| /* |
| * 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.intentresolver; |
| |
| import android.annotation.NonNull; |
| import android.graphics.Rect; |
| import android.view.View; |
| import android.view.ViewGroup; |
| import android.view.accessibility.AccessibilityEvent; |
| |
| import androidx.recyclerview.widget.RecyclerView; |
| import androidx.recyclerview.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(); |
| } |
| } |