如何使用上下文操作栏来处理汉堡包图标和插入符号图标？

Question

Ok, so normally I'm not the asking kinda guy, but I couldn't solve my problem googling. So my first StackOverflow-Question.

I have an activity with a navigation drawer which triggers a few fragments, those fragments have subfragments of their own.

When the user goes deeper in the app, the 'hamburger'-icon is replaced by the up-caret. On pressing the caret or the back-key the subfragment is popped from the backstack and the hamburger-icon is back.

This is what happens in the subfragment:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case android.R.id.home:
        // Called when the up caret in actionbar is pressed
        getActivity().onBackPressed();
        return true;
    }
    return super.onOptionsItemSelected(item);
}

In the activity:

@Override
public void onBackPressed() {
    // turn on the Navigation Drawer image
    FragmentManager fragmentManager = getSupportFragmentManager();

    if (fragmentManager.getBackStackEntryCount () != 0)
        mDrawerToggle.setDrawerIndicatorEnabled(true);
    }
    super.onBackPressed();
}   

So far, so good.

The problem starts when we go deeper in the subfragment. The subfragments has a list and onLongClickItem it shows a contextual actionbar which lets users alter those listitems.

If that contextual actionbar is opened and the back-button is pressed, it closes (as expected) but also changes the up-caret to the drawer-hamburger-icon-thingie. Of course I do understand why this happens, but I don't see (or was able to find online) a clean solution.

Am I going at it the wrong way, or am I just missing a simple step here? I was thinking something along the lines of moving the setDrawerIndicatorEnabled to an onBackStackChangedListener and there listening for a tagged backStackItem.

But I thought; let's take some babysteps in to the wild and ask a question online before I start messing up all my code.

Thanks

Answer 1

The text below first was an edit on the question itselve, but because nobody seemed reluctant to answer my question I've added it as an answer so people who have a similar question are maybe helped by this.

If someone has a better answer, I'm still interested in a cleaner solution.

---

Ok, I managed to solve my own question, but I'm not realy sure I'm satisfied with it. What I did was add a fake entry to the backstack in onCreateActionMode, like so:

@Override
public boolean onCreateActionMode(ActionMode actionmode, Menu menu) {
    MenuInflater inflater = actionmode.getMenuInflater();
    inflater.inflate(R.menu.task_contextual_menu, menu);

    getActivity().getSupportFragmentManager()
                .beginTransaction()
                .addToBackStack(null)
                .add(new Fragment(), FAKE_BACKSTACK_ENTRY)
                .commit();

    return true;
}

and popping that back off in onDestroyActionMode and instead of checking in onBackPressed for (fragmentManager.getBackStackEntryCount () != 0) , I check for (fragmentManager.getBackStackEntryCount () == 1) .

I'm kind of proud of the workaround, but I realise it's not the cleanest of solutions...