| /* |
| * Copyright (C) 2008 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; |
| |
| import android.os.Handler; |
| import android.os.Looper; |
| import android.os.Message; |
| import android.os.MessageQueue; |
| |
| import com.android.launcher3.util.Thunk; |
| |
| import java.util.LinkedList; |
| |
| /** |
| * Queue of things to run on a looper thread. Items posted with {@link #post} will not |
| * be actually enqued on the handler until after the last one has run, to keep from |
| * starving the thread. |
| * |
| * This class is fifo. |
| */ |
| public class DeferredHandler { |
| @Thunk LinkedList<Runnable> mQueue = new LinkedList<>(); |
| private MessageQueue mMessageQueue = Looper.myQueue(); |
| private Impl mHandler = new Impl(); |
| |
| @Thunk class Impl extends Handler implements MessageQueue.IdleHandler { |
| public void handleMessage(Message msg) { |
| Runnable r; |
| synchronized (mQueue) { |
| if (mQueue.size() == 0) { |
| return; |
| } |
| r = mQueue.removeFirst(); |
| } |
| r.run(); |
| synchronized (mQueue) { |
| scheduleNextLocked(); |
| } |
| } |
| |
| public boolean queueIdle() { |
| handleMessage(null); |
| return false; |
| } |
| } |
| |
| private class IdleRunnable implements Runnable { |
| Runnable mRunnable; |
| |
| IdleRunnable(Runnable r) { |
| mRunnable = r; |
| } |
| |
| public void run() { |
| mRunnable.run(); |
| } |
| } |
| |
| public DeferredHandler() { |
| } |
| |
| /** Schedule runnable to run after everything that's on the queue right now. */ |
| public void post(Runnable runnable) { |
| synchronized (mQueue) { |
| mQueue.add(runnable); |
| if (mQueue.size() == 1) { |
| scheduleNextLocked(); |
| } |
| } |
| } |
| |
| /** Schedule runnable to run when the queue goes idle. */ |
| public void postIdle(final Runnable runnable) { |
| post(new IdleRunnable(runnable)); |
| } |
| |
| public void cancelAll() { |
| synchronized (mQueue) { |
| mQueue.clear(); |
| } |
| } |
| |
| /** Runs all queued Runnables from the calling thread. */ |
| public void flush() { |
| LinkedList<Runnable> queue = new LinkedList<>(); |
| synchronized (mQueue) { |
| queue.addAll(mQueue); |
| mQueue.clear(); |
| } |
| for (Runnable r : queue) { |
| r.run(); |
| } |
| } |
| |
| void scheduleNextLocked() { |
| if (mQueue.size() > 0) { |
| Runnable peek = mQueue.getFirst(); |
| if (peek instanceof IdleRunnable) { |
| mMessageQueue.addIdleHandler(mHandler); |
| } else { |
| mHandler.sendEmptyMessage(1); |
| } |
| } |
| } |
| } |
| |