Question

I have a Restore default settingsoption in my PreferenceActivity. After the settings are changed I call onContentChanged(). But for some reason the visual state of my CheckboxPreference is not updated.

The only workaround if found is to update the state manually:

SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
boolean autoStartValue = prefs.getBoolean("auto_start", true);

CheckBoxPreference autoStartPref = (CheckBoxPreference)findPreference("auto_start");
autoStartPref.setChecked(autoStartValue);

// Notify that the preferences changed
EditPreferencesActivity.this.onContentChanged();

What is the correct way of doing this?

Answer 1

You have to register the OnSharedPreferenceChangeListener()
and update your preference yourself.

@Override
protected void onResume() {
    super.onResume();
    // Set up a listener whenever a key changes
    getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
}

@Override
protected void onPause() {
    super.onPause();
    // Unregister the listener whenever a key changes
    getPreferenceScreen().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this);
}

public void onSharedPreferenceChanged(SharedPreferences prefs, String key) {
    Log.i(TAG, "o--> onSharedPreferenceChanged");
    Preference p = findPreference(key);
    if(p instanceof CheckBoxPreference){
        CheckBoxPreference checkBoxPref = (CheckBoxPreference) p;
        checkBoxPref.setChecked(prefs.getBoolean(key, true));
    }
}