from Service, call Activity method (if it's in the foreground) - android

From an Android Service, I would like to call an Activity method, but only if the Activity is in the foreground.
I would like nothing to happen in case the Activity is not in the foreground.
Which is the simplest way to achieve that?

From a Service always better to broadcast events if the activity is listening to that broadcast will respond. If the activity is not listening then nothing will happen it will ignore.
This is the better solution than the one which you have asked.

I found a very simple solution, adapted from this previous answer:
On the Service:
Intent intent = new Intent(MainActivity.RECEIVER_INTENT);
intent.putExtra(MainActivity.RECEIVER_MESSAGE, myMessage);
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
On the Activity:
public static final String RECEIVER_INTENT = "RECEIVER_INTENT";
public static final String RECEIVER_MESSAGE = "RECEIVER_MESSAGE";
Create a listener on onCreate():
public void onCreate(Bundle savedInstanceState) {
...
mBroadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String message = intent.getStringExtra(RECEIVER_MESSAGE);
// call any method you want here
}
};
}
register it in onStart():
#Override
protected void onStart() {
super.onStart();
LocalBroadcastManager.getInstance(this).registerReceiver((mBroadcastReceiver),
new IntentFilter(RECEIVER_INTENT)
);
}
unregister it in onStop():
#Override
protected void onStop() {
LocalBroadcastManager.getInstance(this).unregisterReceiver(mBroadcastReceiver);
super.onStop();
}

You can do this using a Interface just to check if the activity is in background or in foreground.
I am sharing some code to have some idea.
public interface CheckAppInForeground {
boolean isAppInForGround();
}
In your Activity
public class MainActivity extends AppCompatActivity implements CheckAppInForeground {
Boolean isAppInForeGround;
#Override
protected void onResume() {
super.onResume();
isAppInForeGround = true;
}
#Override
protected void onStop() {
super.onStop();
isAppInForeGround = false;
}
#Override
public boolean isAppInForGround() {
return isAppInForeGround;
}
}
And your service class
public class MyService extends Service {
Activity activity;
public MyService(Activity activity) {
this.activity = activity;
}
#Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
throw new UnsupportedOperationException("Not yet implemented");
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
MainActivity mainActivity = (MainActivity) activity;
if (activity != null) {
boolean isActivityInForGround = mainActivity.isAppInForGround();
if (isActivityInForGround) {
// Do what you want to do when activity is in foreground
} else {
// Activity is in background
}
} else {
// Activity is destroyed
}
return super.onStartCommand(intent, flags, startId);
}
}
I think i am clear with the code. If you find something missing or unclear please let me know

Related

Wrong when register two receiver in an activity Android

I have an activity. It will be receive two variable from an service. In the service, I will send two variable to the activity by
// Send first variable
sendBroadcast(new Intent("first_one"));
// Send second variable
sendBroadcast(new Intent("second_one"));
Now, In the activity, I used bellow code to receive the data. There are
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
registerReceiver(firstRec, new IntentFilter("first_one"));
registerReceiver(secondRec, new IntentFilter("second_one"));
}
#Override
protected void onPause() {
super.onPause();
if (firstRec != null) {
unregisterReceiver(firstRec);
firstRec = null;
}
if (secondRec != null) {
unregisterReceiver(secondRec);
secondRec = null;
}
}
private BroadcastReceiver firstRec = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
Log.d("TAG","OK first");
}
};
private BroadcastReceiver secondRec = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
Log.d("TAG","OK second");
}
};
However, I cannot print the log "OK second" when I called sendBroadcast(new Intent("second_one")); in the service. What is happen? How can I fix it? Thank you
UPDATE: my activity is an accept calling activity get from #notz
How can incoming calls be answered programmatically in Android 5.0 (Lollipop)?. Then I create an service as following
public class myService extends Service{
#Override
public void onCreate() {
super.onCreate();
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Intent answerCalintent = new Intent(getApplicationContext(), AcceptCallActivity.class);
answerCalintent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);
answerCalintent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(answerCalintent);
//Send the second command after 10 second and make the calling in background
new CountDownTimer(10000, 100) {
public void onTick(long millisUntilFinished) {
}
public void onFinish() {
sendBroadcast(new Intent("second_one"));
}
}.start();
return START_STICKY;
}
}
You should unregister your reсeiver in a method opposite to that in which you register it:
If you registered receiver in onCreate() - then you should unregister it in onDestroy().
But as i know, for most cases, the best practice is to register receiver in onResume() and unregister it in onPause().

Activity has leaked IntentReceiver Error

before marking this post as closed or duplicate i want to say that i have done all the things that are mentioned on similar posts but none of them worked.
I have 2 receivers which i get data from. So i want to register the receivers when the activity starts and unregister them when the activity is not visible.
My Code:
public class MainActivity extends AppCompatActivity {
private CheckNetworkStatusReceiver checkNetworkStatusReceiver;
private CheckBatteryStatusReceiver checkBatteryStatusReceiver;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
checkConnection();
}
public void checkConnection() {
if(!ConnectionManager.isNetworkAvailable(MainActivity.this)){
ConnectionManager.wifiSettingsDialog(MainActivity.this).show();
}else{
registerReceivers();
}
}
public void registerReceivers() {
checkNetworkStatusReceiver = new CheckNetworkStatusReceiver();
checkBatteryStatusReceiver = new CheckBatteryStatusReceiver();
registerReceiver(checkNetworkStatusReceiver, new IntentFilter(Constants.INTENT_FILTER_CONNECTIVITY_CHANGE));
registerReceiver(checkBatteryStatusReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
}
#Override
protected void onDestroy() {
super.onDestroy();
try{
unregisterReceiver(checkNetworkStatusReceiver);
unregisterReceiver(checkBatteryStatusReceiver);
}catch (Exception e){
e.printStackTrace();
}
}
#Override
protected void onResume() {
registerReceivers();
super.onResume();
}
#Override
protected void onRestart() {
registerReceivers();
super.onRestart();
}
#Override
protected void onStop() {
super.onStop();
try{
unregisterReceiver(checkNetworkStatusReceiver);
unregisterReceiver(checkBatteryStatusReceiver);
}catch (Exception e){
e.printStackTrace();
}
}
}
The receiver code:
public class CheckNetworkStatusReceiver extends BroadcastReceiver{
#Override
public void onReceive(Context context, Intent intent) {
if (intent != null){
Log.e("Action ",intent.getAction());
if(intent.getAction().equalsIgnoreCase(Constants.INTENT_FILTER_CONNECTIVITY_CHANGE)) {
if (!ConnectionManager.isNetworkAvailable(context)){
Toast.makeText(context, R.string.no_internet, Toast.LENGTH_SHORT).show();
}
if (MobileDataManager.slowInternetConnection(context)){
Toast.makeText(context, R.string.slow_internet_delay, Toast.LENGTH_SHORT).show();
}
}
}
}
}
and the battery receiver:
public class CheckBatteryStatusReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent != null){
int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0);
if (level <= 15){
Toast.makeText(context, "Batter level " + level + "% is very low. Please connect to a charger.", Toast.LENGTH_SHORT).show();
}
}
}
}
i get the error on the registerReceivers() method. Any ideas?
You register the receivers in onCreate() and then again in onResume(). This will leak the receivers that you registered in onCreate(), because you overwrite the variables you are using to hold references to them every time registerReceivers() is called.
This is not very robust code. You don't need to create new instances of the BroadcastReceiver every time. What you should do is to create one instance of each BroadcastReceiver in onCreate(). Then declare a boolean member variable in your class called receiversRegistered. In registerReceivers() you should check this boolean. If it is true, the receivers are already registered and you should do nothing. If not, register the receivers and then set the boolean to true. When you unregister the receivers, set the boolean to false.
EDIT: Here it is all done for you:
public class MainActivity extends AppCompatActivity {
private CheckNetworkStatusReceiver checkNetworkStatusReceiver;
private CheckBatteryStatusReceiver checkBatteryStatusReceiver;
private boolean receiversRegistered;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
checkNetworkStatusReceiver = new CheckNetworkStatusReceiver();
checkBatteryStatusReceiver = new CheckBatteryStatusReceiver();
checkConnection();
}
public void checkConnection() {
if(!ConnectionManager.isNetworkAvailable(MainActivity.this)){
ConnectionManager.wifiSettingsDialog(MainActivity.this).show();
}else{
registerReceivers();
}
}
public void registerReceivers() {
// Only register if not already registered
if (!receiversRegistered) {
registerReceiver(checkNetworkStatusReceiver, new IntentFilter(Constants.INTENT_FILTER_CONNECTIVITY_CHANGE));
registerReceiver(checkBatteryStatusReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
receiversRegistered = true;
}
}
#Override
protected void onDestroy() {
super.onDestroy();
if (receiversRegistered) {
unregisterReceiver(checkNetworkStatusReceiver);
unregisterReceiver(checkBatteryStatusReceiver);
}
}
#Override
protected void onResume() {
registerReceivers();
super.onResume();
}
#Override
protected void onRestart() {
registerReceivers();
super.onRestart();
}
#Override
protected void onStop() {
super.onStop();
if (receiversRegistered) {
unregisterReceiver(checkNetworkStatusReceiver);
unregisterReceiver(checkBatteryStatusReceiver);
receiversRegistered = false;
}
}
}
Move the unregisterReceiver inside onPause not in onDestroy.
When your activity is moved in background onDestroy is not called. The activity is only paused. onDestroy is called when the app is closed manually or by the system.
(onPause is called before onDestroy in above situation)

Calling activity class method from Service class

I have seen many posts in SO regarding this but could not get the exact and most easy way to call an activity method from service class. Is broadcast receiver only the option? No easy way out ? I just need to call the following method in Activity class after the media player is prepared in Service class .
Activity class:
public void updateProgress() {
// set Progress bar values
songProgressBar.setProgress(0);
songProgressBar.setMax(100);
// Updating progress bar
updateProgressBar();
}
Service class:
#Override
public IBinder onBind(Intent intent) {
Log.d(this.getClass().getName(), "BIND");
return musicBind;
}
#Override
public boolean onUnbind(Intent intent) {
return false;
}
#Override
public void onPrepared(MediaPlayer mp) {
try {
mp.start();
} catch (IllegalStateException e) {
e.printStackTrace();
}
// updateProgress();// Need to call the Activity method here
}
Define an interface your Service will use to communicate events:
public interface ServiceCallbacks {
void doSomething();
}
Write your Service class. Your Activity will bind to this service, so follow the sample shown here. In addition, we will add a method to set the ServiceCallbacks.
public class MyService extends Service {
// Binder given to clients
private final IBinder binder = new LocalBinder();
// Registered callbacks
private ServiceCallbacks serviceCallbacks;
// Class used for the client Binder.
public class LocalBinder extends Binder {
MyService getService() {
// Return this instance of MyService so clients can call public methods
return MyService.this;
}
}
#Override
public IBinder onBind(Intent intent) {
return binder;
}
public void setCallbacks(ServiceCallbacks callbacks) {
serviceCallbacks = callbacks;
}
}
Write your Activity class following the same guide, but also make it implement your ServiceCallbacks interface. When you bind/unbind from the Service, you will register/unregister it by calling setCallbacks on the Service.
public class MyActivity extends Activity implements ServiceCallbacks {
private MyService myService;
private boolean bound = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(...);
}
#Override
protected void onStart() {
super.onStart();
// bind to Service
Intent intent = new Intent(this, MyService.class);
bindService(intent, serviceConnection, Context.BIND_AUTO_CREATE);
}
#Override
protected void onStop() {
super.onStop();
// Unbind from service
if (bound) {
myService.setCallbacks(null); // unregister
unbindService(serviceConnection);
bound = false;
}
}
/** Callbacks for service binding, passed to bindService() */
private ServiceConnection serviceConnection = new ServiceConnection() {
#Override
public void onServiceConnected(ComponentName className, IBinder service) {
// cast the IBinder and get MyService instance
LocalBinder binder = (LocalBinder) service;
myService = binder.getService();
bound = true;
myService.setCallbacks(MyActivity.this); // register
}
#Override
public void onServiceDisconnected(ComponentName arg0) {
bound = false;
}
};
/* Defined by ServiceCallbacks interface */
#Override
public void doSomething() {
...
}
}
Now when your service wants to communicate back to the activity, just call one of the interface methods from earlier. Inside your service:
if (serviceCallbacks != null) {
serviceCallbacks.doSomething();
}
Use Broadcast receiver with service for updating your view from the service class.
For example:
In my activity class
public class ServiceDemoActivity extends Activity {
Intent intent;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final TextView notification = (TextView) findViewById(R.id.notification);
if (CheckIfServiceIsRunning()) {
} else {
startService(new Intent(this, MyService.class));
}
}
private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
updateDate(intent);
}
};
private void updateDate(Intent intent) {
String time = intent.getStringExtra("time");
Toast.makeText(getApplicationContext(), "Yea!!! Service called", Toast.LENGTH_SHORT).show();
TextView date = (TextView) findViewById(R.id.date);
date.setText(time);
}
#Override
public void onResume() {
super.onResume();
registerReceiver(broadcastReceiver, new IntentFilter(
MyService.BROADCAST_ACTION));
}
}
And in my service class I am calling my update ui after a few interval of time which updates my UI.
public class MyService extends Service {
public static final String
BROADCAST_ACTION = "com.mukesh.service";
private final Handler handler = new Handler();
#Override
public void onCreate() {
intent = new Intent(BROADCAST_ACTION);
}
#Override
public void onDestroy() {
stopService(intent);
}
#Override
public void onStart(Intent intent, int startid) {
int i = 0;
while (i <= 2) {
if (i > 1) {
i++;
this.onDestroy();
} else {
counter = i;
i++;
handler.removeCallbacks(sendUpdatesToUI);
handler.postDelayed(sendUpdatesToUI, 1 * 1000); // 1 sec
}
}
}
private Runnable sendUpdatesToUI = new Runnable() {
public void run() {
DisplayLoggingInfo();
handler.postDelayed(this, 7 * 1000); // 7 sec
}
};
private void DisplayLoggingInfo() {
intent.putExtra("time", new Date().toLocaleString());
intent.putExtra("counter", String.valueOf(counter));
sendBroadcast(intent);
stopService(intent);
}
}
For complete code check this link
I created a general class called Delegate (it's not a special name, you can name it John) and passed MainActivity class into it as a static field. Then I can access it from the service since its global now. I am not sure if it is cost-effective but it solved the problem for me simple.
My service:
package com.some.package;
import com.google.firebase.iid.FirebaseInstanceId;
import com.google.firebase.iid.FirebaseInstanceIdService;
public class FirebaseInstanceIDService extends FirebaseInstanceIdService {
#Override
public void onTokenRefresh() {
String token = FirebaseInstanceId.getInstance().getToken();
Delegate.theMainActivity.onDeviceTokenChange(token);
}
}
Delegate class:
package com.some.package;
public class Delegate {
static MainActivity theMainActivity;
}
What I did in MainActivity:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Delegate.theMainActivity = this;
//rest of the code...
}
public void onDeviceTokenChange(String token){
Log.e("updated token:", token);
}
You can't call your sevices method direcly from your activity or vise versa. There are 3 ways to communicate with a service; using broadcasters and receivers, using Messenger or binding to the service. For further information look at http://developer.android.com/guide/components/bound-services.html
You can call from your service
getContentResolver().notifyChange(uri, null);
and in your activity you set up a
getContentResolver().registerContentObserver(uri, false, new ContentObserver(getHandler())
{
public void onChange(boolean selfChange)
{
updateProgress()
}
};
the onChange method will ba called on the UI thread
You can call a method of activity from service by implementing your own listener like this
https://stackoverflow.com/a/18585247/5361964
You might consider running your activity method in runOnUiThread like this:
// method will be called from service
override fun callback(activity: Activity, result: String) {
runOnUiThread{
Toast.makeText(activity, result, Toast.LENGTH_LONG).show()
}
}
I would prefer to use some very easy and cleaner solution provided by
EventBus

BroadcastReceiver with multiple filters or multiple BroadcastReceivers?

I have an Android Activity that needs to catch two different broadcasts. My current approach is to have a single BroadcastReceiver within the Activity and catch both the broadcasts with it:
public class MyActivity extends Activity {
private MyActivity.BroadcastListener mBroadcastListener;
private boolean mIsActivityPaused = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mylayout);
// Create the broadcast listener and register the filters
mIsActivityPaused = false;
mBroadcastListener = new BroadcastListener();
IntentFilter filter = new IntentFilter();
filter.addAction(Params.INTENT_REFRESH);
filter.addAction(Params.INTENT_UPDATE);
registerReceiver(mBroadcastListener, filter);
}
#Override
protected void onResume() {
super.onResume();
mIsActivityPaused = false;
}
#Override
protected void onPause() {
super.onPause();
mIsActivityPaused = true;
}
#Override
protected void onDestroy() {
unregisterReceiver(mBroadcastListener);
super.onDestroy();
}
private void refresh() {
// refresh
}
private void update() {
// update
}
private class BroadcastListener extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(Params.INTENT_REFRESH && !mIsActivityPaused)) {
refresh();
} else if (intent.getAction().equals(Params.INTENT_UPDATE)) {
update();
}
}
}
}
I want to execute refresh() only if my Activity is visible on the screen, but I want to catch INTENT_UPDATE and execute update() during the entire lifetime of the Activity, regardless of whether the Activity is visible or not.
I didn't find any way to unregister only one of the two filters that I register in onCreate, so I use a flag to enable or disable the action to be executed when the INTENT_REFRESH broadcast is caught, depending on the state of the Activity.
The question is: is this the correct approach?
Or, would it be better to have two separate BroadcastReceivers as follows:
public class MyActivity extends Activity {
private MyActivity.BroadcastListenerRefresh mBroadcastListenerRefresh;
private MyActivity.BroadcastListenerUpdate mBroadcastListenerUpdate;
private boolean mIsBroadcastListenerRefreshRegistered = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Create the broadcast listeners
mBroadcastListenerRefresh = new BroadcastListenerRefresh();
mBroadcastListenerUpdate = new BroadcastListenerUpdate();
registerReceiver(mBroadcastListenerRefresh, new IntentFilter(Params.INTENT_REFRESH));
registerReceiver(mBroadcastListenerUpdate, new IntentFilter(Params.INTENT_UPDATE));
}
#Override
protected void onResume() {
super.onResume();
if (mBroadcastListenerRefresh != null && !mIsBroadcastListenerRefreshRegistered) {
registerReceiver(mBroadcastListenerRefresh, new IntentFilter(Params.INTENT_REFRESH));
mIsBroadcastListenerRefreshRegistered = true;
}
}
#Override
protected void onPause() {
super.onPause();
if (mBroadcastListenerRefresh != null && mIsBroadcastListenerRefreshRegistered) {
unregisterReceiver(mBroadcastListenerRefresh);
mIsBroadcastListenerRefreshRegistered = false;
}
}
#Override
protected void onDestroy() {
unregisterReceiver(mBroadcastListenerRefresh);
unregisterReceiver(mBroadcastListenerUpdate);
super.onDestroy();
}
private void refresh() {
// refresh
}
private void update() {
// update
}
private class BroadcastListenerRefresh extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(Params.INTENT_REFRESH)) {
refresh();
}
}
}
private class BroadcastListenerUpdate extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(Params.INTENT_UPDATE)) {
update();
}
}
}
}
And which one has better performance?
instead, you may provide two different intent filters:
filter for refresh only
IntentFilter filterRefresh = new IntentFilter(Params.INTENT_REFRESH);
filter for refresh and update
IntentFilter filterRefreshUpdate = new IntentFilter();
filterRefreshUpdate.addAction(Params.INTENT_REFRESH);
filterRefreshUpdate.addAction(Params.INTENT_UPDATE);
now you may switch between intent filters by registering and un-registering the desired one but your receiver's implementation would be same
For every action , create IntentFilter and register it.
#Override
protected void onResume() {
super.onResume();
BroadcastListener receiver = new BroadcastListener();
// Register the filter for listening broadcast.
IntentFilter filterRefresh = new IntentFilter(Params.INTENT_REFRESH);
IntentFilter filterUpdate = new IntentFilter(Params.INTENT_UPDATE);
registerReceiver(receiver, filterRefresh);
registerReceiver(receiver, filterUpdate);
}
private class BroadcastListener extends BroadcastReceiver {
public void onReceive(Context ctx, Intent intent) {
if (intent.getAction().equals(Params.INTENT_UPDATE)) {
update();
} else if(intent.getAction().equals(Params.INTENT_REFRESH)) {
refresh();
}
}
}
Using KOTLIN you can do it inline:
broadcastReceiver = NukeBroadcastReceiver()
registerReceiver(broadcastReceiver, IntentFilter().apply {
addAction(ACTION_DESTROY_EVERYTHING)
addAction(ACTION_RESTART_WORLD)
})

Sticky Service Management

I've got a Sticky Service (returns START_STICKY from onStartCommand) which executes some code in an AsyncTask, but I'm having some problems with how and when to start, bind, stop, unbind. I only want the service around whilst the parent activity is alive, I don't want it hanging around in the background when the app has been closed, but I need the service to survive an orientation change. I currently don't need the service to be active for the entire duration of the activity being active, so I call stopSelf() after the main work is done in my AsyncTask in the Service and then start the Service again when needed. Sometimes I'll need to interrupt the work the service is doing, cancel the AsyncTask and start again with different data. The problem is that no matter what I do - I can't seem to get it solid throughout all the different possible scenarios. Can anyone have a look through and tell me what I'm doing wrong?
My Service is :
public class ChordCalculatorService extends Service {
private final IBinder mBinder = new LocalBinder();
private AsyncTask<SearchData, SearchStatusData, List<Item>> currentTask;
#Override
public void onCreate() {}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
// We want this service to continue running until it is explicitly
// stopped, so return sticky.
return START_STICKY;
}
/**
* Class for clients to access. Because we know this service always runs in
* the same process as its clients, we don't need to deal with IPC.
*/
public class LocalBinder extends Binder {
public ChordCalculatorService getService() {
return ChordCalculatorService.this;
}
}
#Override
public void onDestroy() {
super.onDestroy();
}
#Override
public IBinder onBind(Intent intent) {
return mBinder;
}
public SearchData getSearchData() {
return searchData;
}
public void startWork() {
if (currentTask != null && currentTask.getStatus() == Status.RUNNING) {
currentTask.cancel(true);
}
if(searchData != null) {
Worker task = new Worker();
currentTask = task.execute(new SearchData[] { searchData });
} else {
Message msg = handler.obtainMessage(ERROR, "No search data set");
handler.sendMessage(msg);
}
}
class Worker extends AsyncTask<SearchData, SearchStatusData, List<Item>> {
// ... code ...
#Override
protected void onPostExecute(List<Item> result) {
Message msg = handler.obtainMessage(COMPLETE, new StatusData(Status.STATUS_FINISHED, result));
handler.sendMessage(msg);
stopSelf();
}
}
}
Currently I have the Service being started when my custom View is created:
public class MyCustomView extends BasicFretBoardView {
private ServiceConnection conn;
private MyService myService;
private boolean isServiceStarted;
private boolean isServiceBound;
public MyCustomView(Context context, AttributeSet attr) {
super(context, attr);
startService();
}
public void startService() {
Intent serviceIntent = new Intent(getContext(), MyService.class);
conn = new ServiceConnection() {
#Override
public void onServiceConnected(ComponentName name, IBinder service) {
myService = ((LocalBinder) service).getService();
myService.registerHandler(serviceHandler);
}
#Override
public void onServiceDisconnected(ComponentName name) {
myService = null;
}
};
// Explicitly start the service. Don't use BIND_AUTO_CREATE, since it
// causes an implicit service stop when the last binder is removed.
getContext().startService(serviceIntent);
getContext().bindService(serviceIntent, conn, 0);
isServiceStarted = true;
isServiceBound = true;
}
public void stopService() {
if (isServiceStarted) {
Intent serviceIntent = new Intent(getContext(), MyService.class);
getContext().stopService(serviceIntent);
isServiceStarted = false;
}
unBindService();
}
public void unBindService() {
if(isServiceBound) {
getContext().unbindService(conn);
isServiceBound = false;
}
}
// gets called based on some user interaction
private void startServiceWork() {
if(!isServiceStarted) {
startService();
} else {
myService.cancelCalcalation();
}
myService.setData(data);
myService.startWork();
}
}
and stopping the service is handled in the Activity:
public class CustomChordActivity extends Activity {
// ... code ...
#Override
public void onBackPressed() {
super.onBackPressed();
}
#Override
protected void onPause() {
if(isFinishing()) {
chordsView.stopService();
}
super.onPause();
}
#Override
protected void onStop() {
super.onStop();
}
#Override
protected void onDestroy() {
chordsView.unBindService();
super.onDestroy();
}
#Override
protected void finalize() throws Throwable {
super.finalize();
}
}
It seems that you want your task to run on demand, maybe an IntentService would be a more suitable option. When you need work to be done, (startServiceWork()), you just start the service and that kicks off your AsyncTask. The service will then finish after the task has finished.
Now, regarding orientation changes, you would have to implement a Broadcast Receiver whose intent filter is "android.intent.action.CONFIGURATION_CHANGED". (I assume that you want the service to do work when the orientation changes) Place the Broadcast Receiver, within your activity/main ui thread. This will in effect make the hosting process of your Broadcast Receiver to be the main application process making it safer to start the service from within the Broadcast Receiver.

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