PreferenceScreen android:summary update !

Question

In my android application I have a PreferenceScreen parent that has 3 CheckBoxPreferences as children.

When I click the parent preferenceScreen, and the 3 checkboxes are displayed, I select one of them, and in the Preference.OnPreferenceChangeListener asociated with the checkboxes I set the parent's preferenceScreen summary with:

Parent.setSummary("string depending on the selection")

The thing is that when I return to the parent, it's summary is not updated, even if internally the value has correspondingly changed to the value setted.

Has anyone any idea regarding this behavior?

One thing to note, that if the preference of interest is itself `CheckBoxPreference` (or other `TwoStatePreference`, such as `SwitchPreference`), then `setSummary` doesn't work if `android:summaryOn` or `android:summaryOff` was assigned. One should use `setSummaryOn` and `setSummaryOff` in such case, which is not obvious imho. — Stan, Jun 27 '15 at 12:52

score 14 · Answer 1 · answered Mar 07 '13 at 20:59

14

Use

Parent.setSummary("string depending on the selection");
((BaseAdapter)getPreferenceScreen().getRootAdapter()).notifyDataSetChanged();

works like a charm and can be used regardless the place you change the summary.

answered Mar 07 '13 at 20:59

halxinate

1,509
15
22

If the screens are nested within other screens, then this should be done on the immediate parent screen. – Learn OpenGL ES Jun 16 '16 at 15:12

score 2 · Answer 2 · answered May 04 '15 at 14:45

This is the correct way

Preference pref = findPreference(getString(R.string.key_of_pref));
PreferenceScreen parent = (PreferenceScreen) sf.findPreference(getString(R.string.key_of_preference_screen));
pref.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
   @Override
   public boolean onPreferenceChange(Preference preference, Object newValue) {
       boolean newValueBool = (Boolean) newValue;
       parent.setSummary(newValueBool ? "Summary is true" : "Summary is false");                                                  
       ((BaseAdapter) getPreferenceScreen().getRootAdapter()).notifyDataSetChanged();
       // true to update the state of the Preference with the new value
       // in case you want to disallow the change return false
       return true;
  }
});

score 1 · Answer 3 · edited Jan 05 '12 at 08:53

1

I discovered that it seems to work by following up setSummary() with getListView().invalidate()

edited Jan 05 '12 at 08:53

sra

23,820
7
55
89

answered Aug 03 '10 at 02:05

Jonathan Taylor

11
1

score 1 · Answer 4 · edited May 23 '17 at 12:02

1

You can use BaseAdapter.notifyDataSetChanged() on the parent PreferenceScreen to update the UI. See here for example code: Update existing Preference-item in a PreferenceActivity upon returning from a (sub)PreferenceScreen

edited May 23 '17 at 12:02

Community

1
1

answered Feb 18 '11 at 11:47

Asmo Soinio

1,182
12
12

score 1 · Answer 5 · answered Jul 04 '18 at 15:40

If you're using support preference than go for:

findPreference("your_preference").setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {

            public boolean onPreferenceChange(Preference preference, Object o) {
                getListView().getAdapter().notifyDataSetChanged();
                return true;
            }
        });

score 0 · Answer 6 · edited Jun 17 '15 at 15:53

The new insistence on fragments instead of activities seems to make this harder. The invalidate route didn't seem to work nor approaches using the underlying View. Thanks to halxinate's answer I have now managed to work this through. For people who are as new as I am to all this here are a few more details:

When creating the settings fragment, save a reference in your main activity, e.g.:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    switch (item.getItemId()) {
    case R.id.action_preferences:
        if (getFragmentManager().getBackStackEntryCount() < 1) {
            FragmentTransaction trans = getFragmentManager()
                    .beginTransaction();
            // Save a reference to the settings fragment
            settingsFrag = new SettingsFragment();
            trans.replace(R.id.container, settingsFrag);
            trans.addToBackStack(null);
            trans.commit();
        }
        return true;
    default:
        return super.onOptionsItemSelected(item);
    }
}

Then when you want to update the summaries of the outer PreferenceScreen from the OnSharedPreferenceChangeListener use this sort of thing. Note that you need to have defined a key in your preference fragment xml for the outer PreferenceScreen (in this case android:key="prefs_root"):

public static void setOuterSummaries(SettingsFragment sf) {
    // Set the outer preferences summaries
    if (sf == null)
        return;
    //Code to update the summaries....

    // Force the parent screen summaries to update
    prefScr = (PreferenceScreen) sf.findPreference("prefs_root");
    if (prefScr != null)
            ((BaseAdapter) prefScr.getRootAdapter()).notifyDataSetChanged();

}

OnSharedPreferenceChangeListener listener = new SharedPreferences.OnSharedPreferenceChangeListener() {
    public void onSharedPreferenceChanged(SharedPreferences prefs,
            String key) {
        Log.e("L", "Change");
        setOuterSummaries(settingsFrag);
    }
};

Note that you could save a reference to the BaseAdapter instead of to the settings fragment but this approach seems safer when you think of generalizing it to a multi-fragment situation or code which dynamically creates the fragment content.

PreferenceScreen android:summary update !

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