This should do the trick :) I did not test it but it should work.
public void onRightToLeftSwipe(){
Log.i(logTag, "RightToLeftSwipe!");
if(position < mThumbId.length - 1){
position++;
changeBackground();
}
}
public void onLeftToRightSwipe(){
Log.i(logTag, "LeftToRightSwipe!");
if(position > 0){
position--;
changeBackground();
}
}
private void changeBackground(){
full.setBackgroundResource(mThumbId[position]);
}