How to keep only one instance of a fragment, when switching with NavigationDrawer?

Question

My App starts with a AddressFragment. From the NavigationDrawer I start (amongst others) a new AddressFragment with:

getSupportFragmentManag         


        

Answer 1

Step one:

Optimize current code to allow a Fragment to have his own "TAG"

getSupportFragmentManager().beginTransaction()
                .replace(R.id.container, new AddressFragment())
                .addToBackStack(**AddressFragment.class.getName()**)
                .commit();

Step two:

Somewhere in your application flow you will need to determine if a fragment exists:

public static boolean isFragmentInBackstack(final FragmentManager fragmentManager, final String fragmentTagName) {
    for (int entry = 0; entry < fragmentManager.getBackStackEntryCount(); entry++) {
        if (fragmentTagName.equals(fragmentManager.getBackStackEntryAt(entry).getName())) {
            return true;
        }
    }
    return false;
}

Step three:

perform fragment action

if (exists) {
    // Fragment exists, go back to that fragment
    //// you can also use POP_BACK_STACK_INCLUSIVE flag, depending on flow
    mFragmentManager.popBackStackImmediate(AddressFragment.class.getName(), 0);

} else {
    // Fragment doesn't exist
    // STEP 1 + additional backstack management
}