Allow for a slightly delayed theme registration (#200)

mono · Aug 23, 2023 · 58779a0 · 58779a0
1 parent 2a75990
commit 58779a0
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Showing 5 changed files with 29 additions and 15 deletions.
diff --git a/source/SkiaSharp.Extended.UI/Controls/Confetti/SKConfettiView.shared.cs b/source/SkiaSharp.Extended.UI/Controls/Confetti/SKConfettiView.shared.cs
@@ -23,7 +23,7 @@ public class SKConfettiView : SKAnimatedSurfaceView
 
 	public SKConfettiView()
 	{
-		Themes.SKConfettiViewResources.EnsureRegistered();
+		ResourceLoader<Themes.SKConfettiViewResources>.EnsureRegistered(this);
 
 		SizeChanged += OnSizeChanged;
 		PropertyChanged += (_, e) =>

diff --git a/source/SkiaSharp.Extended.UI/Controls/Confetti/SKConfettiViewResources.shared.xaml.cs b/source/SkiaSharp.Extended.UI/Controls/Confetti/SKConfettiViewResources.shared.xaml.cs
@@ -2,13 +2,8 @@
 
 public partial class SKConfettiViewResources : ResourceDictionary
 {
-	private static bool registered;
-
 	public SKConfettiViewResources()
 	{
 		InitializeComponent();
 	}
-
-	internal static void EnsureRegistered() =>
-		ResourceLoader.EnsureRegistered<SKConfettiViewResources>(ref registered);
 }
diff --git a/source/SkiaSharp.Extended.UI/Controls/Lottie/SKLottieView.shared.cs b/source/SkiaSharp.Extended.UI/Controls/Lottie/SKLottieView.shared.cs
@@ -54,7 +54,7 @@ public class SKLottieView : SKAnimatedSurfaceView
 
 	public SKLottieView()
 	{
-		Themes.SKLottieViewResources.EnsureRegistered();
+		ResourceLoader<Themes.SKLottieViewResources>.EnsureRegistered(this);
 
 		IsAnimationEnabled = true;
 	}

diff --git a/source/SkiaSharp.Extended.UI/Controls/Lottie/SKLottieViewResources.shared.xaml.cs b/source/SkiaSharp.Extended.UI/Controls/Lottie/SKLottieViewResources.shared.xaml.cs
@@ -2,13 +2,8 @@
 
 public partial class SKLottieViewResources : ResourceDictionary
 {
-	private static bool registered;
-
 	public SKLottieViewResources()
 	{
 		InitializeComponent();
 	}
-
-	internal static void EnsureRegistered() =>
-		ResourceLoader.EnsureRegistered<SKLottieViewResources>(ref registered);
 }
diff --git a/source/SkiaSharp.Extended.UI/Utils/ResourceLoader.shared.cs b/source/SkiaSharp.Extended.UI/Utils/ResourceLoader.shared.cs
@@ -1,13 +1,16 @@
 namespace SkiaSharp.Extended.UI;
 
-internal static class ResourceLoader
+internal static class ResourceLoader<T>
+	where T : ResourceDictionary, new()
 {
-	internal static void EnsureRegistered<T>(ref bool registered)
-		where T : ResourceDictionary, new()
+	private static bool registered;
+
+	internal static void EnsureRegistered(VisualElement? element = null)
 	{
 		if (registered)
 			return;
 
+		// try register with the current app
 		var merged = Application.Current?.Resources?.MergedDictionaries;
 		if (merged != null)
 		{
@@ -26,5 +29,26 @@ internal static void EnsureRegistered<T>(ref bool registered)
 				registered = true;
 			}
 		}
+
+#if !XAMARIN_FORMS
+		// the app may not be ready yet - if this page is part of the app's constructor
+		// so we will wait until this view gets a window, then we will try again
+		if (!registered && element != null)
+		{
+			element.PropertyChanged += OnPropertyChanged;
+
+			static void OnPropertyChanged(object? sender, PropertyChangedEventArgs e)
+			{
+				if (e.PropertyName != VisualElement.WindowProperty.PropertyName)
+					return;
+
+				// the window changed, so try one more time
+				EnsureRegistered();
+
+				if (sender is VisualElement ve)
+					ve.PropertyChanged -= OnPropertyChanged;
+			}
+		}
+#endif
 	}
 }