Use UP caret in ActionBar to go from Activity to Fragment - Android 4.0+

Issue

I've been researching all day/night for a solution, but it seems there are lots of options to go from an Activity to a Fragment, but none are working for me on S.O. In practice, I am in an Activity, and I want to use my app logo in the ActionBar to click it and then return to a Fragment. This Fragment is the "parent class" of my Activity, meaning there was a button in the Fragment I clicked that took me to my Activity.

But I can't get all the code snippets I've seen to work.

I have put this in my onCreate() of my Activity:

// Shows the up carat near app icon in ActionBar
getSupportActionBar().setDisplayUseLogoEnabled(false);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);

I also included this in my onOptionsItemSelected() method of my Activity:

// Handle action bar actions click
    switch (item.getItemId()) {
        case android.R.id.home:
            android.app.FragmentManager fm= getFragmentManager();
            fm.popBackStack();

            return true;
        default:
            return super.onOptionsItemSelected(item);
    }

The result is that I see a "back button" carat (as shown below), but when I click it nothing happens. I'm supposed to go back to the Fragment I came from. FYI, my Fragment class actually extends Fragment (not FragmentActivity). My Activity extends ActionBarActivity, so I am looking for an answer that will work for Android 4.0+. Also, my Fragment does not need the same instance (necessarily) when it is returned to. It only has buttons on there, so a new instance is fine, if it gets created, upon returning.

Thanks for your help!!

Solution

One small line was needed: finish(). Since the FragmentManager pops off one item in its backstack, by using fm.popBackStack();, it still needs some sort of action to go to the previous fragment. Adding finish() enabled the current Activity to end. The line in context:

@Override
    public boolean onOptionsItemSelected(MenuItem item) {

        // Handle action bar actions click
        switch (item.getItemId()) {
            case android.R.id.home:
                android.app.FragmentManager fm= getFragmentManager();
                fm.popBackStack();
                finish();

                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

The rest of the code I had above was correct and is needed too, to make it all work. Now, I am able to navigate to my NavigationDrawer fragment, click a button there to go to an Activity, then press the navigation UP caret to return to my Fragment at anytime. This was tested successfully on a Samsung Galaxy5 phone.

One thing that you do not read about in the Navigating Up with the App Icon section of the ActionBar Android doc is that since you are using a fragment to return to, you cannot use their <meta-data> tag instruction to specify the parent activity in the manifest file, because you are not returning to an Activity! But rather a Fragment. So a workaround had to be achieved by using FragmentManager.

Answered By - Azurespot