Moving some abstract classes to interfaces, to better use java-8 features

Change-Id: I862af4931c95cbde052130d8b7d4ac3375db782f

src/com/android/launcher3/graphics/BitmapRenderer.java

@@ -23,32 +23,30 @@ import android.os.Build;
 
 import com.android.launcher3.Utilities;
 
-public class BitmapRenderer {
+/**
+ * Interface representing a bitmap draw operation.
+ */
+public interface BitmapRenderer {
 
-     public static final boolean USE_HARDWARE_BITMAP = Utilities.ATLEAST_P;
+    boolean USE_HARDWARE_BITMAP = Utilities.ATLEAST_P;
 
-     public static Bitmap createSoftwareBitmap(int width, int height, Renderer renderer) {
-          Bitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
-          renderer.draw(new Canvas(result));
-          return result;
-     }
+    static Bitmap createSoftwareBitmap(int width, int height, BitmapRenderer renderer) {
+        Bitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+        renderer.draw(new Canvas(result));
+        return result;
+    }
 
-     @TargetApi(Build.VERSION_CODES.P)
-     public static Bitmap createHardwareBitmap(int width, int height, Renderer renderer) {
-          if (!USE_HARDWARE_BITMAP) {
-               return createSoftwareBitmap(width, height, renderer);
-          }
+    @TargetApi(Build.VERSION_CODES.P)
+    static Bitmap createHardwareBitmap(int width, int height, BitmapRenderer renderer) {
+        if (!USE_HARDWARE_BITMAP) {
+            return createSoftwareBitmap(width, height, renderer);
+        }
 
-          Picture picture = new Picture();
-          renderer.draw(picture.beginRecording(width, height));
-          picture.endRecording();
-          return Bitmap.createBitmap(picture);
-     }
+        Picture picture = new Picture();
+        renderer.draw(picture.beginRecording(width, height));
+        picture.endRecording();
+        return Bitmap.createBitmap(picture);
+    }
 
-     /**
-      * Interface representing a bitmap draw operation.
-      */
-     public interface Renderer {
-          void draw(Canvas out);
-     }
+    void draw(Canvas out);
 }