Fix a11y navigation in Chooser

With the `ResolverDrawerLayout`-`RecylerView` combination it was
possibel for accessibility navigation to get off-screen.
The issue is addressed by adding a custom accessibility delegate to the
recycler view which makes sure that an item receving accessibility focus
becomes visible.

Bug: 230132993

Test: Manueal - user accessibility navigation on the Chooser with a long list of
apps; make sure that items that receive a11y focus become visible when
scrollng in both directions.

Change-Id: I448d88660f701ca3c5ea0c92416595c9389af521

core/java/com/android/internal/app/ChooserMultiProfilePagerAdapter.java

@@ -86,7 +86,11 @@ public class ChooserMultiProfilePagerAdapter extends AbstractMultiProfilePagerAd
         final LayoutInflater inflater = LayoutInflater.from(getContext());
         final ViewGroup rootView =
                 (ViewGroup) inflater.inflate(R.layout.chooser_list_per_profile, null, false);
-        return new ChooserProfileDescriptor(rootView, adapter);
+        ChooserProfileDescriptor profileDescriptor =
+                new ChooserProfileDescriptor(rootView, adapter);
+        profileDescriptor.recyclerView.setAccessibilityDelegateCompat(
+                new ChooserRecyclerViewAccessibilityDelegate(profileDescriptor.recyclerView));
+        return profileDescriptor;
     }
 
     RecyclerView getListViewForIndex(int index) {

core/java/com/android/internal/app/ChooserRecyclerViewAccessibilityDelegate.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.app;
+
+import android.annotation.NonNull;
+import android.graphics.Rect;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.accessibility.AccessibilityEvent;
+
+import com.android.internal.widget.RecyclerView;
+import com.android.internal.widget.RecyclerViewAccessibilityDelegate;
+
+class ChooserRecyclerViewAccessibilityDelegate extends RecyclerViewAccessibilityDelegate {
+    private final Rect mTempRect = new Rect();
+    private final int[] mConsumed = new int[2];
+
+    ChooserRecyclerViewAccessibilityDelegate(RecyclerView recyclerView) {
+        super(recyclerView);
+    }
+
+    @Override
+    public boolean onRequestSendAccessibilityEvent(
+            @NonNull ViewGroup host,
+            @NonNull View view,
+            @NonNull AccessibilityEvent event) {
+        boolean result = super.onRequestSendAccessibilityEvent(host, view, event);
+        if (result && event.getEventType() == AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED) {
+            ensureViewOnScreenVisibility((RecyclerView) host, view);
+        }
+        return result;
+    }
+
+    /**
+     * Bring the view that received accessibility focus on the screen.
+     * The method's logic is based on a model where RecyclerView is a child of another scrollable
+     * component (ResolverDrawerLayout) and can be partially scrolled off the screen. In that case,
+     * RecyclerView's children that are positioned fully within RecyclerView bounds but scrolled
+     * out of the screen by the outer component, when selected by the accessibility navigation will
+     * remain off the screen (as neither components detect such specific case).
+     * If the view that receiving accessibility focus is scrolled of the screen, perform the nested
+     * scrolling to make in visible.
+     */
+    private void ensureViewOnScreenVisibility(RecyclerView recyclerView, View view) {
+        View child = recyclerView.findContainingItemView(view);
+        if (child == null) {
+            return;
+        }
+        recyclerView.getBoundsOnScreen(mTempRect, true);
+        int recyclerOnScreenTop = mTempRect.top;
+        int recyclerOnScreenBottom = mTempRect.bottom;
+        child.getBoundsOnScreen(mTempRect);
+        int dy = 0;
+        // if needed, do the page-length scroll instead of just a row-length scroll as
+        // ResolverDrawerLayout snaps to the compact view and the row-length scroll can be snapped
+        // back right away.
+        if (mTempRect.top < recyclerOnScreenTop) {
+            // snap to the bottom
+            dy = mTempRect.bottom - recyclerOnScreenBottom;
+        } else if (mTempRect.bottom > recyclerOnScreenBottom) {
+            // snap to the top
+            dy = mTempRect.top - recyclerOnScreenTop;
+        }
+        nestedVerticalScrollBy(recyclerView, dy);
+    }
+
+    private void nestedVerticalScrollBy(RecyclerView recyclerView, int dy) {
+        if (dy == 0) {
+            return;
+        }
+        recyclerView.startNestedScroll(View.SCROLL_AXIS_VERTICAL);
+        if (recyclerView.dispatchNestedPreScroll(0, dy, mConsumed, null)) {
+            dy -= mConsumed[1];
+        }
+        recyclerView.scrollBy(0, dy);
+        recyclerView.stopNestedScroll();
+    }
+}