1 /** 2 * Copyright (C) 2015 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.util; 18 19 import static com.android.launcher3.util.Executors.MODEL_EXECUTOR; 20 21 import android.os.Process; 22 import android.view.View; 23 import android.view.View.OnAttachStateChangeListener; 24 import android.view.ViewTreeObserver.OnDrawListener; 25 26 import androidx.annotation.VisibleForTesting; 27 28 import com.android.launcher3.Launcher; 29 30 import java.util.ArrayList; 31 import java.util.concurrent.Executor; 32 import java.util.function.Consumer; 33 34 /** 35 * An executor which runs all the tasks after the first onDraw is called on the target view. 36 */ 37 public class ViewOnDrawExecutor implements Executor, OnDrawListener, Runnable, 38 OnAttachStateChangeListener { 39 40 private final ArrayList<Runnable> mTasks = new ArrayList<>(); 41 42 private Consumer<ViewOnDrawExecutor> mOnClearCallback; 43 private View mAttachedView; 44 private boolean mCompleted; 45 46 private boolean mLoadAnimationCompleted; 47 private boolean mFirstDrawCompleted; 48 attachTo(Launcher launcher)49 public void attachTo(Launcher launcher) { 50 attachTo(launcher.getWorkspace(), true /* waitForLoadAnimation */, 51 launcher::clearPendingExecutor); 52 } 53 54 /** 55 * Attached the executor to the existence of the view 56 */ attachTo(View attachedView, boolean waitForLoadAnimation, Consumer<ViewOnDrawExecutor> onClearCallback)57 public void attachTo(View attachedView, boolean waitForLoadAnimation, 58 Consumer<ViewOnDrawExecutor> onClearCallback) { 59 mOnClearCallback = onClearCallback; 60 mAttachedView = attachedView; 61 mAttachedView.addOnAttachStateChangeListener(this); 62 if (!waitForLoadAnimation) { 63 mLoadAnimationCompleted = true; 64 } 65 66 if (mAttachedView.isAttachedToWindow()) { 67 attachObserver(); 68 } 69 } 70 attachObserver()71 private void attachObserver() { 72 if (!mCompleted) { 73 mAttachedView.getViewTreeObserver().addOnDrawListener(this); 74 } 75 } 76 77 @Override execute(Runnable command)78 public void execute(Runnable command) { 79 mTasks.add(command); 80 MODEL_EXECUTOR.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND); 81 } 82 83 @Override onViewAttachedToWindow(View v)84 public void onViewAttachedToWindow(View v) { 85 attachObserver(); 86 } 87 88 @Override onViewDetachedFromWindow(View v)89 public void onViewDetachedFromWindow(View v) {} 90 91 @Override onDraw()92 public void onDraw() { 93 mFirstDrawCompleted = true; 94 mAttachedView.post(this); 95 } 96 onLoadAnimationCompleted()97 public void onLoadAnimationCompleted() { 98 mLoadAnimationCompleted = true; 99 if (mAttachedView != null) { 100 mAttachedView.post(this); 101 } 102 } 103 104 @Override run()105 public void run() { 106 // Post the pending tasks after both onDraw and onLoadAnimationCompleted have been called. 107 if (mLoadAnimationCompleted && mFirstDrawCompleted && !mCompleted) { 108 runAllTasks(); 109 } 110 } 111 markCompleted()112 public void markCompleted() { 113 mTasks.clear(); 114 mCompleted = true; 115 if (mAttachedView != null) { 116 mAttachedView.getViewTreeObserver().removeOnDrawListener(this); 117 mAttachedView.removeOnAttachStateChangeListener(this); 118 } 119 if (mOnClearCallback != null) { 120 mOnClearCallback.accept(this); 121 } 122 MODEL_EXECUTOR.setThreadPriority(Process.THREAD_PRIORITY_DEFAULT); 123 } 124 isCompleted()125 protected boolean isCompleted() { 126 return mCompleted; 127 } 128 129 /** 130 * Executes all tasks immediately 131 */ 132 @VisibleForTesting runAllTasks()133 public void runAllTasks() { 134 for (final Runnable r : mTasks) { 135 r.run(); 136 } 137 markCompleted(); 138 } 139 } 140