swap fragment in an activity via animation

Old questiion and you probably already figured it out, but for future reference:

here's what you use to set a custom animation when you replace a fragment via code:

FragmentTransaction ft = getSupportFragmentManager().beginTransaction();

ft.setCustomAnimations(R.anim.slide_in_left, R.anim.slide_out_right);
ft.replace(R.id.fragment_container, newFragment, "fragment");
// Start the animated transition.
ft.commit();

Here is an example of the slide_in_left animation:

<?xml version="1.0" encoding="utf-8"?>
<set>
  <translate xmlns:android="http://schemas.android.com/apk/res/android"
   android:fromXDelta="-100%"
   android:toXDelta="0"
   android:interpolator="@android:anim/decelerate_interpolator"
   android:duration="500"/>
</set>

Note that this is the animation if you are using the compatibility library. Instead if you are using and SDK with native support for the FragmentManager then your animation will look like this:

<?xml version="1.0" encoding="utf-8"?>
<set>
  <objectAnimator xmlns:android="http://schemas.android.com/apk/res/android"
    android:propertyName="x" 
    android:valueType="floatType"
    android:valueFrom="-1280"
    android:valueTo="0" 
    android:duration="500"/>
</set>

This is because the compatibility library does not support the new objectAnimator type and instead only implement the old animation framework.