How to reflect changes in preferences to class?

Question

I created a simple class "User" that has an attribute String username. I'm assuming that since Android uses Java, I can create custom classes and it'll use them accordingly. In my SettingsActivity.java, I have:

protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
    addPreferencesFromResource(R.xml.pref_general);


    SharedPreferences sharedPref = getPreferenceScreen().getSharedPreferences();
    EditTextPreference editTextPref = (EditTextPreference) findPreference("username");
    editTextPref.setSummary(sharedPref.getString("username", "Default"));
    //sharedPref.registerOnSharedPreferenceChangeListener(this);

}

public void onSharedPreferenceChanged(SharedPreferences arg0, String arg1) {
    // Get current summary
    Preference pref = findPreference(arg1);
    if(pref instanceof EditTextPreference){
        EditTextPreference etp = (EditTextPreference) pref;
        pref.setSummary(etp.getText());
        MainMenu.user.setName(etp.getText()); //This is where I try to update my class
    }
}

As of right now, whenever I change the value of my EditTextPreference widget, it doesn't update the public static user object located in MainMenu. Also, a followup question - since Android saves the preferences with each instance of app launch, how would I update my User.username String on startup?

Answer 1

In onPostCreate remove the comment //

sharedPref.registerOnSharedPreferenceChangeListener(this);