I have checked the official Android documentation/guide for Looper, Handler and MessageQueue . But I couldn't get it. I am new to android, and got very confused with these concepts.

I created a class extending Thread to retrieve user location through LocationManager in a non-ui thread. I implemented this as a thread because it has to be started on request and do its work just ...

I have tasks completed by AsyncTask in background. At some point I need to issue a Toast that something is completed. I've tried and I failed because Caused by: java.lang.RuntimeException: Can't...

I have a worker thread that sits in the background, processing messages. Something like this: class Worker extends Thread { public volatile Handler handler; // actually private, of course publ...

Consider the following snippet: Looper.prepare(); handler = new Handler() { @Override public void handleMessage(Message msg) { super.handleMessage(msg); getLooper().quitSafely(); } }; for(in...

I know the general problem of "Can't create handler inside thread that has not called Looper.prepare()" has been asked before, but I am struggling to understand how it applies in this case. I am ...

I'm having a bit of trouble understanding how to use the Looper prepare()/loop()/quit() logic. I have three threads: one is the UI thread, one is a game logic thread and the last is a network com...

I have a problem with a looper. I call looper.prepare(), and after doing something it all works fine. But if I rotate the device I get an exception on the prepare. 07-12 16:40:09.760: E/activity(1...

Normally an error while doing something on the UI thread from another thread I thought, but I don't get what I'm doing wrong. The error seems only to appear when the phone is travelling, so with a ...

We're building an app that does a lot of animations and downloads a lot of images. After a certain amount of transactions (a predictable number), the app is crashing with the error: A/Looper: Coul...

I have a HandlerThread, to which I keep posting a runnable every 5 seconds. Something like this: HandlerThread thread = new HandlerThread("MyThread"); thread.start(); Handler handler = new Handler...

I am trying to implement Handlers listening on the same Looper from different threads. Below I have two Handlers, one created in the main thread, another in the child thread, however both are init...

Can anyone explain why someone should use the Android Looper feature to create a "pipeline thread" instead of making a normal thread that pulls tasks from a BlockingQueue? On the surface, it seems ...

I use the android.os.Handler class to perform tasks on the background. When unit testing these, I call Looper.loop() to make the test thread wait for the background task thread to do its thing. Lat...

I don't understand why I'm getting this error. I'm using AsyncTask to run some processes in the background. I have: protected void onPreExecute() { connectionProgressDialog = new ProgressDialog...

This question is about event handling on Android. It is not specific to c++. I need to process UI/OS events, without blocking when all events have been processed. The reason is that the applicat...

I am using simple thread to execute the httpGet to server when a button is clicked, but I get this after execution. Button b_back = (Button) findViewById(R.id.bback); b_back.setOnClickListener(thi...

i have some threads in which i create some views and prepare them to be displayed. Among them i also have a WebView. This code is executed in thread: WebView lGraphWebView = null; try{ lGraphWeb...

Ok this is a very weird problem I am having, and I'm pretty sure that I am messing up somewhere, but I can't quite figure out where. What I am trying is - Schedule a Timer to execute a TimerTas...

I have Activity with Handler (UI thread) I start new Thread and make handler.post(new MyRunnable()) - (new work thread) Android documentation said about post method: "Causes the Runnable r to be...

I have the following code class OverlayTask extends AsyncTask<Void, Void, Void> { @Override public void onPreExecute() { if (sites != null) { myMapView.getOverlays().remove(sites); myM...