[android] reduce interop calls in MauiDrawable

src/Core/AndroidNative/maui/src/main/java/com/microsoft/maui/PlatformInterop.java

@@ -2,10 +2,17 @@
 
 import android.content.Context;
 import android.content.res.ColorStateList;
+import android.graphics.Canvas;
 import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.Path;
+import android.graphics.PathEffect;
 import android.graphics.Typeface;
 import android.graphics.drawable.Drawable;
+import android.graphics.drawable.PaintDrawable;
 import android.net.Uri;
+import android.os.Build;
+import android.util.TypedValue;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewGroup;
@@ -373,6 +380,81 @@ public static ColorStateList createEditTextColorStateList(ColorStateList colorSt
         return null;
     }
 
+    /**
+     * Sets many values at once on a Paint object
+     * @param paint
+     * @param strokeWidth
+     * @param strokeJoin
+     * @param strokeCap
+     * @param strokeMiter
+     * @param pathEffect
+     */
+    public static void setPaintValues(Paint paint, float strokeWidth, Paint.Join strokeJoin, Paint.Cap strokeCap, float strokeMiter, PathEffect pathEffect)
+    {
+        paint.setStrokeWidth(strokeWidth);
+        paint.setStrokeJoin(strokeJoin);
+        paint.setStrokeCap(strokeCap);
+        paint.setStrokeMiter(strokeMiter);
+        if (pathEffect != null) {
+            paint.setPathEffect(pathEffect);
+        }
+    }
+
+    /**
+     * Calls canvas.saveLayer(), draws paths for clipPath & borderPaint, then canvas.restoreToCount()
+     * @param drawable
+     * @param canvas
+     * @param width
+     * @param height
+     * @param clipPath
+     * @param borderPaint
+     */
+    public static void drawMauiDrawablePath(PaintDrawable drawable, Canvas canvas, int width, int height, @NonNull Path clipPath, Paint borderPaint)
+    {
+        int saveCount = canvas.saveLayer(0, 0, width, height, null);
+
+        Paint paint = drawable.getPaint();
+        if (paint != null) {
+            canvas.drawPath(clipPath, paint);
+        }
+        if (borderPaint != null) {
+            canvas.drawPath(clipPath, borderPaint);
+        }
+
+        canvas.restoreToCount(saveCount);
+    }
+
+    /**
+     * Gets the value of android.R.attr.windowBackground from the given Context
+     * @param context
+     * @return the color or -1 if not found
+     */
+    public static int getWindowBackgroundColor(Context context)
+    {
+        TypedValue value = new TypedValue();
+        if (!context.getTheme().resolveAttribute(android.R.attr.windowBackground, value, true) && isColorType(value)) {
+            return value.data;
+        } else {
+            return -1;
+        }
+    }
+
+    /**
+     * Needed because TypedValue.isColorType() is only API Q+
+     * https://github.com/aosp-mirror/platform_frameworks_base/blob/1d896eeeb8744a1498128d62c09a3aa0a2a29a16/core/java/android/util/TypedValue.java#L266-L268
+     * @param value
+     * @return true if the TypedValue is a Color
+     */
+    private static boolean isColorType(TypedValue value)
+    {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            return value.isColorType();
+        } else {
+            // Implementation from AOSP
+            return (value.type >= TypedValue.TYPE_FIRST_COLOR_INT && value.type <= TypedValue.TYPE_LAST_COLOR_INT);
+        }
+    }
+
     private static class ColorStates
     {
         static final int[] EMPTY = new int[] { };

src/Core/src/Graphics/MauiDrawable.Android.cs

@@ -388,18 +388,12 @@ protected override void OnDraw(Shape? shape, Canvas? canvas, APaint? paint)
 
 				if (_borderPaint != null)
 				{
-					_borderPaint.StrokeWidth = _strokeThickness;
-					_borderPaint.StrokeJoin = _strokeLineJoin;
-					_borderPaint.StrokeCap = _strokeLineCap;
-					_borderPaint.StrokeMiter = _strokeMiterLimit * 2;
-
-					if (_borderPathEffect != null)
-						_borderPaint.SetPathEffect(_borderPathEffect);
+					PlatformInterop.SetPaintValues(_borderPaint, _strokeThickness, _strokeLineJoin, _strokeLineCap, _strokeMiterLimit * 2, _borderPathEffect);
 
 					if (_borderColor != null)
-#pragma warning disable CA1416 // https://github.com/xamarin/xamarin-android/issues/6962
+					{
 						_borderPaint.Color = _borderColor.Value;
-#pragma warning restore CA1416
+					}
 					else
 					{
 						if (_stroke != null)
@@ -427,18 +421,10 @@ protected override void OnDraw(Shape? shape, Canvas? canvas, APaint? paint)
 					}
 				}
 
-				if (canvas == null)
+				if (canvas == null || _clipPath == null)
 					return;
 
-				var saveCount = canvas.SaveLayer(0, 0, _width, _height, null);
-
-				if (_clipPath != null && Paint != null)
-					canvas.DrawPath(_clipPath, Paint);
-
-				if (_clipPath != null && _borderPaint != null)
-					canvas.DrawPath(_clipPath, _borderPaint);
-
-				canvas.RestoreToCount(saveCount);
+				PlatformInterop.DrawMauiDrawablePath(this, canvas, _width, _height, _clipPath, _borderPaint);
 			}
 			else
 			{
@@ -512,22 +498,10 @@ void InitializeBorderIfNeeded()
 
 		void SetDefaultBackgroundColor()
 		{
-			using (var background = new TypedValue())
+			var color = PlatformInterop.GetWindowBackgroundColor(_context);
+			if (color != -1)
 			{
-				if (_context == null || _context.Theme == null || _context.Resources == null)
-					return;
-
-				if (_context.Theme.ResolveAttribute(global::Android.Resource.Attribute.WindowBackground, background, true))
-				{
-					var resource = _context.Resources.GetResourceTypeName(background.ResourceId);
-					var type = resource?.ToLowerInvariant();
-
-					if (type == "color")
-					{
-						var color = new AColor(ContextCompat.GetColor(_context, background.ResourceId));
-						_backgroundColor = color;
-					}
-				}
+				_backgroundColor = new AColor(color);
 			}
 		}