Existe alguma maneira de aumentar e diminuir o zoom?ImageView continuamente no Android. Eu tentei usar o código abaixo, mas apenas um da função Zoom está funcionando.

zoomin.xml

    <?xml version="1.0" encoding="utf-8"?>
    <set xmlns:android="http://schemas.android.com/apk/res/android"
    android:fillAfter="true" > 
    <scale
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:duration="20000"
        android:fromXScale="1"
        android:fromYScale="1"
        android:pivotX="50%"
        android:pivotY="50%"
        android:toXScale="3"
        android:toYScale="3" >
    </scale>

</set>

zoomout.xml

    <?xml version="1.0" encoding="utf-8"?>
    <set xmlns:android="http://schemas.android.com/apk/res/android"
    android:fillAfter="true" > 
    <scale
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:duration="20000"
        android:fromXScale="1.0"
        android:fromYScale="1.0"
        android:pivotX="50%"
        android:pivotY="50%"
        android:toXScale="0.5"
        android:toYScale="0.5" >
    </scale>

</set>

E aActivity classe que eu tenho:

Animation zoomin, zoomout; //declared as public

@Override
public void onCreate(Bundle savedInstanceState) {
   // animation
    zoomin = AnimationUtils.loadAnimation(this, R.anim.zoomin);
    zoomout = AnimationUtils.loadAnimation(this, R.anim.zoomout);
    bgImage.setAnimation(zoomin);
    bgImage.setAnimation(zoomout);
    Thread t = new Thread(new Zoom());
    t.start();
}
private class Zoom implements Runnable {
    @Override
    public void run() {
        while (true) {              
            bgImage.startAnimation(zoomin);
            try {
                Thread.sleep(8000);
            } catch (InterruptedException e) {
                                    e.printStackTrace();
            }               
            bgImage.startAnimation(zoomout);
        }
    }
}

Aqui ozoomin animação parece estar funcionando bem. Existe alguma maneira de implementar ozoomin ezoomout animação continuamente ???

obrigado