[Carousel][A11y] Fix some a11y bugs in Carousel

PiperOrigin-RevId: 559881261
material-components · Aug 25, 2023 · 3d84841 · 3d84841
1 parent 5f1cab6
commit 3d84841
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Showing 2 changed files with 25 additions and 6 deletions.
diff --git a/catalog/java/io/material/catalog/carousel/FullScreenStrategyDemoFragment.java b/catalog/java/io/material/catalog/carousel/FullScreenStrategyDemoFragment.java
@@ -18,6 +18,8 @@
 
 import io.material.catalog.R;
 
+import android.annotation.SuppressLint;
+import android.content.pm.ActivityInfo;
 import android.os.Bundle;
 import androidx.recyclerview.widget.RecyclerView;
 import androidx.recyclerview.widget.SnapHelper;
@@ -48,10 +50,14 @@ public class FullScreenStrategyDemoFragment extends DemoFragment {
 
   @NonNull
   @Override
+  @SuppressLint("SourceLockedOrientationActivity")
   public View onCreateDemoView(
       @NonNull LayoutInflater layoutInflater,
       @Nullable ViewGroup viewGroup,
       @Nullable Bundle bundle) {
+    // We want to force portrait mode for the fullscreen vertical carousel
+    getActivity().setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
+
     return layoutInflater.inflate(
         R.layout.cat_carousel_full_screen_fragment, viewGroup, false /* attachToRoot */);
   }
@@ -90,8 +96,7 @@ public void onClick(View v) {
     RecyclerView fullscreenRecyclerView =
         view.findViewById(R.id.fullscreen_carousel_recycler_view);
     CarouselLayoutManager carouselLayoutManager =
-        new CarouselLayoutManager(new FullScreenCarouselStrategy(),
-            RecyclerView.VERTICAL);
+        new CarouselLayoutManager(new FullScreenCarouselStrategy(), RecyclerView.VERTICAL);
     carouselLayoutManager.setDebuggingEnabled(
         fullscreenRecyclerView, debugSwitch.isChecked());
     fullscreenRecyclerView.setLayoutManager(carouselLayoutManager);

diff --git a/lib/java/com/google/android/material/carousel/CarouselLayoutManager.java b/lib/java/com/google/android/material/carousel/CarouselLayoutManager.java
@@ -1211,9 +1211,13 @@ public boolean requestChildRectangleOnScreen(
         getOffsetToScrollToPosition(
             getPosition(child), getKeylineStateForPosition(getPosition(child)));
     if (!focusedChildVisible) {
+      // TODO(b/266816148): Implement smoothScrollBy when immediate is false.
       if (delta != 0) {
-        // TODO(b/266816148): Implement smoothScrollBy when immediate is false.
-        parent.scrollBy(delta, 0);
+        if (isHorizontal()) {
+          parent.scrollBy(delta, 0);
+        } else {
+          parent.scrollBy(0, delta);
+        }
         return true;
       }
     }
@@ -1307,7 +1311,12 @@ public int computeHorizontalScrollOffset(@NonNull State state) {
    */
   @Override
   public int computeHorizontalScrollExtent(@NonNull State state) {
-    return keylineStateList == null ? 0 : (int) keylineStateList.getDefaultState().getItemSize();
+    if (getChildCount() == 0 || keylineStateList == null || getItemCount() <= 1) {
+      return 0;
+    }
+    float itemRatio =
+        (keylineStateList.getDefaultState().getItemSize() / computeHorizontalScrollRange(state));
+    return (int) (getWidth() * itemRatio);
   }
 
   /**
@@ -1329,7 +1338,12 @@ public int computeVerticalScrollOffset(@NonNull State state) {
 
   @Override
   public int computeVerticalScrollExtent(@NonNull State state) {
-    return keylineStateList == null ? 0 : (int) keylineStateList.getDefaultState().getItemSize();
+    if (getChildCount() == 0 || keylineStateList == null || getItemCount() <= 1) {
+      return 0;
+    }
+    float itemRatio =
+        (keylineStateList.getDefaultState().getItemSize() / computeVerticalScrollRange(state));
+    return (int) (getHeight() * itemRatio);
   }
 
   @Override