[Android] Implemented material3 support for ActivityIndicator

src/Controls/src/Core/Hosting/AppHostBuilderExtensions.cs

@@ -71,7 +71,6 @@ internal static IMauiHandlersCollection AddControlsHandlers(this IMauiHandlersCo
 		handlersCollection.AddHandler<CarouselView, CarouselViewHandler>();
 #endif
 		handlersCollection.AddHandler<Application, ApplicationHandler>();
-		handlersCollection.AddHandler<ActivityIndicator, ActivityIndicatorHandler>();
 		handlersCollection.AddHandler<BoxView, BoxViewHandler>();
 		handlersCollection.AddHandler<Button, ButtonHandler>();
 		handlersCollection.AddHandler<DatePicker, DatePickerHandler>();
@@ -95,6 +94,19 @@ internal static IMauiHandlersCollection AddControlsHandlers(this IMauiHandlersCo
 			// NOTE: not registered under NativeAOT or TrimMode=Full scenarios
 			handlersCollection.AddHandler<HybridWebView, HybridWebViewHandler>();
 		}
+
+#if ANDROID
+		if (RuntimeFeature.IsMaterial3Enabled)
+		{
+			handlersCollection.AddHandler<ActivityIndicator, ActivityIndicatorHandler2>();
+		}
+		else
+		{
+			handlersCollection.AddHandler<ActivityIndicator, ActivityIndicatorHandler>();
+		}
+#else
+		handlersCollection.AddHandler<ActivityIndicator, ActivityIndicatorHandler>();
+#endif
 		handlersCollection.AddHandler<Border, BorderHandler>();
 		handlersCollection.AddHandler<IContentView, ContentViewHandler>();
 		handlersCollection.AddHandler<ContentView, ContentViewHandler>();

src/Core/src/Handlers/ActivityIndicator/ActivityIndicatorHandler.Android.cs

@@ -1,4 +1,6 @@
-using Android.Widget;
+using System;
+using Android.Widget;
+using Microsoft.Maui.Graphics;
 
 namespace Microsoft.Maui.Handlers
 {
@@ -16,4 +18,41 @@ public static partial void MapColor(IActivityIndicatorHandler handler, IActivity
 			handler.PlatformView?.UpdateColor(activityIndicator);
 		}
 	}
-}
+
+	// TODO: material3 - make it public in .net 11
+	internal class ActivityIndicatorHandler2 : ActivityIndicatorHandler
+	{
+		protected override MaterialActivityIndicator CreatePlatformView()
+		{
+			return new MaterialActivityIndicator(Context)
+			{
+				Indeterminate = true
+			};
+		}
+
+		public override void PlatformArrange(Rect frame)
+		{
+			if (Context == null || PlatformView == null)
+			{
+				return;
+			}
+
+			// Get the child's desired size (what it measured at)
+			var desiredWidth = VirtualView?.DesiredSize.Width ?? frame.Width;
+			var desiredHeight = VirtualView?.DesiredSize.Height ?? frame.Height;
+
+			// Constrain to desired size (don't let parent stretch us)
+			var constrainedWidth = Math.Min(frame.Width, desiredWidth);
+			var constrainedHeight = Math.Min(frame.Height, desiredHeight);
+
+			// Create new frame with constrained size, centered if necessary
+			var arrangeFrame = new Rect(
+				frame.X + (frame.Width - constrainedWidth) / 2,
+				frame.Y + (frame.Height - constrainedHeight) / 2,
+				constrainedWidth,
+				constrainedHeight);
+
+			base.PlatformArrange(arrangeFrame);
+		}
+	}
+}

src/Core/src/Platform/Android/MaterialActivityIndicator.cs

@@ -0,0 +1,45 @@
+using System;
+using Android.Content;
+using Android.Runtime;
+using Android.Util;
+using Google.Android.Material.ProgressIndicator;
+
+namespace Microsoft.Maui.Platform;
+
+// TODO: material3 - make it public in .net 11
+internal class MaterialActivityIndicator : CircularProgressIndicator
+{
+    public MaterialActivityIndicator(Context context)
+     : base(MauiMaterialContextThemeWrapper.Create(context))
+    {
+    }
+
+    protected MaterialActivityIndicator(nint javaReference, JniHandleOwnership transfer) : base(javaReference, transfer)
+    {
+    }
+
+    public MaterialActivityIndicator(Context context, IAttributeSet? attrs) : base(MauiMaterialContextThemeWrapper.Create(context), attrs)
+    {
+    }
+
+    public MaterialActivityIndicator(Context context, IAttributeSet? attrs, int defStyleAttr) : base(context, attrs, defStyleAttr)
+    {
+
+    }
+
+    protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
+    {
+        // Calculate desired size including indicator size and padding
+        var desiredSize =
+            IndicatorSize +
+            Math.Max(PaddingLeft + PaddingRight, PaddingTop + PaddingBottom);
+
+        var width = ResolveSize(desiredSize, widthMeasureSpec);
+        var height = ResolveSize(desiredSize, heightMeasureSpec);
+
+        // ActivityIndicator must always be square
+        var finalSize = Math.Min(width, height);
+
+        SetMeasuredDimension(finalSize, finalSize);
+    }
+}