Reacting to Preference changes

When a user changes a preference your program needs to react and update according to the change. The way to catch the change is to use PreferenceChangeListner. It implemented like this:

listener = new SharedPreferences.OnSharedPreferenceChangeListener() {
        public void onSharedPreferenceChanged(SharedPreferences prefs, String key) {
  // code goes here to implement changes
}

};

prefs.registerOnSharedPreferenceChangeListener(listener);