Drawable Transition animation

DrawableTransition.kt

/* 
** res/drawable/transition_background.xml **
<transition xmlns:android="http://schemas.android.com/apk/res/android">

  <item android:drawable="@drawable/shape_selection_label_background_gray" />
  <item android:drawable="@drawable/shape_selection_label_background_blue" />

</transition>

** layout file **
<TextView
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:background="@drawable/transition_background"/>
  
*/

// Usage
val transition = textView.background as Transition
transition.startTransition(300)
transition.reverseTransition(300)