1 /* 2 * Copyright (C) 2017 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 android.os.Looper; 20 import android.os.MessageQueue; 21 22 /** 23 * Utility class to block execution until the UI looper is idle. 24 */ 25 public class LooperIdleLock implements MessageQueue.IdleHandler, Runnable { 26 27 private final Object mLock; 28 29 private boolean mIsLocked; 30 LooperIdleLock(Object lock, Looper looper)31 public LooperIdleLock(Object lock, Looper looper) { 32 mLock = lock; 33 mIsLocked = true; 34 looper.getQueue().addIdleHandler(this); 35 } 36 37 @Override run()38 public void run() { 39 Looper.myQueue().addIdleHandler(this); 40 } 41 42 @Override queueIdle()43 public boolean queueIdle() { 44 synchronized (mLock) { 45 mIsLocked = false; 46 mLock.notify(); 47 } 48 return false; 49 } 50 awaitLocked(long ms)51 public boolean awaitLocked(long ms) { 52 if (mIsLocked) { 53 try { 54 // Just in case mFlushingWorkerThread changes but we aren't woken up, 55 // wait no longer than 1sec at a time 56 mLock.wait(ms); 57 } catch (InterruptedException ex) { 58 // Ignore 59 } 60 } 61 return mIsLocked; 62 } 63 } 64