onActivityResult() called prematurely

Question

I start the Activity (descendant of PreferenceActivity) from my worker activity as follows:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == 1458)
        loadInfo();
}

void showSettingsDialog()
{
    startActivityForResult(new Intent().setClass(this, MyConfigure.class), 1458);
}

MyConfigure class does NOT have any setResult() calls. In fact, MyConfigure class doesn't have any code except OnCreate() where it loads preferences using addPreferencesFromResource.

Now onActivityResult is called with requestCode of 1458 prematurely, right after MyConfigure activity is run. Tested on 1.6 and 2.1 emulators as well as 2.1 device. Is there a call to setResult() buried somewhere in PreferenceActivity? Or how else can this premature call be explained?

An activity doesn't end on setResults(), it ends on finish(). Can you show the onCreate method of your MyConfigure activity? — Cheryl Simon
Right, it doesn't. However, something does call setResult() ahead of time and I am wondering, what it is. The code of onCreate is trivial: public class MyConfigure extends PreferenceActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.preferences); } } — Eugene Mayevski 'Callback
That is exactly what I created the question for. To find out, why onActivityResult is called prematurely. — Eugene Mayevski 'Callback
What does the logcat output say around this period? Specifically the "ActivityManager" tag, which shows which Intents are being called. — Christopher Orr

Eugene Mayevski 'Callback Eugene Mayevski 'Callback · Accepted Answer · 2010-08-23T09:51:30

This is fixed by changing the launch mode to singleTop:

    <activity
        android:name=".MainActivity"
        android:launchMode="singleTop">

There's a bug / feature (?) in Android, which immediately reports result (which has not been set yet) for Activity, declared as singleTask (despite the fact that the activity continues to run). If we change launchMode of the parent activity from singleTask to singleTop, everything works as expected - result is reported only after the activity is finished. While this behavior has certain explanation (only one singleTask activity can exist and there can happen multiple waiters for it), this is still a not logical restriction for me.

onActivityResult() called prematurely

5 Answers