[Carousel] Fix issue with next carousel item not being masked properly

PiperOrigin-RevId: 551644125
material-components · Jul 28, 2023 · a16f180 · a16f180
1 parent 4e5166f
commit a16f180
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Showing 3 changed files with 18 additions and 4 deletions.
diff --git a/lib/java/com/google/android/material/carousel/CarouselOrientationHelper.java b/lib/java/com/google/android/material/carousel/CarouselOrientationHelper.java
@@ -18,6 +18,7 @@
 import static com.google.android.material.carousel.CarouselLayoutManager.HORIZONTAL;
 import static com.google.android.material.carousel.CarouselLayoutManager.VERTICAL;
 import static java.lang.Math.max;
+import static java.lang.Math.min;
 
 import android.graphics.Rect;
 import android.graphics.RectF;
@@ -222,9 +223,15 @@ public void moveMaskOnEdgeOutsideBounds(
           RectF maskRect, RectF offsetMaskRect, RectF parentBoundsRect) {
         if (offsetMaskRect.bottom <= parentBoundsRect.top) {
           maskRect.bottom = (float) Math.floor(maskRect.bottom) - 1;
+          // Make sure that maskRect.top is equal to or smaller than maskRect.bottom.
+          // Otherwise the mask may not be re-drawn as the mask is invalid.
+          maskRect.top = min(maskRect.top, maskRect.bottom);
         }
         if (offsetMaskRect.top >= parentBoundsRect.bottom) {
           maskRect.top = (float) Math.ceil(maskRect.top) + 1;
+          // Make sure that maskRect.bottom is equal to or bigger than maskRect.top.
+          // Otherwise the mask may not be re-drawn as the mask is invalid.
+          maskRect.bottom = max(maskRect.top, maskRect.bottom);
         }
       }
 
@@ -310,9 +317,15 @@ public void moveMaskOnEdgeOutsideBounds(
           RectF maskRect, RectF offsetMaskRect, RectF parentBoundsRect) {
         if (offsetMaskRect.right <= parentBoundsRect.left) {
           maskRect.right = (float) Math.floor(maskRect.right) - 1;
+          // Make sure that maskRect.left is equal to or smaller than maskRect.right.
+          // Otherwise the mask may not be re-drawn as the mask is invalid.
+          maskRect.left = min(maskRect.left, maskRect.right);
         }
         if (offsetMaskRect.left >= parentBoundsRect.right) {
           maskRect.left = (float) Math.ceil(maskRect.left) + 1;
+          // Make sure that maskRect.right is equal to or bigger than maskRect.left.
+          // Otherwise the mask may not be re-drawn as the mask is invalid.
+          maskRect.right = max(maskRect.left, maskRect.right);
         }
       }
 

diff --git a/lib/java/com/google/android/material/carousel/MaskableFrameLayout.java b/lib/java/com/google/android/material/carousel/MaskableFrameLayout.java
@@ -167,9 +167,6 @@ public void setOnMaskChangedListener(@Nullable OnMaskChangedListener onMaskChang
   }
 
   private void onMaskChanged() {
-    if (getWidth() == 0) {
-      return;
-    }
     shapeableDelegate.onMaskChanged(this, maskRect);
     if (onMaskChangedListener != null) {
       onMaskChangedListener.onMaskChanged(maskRect);

diff --git a/lib/java/com/google/android/material/shape/ShapeableDelegate.java b/lib/java/com/google/android/material/shape/ShapeableDelegate.java
@@ -140,12 +140,16 @@ public void onMaskChanged(@NonNull View view, @NonNull RectF maskBounds) {
   }
 
   private void updateShapePath() {
-    if (!maskBounds.isEmpty() && shapeAppearanceModel != null) {
+    if (isMaskBoundsValid() && shapeAppearanceModel != null) {
       ShapeAppearancePathProvider.getInstance()
           .calculatePath(shapeAppearanceModel, 1F, maskBounds, shapePath);
     }
   }
 
+  private boolean isMaskBoundsValid() {
+    return maskBounds.left <= maskBounds.right && maskBounds.top <= maskBounds.bottom;
+  }
+
   public void maybeClip(@NonNull Canvas canvas, @NonNull CanvasOperation op) {
     if (shouldUseCompatClipping() && !shapePath.isEmpty()) {
       canvas.save();