Add support for existing IImage loading in AdvancedImage. Close #17

Author: SKProCH

AsyncImageLoader.Avalonia.Demo/Converters/GetClassNameConverter.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Globalization;
+using Avalonia.Data.Converters;
+
+namespace AsyncImageLoader.Avalonia.Demo.Converters;
+
+public class GetClassNameConverter : IValueConverter {
+    public static GetClassNameConverter Instance { get; } = new();
+
+    /// <inheritdoc />
+    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture) {
+        if (value is null) {
+            return "null";
+        }
+
+        return value.GetType().Name;
+    }
+
+    /// <inheritdoc />
+    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture) {
+        throw new NotSupportedException();
+    }
+}

AsyncImageLoader.Avalonia.Demo/Pages/AdvancedImagePage.axaml

@@ -4,9 +4,10 @@
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              xmlns:asyncImageLoader="clr-namespace:AsyncImageLoader;assembly=AsyncImageLoader.Avalonia"
              xmlns:services="clr-namespace:AsyncImageLoader.Avalonia.Demo.Services"
-             mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+             xmlns:converters="clr-namespace:AsyncImageLoader.Avalonia.Demo.Converters"
+             mc:Ignorable="d" d:DesignWidth="800"
              x:Class="AsyncImageLoader.Avalonia.Demo.Pages.AdvancedImagePage">
-  <Grid ColumnDefinitions="* 8 150 150" RowDefinitions="Auto Auto Auto Auto Auto"
+  <Grid ColumnDefinitions="* 8 150 150" RowDefinitions="Auto Auto Auto Auto Auto Auto"
         HorizontalAlignment="Center">
     <TextBlock Grid.Column="2" Grid.Row="0" HorizontalAlignment="Center" Text="AdvancedImage" />
     <TextBlock Grid.Column="3" Grid.Row="0" HorizontalAlignment="Center" Text="Image" />
@@ -60,8 +61,32 @@
     <asyncImageLoader:AdvancedImage Grid.Row="4" Grid.Column="2"
                                     Width="150" Height="150" CornerRadius="5 10 15 20"
                                     Source="/Assets/cat5.jpg" />
-    <Border Grid.Row="4" Grid.Column="3" CornerRadius="5 10 15 20" ClipToBounds="True"  Width="150" Height="150">
+    <Border Grid.Row="4" Grid.Column="3" CornerRadius="5 10 15 20" ClipToBounds="True" Width="150" Height="150">
       <Image Source="/Assets/cat5.jpg" Width="150" Height="150" />
     </Border>
+
+    <StackPanel Grid.Row="5" Grid.Column="0" HorizontalAlignment="Left">
+      <TextBlock TextWrapping="Wrap">
+        <TextBlock.Text>
+          You can set CurrentImage property by youself. This sets Source back to null.
+        </TextBlock.Text>
+      </TextBlock>
+      <TextBlock>
+        <Run>Source: </Run>
+        <Run Text="{Binding #CurrentImageExample.Source}"></Run>
+      </TextBlock>
+      <TextBlock>
+        <Run>CurrentImage: </Run>
+        <Run Text="{Binding #CurrentImageExample.CurrentImage, Converter={x:Static converters:GetClassNameConverter.Instance}, Mode=OneWay}" />
+      </TextBlock>
+      <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
+        <Button Click="SetSourceButton_OnClick">Set Source</Button>
+        <Button Click="SetCurrentImageButton_OnClick">Set CurrentImage</Button>
+      </StackPanel>
+    </StackPanel>
+    <asyncImageLoader:AdvancedImage Grid.Row="5" Grid.Column="2"
+                                    Name="CurrentImageExample"
+                                    Width="150" Height="150"
+                                    Source="/Assets/cat5.jpg" />
   </Grid>
 </UserControl>

AsyncImageLoader.Avalonia.Demo/Pages/AdvancedImagePage.axaml.cs

@@ -1,22 +1,29 @@
-using Avalonia;
+using System;
+using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Interactivity;
 using Avalonia.Markup.Xaml;
+using Avalonia.Media.Imaging;
+using Avalonia.Platform;
 
 namespace AsyncImageLoader.Avalonia.Demo.Pages {
     public partial class AdvancedImagePage : UserControl {
         public AdvancedImagePage() {
             InitializeComponent();
         }
 
-        private void InitializeComponent() {
-            AvaloniaXamlLoader.Load(this);
-        }
-
         private void ReloadButton_OnClick(object? sender, RoutedEventArgs e) {
-            var advancedImage = this.FindControl<AdvancedImage>("ReloadableAdvancedImage");
-            advancedImage.Source = null;
-            advancedImage.Source = "https://github.com/AvaloniaUtils/AsyncImageLoader.Avalonia/raw/master/AsyncImageLoader.Avalonia.Demo/Assets/cat0.jpg";
+            ReloadableAdvancedImage.Source = null;
+            ReloadableAdvancedImage.Source = "https://github.com/AvaloniaUtils/AsyncImageLoader.Avalonia/raw/master/AsyncImageLoader.Avalonia.Demo/Assets/cat0.jpg";
+        }
+        
+        private void SetSourceButton_OnClick(object? sender, RoutedEventArgs e) {
+            CurrentImageExample.Source = "/Assets/cat5.jpg";
+        }
+        
+        private void SetCurrentImageButton_OnClick(object? sender, RoutedEventArgs e) {
+            using var stream = AssetLoader.Open(new Uri("avares://AsyncImageLoader.Avalonia.Demo/Assets/cat4.jpg", UriKind.RelativeOrAbsolute));
+            CurrentImageExample.CurrentImage = new Bitmap(stream);
         }
     }
 }

AsyncImageLoader.Avalonia/AdvancedImage.axaml.cs

@@ -142,7 +142,7 @@ public bool IsLoading
     public IImage? CurrentImage
     {
         get => _currentImage;
-        private set => SetAndRaise(CurrentImageProperty, ref _currentImage, value);
+        set => SetAndRaise(CurrentImageProperty, ref _currentImage, value);
     }
 
     /// <summary>
@@ -169,16 +169,31 @@ protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs chang
             UpdateImage(change.GetNewValue<string>(), Loader);
         else if (change.Property == LoaderProperty && ShouldLoaderChangeTriggerUpdate)
             UpdateImage(change.GetNewValue<string>(), Loader);
+        else if (change.Property == CurrentImageProperty)
+            ClearSourceIfUserProvideImage();
         else if (change.Property == CornerRadiusProperty)
             UpdateCornerRadius(change.GetNewValue<CornerRadius>());
         else if (change.Property == BoundsProperty && CornerRadius != default) UpdateCornerRadius(CornerRadius);
         base.OnPropertyChanged(change);
     }
 
+    private void ClearSourceIfUserProvideImage() {
+        if (CurrentImage is not null and not ImageWrapper) {
+            // User provided image himself
+            Source = null;
+        }
+    }
+
     private async void UpdateImage(string? source, IAsyncImageLoader? loader)
     {
 		_updateCancellationToken?.Cancel();
 		_updateCancellationToken?.Dispose();
+        _updateCancellationToken = null;
+        if (source is null && CurrentImage is not ImageWrapper) {
+            // User provided image himself
+            return;
+        }
+        
 		var cancellationTokenSource = _updateCancellationToken = new CancellationTokenSource();
 		IsLoading = true;
 		CurrentImage = null;
@@ -219,8 +234,8 @@ private async void UpdateImage(string? source, IAsyncImageLoader? loader)
 
 		if (cancellationTokenSource.IsCancellationRequested)
             return;
-		CurrentImage = bitmap;
-		IsLoading = false;
+        CurrentImage = bitmap is null ? null : new ImageWrapper(bitmap);
+        IsLoading = false;
 	}
 
     private void UpdateCornerRadius(CornerRadius radius)
@@ -280,4 +295,18 @@ protected override Size ArrangeOverride(Size finalSize)
             ? Stretch.CalculateSize(finalSize, CurrentImage.Size)
             : base.ArrangeOverride(finalSize);
     }
+    
+    public sealed class ImageWrapper : IImage {
+        public IImage ImageImplementation { get; }
+        internal ImageWrapper(IImage imageImplementation) {
+            ImageImplementation = imageImplementation;
+        }
+        /// <inheritdoc />
+        public void Draw(DrawingContext context, Rect sourceRect, Rect destRect) {
+            ImageImplementation.Draw(context, sourceRect, destRect);
+        }
+
+        /// <inheritdoc />
+        public Size Size => ImageImplementation.Size;
+    }
 }