Adding function to addToBackStack()

Question

I'm using an OnClickListener to do a fragment replacement. I'm toggling 3 LinearLayouts to 'GONE' within the OnClickListener also.

I would like to add a function to set the 3 LinearLayouts back to VISIBLE when the back button is pressed. The fragments swap back, but the LinearLayouts don't change their state.

Any help is appreciated, thanks!

final OnClickListener swapFragments = new OnClickListener() {
    @Override
    public void onClick(View v) {
        if (myAdapter.isEmpty() != true) {
            FragmentTransaction ft = getFragmentManager()
                    .beginTransaction();

            FragmentTwoTop ftt = new FragmentTwoTop();
            FragmentTwoBottom ftb = new FragmentTwoBottom();

            ft.replace(R.id.leftTopHolder, ftt, "fragmenttwotop");
            ft.replace(R.id.leftBottomtHolder, ftb, "fragmenttwobottom");

            layoutOne.setVisibility(View.GONE);
            layoutTwo.setVisibility(View.GONE);
            layoutThree.setVisibility(View.GONE);

            ft.addToBackStack("swapfragments");

            ft.commit();

        } else {

        }
    }
};

Answer 1

You could try adding a listener to the backstack: http://developer.android.com/reference/android/app/FragmentManager.html#addOnBackStackChangedListener(android.app.FragmentManager.OnBackStackChangedListener)

It will be called any time "something" is added or removed from/to the backstack.

You can then check the type of the class of the fragment (or maybe your holding the current fragment in a class - your Activity - variable) to decide if it's necessary to execute your animation.

The method in which you manage the layouts could simply check the visibility (getVisibility) and if it's VISIBLE then set to GONE, if it's GONE set to VISIBLE.