1. Android Listeners:
http://developer.android.com/reference/android/view/View.html
2. States event:
1). http://*.com/questions/8411418/android-button-states-programmatically-in-java-not-xml
2). http://*.com/questions/5092649/android-how-to-update-the-selectorstatelistdrawable-programmatically
3).http://developer.android.com/reference/android/graphics/drawable/StateListDrawable.html
4). http://developer.android.com/reference/android/widget/ImageButton.html