
{
// Draw background if not opaque
if (!IsOpaque && BackgroundColor != SKColors.Transparent)
var bgColor = ImageBackgroundColor != null ? ToSKColor(ImageBackgroundColor) : SKColors.Transparent;
if (!IsOpaque && bgColor != SKColors.Transparent)
{
using var bgPaint = new SKPaint
{
Color = BackgroundColor,
Color = bgColor,
Style = SKPaintStyle.Fill
};
canvas.DrawRect(bounds, bgPaint);
@@ -176,7 +461,6 @@ public class SkiaImage : SkiaView
{
_isLoading = true;
Invalidate();
Console.WriteLine($"[SkiaImage] LoadFromFileAsync: {filePath}, WidthRequest={WidthRequest}, HeightRequest={HeightRequest}");
try
{
@@ -204,40 +488,63 @@ public class SkiaImage : SkiaView
if (File.Exists(path))
{
foundPath = path;
Console.WriteLine("[SkiaImage] Found file at: " + path);
break;
}
}
if (foundPath == null)
{
Console.WriteLine("[SkiaImage] File not found: " + filePath);
_isLoading = false;
_isSvg = false;
_currentFilePath = null;
_cacheKey = null;
ImageLoadingError?.Invoke(this, new ImageLoadingErrorEventArgs(new FileNotFoundException(filePath)));
return;
}
_isSvg = foundPath.EndsWith(".svg", StringComparison.OrdinalIgnoreCase);
_currentFilePath = foundPath;
_cacheKey = foundPath;
if (!_isSvg)
// Check cache first
if (_imageCache.TryGetValue(foundPath, out var cached))
{
await Task.Run(() =>
cached.LastAccessed = DateTime.UtcNow;
if (cached.IsAnimated && cached.Frames != null)
{
using FileStream stream = File.OpenRead(foundPath);
SKBitmap? bitmap = SKBitmap.Decode(stream);
if (bitmap != null)
_isAnimatedImage = true;
_animationFrames = cached.Frames;
_currentFrameIndex = 0;
if (cached.Frames.Count > 0 && cached.Frames[0].Bitmap != null)
{
Bitmap = bitmap;
Console.WriteLine("[SkiaImage] Loaded image: " + foundPath);
_image?.Dispose();
_image = SKImage.FromBitmap(cached.Frames[0].Bitmap);
}
});
if (IsAnimationPlaying)
{
StartAnimation();
}
}
else if (cached.Bitmap != null)
{
_isAnimatedImage = false;
_bitmap = cached.Bitmap;
_image?.Dispose();
_image = SKImage.FromBitmap(cached.Bitmap);
}
_isLoading = false;
ImageLoaded?.Invoke(this, EventArgs.Empty);
Invalidate();
return;
}
if (_isSvg)
{
await LoadSvgAtSizeAsync(foundPath, WidthRequest, HeightRequest);
}
else
{
await LoadSvgAtSizeAsync(foundPath, WidthRequest, HeightRequest);
await LoadImageWithAnimationSupportAsync(foundPath);
}
_isLoading = false;
@@ -252,6 +559,103 @@ public class SkiaImage : SkiaView
Invalidate();
}
private async Task LoadImageWithAnimationSupportAsync(string filePath)
{
await Task.Run(() =>
{
using var stream = File.OpenRead(filePath);
using var codec = SKCodec.Create(stream);
if (codec == null)
{
// Fallback to simple decode
stream.Position = 0;
var bitmap = SKBitmap.Decode(stream);
if (bitmap != null)
{
CacheAndSetBitmap(filePath, bitmap, false);
}
return;
}
int frameCount = codec.FrameCount;
if (frameCount > 1)
{
// Animated image (GIF)
_isAnimatedImage = true;
_animationFrames = new List<AnimationFrame>();
var info = codec.Info;
for (int i = 0; i < frameCount; i++)
{
var frameInfo = codec.FrameInfo[i];
var bitmap = new SKBitmap(info.Width, info.Height);
var options = new SKCodecOptions(i);
codec.GetPixels(bitmap.Info, bitmap.GetPixels(), options);
_animationFrames.Add(new AnimationFrame
{
Bitmap = bitmap,
Duration = frameInfo.Duration > 0 ? frameInfo.Duration : 100
});
}
// Cache the animation frames
long memorySize = _animationFrames.Sum(f => (long)(f.Bitmap?.ByteCount ?? 0));
_imageCache[filePath] = new CachedImage
{
Frames = _animationFrames,
IsAnimated = true,
LastAccessed = DateTime.UtcNow,
MemorySize = memorySize
};
TrimCacheIfNeeded();
// Set first frame as current image
_currentFrameIndex = 0;
if (_animationFrames.Count > 0 && _animationFrames[0].Bitmap != null)
{
_image?.Dispose();
_image = SKImage.FromBitmap(_animationFrames[0].Bitmap);
}
// Start animation if requested
if (IsAnimationPlaying)
{
StartAnimation();
}
}
else
{
// Static image
_isAnimatedImage = false;
var bitmap = SKBitmap.Decode(codec, codec.Info);
if (bitmap != null)
{
CacheAndSetBitmap(filePath, bitmap, false);
}
}
});
}
private void CacheAndSetBitmap(string cacheKey, SKBitmap bitmap, bool isAnimated)
{
_imageCache[cacheKey] = new CachedImage
{
Bitmap = bitmap,
IsAnimated = isAnimated,
LastAccessed = DateTime.UtcNow,
MemorySize = bitmap.ByteCount
};
TrimCacheIfNeeded();
_bitmap = bitmap;
_image?.Dispose();
_image = SKImage.FromBitmap(bitmap);
}
private async Task LoadSvgAtSizeAsync(string svgPath, double targetWidth, double targetHeight)
{
_loadCts?.Cancel();
@@ -293,8 +697,6 @@ public class SkiaImage : SkiaView
canvas.Clear(SKColors.Transparent);
canvas.Scale(scale);
canvas.DrawPicture(svg.Picture, null);
Console.WriteLine($"[SkiaImage] Loaded SVG: {svgPath} at {bitmapWidth}x{bitmapHeight} (requested {targetWidth}x{targetHeight})");
}
}, cts.Token);
@@ -302,6 +704,7 @@ public class SkiaImage : SkiaView
{
_svgLoadedWidth = (targetWidth > 0.0) ? targetWidth : newBitmap.Width;
_svgLoadedHeight = (targetHeight > 0.0) ? targetHeight : newBitmap.Height;
_isAnimatedImage = false;
Bitmap = newBitmap;
}
else
@@ -318,16 +721,71 @@ public class SkiaImage : SkiaView
public async Task LoadFromStreamAsync(Stream stream)
{
_isLoading = true;
_cacheKey = null; // Streams are not cached by default
Invalidate();
try
{
await Task.Run(() =>
{
SKBitmap? bitmap = SKBitmap.Decode(stream);
if (bitmap != null)
using var codec = SKCodec.Create(stream);
if (codec == null)
{
Bitmap = bitmap;
stream.Position = 0;
var bitmap = SKBitmap.Decode(stream);
if (bitmap != null)
{
_isAnimatedImage = false;
Bitmap = bitmap;
}
return;
}
int frameCount = codec.FrameCount;
if (frameCount > 1)
{
// Animated image
_isAnimatedImage = true;
_animationFrames = new List<AnimationFrame>();
var info = codec.Info;
for (int i = 0; i < frameCount; i++)
{
var frameInfo = codec.FrameInfo[i];
var bitmap = new SKBitmap(info.Width, info.Height);
var options = new SKCodecOptions(i);
codec.GetPixels(bitmap.Info, bitmap.GetPixels(), options);
_animationFrames.Add(new AnimationFrame
{
Bitmap = bitmap,
Duration = frameInfo.Duration > 0 ? frameInfo.Duration : 100
});
}
_currentFrameIndex = 0;
if (_animationFrames.Count > 0 && _animationFrames[0].Bitmap != null)
{
_image?.Dispose();
_image = SKImage.FromBitmap(_animationFrames[0].Bitmap);
}
if (IsAnimationPlaying)
{
StartAnimation();
}
}
else
{
_isAnimatedImage = false;
var bitmap = SKBitmap.Decode(codec, codec.Info);
if (bitmap != null)
{
Bitmap = bitmap;
}
}
});
@@ -346,18 +804,121 @@ public class SkiaImage : SkiaView
public async Task LoadFromUriAsync(Uri uri)
{
_isLoading = true;
_cacheKey = uri.ToString();
Invalidate();
try
{
using HttpClient httpClient = new HttpClient();
using MemoryStream stream = new MemoryStream(await httpClient.GetByteArrayAsync(uri));
SKBitmap? bitmap = SKBitmap.Decode(stream);
if (bitmap != null)
// Check cache first
if (_imageCache.TryGetValue(_cacheKey, out var cached))
{
Bitmap = bitmap;
cached.LastAccessed = DateTime.UtcNow;
if (cached.IsAnimated && cached.Frames != null)
{
_isAnimatedImage = true;
_animationFrames = cached.Frames;
_currentFrameIndex = 0;
if (cached.Frames.Count > 0 && cached.Frames[0].Bitmap != null)
{
_image?.Dispose();
_image = SKImage.FromBitmap(cached.Frames[0].Bitmap);
}
if (IsAnimationPlaying)
{
StartAnimation();
}
}
else if (cached.Bitmap != null)
{
_isAnimatedImage = false;
_bitmap = cached.Bitmap;
_image?.Dispose();
_image = SKImage.FromBitmap(cached.Bitmap);
}
_isLoading = false;
ImageLoaded?.Invoke(this, EventArgs.Empty);
Invalidate();
return;
}
using HttpClient httpClient = new HttpClient();
var data = await httpClient.GetByteArrayAsync(uri);
using var stream = new MemoryStream(data);
await Task.Run(() =>
{
using var codec = SKCodec.Create(stream);
if (codec == null)
{
stream.Position = 0;
var bitmap = SKBitmap.Decode(stream);
if (bitmap != null)
{
_isAnimatedImage = false;
CacheAndSetBitmap(_cacheKey, bitmap, false);
}
return;
}
int frameCount = codec.FrameCount;
if (frameCount > 1)
{
// Animated image
_isAnimatedImage = true;
_animationFrames = new List<AnimationFrame>();
var info = codec.Info;
for (int i = 0; i < frameCount; i++)
{
var frameInfo = codec.FrameInfo[i];
var bitmap = new SKBitmap(info.Width, info.Height);
var options = new SKCodecOptions(i);
codec.GetPixels(bitmap.Info, bitmap.GetPixels(), options);
_animationFrames.Add(new AnimationFrame
{
Bitmap = bitmap,
Duration = frameInfo.Duration > 0 ? frameInfo.Duration : 100
});
}
// Cache the animation frames
long memorySize = _animationFrames.Sum(f => (long)(f.Bitmap?.ByteCount ?? 0));
_imageCache[_cacheKey] = new CachedImage
{
Frames = _animationFrames,
IsAnimated = true,
LastAccessed = DateTime.UtcNow,
MemorySize = memorySize
};
TrimCacheIfNeeded();
_currentFrameIndex = 0;
if (_animationFrames.Count > 0 && _animationFrames[0].Bitmap != null)
{
_image?.Dispose();
_image = SKImage.FromBitmap(_animationFrames[0].Bitmap);
}
if (IsAnimationPlaying)
{
StartAnimation();
}
}
else
{
_isAnimatedImage = false;
var bitmap = SKBitmap.Decode(codec, codec.Info);
if (bitmap != null)
{
CacheAndSetBitmap(_cacheKey, bitmap, false);
}
}
});
_isLoading = false;
ImageLoaded?.Invoke(this, EventArgs.Empty);
}
@@ -374,12 +935,69 @@ public class SkiaImage : SkiaView
{
try
{
using MemoryStream stream = new MemoryStream(data);
SKBitmap? bitmap = SKBitmap.Decode(stream);
if (bitmap != null)
_cacheKey = null;
using var stream = new MemoryStream(data);
using var codec = SKCodec.Create(stream);
if (codec == null)
{
Bitmap = bitmap;
stream.Position = 0;
var bitmap = SKBitmap.Decode(stream);
if (bitmap != null)
{
_isAnimatedImage = false;
Bitmap = bitmap;
}
ImageLoaded?.Invoke(this, EventArgs.Empty);
return;
}
int frameCount = codec.FrameCount;
if (frameCount > 1)
{
// Animated image
_isAnimatedImage = true;
_animationFrames = new List<AnimationFrame>();
var info = codec.Info;
for (int i = 0; i < frameCount; i++)
{
var frameInfo = codec.FrameInfo[i];
var bitmap = new SKBitmap(info.Width, info.Height);
var options = new SKCodecOptions(i);
codec.GetPixels(bitmap.Info, bitmap.GetPixels(), options);
_animationFrames.Add(new AnimationFrame
{
Bitmap = bitmap,
Duration = frameInfo.Duration > 0 ? frameInfo.Duration : 100
});
}
_currentFrameIndex = 0;
if (_animationFrames.Count > 0 && _animationFrames[0].Bitmap != null)
{
_image?.Dispose();
_image = SKImage.FromBitmap(_animationFrames[0].Bitmap);
}
if (IsAnimationPlaying)
{
StartAnimation();
}
}
else
{
_isAnimatedImage = false;
var bitmap = SKBitmap.Decode(codec, codec.Info);
if (bitmap != null)
{
Bitmap = bitmap;
}
}
ImageLoaded?.Invoke(this, EventArgs.Empty);
}
catch (Exception ex)
@@ -397,6 +1015,10 @@ public class SkiaImage : SkiaView
{
_isSvg = false;
_currentFilePath = null;
_cacheKey = null;
_isAnimatedImage = false;
StopAnimation();
_animationFrames = null;
Bitmap = bitmap;
_isLoading = false;
ImageLoaded?.Invoke(this, EventArgs.Empty);
@@ -426,7 +1048,6 @@ public class SkiaImage : SkiaView
(width != _lastArrangedBounds.Width || height != _lastArrangedBounds.Height))
{
_lastArrangedBounds = bounds;
Console.WriteLine($"[SkiaImage] Arrange detected larger bounds: {width}x{height} vs loaded {_svgLoadedWidth}x{_svgLoadedHeight}");
_ = LoadSvgAtSizeAsync(_currentFilePath, width, height);
}
}
@@ -435,42 +1056,24 @@ public class SkiaImage : SkiaView
protected override SKRect ArrangeOverride(SKRect bounds)
{
// If we have explicit size requests, constrain to desired size
// This follows MAUI standard behavior - controls respect WidthRequest/HeightRequest
var desiredWidth = DesiredSize.Width;
var desiredHeight = DesiredSize.Height;
// If desired size is smaller than available bounds, align within bounds
if (desiredWidth > 0 && desiredHeight > 0 &&
(desiredWidth < bounds.Width || desiredHeight < bounds.Height))
{
float finalWidth = Math.Min(desiredWidth, bounds.Width);
float finalHeight = Math.Min(desiredHeight, bounds.Height);
// Calculate position based on HorizontalOptions
// LayoutAlignment: Start=0, Center=1, End=2, Fill=3
float x = bounds.Left;
var hAlignValue = (int)HorizontalOptions.Alignment;
if (hAlignValue == 1) // Center
{
x = bounds.Left + (bounds.Width - finalWidth) / 2;
}
else if (hAlignValue == 2) // End
{
x = bounds.Right - finalWidth;
}
if (hAlignValue == 1) x = bounds.Left + (bounds.Width - finalWidth) / 2;
else if (hAlignValue == 2) x = bounds.Right - finalWidth;
// Calculate position based on VerticalOptions
float y = bounds.Top;
var vAlignValue = (int)VerticalOptions.Alignment;
if (vAlignValue == 1) // Center
{
y = bounds.Top + (bounds.Height - finalHeight) / 2;
}
else if (vAlignValue == 2) // End
{
y = bounds.Bottom - finalHeight;
}
if (vAlignValue == 1) y = bounds.Top + (bounds.Height - finalHeight) / 2;
else if (vAlignValue == 2) y = bounds.Bottom - finalHeight;
return new SKRect(x, y, x + finalWidth, y + finalHeight);
}
@@ -483,40 +1086,31 @@ public class SkiaImage : SkiaView
double widthRequest = base.WidthRequest;
double heightRequest = base.HeightRequest;
// If both dimensions explicitly requested, use them
if (widthRequest > 0.0 && heightRequest > 0.0)
{
return new SKSize((float)widthRequest, (float)heightRequest);
}
// If no image, return default or requested size
if (_image == null)
{
if (widthRequest > 0.0)
return new SKSize((float)widthRequest, (float)widthRequest);
if (heightRequest > 0.0)
return new SKSize((float)heightRequest, (float)heightRequest);
if (widthRequest > 0.0) return new SKSize((float)widthRequest, (float)widthRequest);
if (heightRequest > 0.0) return new SKSize((float)heightRequest, (float)heightRequest);
return new SKSize(100f, 100f);
}
float imageWidth = _image.Width;
float imageHeight = _image.Height;
// If only width requested, scale height proportionally
if (widthRequest > 0.0)
{
float scale = (float)widthRequest / imageWidth;
return new SKSize((float)widthRequest, imageHeight * scale);
}
// If only height requested, scale width proportionally
if (heightRequest > 0.0)
{
float scale = (float)heightRequest / imageHeight;
return new SKSize(imageWidth * scale, (float)heightRequest);
}
// Scale to fit available size
if (availableSize.Width < float.MaxValue && availableSize.Height < float.MaxValue)
{
float scale = Math.Min(availableSize.Width / imageWidth, availableSize.Height / imageHeight);
@@ -542,7 +1136,20 @@ public class SkiaImage : SkiaView
{
if (disposing)
{
_bitmap?.Dispose();
StopAnimation();
// Only dispose if not cached
if (_cacheKey == null || !_imageCache.ContainsKey(_cacheKey))
{
_bitmap?.Dispose();
if (_animationFrames != null)
{
foreach (var frame in _animationFrames)
{
frame.Bitmap?.Dispose();
}
}
}
_image?.Dispose();
}
base.Dispose(disposing);

319
Views/SkiaImageButton.cs
View File

@@ -6,6 +6,9 @@ using System.Collections.Generic;
using System.IO;
using System.Net.Http;
using System.Threading.Tasks;
using System.Windows.Input;
using Microsoft.Maui.Controls;
using Microsoft.Maui.Graphics;
using SkiaSharp;
using Svg.Skia;
@@ -14,12 +17,79 @@ namespace Microsoft.Maui.Platform;
/// <summary>
/// Skia-rendered image button control.
/// Combines button behavior with image display.
/// Implements MAUI IImageButton interface requirements.
/// </summary>
public class SkiaImageButton : SkiaView
{
#region Private Fields
private SKBitmap? _bitmap;
private SKImage? _image;
private bool _isLoading;
#endregion
#region SKColor Helper
private static SKColor ToSKColor(Color? color)
{
if (color == null) return SKColors.Transparent;
return new SKColor(
(byte)(color.Red * 255),
(byte)(color.Green * 255),
(byte)(color.Blue * 255),
(byte)(color.Alpha * 255));
}
#endregion
#region BindableProperties
public static readonly BindableProperty AspectProperty = BindableProperty.Create(
nameof(Aspect), typeof(Aspect), typeof(SkiaImageButton), Aspect.AspectFit,
propertyChanged: (b, o, n) => ((SkiaImageButton)b).Invalidate());
public static readonly BindableProperty IsOpaqueProperty = BindableProperty.Create(
nameof(IsOpaque), typeof(bool), typeof(SkiaImageButton), false,
propertyChanged: (b, o, n) => ((SkiaImageButton)b).Invalidate());
public static readonly BindableProperty StrokeColorProperty = BindableProperty.Create(
nameof(StrokeColor), typeof(Color), typeof(SkiaImageButton), Colors.Transparent,
propertyChanged: (b, o, n) => ((SkiaImageButton)b).Invalidate());
public static readonly BindableProperty StrokeThicknessProperty = BindableProperty.Create(
nameof(StrokeThickness), typeof(double), typeof(SkiaImageButton), 0.0,
propertyChanged: (b, o, n) => ((SkiaImageButton)b).Invalidate());
public static readonly BindableProperty CornerRadiusProperty = BindableProperty.Create(
nameof(CornerRadius), typeof(int), typeof(SkiaImageButton), 0,
propertyChanged: (b, o, n) => ((SkiaImageButton)b).Invalidate());
public static readonly BindableProperty PaddingProperty = BindableProperty.Create(
nameof(Padding), typeof(Thickness), typeof(SkiaImageButton), new Thickness(0),
propertyChanged: (b, o, n) => ((SkiaImageButton)b).Invalidate());
public static readonly BindableProperty PressedBackgroundColorProperty = BindableProperty.Create(
nameof(PressedBackgroundColor), typeof(Color), typeof(SkiaImageButton),
Color.FromRgba(0, 0, 0, 30),
propertyChanged: (b, o, n) => ((SkiaImageButton)b).Invalidate());
public static readonly BindableProperty HoveredBackgroundColorProperty = BindableProperty.Create(
nameof(HoveredBackgroundColor), typeof(Color), typeof(SkiaImageButton),
Color.FromRgba(0, 0, 0, 15),
propertyChanged: (b, o, n) => ((SkiaImageButton)b).Invalidate());
public static readonly BindableProperty ImageBackgroundColorProperty = BindableProperty.Create(
nameof(ImageBackgroundColor), typeof(Color), typeof(SkiaImageButton), null,
propertyChanged: (b, o, n) => ((SkiaImageButton)b).Invalidate());
public static readonly BindableProperty CommandProperty = BindableProperty.Create(
nameof(Command), typeof(ICommand), typeof(SkiaImageButton), null,
propertyChanged: OnCommandChanged);
public static readonly BindableProperty CommandParameterProperty = BindableProperty.Create(
nameof(CommandParameter), typeof(object), typeof(SkiaImageButton), null,
propertyChanged: (b, o, n) => ((SkiaImageButton)b).UpdateCommandCanExecute());
#endregion
#region Properties
public SKBitmap? Bitmap
{
@@ -34,57 +104,172 @@ public class SkiaImageButton : SkiaView
}
}
// Image properties
public Aspect Aspect { get; set; } = Aspect.AspectFit;
public bool IsOpaque { get; set; }
public Aspect Aspect
{
get => (Aspect)GetValue(AspectProperty);
set => SetValue(AspectProperty, value);
}
public bool IsOpaque
{
get => (bool)GetValue(IsOpaqueProperty);
set => SetValue(IsOpaqueProperty, value);
}
public bool IsLoading => _isLoading;
// Button stroke properties
public SKColor StrokeColor { get; set; } = SKColors.Transparent;
public float StrokeThickness { get; set; } = 0;
public float CornerRadius { get; set; } = 0;
public Color StrokeColor
{
get => (Color)GetValue(StrokeColorProperty);
set => SetValue(StrokeColorProperty, value);
}
public double StrokeThickness
{
get => (double)GetValue(StrokeThicknessProperty);
set => SetValue(StrokeThicknessProperty, value);
}
public int CornerRadius
{
get => (int)GetValue(CornerRadiusProperty);
set => SetValue(CornerRadiusProperty, value);
}
public Thickness Padding
{
get => (Thickness)GetValue(PaddingProperty);
set => SetValue(PaddingProperty, value);
}
public Color PressedBackgroundColor
{
get => (Color)GetValue(PressedBackgroundColorProperty);
set => SetValue(PressedBackgroundColorProperty, value);
}
public Color HoveredBackgroundColor
{
get => (Color)GetValue(HoveredBackgroundColorProperty);
set => SetValue(HoveredBackgroundColorProperty, value);
}
public Color? ImageBackgroundColor
{
get => (Color?)GetValue(ImageBackgroundColorProperty);
set => SetValue(ImageBackgroundColorProperty, value);
}
public ICommand? Command
{
get => (ICommand?)GetValue(CommandProperty);
set => SetValue(CommandProperty, value);
}
public object? CommandParameter
{
get => GetValue(CommandParameterProperty);
set => SetValue(CommandParameterProperty, value);
}
// Button state
public bool IsPressed { get; private set; }
public bool IsHovered { get; private set; }
// Visual state colors
public SKColor PressedBackgroundColor { get; set; } = new SKColor(0, 0, 0, 30);
public SKColor HoveredBackgroundColor { get; set; } = new SKColor(0, 0, 0, 15);
// Padding for the image content
public float PaddingLeft { get; set; }
public float PaddingTop { get; set; }
public float PaddingRight { get; set; }
public float PaddingBottom { get; set; }
#endregion
#region Events
public event EventHandler? Clicked;
public event EventHandler? Pressed;
public event EventHandler? Released;
public event EventHandler? ImageLoaded;
public event EventHandler<ImageLoadingErrorEventArgs>? ImageLoadingError;
#endregion
#region Constructor
public SkiaImageButton()
{
IsFocusable = true;
}
#endregion
#region Command Support
private static void OnCommandChanged(BindableObject bindable, object oldValue, object newValue)
{
var button = (SkiaImageButton)bindable;
if (oldValue is ICommand oldCommand)
{
oldCommand.CanExecuteChanged -= button.OnCommandCanExecuteChanged;
}
if (newValue is ICommand newCommand)
{
newCommand.CanExecuteChanged += button.OnCommandCanExecuteChanged;
}
button.UpdateCommandCanExecute();
}
private void OnCommandCanExecuteChanged(object? sender, EventArgs e)
{
UpdateCommandCanExecute();
}
private void UpdateCommandCanExecute()
{
if (Command != null)
{
IsEnabled = Command.CanExecute(CommandParameter);
}
}
private void ExecuteCommand()
{
if (Command?.CanExecute(CommandParameter) == true)
{
Command.Execute(CommandParameter);
}
}
#endregion
#region Rendering
protected override void OnDraw(SKCanvas canvas, SKRect bounds)
{
// Apply padding
var padding = Padding;
var contentBounds = new SKRect(
bounds.Left + PaddingLeft,
bounds.Top + PaddingTop,
bounds.Right - PaddingRight,
bounds.Bottom - PaddingBottom);
bounds.Left + (float)padding.Left,
bounds.Top + (float)padding.Top,
bounds.Right - (float)padding.Right,
bounds.Bottom - (float)padding.Bottom);
// Draw background based on state
if (IsPressed || IsHovered || !IsOpaque && BackgroundColor != SKColors.Transparent)
// Determine background color
SKColor bgColor;
if (IsPressed)
{
var bgColor = IsPressed ? PressedBackgroundColor
: IsHovered ? HoveredBackgroundColor
: BackgroundColor;
bgColor = ToSKColor(PressedBackgroundColor);
}
else if (IsHovered)
{
bgColor = ToSKColor(HoveredBackgroundColor);
}
else if (ImageBackgroundColor != null)
{
bgColor = ToSKColor(ImageBackgroundColor);
}
else
{
bgColor = BackgroundColor;
}
// Draw background
if (bgColor != SKColors.Transparent || !IsOpaque)
{
using var bgPaint = new SKPaint
{
Color = bgColor,
@@ -130,13 +315,15 @@ public class SkiaImageButton : SkiaView
}
// Draw stroke/border
if (StrokeThickness > 0 && StrokeColor != SKColors.Transparent)
var strokeThickness = (float)StrokeThickness;
var strokeColor = ToSKColor(StrokeColor);
if (strokeThickness > 0 && strokeColor != SKColors.Transparent)
{
using var strokePaint = new SKPaint
{
Color = StrokeColor,
Color = strokeColor,
Style = SKPaintStyle.Stroke,
StrokeWidth = StrokeThickness,
StrokeWidth = strokeThickness,
IsAntialias = true
};
@@ -210,7 +397,10 @@ public class SkiaImageButton : SkiaView
}
}
// Image loading methods
#endregion
#region Image Loading
public async Task LoadFromFileAsync(string filePath)
{
_isLoading = true;
@@ -257,6 +447,7 @@ public class SkiaImageButton : SkiaView
return;
}
var padding = Padding;
await Task.Run(() =>
{
if (foundPath.EndsWith(".svg", StringComparison.OrdinalIgnoreCase))
@@ -272,10 +463,10 @@ public class SkiaImageButton : SkiaView
// Default to 24x24 for icons when no size specified
const float DefaultIconSize = 24f;
float targetWidth = hasWidth
? (float)(WidthRequest - PaddingLeft - PaddingRight)
? (float)(WidthRequest - padding.Left - padding.Right)
: DefaultIconSize;
float targetHeight = hasHeight
? (float)(HeightRequest - PaddingTop - PaddingBottom)
? (float)(HeightRequest - padding.Top - padding.Bottom)
: DefaultIconSize;
float scale = Math.Min(targetWidth / cullRect.Width, targetHeight / cullRect.Height);
@@ -376,6 +567,12 @@ public class SkiaImageButton : SkiaView
{
try
{
if (data == null || data.Length == 0)
{
Bitmap = null;
return;
}
using var stream = new MemoryStream(data);
var bitmap = SKBitmap.Decode(stream);
if (bitmap != null)
@@ -390,7 +587,16 @@ public class SkiaImageButton : SkiaView
}
}
// Pointer event handlers
public void LoadFromBitmap(SKBitmap bitmap)
{
Bitmap = bitmap;
ImageLoaded?.Invoke(this, EventArgs.Empty);
}
#endregion
#region Pointer Event Handlers
public override void OnPointerEntered(PointerEventArgs e)
{
if (!IsEnabled) return;
@@ -438,10 +644,14 @@ public class SkiaImageButton : SkiaView
if (wasPressed && Bounds.Contains(new SKPoint(e.X, e.Y)))
{
Clicked?.Invoke(this, EventArgs.Empty);
ExecuteCommand();
}
}
// Keyboard event handlers
#endregion
#region Keyboard Event Handlers
public override void OnKeyDown(KeyEventArgs e)
{
if (!IsEnabled) return;
@@ -467,13 +677,22 @@ public class SkiaImageButton : SkiaView
Invalidate();
Released?.Invoke(this, EventArgs.Empty);
Clicked?.Invoke(this, EventArgs.Empty);
ExecuteCommand();
}
e.Handled = true;
}
}
#endregion
#region Layout
protected override SKSize MeasureOverride(SKSize availableSize)
{
var padding = Padding;
var paddingWidth = (float)(padding.Left + padding.Right);
var paddingHeight = (float)(padding.Top + padding.Bottom);
// Respect explicit WidthRequest/HeightRequest first (MAUI standard behavior)
if (WidthRequest > 0 && HeightRequest > 0)
{
@@ -497,10 +716,8 @@ public class SkiaImageButton : SkiaView
}
// No explicit size - calculate from content
var padding = new SKSize(PaddingLeft + PaddingRight, PaddingTop + PaddingBottom);
if (_image == null)
return new SKSize(44 + padding.Width, 44 + padding.Height); // Default touch target size
return new SKSize(44 + paddingWidth, 44 + paddingHeight); // Default touch target size
var imageWidth = _image.Width;
var imageHeight = _image.Height;
@@ -508,25 +725,25 @@ public class SkiaImageButton : SkiaView
if (availableSize.Width < float.MaxValue && availableSize.Height < float.MaxValue)
{
var availableContent = new SKSize(
availableSize.Width - padding.Width,
availableSize.Height - padding.Height);
availableSize.Width - paddingWidth,
availableSize.Height - paddingHeight);
var scale = Math.Min(availableContent.Width / imageWidth, availableContent.Height / imageHeight);
return new SKSize(imageWidth * scale + padding.Width, imageHeight * scale + padding.Height);
return new SKSize(imageWidth * scale + paddingWidth, imageHeight * scale + paddingHeight);
}
else if (availableSize.Width < float.MaxValue)
{
var availableWidth = availableSize.Width - padding.Width;
var availableWidth = availableSize.Width - paddingWidth;
var scale = availableWidth / imageWidth;
return new SKSize(availableSize.Width, imageHeight * scale + padding.Height);
return new SKSize(availableSize.Width, imageHeight * scale + paddingHeight);
}
else if (availableSize.Height < float.MaxValue)
{
var availableHeight = availableSize.Height - padding.Height;
var availableHeight = availableSize.Height - paddingHeight;
var scale = availableHeight / imageHeight;
return new SKSize(imageWidth * scale + padding.Width, availableSize.Height);
return new SKSize(imageWidth * scale + paddingWidth, availableSize.Height);
}
return new SKSize(imageWidth + padding.Width, imageHeight + padding.Height);
return new SKSize(imageWidth + paddingWidth, imageHeight + paddingHeight);
}
protected override SKRect ArrangeOverride(SKRect bounds)
@@ -576,13 +793,25 @@ public class SkiaImageButton : SkiaView
return bounds;
}
#endregion
#region Dispose
protected override void Dispose(bool disposing)
{
if (disposing)
{
// Unsubscribe from command
if (Command != null)
{
Command.CanExecuteChanged -= OnCommandCanExecuteChanged;
}
_bitmap?.Dispose();
_image?.Dispose();
}
base.Dispose(disposing);
}
#endregion
}