Material Design layout animation

Question

One of the ideas of Android L is that popup window need to start their apparition from the point where the user tapped the screen.
For example, in Chrome Beta (@time * 5) :

The idea is to be able to make the view grow from any pivot point (not just the predetermined position of the overflow button) Has anybody been able to do this or is not doable at the moment ?

Answer 1

It seems like it there is no clean way to do this.
The only viable option I have found is to write 4 different xml animations (for the 4 corners, more if you want to allow for centered growing), all ScaleAnimations from 0 to 1, with different pivot points for each (the 4 corners).

Then, use a DialogFragment :

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) 
{
    final Dialog dialog = super.onCreateDialog(savedInstanceState);
    dialog.getWindow().getAttributes().windowAnimations = 
         R.style.downRightCornerAnimation;
    //instead of referring to R.*, call a method to get the specific
    //resource you need for a given start position
    return dialog;
}

And one example of such an animation :

<?xml version="1.0" encoding="utf-8"?>
<scale xmlns:android="http://schemas.android.com/apk/res/android"
       android:interpolator="@android:anim/linear_interpolator"
       android:fromXScale="0.0"
       android:toXScale="1.0"
       android:fromYScale="0.0"
       android:toYScale="1.0"
       android:fillAfter="false"
       android:duration="200" 
       android:pivotX = "0%"
       android:pivotY = "100%"/>   

It is very unwieldy and hacky but I don't think the SDK gives us a better tool to do this (AFAIK you can't just inject a dynamic ObjectAnimator in DialogFragment or PopupWindow)