/*
/*
* 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.emailcommon.service;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Debug;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;
/**
* The EmailServiceProxy class provides a simple interface for the UI to call into the various
* EmailService classes (e.g. ExchangeService for EAS). It wraps the service connect/disconnect
* process so that the caller need not be concerned with it.
*
* Use the class like this:
* new EmailServiceClass(context, class).loadAttachment(attachmentId, callback)
*
* Methods without a return value return immediately (i.e. are asynchronous); methods with a
* return value wait for a result from the Service (i.e. they should not be called from the UI
* thread) with a default timeout of 30 seconds (settable)
*
* An EmailServiceProxy object cannot be reused (trying to do so generates a RemoteException)
*/
public abstract class ServiceProxy {
private static final boolean DEBUG_PROXY = false; // DO NOT CHECK THIS IN SET TO TRUE
private final String mTag;
private final Context mContext;
protected final Intent mIntent;
private Runnable mRunnable = new ProxyRunnable();
private ProxyTask mTask;
private String mName = " unnamed";
private final ServiceConnection mConnection = new ProxyConnection();
// Service call timeout (in seconds)
private int mTimeout = 45;
private long mStartTime;
private boolean mDead = false;
public abstract void onConnected(IBinder binder);
public ServiceProxy(Context _context, Intent _intent) {
mContext = _context;
mIntent = _intent;
mTag = getClass().getSimpleName();
if (Debug.isDebuggerConnected()) {
mTimeout <<= 2;
}
}
private class ProxyConnection implements ServiceConnection {
public void onServiceConnected(ComponentName name, IBinder binder) {
onConnected(binder);
if (DEBUG_PROXY) {
Log.v(mTag, "Connected: " + name.getShortClassName());
}
// Run our task on a new thread
new Thread(new Runnable() {
public void run() {
try {
runTask();
} finally {
endTask();
}
}}).start();
}
public void onServiceDisconnected(ComponentName name) {
if (DEBUG_PROXY) {
Log.v(mTag, "Disconnected: " + name.getShortClassName());
}
}
}
public interface ProxyTask {
public void run() throws RemoteException;
}
private class ProxyRunnable implements Runnable {
@Override
public void run() {
try {
mTask.run();
} catch (RemoteException e) {
}
}
}
public ServiceProxy setTimeout(int secs) {
mTimeout = secs;
return this;
}
public int getTimeout() {
return mTimeout;
}
public void endTask() {
try {
mContext.unbindService(mConnection);
} catch (IllegalArgumentException e) {
// This can happen if the user ended the activity that was using the service
// This is harmless, but we've got to catch it
}
mDead = true;
synchronized(mConnection) {
if (DEBUG_PROXY) {
Log.v(mTag, "Task " + mName + " completed; disconnecting");
}
mConnection.notify();
}
}
private void runTask() {
Thread thread = new Thread(mRunnable);
thread.start();
try {
thread.join();
} catch (InterruptedException e) {
}
}
public boolean setTask(ProxyTask task, String name) {
mName = name;
return setTask(task);
}
public boolean setTask(ProxyTask task) throws IllegalStateException {
if (mDead) {
throw new IllegalStateException();
}
mTask = task;
mStartTime = System.currentTimeMillis();
if (DEBUG_PROXY) {
Log.v(mTag, "Bind requested for task " + mName);
}
return mContext.bindService(mIntent, mConnection, Context.BIND_AUTO_CREATE);
}
public void waitForCompletion() {
synchronized (mConnection) {
long time = System.currentTimeMillis();
try {
if (DEBUG_PROXY) {
Log.v(mTag, "Waiting for task " + mName + " to complete...");
}
mConnection.wait(mTimeout * 1000L);
} catch (InterruptedException e) {
// Can be ignored safely
}
if (DEBUG_PROXY) {
Log.v(mTag, "Wait for " + mName + " finished in " +
(System.currentTimeMillis() - time) + "ms");
}
}
}
public void close() throws RemoteException {
if (mDead) {
throw new RemoteException();
}
endTask();
}
/**
* Connection test; return indicates whether the remote service can be connected to
* @return the result of trying to connect to the remote service
*/
public boolean test() {
try {
return setTask(new ProxyTask() {
public void run() throws RemoteException {
if (DEBUG_PROXY) {
Log.v(mTag, "Connection test succeeded in " +
(System.currentTimeMillis() - mStartTime) + "ms");
}
}
}, "test");
} catch (Exception e) {
// For any failure, return false.
return false;
}
}
}