I've got a massive problem with the way the android fragment backstack seems to work and would be most grateful for any help that is offered.

Imagine you have 3 Fragments

[1] [2] [3]

I want the user to be able to navigate [1] > [2] > [3] but on the way back (pressing back button) [3] > [1].

As I would have imagined this would be accomplished by not calling addToBackStack(..) when creating the transaction that brings fragment [2] into the fragment holder defined in XML.

The reality of this seems as though that if I dont want [2] to appear again when user presses back button on [3], I must not call addToBackStack in the transaction that shows fragment [3]. This seems completely counter-intuitive (perhaps coming from the iOS world).

Anyway if i do it this way, when I go from [1] > [2] and press back I arrive back at [1] as expected.

If I go [1] > [2] > [3] and then press back I jump back to [1] (as expected). Now the strange behavior happens when I try and jump to [2] again from [1]. First of all [3] is briefly displayed before [2] comes into view. If I press back at this point [3] is displayed, and if I press back once again the app exits.

Can anyone help me to understand whats going on here?

And here is the layout xml file for my main activity:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"
          android:orientation="vertical" >

<fragment
        android:id="@+id/headerFragment"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        class="com.fragment_test.FragmentControls" >
    <!-- Preview: layout=@layout/details -->
</fragment>
<FrameLayout
        android:id="@+id/detailFragment"
        android:layout_width="match_parent"
        android:layout_height="fill_parent"

        />

Update This is the code I'm using to build by nav heirarchy

    Fragment frag;
    FragmentTransaction transaction;


    //Create The first fragment [1], add it to the view, BUT Dont add the transaction to the backstack
    frag = new Fragment1();

    transaction = getSupportFragmentManager().beginTransaction();
    transaction.replace(R.id.detailFragment, frag);
    transaction.commit();

    //Create the second [2] fragment, add it to the view and add the transaction that replaces the first fragment to the backstack
    frag = new Fragment2();

    transaction = getSupportFragmentManager().beginTransaction();
    transaction.replace(R.id.detailFragment, frag);
    transaction.addToBackStack(null);
    transaction.commit();


    //Create third fragment
    frag = new Fragment3();
    transaction = getSupportFragmentManager().beginTransaction();
    transaction.replace(R.id.detailFragment, frag);
    transaction.commit();


     //END OF SETUP CODE-------------------------
    //NOW:
    //Press back once and then issue the following code:
    frag = new Fragment2();
    transaction = getSupportFragmentManager().beginTransaction();
    transaction.replace(R.id.detailFragment, frag);
    transaction.addToBackStack(null);
    transaction.commit();

    //Now press back again and you end up at fragment [3] not [1]

Many thanks