fragments, android:zAdjustment (z order) and animations

Question

I\'m using the support library. Now, I want to have a fragment shifting in from the bottom, moving OVER the previous one.

For this I use this to keep the previous fragme

Answer 1

I've also got stuck with that problem. So instead of using transaction.replace(containerId, newFragment) I've created two containers for fragments and now my code looks like this one

Add first fragment:

transaction.add(containerId1, firstFragment).commit();

Add second fragment with animation over the first one:

findViewById(containerId2).bringToFront();
transaction.setCustomAnimations(R.anim.slide_in_up,
 R.anim.stay).remove(oldFragment).add(containerId2, newFragment).commit()

Answer 2

You can override the onCreateAnimation method and for any animations you can check what animation is currently running and if you need it to be on top, set the Z-axis from there.

override fun onCreateAnimation(transit: Int, enter: Boolean, nextAnim: Int): Animation? {
    if (nextAnim == R.anim.enter_from_right || nextAnim == R.anim.exit_to_right) {
        ViewCompat.setTranslationZ(view, 1f)
    } else {
        ViewCompat.setTranslationZ(view, 0f)
    }

    return super.onCreateAnimation(transit, enter, nextAnim)
}

Recommend implementing this as a base Fragment class for all your fragments.

Answer 3

According to this google group thread Z adjustment only works for window animations.

"The Z adjustment only works for window animations. I thought this was documented, but apparently not." -- Dianne Hackborn (Android framework engineer)