So right now I have swipe to refresh in my app. When it is activated, a service which runs an async background task is executed. Problem is, the swipe to refresh indicator disappears immediately. How do I keep it displayed (and update my recycler view) when the service has finished running?
Here is some code:
mSwipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.activity_main_swipe_refresh_layout);
mSwipeRefreshLayout.setColorSchemeResources(R.color.StatusbarColor,R.color.Accent);
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
db = new DatabaseHelper(getApplicationContext());
callRefreshService();
}
});
Here is the callRefreshService method:
public void callRefreshService() {
try{
Intent service = new Intent(getApplicationContext(), UpdateScoresService.class);
startService(service);
}
finally {
list.clear();
list.addAll(db.getTracked());
db.closeDB();
adapter.notifyDataSetChanged();
mSwipeRefreshLayout.setRefreshing(false);
}
}
As you can see I tried using try and finally but that doesn't help.
startService(Intent) does not block, it returns immediately.
You got two options:
Ditch the Service for AsyncTask
Allow the Service to communicate with your Activity
Choose 1 for something trivial like a one-off JSON download task. Call mSwipeRefreshLayout.setRefreshing(false) in the onPostExecute (Result result) block.
Choose 2 if you got something complex setup already.
Communication between Activity and Service is slightly complicated, what you need is a bind service. If you want something simple, you can look take a look at event bus, it decouple things quite nicely.
Here are some implementations of an event bus:
Otto
EventBus
Create a BroadcastReceiver inside your activity
BroadcastReceiver receiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
// stop refreshing the layout
mSwipeRefreshLayout.setRefreshing(false);
}
};
register it to your activity inside onResume() to listen to some Intenet and unregister it inside onPause()
#Override
protected void onResume() {
super.onResume();
// register the receiver
registerReceiver(receiver, new IntentFilter("com.example.app.STOP_REFRESH"));
}
#Override
protected void onPause() {
super.onPause();
// unregister the receiver
unregisterReceiver(receiver);
}
then inside your AsyncTask onPostExecute() send the message with the Intent
Intent intent = new Intent("com.example.app.STOP_REFRESH");
// you can also add extras to this intent
// intent.putExtra("key", value);
sendBroadcast(intent);
Related
My service:
#Override
public void onCreate() {
if (debug_mode) {Log.i(TAG,"onCreate");}
super.onCreate();
// set receivers
m_filter.addAction("PREPARE_AUDIO");
m_receiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
if (debug_mode) {Log.i(TAG,"broadcast received: " + intent.getAction());}
if (intent.getAction().equals("PREPARE_AUDIO")) {
set_up_audio();
}
}
};
registerReceiver(m_receiver, m_filter);
}
and my activity:
#Override
protected void onStart() {
super.onCreate(savedInstanceState);
if (debug_mode) Log.i(TAG, "onCreate");
setContentView(R.layout.activity_guide);
// start service
startService(new Intent(this, PlayerService.class));
}
#Override
protected void onStart() {
if (debug_mode) {Log.i(TAG,"onStart");}
super.onStart();
// prepare audio
Intent intent = new Intent();
intent.setAction("PREPARE_AUDIO");
sendBroadcast(intent);
}
This won't trigger the BroadcastReceiver in my service. It won't trigger it either if I put the code on onCreate or onResume. It will trigger it, however, if put e.g. on some Listener associated with a Button, or in the activity's onStop callback. Why is that?
Rather than try to send a broadcast right away, just have the service do its setup work in its onCreate() or onStartCommand() method.
Note that using system broadcasts for this is a fairly bad idea, unless your service is in a separate process from your UI. Even then, you need to think through the security, as any app can tell your service what to do, by sending it broadcasts.
If your service and UI will be in the same process, use an in-process event bus (e.g., LocalBroadcastManager, greenrobot's EventBus), not only for improved security, but for better performance.
I am trying to implement an Async task that gets a string from a url inside a service.
I am using a startedService which calls the Async task get the correct string, update a public DB class content and return to the main activity, the problem is that the list adapter which i need to notify of the change in the DB is at the main activity and i don't have access to it from the Service , I am a a noobie so I am not familiar with what better to use , started or bind service for that job, any sugestions ?
thank you
You can use BroadcastReceiver :
In your Activity:
#Override
public void onResume() {
super.onResume();
// Register mMessageReceiver to receive messages.
LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver,
new IntentFilter("mybroadcast"));
}
// handler for received Intents for the "my-event" event
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
// Extract data included in the Intent
String message = intent.getStringExtra("message");
Log.d("receiver", "Got message: " + message);
}
};
#Override
protected void onPause() {
// Unregister since the activity is not visible
LocalBroadcastManager.getInstance(this).unregisterReceiver(mMessageReceiver);
super.onPause();
}
And to Broadcast from service use:
Intent intent = new Intent();
intent.setAction("mybroadcast");
sendBroadcast(intent)
So i have this receiver in my Fragment.class
private BroadcastReceiver receiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(WeekplanHepler.ACTION_SERVICE_BINDED) && getUpdateService() != null) {
getCounts();
}
if (intent.getAction().equals(Helper.UpdateCounts)) {
HashMap<String, Integer> counts = (HashMap<String, Integer>) intent.getSerializableExtra(Helper.PARAM_LIST_COUNTS);
// Updating counts
}
}
};
For registering/uregistering this receiver i'm using this code:
#Override
public void onStart() {
super.onStart();
getCounts(true);
getActivity().registerReceiver(receiver, getIntentFilter());
}
#Override
public void onStop() {
super.onStop();
getActivity().unregisterReceiver(receiver);
}
getCounts() is a RetrofitRequest puted in UpdateService, which is getUpdateService() here
So, when retrofit request has been finished, it returns counts through Intent and then, as you see, i'm updating them. But if i go to next Activity and then returns, request will work fine, and it will send intent, but receiver wont get it. I think this can be caused by method service is binded in first place. So i have BaseFragment, which binds service for all Fragments needed
public abstract class BaseFragment<T> extends CustomListFragment<T> {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActivity().getApplicationContext().bindService(new Intent(getActivity().getApplicationContext(),
WeekplanUpdateService.class), connection, Context.BIND_AUTO_CREATE);
}
}
When i go to next activity, it fragment will bind service, and my previous fragment will call request again, and will have counts. Maybe receiver has some limitations for how much he can get same intents, but i don't think so. Please help
Oh, i forgot to mention how i'm sending intent
sendBroadcast(new Intent(Helper.UpdateCounts).putExtra(Helper.PARAM_LIST_COUNTS, counts));
So, when i've started to use
sendStickyBroadcast(new Intent(Helper.UpdateCounts)
.putExtra(Helper.PARAM_LIST_COUNTS, counts));
instead of
sendBroadcast(new Intent(Helper.UpdateCounts)
.putExtra(Helper.PARAM_LIST_COUNTS, counts));
it worked.
Good day, I have an activity which i navigate to from an icon on an appwidget using pending Intents. Everything is being done in a service class. Now, the activity has a refresh button which when pressed, it sends an intent that calls the onStart() method on the service to update itself and perform some web operations. How do i go about reflecting the changes that could have occurred from the service in the activity without temporarily existing the activity.
Service to Activity:
if(intent.getExtras()!= null){
appWidgetId = intent.getExtras().getInt(AppWidgetManager.EXTRA_APPWIDGET_ID);
//if i get this action from my detailedinfo class add a boolean to it
if(intent.getAction() == refresh_action){
// boolean variable to hold condition
my_action = true;
}
Intent forecast = new Intent(this,detailedInfo.class );
forecast.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);
forecast.putExtra("cityname", city);
PendingIntent forecastIntent = PendingIntent.getActivity(this, 0, forecast, 0);
/*onclick to go to detailedInfo class*/
remoteView.setOnClickPendingIntent(R.id.city_image_id, forecastIntent);
if(my_action == true){
//Log.d(TAG, "my_action is true, performing pending intent");
try {
forecastIntent.send(this, 0, forecast);
} catch (CanceledException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
And in the Activity class:
Intent service = new Intent(this, cityService.class);
service.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
service.setAction(refresh_action);
Uri data = Uri.withAppendedPath(Uri.parse(CityWidgetProvider.URI_SCHEME + "://widget/id/"), String.valueOf(appWidgetId));
service.setData(data);
startService(service);
I tried adding a setAction() method to the intent that calls the service and then use the same pendingIntent(even though i think is a long shot) but they seems to be ignored. Please how do i go about this and what could i have been doing wrong.? As usual any help is highly appreciated. Thank you.
I'm not 100% clear on what you're trying to do, but the easiest thing to do would be to register a BroadcastReceiver in your Activity onResume (remove it in onPause). When the service is done with whatever it needs to do, broadcast that info.
In the Activity
public static final String ACTION_STRING = "THE_BIG_ACTION";
private BroadcastReceiver receiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
// Do whatever you want here
Toast.makeText(getApplicationContext(), "received", Toast.LENGTH_SHORT);
}
};
#Override
protected void onResume() {
super.onResume();
registerReceiver(receiver, new IntentFilter(ACTION_STRING));
}
#Override
protected void onPause() {
super.onPause();
unregisterReceiver(receiver);
}
In the service, when you're done, just call...
sendBroadcast(new Intent(YourActivityClass.ACTION_STRING));
If you want to include some data, just put it in the intent like you would when starting an Activity.
If your Activity is off screen when the service completes, and the user goes back to it, you'll have missed the notification. That's a different issue to resolve.
In my android application, I am using the tab view and so I have two tabs: parameters and results.
the user enters the various parameters on the first tab and then switches to the second tab to view the results.
i have a service that performs some long-running calculations. the user enters parameters on the first tab and hits 'calculate'. They can make adjustments and hit 'recalculate' and the service is updated with the new parameters.
As these calculations progress, I want the user to be able to switch to the results tab to view the results of the latest calculation. They would then view the results and be able to switch back to the parameters tab to make adjustments.
I can think of two approaches:
-register the 'results tab' with the service and when the service reaches a milestone, it calls directly to the 'results tab'.
-have a timer running in the 'results tab' and have it query against the bound service on a regular interval and update accordingly.
Do people have comments or recommendations for these two approaches?
AsyncTask has a publishProgress method that should make it really painless to push updates from your background task to the UI thread.
Using broadcast Receiver
public class Detail extends GDActivity {
private final BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
if(intent.getAction().equals(DownloadService.CUSTOM_INTENT)) {
mProgressDialog.setProgress(intent.getFlags());
}
}
};
// Flag if receiver is registered
private boolean mReceiversRegistered = false;
// Define a handler and a broadcast receiver
private final Handler mHandler = new Handler();
#Override
protected void onResume() {
super.onResume();
// Register Sync Recievers
IntentFilter intentToReceiveFilter = new IntentFilter();
intentToReceiveFilter.addAction(DownloadService.CUSTOM_INTENT);
this.registerReceiver(mIntentReceiver, intentToReceiveFilter, null, mHandler);
mReceiversRegistered = true;
}
#Override
public void onPause() {
super.onPause();
// Make sure you unregister your receivers when you pause your activity
if(mReceiversRegistered) {
unregisterReceiver(mIntentReceiver);
mReceiversRegistered = false;
}
}
}
}
and the Sender
#Override
protected void onProgressUpdate(Integer... progress) {
Intent i = new Intent();
i.setAction(CUSTOM_INTENT);
i.setFlags(progress[0]);
ctx.sendBroadcast(i);
}