Clicking app icon doesn't trigger onOptionsItemSelected()

Question

I'm currently working on an Android app. I would like to use the app icon in the action bar to navigate to the "home" activity. I read on this page that all that needs to be done is to add an onOptionsItemSelected and look for the id android.R.id.home.

This is the code that I have implemented in my activity where I want to press the app icon to return to HomeActivity.

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch(item.getItemId()) {
    case android.R.id.home:
        Intent intent = new Intent(this, HomeActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        startActivity(intent);
        return true;
    default:
        return super.onOptionsItemSelected(item);
    }
}

However, nothing happens. When debugging, I can see that clicking the icon doesn't trigger the onOptionsItemSelected() at all. Do I have to do something with the icon somewhere? As of now, it's all default, just this in the AndroidManifest.xml

<application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" >