/*
* Copyright (C) 2011 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.contacts.util;
import android.os.AsyncTask;
import java.util.concurrent.Executor;
/**
* Interface used to submit {@link AsyncTask} objects to run in the background.
* <p>
* This interface has a direct parallel with the {@link Executor} interface. It exists to decouple
* the mechanics of AsyncTask submission from the description of how that AsyncTask will execute.
* <p>
* One immediate benefit of this approach is that testing becomes much easier, since it is easy to
* introduce a mock or fake AsyncTaskExecutor in unit/integration tests, and thus inspect which
* tasks have been submitted and control their execution in an orderly manner.
* <p>
* Another benefit in due course will be the management of the submitted tasks. An extension to this
* interface is planned to allow Activities to easily cancel all the submitted tasks that are still
* pending in the onDestroy() method of the Activity.
*/
public interface AsyncTaskExecutor {
/**
* Executes the given AsyncTask with the default Executor.
* <p>
* This method <b>must only be called from the ui thread</b>.
* <p>
* The identifier supplied is any Object that can be used to identify the task later. Most
* commonly this will be an enum which the tests can also refer to. {@code null} is also
* accepted, though of course this won't help in identifying the task later.
*/
<T> AsyncTask<T, ?, ?> submit(Object identifier, AsyncTask<T, ?, ?> task, T... params);
}