1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.launcher3.accessibility; 18 19 import android.view.View; 20 import android.view.ViewGroup; 21 import android.view.ViewGroup.OnHierarchyChangeListener; 22 23 import com.android.launcher3.CellLayout; 24 import com.android.launcher3.DropTarget.DragObject; 25 import com.android.launcher3.Launcher; 26 import com.android.launcher3.dragndrop.DragController.DragListener; 27 import com.android.launcher3.dragndrop.DragOptions; 28 29 import java.util.function.Function; 30 31 /** 32 * Utility listener to enable/disable accessibility drag flags for a ViewGroup 33 * containing CellLayouts 34 */ 35 public class AccessibleDragListenerAdapter implements DragListener, OnHierarchyChangeListener { 36 37 private final ViewGroup mViewGroup; 38 private final Function<CellLayout, DragAndDropAccessibilityDelegate> mDelegateFactory; 39 40 /** 41 * @param parent the viewgroup containing all the children 42 * @param delegateFactory function to create no delegates 43 */ AccessibleDragListenerAdapter(ViewGroup parent, Function<CellLayout, DragAndDropAccessibilityDelegate> delegateFactory)44 public AccessibleDragListenerAdapter(ViewGroup parent, 45 Function<CellLayout, DragAndDropAccessibilityDelegate> delegateFactory) { 46 mViewGroup = parent; 47 mDelegateFactory = delegateFactory; 48 } 49 50 @Override onDragStart(DragObject dragObject, DragOptions options)51 public void onDragStart(DragObject dragObject, DragOptions options) { 52 mViewGroup.setOnHierarchyChangeListener(this); 53 enableAccessibleDrag(true); 54 } 55 56 @Override onDragEnd()57 public void onDragEnd() { 58 mViewGroup.setOnHierarchyChangeListener(null); 59 enableAccessibleDrag(false); 60 Launcher.getLauncher(mViewGroup.getContext()).getDragController().removeDragListener(this); 61 } 62 63 64 @Override onChildViewAdded(View parent, View child)65 public void onChildViewAdded(View parent, View child) { 66 if (parent == mViewGroup) { 67 setEnableForLayout((CellLayout) child, true); 68 } 69 } 70 71 @Override onChildViewRemoved(View parent, View child)72 public void onChildViewRemoved(View parent, View child) { 73 if (parent == mViewGroup) { 74 setEnableForLayout((CellLayout) child, false); 75 } 76 } 77 enableAccessibleDrag(boolean enable)78 protected void enableAccessibleDrag(boolean enable) { 79 for (int i = 0; i < mViewGroup.getChildCount(); i++) { 80 setEnableForLayout((CellLayout) mViewGroup.getChildAt(i), enable); 81 } 82 } 83 setEnableForLayout(CellLayout layout, boolean enable)84 protected final void setEnableForLayout(CellLayout layout, boolean enable) { 85 layout.setDragAndDropAccessibilityDelegate(enable ? mDelegateFactory.apply(layout) : null); 86 } 87 } 88