[Carousel] Fixed MaskableFrameLayout not updating mask after size change when setting the mask using setMaskXPercentage.

This also fixes the default list catalog demo not displaying any items due to every item's mask having an empty maskRect.

Resolves #3450

PiperOrigin-RevId: 546859519

Author: hunterstich

lib/java/com/google/android/material/carousel/MaskableFrameLayout.java

@@ -40,8 +40,10 @@
 /** A {@link FrameLayout} than is able to mask itself and all children. */
 public class MaskableFrameLayout extends FrameLayout implements Maskable, Shapeable {
 
-  private float maskXPercentage = 0F;
-  private final RectF maskRect = new RectF();
+  private static final float MASK_X_PERCENTAGE_UNSET = -1F;
+
+  private float maskXPercentage = MASK_X_PERCENTAGE_UNSET;
+  @Nullable private RectF maskRect = null;
   @Nullable private OnMaskChangedListener onMaskChangedListener;
   @NonNull private ShapeAppearanceModel shapeAppearanceModel;
   private final ShapeableDelegate shapeableDelegate = ShapeableDelegate.create(this);
@@ -65,7 +67,13 @@ public MaskableFrameLayout(
   @Override
   protected void onSizeChanged(int w, int h, int oldw, int oldh) {
     super.onSizeChanged(w, h, oldw, oldh);
-    onMaskChanged();
+    if (maskXPercentage != MASK_X_PERCENTAGE_UNSET) {
+      // If the mask x percentage has been set, the mask rect needs to be recalculated by calling
+      // setMaskXPercentage which will then handle calling onMaskChanged
+      setMaskXPercentage(maskXPercentage);
+    } else {
+      onMaskChanged();
+    }
   }
 
   @Override
@@ -120,23 +128,28 @@ public ShapeAppearanceModel getShapeAppearanceModel() {
   @Override
   @Deprecated
   public void setMaskXPercentage(float percentage) {
-    percentage = MathUtils.clamp(percentage, 0F, 1F);
-    if (maskXPercentage != percentage) {
-      this.maskXPercentage = percentage;
-      // Translate the percentage into an actual pixel value of how much of this view should be
-      // masked away.
-      float maskWidth = AnimationUtils.lerp(0f, getWidth() / 2F, 0f, 1f, maskXPercentage);
-      setMaskRectF(new RectF(maskWidth, 0F, (getWidth() - maskWidth), getHeight()));
-    }
+    this.maskXPercentage = MathUtils.clamp(percentage, 0F, 1F);
+    // Translate the percentage into an actual pixel value of how much of this view should be
+    // masked away.
+    float maskWidth = AnimationUtils.lerp(0f, getWidth() / 2F, 0f, 1f, maskXPercentage);
+    updateMaskRectF(new RectF(maskWidth, 0F, (getWidth() - maskWidth), getHeight()));
   }
 
   /**
    * Sets the {@link RectF} that this {@link View} will be masked by.
    *
+   * <p>Calling this method will overwrite any mask set using {@link #setMaskXPercentage(float)}.
+   *
    * @param maskRect a rect in the view's coordinates to mask by
    */
   @Override
   public void setMaskRectF(@NonNull RectF maskRect) {
+    this.maskXPercentage = MASK_X_PERCENTAGE_UNSET;
+    updateMaskRectF(maskRect);
+  }
+
+  private void updateMaskRectF(@NonNull RectF maskRect) {
+    ensureMaskRectF();
     this.maskRect.set(maskRect);
     onMaskChanged();
   }
@@ -158,21 +171,28 @@ public float getMaskXPercentage() {
   @NonNull
   @Override
   public RectF getMaskRectF() {
+    ensureMaskRectF();
     return maskRect;
   }
 
+  private void ensureMaskRectF() {
+    if (maskRect == null) {
+      maskRect = new RectF(0F, 0F, getWidth(), getHeight());
+    }
+  }
+
   @Override
   public void setOnMaskChangedListener(@Nullable OnMaskChangedListener onMaskChangedListener) {
     this.onMaskChangedListener = onMaskChangedListener;
   }
 
   private void onMaskChanged() {
-    if (getWidth() == 0) {
+    if (getWidth() == 0 || getHeight() == 0) {
       return;
     }
-    shapeableDelegate.onMaskChanged(this, maskRect);
+    shapeableDelegate.onMaskChanged(this, getMaskRectF());
     if (onMaskChangedListener != null) {
-      onMaskChangedListener.onMaskChanged(maskRect);
+      onMaskChangedListener.onMaskChanged(getMaskRectF());
     }
   }
 
@@ -191,10 +211,10 @@ public void setForceCompatClipping(boolean forceCompatClipping) {
   @Override
   public boolean onTouchEvent(MotionEvent event) {
     // Only handle touch events that are within the masked bounds of this view.
-    if (!maskRect.isEmpty() && event.getAction() == MotionEvent.ACTION_DOWN) {
+    if (!getMaskRectF().isEmpty() && event.getAction() == MotionEvent.ACTION_DOWN) {
       float x = event.getX();
       float y = event.getY();
-      if (!maskRect.contains(x, y)) {
+      if (!getMaskRectF().contains(x, y)) {
         return false;
       }
     }

lib/javatests/com/google/android/material/carousel/CarouselLayoutManagerRtlTest.java

@@ -114,7 +114,7 @@ KeylineState onFirstChildMeasuredWithMargins(
   public void testSingleItem_shouldBeInFocalRange() throws Throwable {
     setAdapterItems(recyclerView, layoutManager, adapter, CarouselHelper.createDataSetWithSize(1));
 
-    assertThat(((Maskable) recyclerView.getChildAt(0)).getMaskXPercentage()).isEqualTo(0F);
+    assertThat(recyclerView.getChildAt(0).getWidth()).isEqualTo(DEFAULT_ITEM_WIDTH);
   }
 
   @Test

lib/javatests/com/google/android/material/carousel/CarouselLayoutManagerTest.java

@@ -255,7 +255,7 @@ public void testEmptyAdapter_shouldClearAllViewsFromRecyclerView() throws Throwa
   public void testSingleItem_shouldBeInFocalRange() throws Throwable {
     setAdapterItems(recyclerView, layoutManager, adapter, createDataSetWithSize(1));
 
-    assertThat(((Maskable) recyclerView.getChildAt(0)).getMaskXPercentage()).isEqualTo(0F);
+    assertThat(recyclerView.getChildAt(0).getWidth()).isEqualTo(DEFAULT_ITEM_WIDTH);
   }
 
   @Test

lib/javatests/com/google/android/material/carousel/MaskableFrameLayoutTest.java

@@ -131,6 +131,54 @@ public void testCutCornersApi33_usesViewOutlineProvider() {
     assertThat(maskableFrameLayout.getClipToOutline()).isTrue();
   }
 
+  @Test
+  public void testUseMaskRect_shouldIgnoreMaskXPercentage() {
+    MaskableFrameLayout maskableFrameLayout = createMaskableFrameLayoutWithSize(50, 50);
+    ShapeAppearanceModel model = new ShapeAppearanceModel.Builder().setAllCornerSizes(10F).build();
+    maskableFrameLayout.setShapeAppearanceModel(model);
+
+    maskableFrameLayout.setMaskXPercentage(.5F);
+    maskableFrameLayout.setMaskRectF(new RectF(0F, 0F, 50F, 50F));
+
+    assertThat(maskableFrameLayout.getMaskXPercentage()).isEqualTo(-1F);
+  }
+
+  @Test
+  public void testOnSizeChangedWithMaskXPercentageSet_shouldUpdateMaskRect() {
+    MaskableFrameLayout maskableFrameLayout = createMaskableFrameLayoutWithSize(50, 50);
+    ShapeAppearanceModel model = new ShapeAppearanceModel.Builder().setAllCornerSizes(10F).build();
+    maskableFrameLayout.setShapeAppearanceModel(model);
+    maskableFrameLayout.setMaskXPercentage(.5F);
+
+    maskableFrameLayout.setLayoutParams(new LayoutParams(100, 100));
+    maskableFrameLayout.measure(
+        MeasureSpec.makeMeasureSpec(100, MeasureSpec.EXACTLY),
+        MeasureSpec.makeMeasureSpec(100, MeasureSpec.EXACTLY));
+    maskableFrameLayout.layout(
+        0, 0, maskableFrameLayout.getMeasuredWidth(), maskableFrameLayout.getMeasuredHeight());
+
+    assertThat(maskableFrameLayout.getMaskRectF()).isEqualTo(new RectF(25F, 0F, 75F, 100F));
+  }
+
+  @Test
+  public void testOnSizeChangedWithMaskRect_shouldNotChangeMaskRect() {
+    MaskableFrameLayout maskableFrameLayout = createMaskableFrameLayoutWithSize(50, 50);
+    ShapeAppearanceModel model = new ShapeAppearanceModel.Builder().setAllCornerSizes(10F).build();
+    maskableFrameLayout.setShapeAppearanceModel(model);
+
+    RectF mask = new RectF(10F, 0F, 40F, 50F);
+    maskableFrameLayout.setMaskRectF(mask);
+
+    maskableFrameLayout.setLayoutParams(new LayoutParams(100, 100));
+    maskableFrameLayout.measure(
+        MeasureSpec.makeMeasureSpec(100, MeasureSpec.EXACTLY),
+        MeasureSpec.makeMeasureSpec(100, MeasureSpec.EXACTLY));
+    maskableFrameLayout.layout(
+        0, 0, maskableFrameLayout.getMeasuredWidth(), maskableFrameLayout.getMeasuredHeight());
+
+    assertThat(maskableFrameLayout.getMaskRectF()).isEqualTo(mask);
+  }
+
   private static MaskableFrameLayout createMaskableFrameLayoutWithSize(int width, int height) {
     MaskableFrameLayout maskableFrameLayout =
         new MaskableFrameLayout(ApplicationProvider.getApplicationContext());