Use fade-in/fade-out transition on background image

Author: neon-nyan

CollapseLauncher/Classes/GameManagement/ImageBackground/ImageBackgroundManager.Loaders.cs

@@ -240,7 +240,6 @@ private void SpawnImageLayer(Uri? overlayFilePath,
                                   bindingMode: BindingMode.OneWay,
                                   converter: StaticConverter<InverseBooleanConverter>.Shared);
 
-        layerElement.Transitions.Add(new PopupThemeTransition());
         layerElement.ImageLoaded += LayerElementOnLoaded;
         PresenterGrid?.Children.Add(layerElement);
 
@@ -249,6 +248,7 @@ private void SpawnImageLayer(Uri? overlayFilePath,
 
     private void LayerElementOnLoaded(LayeredBackgroundImage layerElement)
     {
+        layerElement.Transitions.Add(new PopupThemeTransition());
         layerElement.ImageLoaded -= LayerElementOnLoaded;
 
         if (PresenterGrid?.Children.Count > 1)

CollapseLauncher/XAMLs/MainApp/MainPage.xaml

@@ -29,7 +29,11 @@
         <Grid x:Name="BackgroundPresenterGrid"
               x:FieldModifier="internal">
             <customControls:LayeredBackgroundImage BackgroundSource="{x:Bind PlaceholderBackgroundImage}"
-                                                   MediaSourceCacheDir="{x:Bind PlaceholderDecodedCacheDir}" />
+                                                   MediaSourceCacheDir="{x:Bind PlaceholderDecodedCacheDir}">
+                <customControls:LayeredBackgroundImage.Transitions>
+                    <PopupThemeTransition/>
+                </customControls:LayeredBackgroundImage.Transitions>
+            </customControls:LayeredBackgroundImage>
         </Grid>
         <Grid HorizontalAlignment="Left"
               VerticalAlignment="Top"

CollapseLauncher/XAMLs/Theme/CustomControls/LayeredBackgroundImage.Events.Loaders.cs

@@ -291,7 +291,6 @@ private static async ValueTask<bool> LoadImageFromSourceAsync(
             image.BindProperty(instance, horizontalAlignmentProperty, HorizontalAlignmentProperty, BindingMode.OneWay);
             image.BindProperty(instance, verticalAlignmentProperty,   VerticalAlignmentProperty,   BindingMode.OneWay);
 
-            image.Transitions.Add(new ContentThemeTransition());
             grid.Children.Add(image);
 
             image.Tag         =  (grid, instance);