[Carousel] Update mask size on size change if mask x percentage has been set

Resolves #3450

GIT_ORIGIN_REV_ID=df8a325da6e4a796ab33d93e2ba165e40da8733e
Co-authored-by: imhappi
PiperOrigin-RevId: 558207460

Author: pubiqq

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

@@ -40,7 +40,9 @@
 /** 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 static final int NOT_SET = -1;
+
+  private float maskXPercentage = NOT_SET;
   private final RectF maskRect = new RectF();
   @Nullable private OnMaskChangedListener onMaskChangedListener;
   @NonNull private ShapeAppearanceModel shapeAppearanceModel;
@@ -65,7 +67,9 @@ public MaskableFrameLayout(
   @Override
   protected void onSizeChanged(int w, int h, int oldw, int oldh) {
     super.onSizeChanged(w, h, oldw, oldh);
-    onMaskChanged();
+    if (maskXPercentage != NOT_SET) {
+      updateMaskRectForMaskXPercentage();
+    }
   }
 
   @Override
@@ -123,10 +127,16 @@ 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()));
+      updateMaskRectForMaskXPercentage();
+    }
+  }
+
+  private void updateMaskRectForMaskXPercentage() {
+    if (maskXPercentage != NOT_SET) {
+    // 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()));
     }
   }
 

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

@@ -28,6 +28,7 @@
 import static com.google.common.truth.Truth.assertThat;
 
 import android.content.Context;
+import android.graphics.RectF;
 import android.os.Build.VERSION_CODES;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.recyclerview.widget.RecyclerView;
@@ -107,8 +108,9 @@ public void testScrollBeyondMaxHorizontalScroll_shouldLimitToMaxScrollOffset() t
   @Test
   public void testSingleItem_shouldBeInFocalRange() throws Throwable {
     setAdapterItems(recyclerView, layoutManager, adapter, CarouselHelper.createDataSetWithSize(1));
+    RectF maskRect = ((Maskable) recyclerView.getChildAt(0)).getMaskRectF();
 
-    assertThat(((Maskable) recyclerView.getChildAt(0)).getMaskXPercentage()).isEqualTo(0F);
+    assertThat((int) (maskRect.right - maskRect.left)).isEqualTo(DEFAULT_ITEM_WIDTH);
   }
 
   @Test

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

@@ -254,8 +254,9 @@ public void testEmptyAdapter_shouldClearAllViewsFromRecyclerView() throws Throwa
   @Test
   public void testSingleItem_shouldBeInFocalRange() throws Throwable {
     setAdapterItems(recyclerView, layoutManager, adapter, createDataSetWithSize(1));
+    RectF maskRect = ((Maskable) recyclerView.getChildAt(0)).getMaskRectF();
 
-    assertThat(((Maskable) recyclerView.getChildAt(0)).getMaskXPercentage()).isEqualTo(0F);
+    assertThat((int) (maskRect.right - maskRect.left)).isEqualTo(DEFAULT_ITEM_WIDTH);
   }
 
   @Test