Canvas: fix some issues spotted by the CTS

src/api-impl/android/graphics/Bitmap.java

@@ -43,6 +43,7 @@ public final class Bitmap {
 	private boolean hasAlpha = true;
 	long bytes = 0;  // used by native function AndroidBitmap_lockPixels()
 	private boolean recycled = false;
+	boolean mutable = true;
 
 	Bitmap(long texture) {
 		this(native_get_width(texture), native_get_height(texture), Config.ARGB_8888);
@@ -194,7 +195,7 @@ public final class Bitmap {
 	}
 
 	public boolean isMutable() {
-		return true;
+		return mutable;
 	}
 
 	public boolean compress(Bitmap.CompressFormat format, int quality, OutputStream stream) throws IOException {

src/api-impl/android/graphics/BitmapFactory.java

@@ -443,7 +443,11 @@ public class BitmapFactory {
 	 *         size be returned (in opts.outWidth and opts.outHeight)
 	 */
 	public static Bitmap decodeResource(Resources res, int id, Options opts) throws NotFoundException {
-		return decodeStreamInternal(res.openRawResource(id), null, opts);
+		Bitmap bitmap = decodeStreamInternal(res.openRawResource(id), null, opts);
+		if (opts != null && opts.inScaled == false) {
+			bitmap.mutable = false;
+		}
+		return bitmap;
 	}
 
 	/**

src/api-impl/android/graphics/Canvas.java

@@ -380,6 +380,9 @@ public class Canvas {
 	}
 
 	public void setBitmap(Bitmap bitmap) {
+		if (!bitmap.isMutable()) {
+			throw new IllegalStateException("Bitmap must be mutable");
+		}
 		this.bitmap = bitmap;
 		gsk_canvas.snapshot = bitmap == null ? 0 : bitmap.getSnapshot();
 	}
@@ -393,7 +396,10 @@ public class Canvas {
 		return false;
 	}
 
-	public void restoreToCount(int count) {}
+	public void restoreToCount(int count) {
+		gsk_canvas.snapshot = bitmap.getSnapshot();
+		gsk_canvas.restoreToCount(count);
+	}
 
 	public void drawRoundRect(RectF rect, float rx, float ry, Paint paint) {
 		if (paint.getShader() instanceof BitmapShader) {
@@ -425,11 +431,11 @@ public class Canvas {
 	}
 
 	public int getWidth() {
-		return 10; //FIXME
+		return (bitmap == null) ? 0 : bitmap.getWidth();
 	}
 
 	public int getHeight() {
-		return 10; //FIXME
+		return (bitmap == null) ? 0 : bitmap.getHeight();
 	}
 
 	public void drawColor(int dummy) {}

src/api-impl/android/graphics/GskCanvas.java

@@ -6,7 +6,7 @@ package android.graphics;
  */
 public class GskCanvas extends Canvas {
 	public long snapshot;
-	private int save_count = 0;
+	private int save_count = 1;
 
 	private static Paint default_paint = new Paint();
 
@@ -28,6 +28,9 @@ public class GskCanvas extends Canvas {
 
 	@Override
 	public void restoreToCount(int count) {
+		if (count < 1) {
+			throw new IllegalArgumentException("count must be >= 1");
+		}
 		while (save_count > count) {
 			restore();
 		}