When you press the button, it starts the change method using the Animation Scale and Alpha IAMGEView, it happens normally, and it happens the error

Android “Only The Original Thread That Created A View Hierarchy Can Touch Its Views.

// code is inside a listener for a button
NEW Thread (new Runnable () {
            Public void Run () {
              imageviewRipple2.startanimation (Animation2);
            }
          }). start ();

Answer 1, Authority 100%

Any actions with UI must be performed in the UI stream, otherwise – an error. But if you need to perform calculations in another stream, and then post the result in UI, then use Handler .