| /* |
| * Copyright (C) 2018 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.icons.cache; |
| |
| import android.os.Handler; |
| |
| import java.util.concurrent.Executor; |
| import java.util.function.Consumer; |
| import java.util.function.Supplier; |
| |
| /** |
| * A runnable that can be posted to a {@link Handler} which can be canceled. |
| */ |
| public class HandlerRunnable<T> implements Runnable { |
| |
| private final Handler mWorkerHandler; |
| private final Supplier<T> mTask; |
| |
| private final Executor mCallbackExecutor; |
| private final Consumer<T> mCallback; |
| private final Runnable mEndRunnable; |
| |
| private boolean mEnded = false; |
| private boolean mCanceled = false; |
| |
| public HandlerRunnable(Handler workerHandler, Supplier<T> task, Executor callbackExecutor, |
| Consumer<T> callback) { |
| this(workerHandler, task, callbackExecutor, callback, () -> { }); |
| } |
| |
| public HandlerRunnable(Handler workerHandler, Supplier<T> task, Executor callbackExecutor, |
| Consumer<T> callback, Runnable endRunnable) { |
| mWorkerHandler = workerHandler; |
| mTask = task; |
| mCallbackExecutor = callbackExecutor; |
| mCallback = callback; |
| mEndRunnable = endRunnable; |
| } |
| |
| /** |
| * Cancels this runnable from being run, only if it has not already run. |
| */ |
| public void cancel() { |
| mWorkerHandler.removeCallbacks(this); |
| mCanceled = true; |
| mCallbackExecutor.execute(this::onEnd); |
| } |
| |
| @Override |
| public void run() { |
| T value = mTask.get(); |
| mCallbackExecutor.execute(() -> { |
| if (!mCanceled) { |
| mCallback.accept(value); |
| } |
| onEnd(); |
| }); |
| } |
| |
| private void onEnd() { |
| if (!mEnded) { |
| mEnded = true; |
| mEndRunnable.run(); |
| } |
| } |
| } |