android asynchronous get foreground activity

Question

Is there a (thread safe) method I can call from Java on Android which will give me a handle to the foreground activity from a background task? I would like to be able to do so in order to safely post toasts on top of the top window.

Thanks.

score 0 · Answer 1 · answered May 19 '13 at 14:53

0

You wouldn't necessarily have to get a handle to the foreground UI activity to show a toast message. You can do this from a background thread like this:

runOnUiThread(new Runnable() {
    public void run() {
        // make toast, show toast
    }
});

answered May 19 '13 at 14:53

Andrey Butov

2,279
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27

score 0 · Answer 2 · answered May 19 '13 at 17:22

Create your own class that extends AsyncTask and pass the Activity as one of the parameters:

public class MyAsyncTask extends AsyncTask<String, String, String>{

    Activity mActivity;

    public MyAsyncTask (Activity mActivity){
        this.mActivity = mActivity;
    }

    @Override
    protected String doInBackground(String... urls) {


        return null;

    }

    @Override
    protected void onPostExecute(String result) {

    }

}

Doing that should allow you to access the Activity (assuming it's still the foreground throughout; which may not necessarily be the case).

If there's a chance that it's not the foreground Activity, you may want to just use the:

runOnUiThread(new Runnable() {
    public void run() {
        // Do UI stuff here
    }
});

However, that isn't necessarily thread-safe

android asynchronous get foreground activity

2 Answers2