326 lines
10 KiB
C#
326 lines
10 KiB
C#
// Licensed to the .NET Foundation under one or more agreements.
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// The .NET Foundation licenses this file to you under the MIT license.
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using System.IO;
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using Microsoft.Maui.Controls;
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using Microsoft.Maui.Handlers;
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using Microsoft.Maui.Graphics;
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using SkiaSharp;
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namespace Microsoft.Maui.Platform.Linux.Handlers;
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/// <summary>
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/// Handler for Image on Linux using Skia rendering.
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/// Maps IImage interface to SkiaImage platform view.
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/// IImage has: Aspect, IsOpaque (inherits from IImageSourcePart)
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/// </summary>
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public partial class ImageHandler : ViewHandler<IImage, SkiaImage>
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{
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public static IPropertyMapper<IImage, ImageHandler> Mapper = new PropertyMapper<IImage, ImageHandler>(ViewHandler.ViewMapper)
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{
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[nameof(IImage.Aspect)] = MapAspect,
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[nameof(IImage.IsOpaque)] = MapIsOpaque,
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[nameof(IImageSourcePart.Source)] = MapSource,
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[nameof(IView.Background)] = MapBackground,
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["Width"] = MapWidth,
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["Height"] = MapHeight,
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["HorizontalOptions"] = MapHorizontalOptions,
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["VerticalOptions"] = MapVerticalOptions,
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};
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public static CommandMapper<IImage, ImageHandler> CommandMapper = new(ViewHandler.ViewCommandMapper)
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{
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};
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public ImageHandler() : base(Mapper, CommandMapper)
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{
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}
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public ImageHandler(IPropertyMapper? mapper, CommandMapper? commandMapper = null)
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: base(mapper ?? Mapper, commandMapper ?? CommandMapper)
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{
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}
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protected override SkiaImage CreatePlatformView()
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{
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return new SkiaImage();
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}
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protected override void ConnectHandler(SkiaImage platformView)
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{
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base.ConnectHandler(platformView);
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platformView.ImageLoaded += OnImageLoaded;
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platformView.ImageLoadingError += OnImageLoadingError;
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}
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protected override void DisconnectHandler(SkiaImage platformView)
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{
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platformView.ImageLoaded -= OnImageLoaded;
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platformView.ImageLoadingError -= OnImageLoadingError;
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base.DisconnectHandler(platformView);
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}
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private void OnImageLoaded(object? sender, EventArgs e)
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{
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// Notify that the image has been loaded
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if (VirtualView is IImageSourcePart imageSourcePart)
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{
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imageSourcePart.UpdateIsLoading(false);
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}
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}
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private void OnImageLoadingError(object? sender, ImageLoadingErrorEventArgs e)
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{
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// Handle loading error
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if (VirtualView is IImageSourcePart imageSourcePart)
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{
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imageSourcePart.UpdateIsLoading(false);
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}
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}
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public static void MapAspect(ImageHandler handler, IImage image)
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{
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if (handler.PlatformView is null) return;
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handler.PlatformView.Aspect = image.Aspect;
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}
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public static void MapIsOpaque(ImageHandler handler, IImage image)
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{
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if (handler.PlatformView is null) return;
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handler.PlatformView.IsOpaque = image.IsOpaque;
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}
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public static void MapSource(ImageHandler handler, IImage image)
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{
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if (handler.PlatformView is null) return;
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// Extract width/height requests from Image control
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if (image is Image img)
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{
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if (img.WidthRequest > 0)
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{
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handler.PlatformView.WidthRequest = img.WidthRequest;
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}
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if (img.HeightRequest > 0)
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{
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handler.PlatformView.HeightRequest = img.HeightRequest;
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}
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}
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handler.SourceLoader.UpdateImageSourceAsync();
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}
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public static void MapBackground(ImageHandler handler, IImage image)
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{
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if (handler.PlatformView is null) return;
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if (image.Background is SolidPaint solidPaint && solidPaint.Color is not null)
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{
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handler.PlatformView.ImageBackgroundColor = solidPaint.Color;
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}
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}
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public static void MapWidth(ImageHandler handler, IImage image)
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{
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if (handler.PlatformView is null) return;
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if (image is Image img && img.WidthRequest > 0)
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{
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handler.PlatformView.WidthRequest = img.WidthRequest;
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Console.WriteLine($"[ImageHandler] MapWidth: {img.WidthRequest}");
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}
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else if (image.Width > 0)
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{
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handler.PlatformView.WidthRequest = image.Width;
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}
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}
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public static void MapHeight(ImageHandler handler, IImage image)
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{
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if (handler.PlatformView is null) return;
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if (image is Image img && img.HeightRequest > 0)
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{
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handler.PlatformView.HeightRequest = img.HeightRequest;
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Console.WriteLine($"[ImageHandler] MapHeight: {img.HeightRequest}");
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}
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else if (image.Height > 0)
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{
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handler.PlatformView.HeightRequest = image.Height;
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}
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}
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public static void MapHorizontalOptions(ImageHandler handler, IImage image)
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{
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if (handler.PlatformView is null) return;
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if (image is Image img)
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{
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handler.PlatformView.HorizontalOptions = img.HorizontalOptions;
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}
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}
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public static void MapVerticalOptions(ImageHandler handler, IImage image)
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{
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if (handler.PlatformView is null) return;
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if (image is Image img)
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{
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handler.PlatformView.VerticalOptions = img.VerticalOptions;
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}
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}
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// Image source loading helper
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private ImageSourceServiceResultManager _sourceLoader = null!;
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private ImageSourceServiceResultManager SourceLoader =>
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_sourceLoader ??= new ImageSourceServiceResultManager(this);
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internal class ImageSourceServiceResultManager
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{
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private readonly ImageHandler _handler;
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private CancellationTokenSource? _cts;
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public ImageSourceServiceResultManager(ImageHandler handler)
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{
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_handler = handler;
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}
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public async void UpdateImageSourceAsync()
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{
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_cts?.Cancel();
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_cts = new CancellationTokenSource();
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var token = _cts.Token;
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try
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{
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var source = _handler.VirtualView?.Source;
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if (source == null)
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{
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_handler.PlatformView?.LoadFromData(Array.Empty<byte>());
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return;
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}
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if (_handler.VirtualView is IImageSourcePart imageSourcePart)
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{
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imageSourcePart.UpdateIsLoading(true);
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}
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// Handle different image source types
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if (source is IFileImageSource fileSource)
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{
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var file = fileSource.File;
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if (!string.IsNullOrEmpty(file))
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{
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await _handler.PlatformView!.LoadFromFileAsync(file);
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}
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}
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else if (source is IUriImageSource uriSource)
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{
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var uri = uriSource.Uri;
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if (uri != null)
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{
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await _handler.PlatformView!.LoadFromUriAsync(uri);
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}
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}
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else if (source is IStreamImageSource streamSource)
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{
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var stream = await streamSource.GetStreamAsync(token);
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if (stream != null)
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{
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await _handler.PlatformView!.LoadFromStreamAsync(stream);
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}
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}
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else if (source is FontImageSource fontSource)
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{
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var bitmap = RenderFontImageSource(fontSource, _handler.PlatformView!.WidthRequest, _handler.PlatformView.HeightRequest);
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if (bitmap != null)
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{
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_handler.PlatformView.LoadFromBitmap(bitmap);
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}
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}
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}
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catch (OperationCanceledException)
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{
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// Loading was cancelled
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}
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catch (Exception)
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{
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// Handle error
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if (_handler.VirtualView is IImageSourcePart imageSourcePart)
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{
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imageSourcePart.UpdateIsLoading(false);
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}
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}
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}
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private static SKBitmap? RenderFontImageSource(FontImageSource fontSource, double requestedWidth, double requestedHeight)
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{
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string glyph = fontSource.Glyph;
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if (string.IsNullOrEmpty(glyph))
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{
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return null;
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}
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int size = (int)Math.Max(requestedWidth > 0 ? requestedWidth : 24.0, requestedHeight > 0 ? requestedHeight : 24.0);
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size = Math.Max(size, 16);
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SKColor color = fontSource.Color?.ToSKColor() ?? SKColors.Black;
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SKBitmap bitmap = new SKBitmap(size, size, false);
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using SKCanvas canvas = new SKCanvas(bitmap);
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canvas.Clear(SKColors.Transparent);
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SKTypeface? typeface = null;
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if (!string.IsNullOrEmpty(fontSource.FontFamily))
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{
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string[] fontPaths = new string[]
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{
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"/usr/share/fonts/truetype/" + fontSource.FontFamily + ".ttf",
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"/usr/share/fonts/opentype/" + fontSource.FontFamily + ".otf",
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"/usr/local/share/fonts/" + fontSource.FontFamily + ".ttf",
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Path.Combine(AppContext.BaseDirectory, fontSource.FontFamily + ".ttf")
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};
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foreach (string path in fontPaths)
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{
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if (File.Exists(path))
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{
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typeface = SKTypeface.FromFile(path, 0);
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if (typeface != null)
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{
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break;
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}
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}
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}
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if (typeface == null)
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{
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typeface = SKTypeface.FromFamilyName(fontSource.FontFamily);
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}
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}
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if (typeface == null)
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{
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typeface = SKTypeface.Default;
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}
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float fontSize = size * 0.8f;
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using SKFont font = new SKFont(typeface, fontSize, 1f, 0f);
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using SKPaint paint = new SKPaint(font)
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{
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Color = color,
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IsAntialias = true,
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TextAlign = SKTextAlign.Center
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};
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SKRect bounds = default;
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paint.MeasureText(glyph, ref bounds);
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float x = size / 2f;
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float y = (size - bounds.Top - bounds.Bottom) / 2f;
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canvas.DrawText(glyph, x, y, paint);
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return bitmap;
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}
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}
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}
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