Android ListenableAsyncTask: AsyncTask extension that lets you set an onPostExecute listener from a task's client

ListenableAsyncTask.java

public abstract class ListenableAsyncTask<Params, Progress, Result> extends AsyncTask<Params, Progress, Result>{

	@Override
    protected final void onPostExecute(Result result) {
		notifyListenerOnPostExecute(result);
	}

	private AsyncTaskListener<Result> mListener;
	public interface AsyncTaskListener<Result>{
		public void onPostExecute(Result result);
	}
	public void listenWith(AsyncTaskListener<Result> l){
		mListener = l;
	}
	private void notifyListenerOnPostExecute(Result result){
		if(mListener != null)
			mListener.onPostExecute(result);
	}

}

I kept coming to this point where it felt more natural to set a listener for onPostExecute from a given task instance's client context. So I tried this abstract extension class and it worked quite swell. Just derive your concrete task class from ListenableAsyncTask instead of the SDK's AsyncTask. Everything else works the same as AsyncTask with the added feature that you can now be notified about onPostExecute from outside the task instance.

hey,

i think you solved my problem : ) AsyncTask's by nature aren't meant to be singletons. They can't outlive their listeners. from what you have written, it seems clear that the listener can be re-bound at any point between doInBackground() and onPostExecute(). i will try this tonight.

thanks.