Question

Quick question: I have an activitygroup. Within that Activitygroup I have an activity. If I press back while inside this activity. the onBackPressed method of the activity is called – Not the Activitygroups onBackPressed – Why is that ?

EDIT: Got my answer but the problem remains. Here follows code and explanation of my original issue:

I am using ActivityGroups within a TabHost and as such have been “forced” into overriding onBackPressed. I can navigate through my application without issue by pressing back on my phone and by pressing the tabs on my tabhost. But I cannot interact with the interface after pressing Back.
Once I press one of the tabs on the tabhost again I can interact with everything like normal. Why is this happening? Do I need to override onResume?

Relevant code

SettingsActivityGroup :

public class SettingsActivityGroup extends ActivityGroup 
{
// Keep this in a static variable to make it accessible for all the nested activities, lets them manipulate the view
public static SettingsActivityGroup group;

// Need to keep track of the history if you want the back-button to work properly, don't use this if your activities requires a lot of memory.
private ArrayList<View> history;

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);

    // Allocate history
    this.history = new ArrayList<View>();

    // Set group
    group = this;             

    // Start root (first) activity
    Intent myIntent = new Intent(this, SettingsActivity.class); // Change to the first activity of your ActivityGroup
    myIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    ReplaceView("SettingsActivity", myIntent);
}

/*
 * Replace the activity with a new activity and add previous one to history
 */
public void ReplaceView(String pId, Intent pIntent)
{
    Window window = getLocalActivityManager().startActivity(pId, pIntent);
    View view = (window != null) ? window.getDecorView() : null;

    // Add the old activity to the history
    history.add(view);

    // Set content view to new activity
    setContentView(view);
}

/*
 * Go back from previous activity or close application if there is no previous activity
 */
public void back()
{
    if(history.size() > 1)
    {
        // Remove previous activity from history
        history.remove(history.size()-1);

        // Go to activity
        View view = history.get(history.size() - 1);
        Activity activity = (Activity) view.getContext();

        // "Hack" used to determine when going back from a previous activity
        // This is not necessary, if you don't need to redraw an activity when going back
        activity.onWindowFocusChanged(true);
        // Set content view to new activity
        setContentView(view);
    }
    else
    {
        // Close the application
        finish();

    }
}
/*
 * Overwrite the back button
 */
@Override
public void onBackPressed() 
{
    // Go one back, if the history is not empty
    // If history is empty, close the application
    SettingsActivityGroup.group.back();

    return;
}
}

Arbitrary child of SettingsActivityGroup(CallForwardActivity)

public class CallForwardActivity extends ListActivity 
{
....
    @Override
    public void onBackPressed() 
    {
        // Go one back, if the history is not empty
        // If history is empty, close the application
        SettingsActivityGroup.group.back();

        return;
    }

}

Answer 1

Because I believe calling onBackPressed() of the currently selected activity is the desired behavior.

It’s also worth noting that ActivityGroup is deprecated, but I assume you are coding for <3.0 and don’t fancy working with the support libraries.

Regarding your edited question:
Another question on this site cites this article as a good ActivityGroup example, and I would agree http://ericharlow.blogspot.com/2010/09/experience-multiple-android-activities.html
This example just calls finish() on the current activity when back is pressed, and lets the os restart the previous activity, which is simpler than what you are doing, and will hopefully work! You can just call getParent() in your child activities too to avoid using that static reference (just seems easier to read to me that way!).