package kc.spark.pixels.android.cloud.requestservice;
/*
* 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.
*/
import android.app.Service;
import android.content.Intent;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.IBinder;
import android.os.Looper;
import android.os.Message;
/**
* This is just a subclass of IntentService which can have its queue cleared
* when by sending "ACTION_CLEAR_INTENT_QUEUE"
*
*
* IntentService is a base class for {@link Service}s that handle asynchronous
* requests (expressed as {@link Intent}s) on demand. Clients send requests
* through {@link android.content.Context#startService(Intent)} calls; the
* service is started as needed, handles each Intent in turn using a worker
* thread, and stops itself when it runs out of work.
*
* <p>
* This "work queue processor" pattern is commonly used to offload tasks from an
* application's main thread. The IntentService class exists to simplify this
* pattern and take care of the mechanics. To use it, extend IntentService and
* implement {@link #onHandleIntent(Intent)}. IntentService will receive the
* Intents, launch a worker thread, and stop the service as appropriate.
*
* <p>
* All requests are handled on a single worker thread -- they may take as long
* as necessary (and will not block the application's main loop), but only one
* request will be processed at a time.
*
* <div class="special reference">
* <h3>Developer Guides</h3>
* <p>
* For a detailed discussion about how to create services, read the <a
* href="{@docRoot}guide/topics/fundamentals/services.html">Services</a>
* developer guide.
* </p>
* </div>
*
* @see android.os.AsyncTask
*/
public abstract class ClearableIntentService extends Service {
public static final String ACTION_CLEAR_INTENT_QUEUE = "ACTION_CLEAR_INTENT_QUEUE";
private volatile Looper mServiceLooper;
private volatile ServiceHandler mServiceHandler;
private String mName;
private boolean mRedelivery;
private final class ServiceHandler extends Handler {
public ServiceHandler(Looper looper) {
super(looper);
}
@Override
public void handleMessage(Message msg) {
onHandleIntent((Intent) msg.obj);
stopSelf(msg.arg1);
}
}
/**
* Creates an IntentService. Invoked by your subclass's constructor.
*
* @param name
* Used to name the worker thread, important only for debugging.
*/
public ClearableIntentService(String name) {
super();
mName = name;
}
/**
* Sets intent redelivery preferences. Usually called from the constructor
* with your preferred semantics.
*
* <p>
* If enabled is true, {@link #onStartCommand(Intent, int, int)} will return
* {@link Service#START_REDELIVER_INTENT}, so if this process dies before
* {@link #onHandleIntent(Intent)} returns, the process will be restarted
* and the intent redelivered. If multiple Intents have been sent, only the
* most recent one is guaranteed to be redelivered.
*
* <p>
* If enabled is false (the default),
* {@link #onStartCommand(Intent, int, int)} will return
* {@link Service#START_NOT_STICKY}, and if the process dies, the Intent
* dies along with it.
*/
public void setIntentRedelivery(boolean enabled) {
mRedelivery = enabled;
}
@Override
public void onCreate() {
super.onCreate();
HandlerThread thread = new HandlerThread("IntentService[" + mName + "]");
thread.start();
mServiceLooper = thread.getLooper();
mServiceHandler = new ServiceHandler(mServiceLooper);
}
@Override
public void onStart(Intent intent, int startId) {
if (intent.getAction().equals(ACTION_CLEAR_INTENT_QUEUE)) {
mServiceHandler.removeMessages(0);
stopSelf(startId);
} else {
Message msg = mServiceHandler.obtainMessage();
msg.arg1 = startId;
msg.obj = intent;
mServiceHandler.sendMessage(msg);
}
}
/**
* You should not override this method for your IntentService. Instead,
* override {@link #onHandleIntent}, which the system calls when the
* IntentService receives a start request.
*
* @see android.app.Service#onStartCommand
*/
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
onStart(intent, startId);
return mRedelivery ? START_REDELIVER_INTENT : START_NOT_STICKY;
}
@Override
public void onDestroy() {
mServiceLooper.quit();
}
/**
* Unless you provide binding for your service, you don't need to implement
* this method, because the default implementation returns null.
*
* @see android.app.Service#onBind
*/
@Override
public IBinder onBind(Intent intent) {
return null;
}
/**
* This method is invoked on the worker thread with a request to process.
* Only one Intent is processed at a time, but the processing happens on a
* worker thread that runs independently from other application logic. So,
* if this code takes a long time, it will hold up other requests to the
* same IntentService, but it will not hold up anything else. When all
* requests have been handled, the IntentService stops itself, so you should
* not call {@link #stopSelf}.
*
* @param intent
* The value passed to
* {@link android.content.Context#startService(Intent)}.
*/
protected abstract void onHandleIntent(Intent intent);
}