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/*
* Copyright (C) 2017 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.launcher3.util;
import android.os.Looper;
import android.os.MessageQueue;
import com.android.launcher3.Utilities;
/**
* Utility class to block execution until the UI looper is idle.
*/
public class LooperIdleLock implements MessageQueue.IdleHandler, Runnable {
private final Object mLock;
private boolean mIsLocked;
public LooperIdleLock(Object lock, Looper looper) {
mLock = lock;
mIsLocked = true;
if (Utilities.ATLEAST_MARSHMALLOW) {
looper.getQueue().addIdleHandler(this);
} else {
// Looper.myQueue() only gives the current queue. Move the execution to the UI thread
// so that the IdleHandler is attached to the correct message queue.
new LooperExecutor(looper).execute(this);
}
}
@Override
public void run() {
Looper.myQueue().addIdleHandler(this);
}
@Override
public boolean queueIdle() {
synchronized (mLock) {
mIsLocked = false;
mLock.notify();
}
return false;
}
public boolean awaitLocked(long ms) {
if (mIsLocked) {
try {
// Just in case mFlushingWorkerThread changes but we aren't woken up,
// wait no longer than 1sec at a time
mLock.wait(ms);
} catch (InterruptedException ex) {
// Ignore
}
}
return mIsLocked;
}
}