I am trying to implement preferences with sub-screens using AppCompatActivity and support.v7.preference
According to the docs, every PreferenceScreen within another PreferenceScreen functions as a sub-screen, and the framework will handle displaying it when clicked. http://developer.android.com/guide/topics/ui/settings.html#Subscreens
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"> <!-- opens a subscreen of settings --> <PreferenceScreen android:key="button_voicemail_category_key" android:title="@string/voicemail" android:persistent="false"> <ListPreference android:key="button_voicemail_provider_key" android:title="@string/voicemail_provider" ... /> <!-- opens another nested subscreen --> <PreferenceScreen android:key="button_voicemail_setting_key" android:title="@string/voicemail_settings" android:persistent="false"> ... </PreferenceScreen> <RingtonePreference android:key="button_voicemail_ringtone_key" android:title="@string/voicemail_ringtone_title" android:ringtoneType="notification" ... /> ... </PreferenceScreen> ... </PreferenceScreen>
This works fine using native Activity, PreferenceFragment... but using AppCompatActivity and PreferenceFragmentCompat, clicking the Preference element just highlights it, but doesn't open the sub-screen.
I couldn't find anything on this reading the docs and the code... do I need to implement any additional callbacks?
EDIT: just for completeness...
This works and opens the sub-screen:
public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); if (savedInstanceState == null) { getFragmentManager().beginTransaction() .replace(android.R.id.content, new DemoPreferenceFragment()) .commit(); } } static public class DemoPreferenceFragment extends PreferenceFragment { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.preferences); } } }
This doesn't work/open the sub-screen:
public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); if (savedInstanceState == null) { getSupportFragmentManager().beginTransaction() .replace(android.R.id.content, new DemoPreferenceFragment()) .commit(); } } static public class DemoPreferenceFragment extends PreferenceFragmentCompat { @Override public void onCreatePreferences(Bundle bundle, String s) { addPreferencesFromResource(R.xml.preferences); } } }
Edit: 25/01/2016
After fiddling with support.v7.preference for a few days, I've summed up my findings here, hoping it may help others: HowTo use support.v7.preference with AppCompat and potential drawbacks
The preference option doesn't exist anymore. You will need to right click the res -> new -> Android resource file and choose the resource type as xml in the dropdown. Then you will manually need to add the layout for preference xml.
Use the AndroidX Preference Library for consistent behavior across all devices. For more information on using the AndroidX Preference Library see Settings. Represents a top-level Preference that is the root of a Preference hierarchy. A PreferenceActivity points to an instance of this class to show the preferences.
It looks like a bug in PreferenceFragmentCompat or insufficiency of docs. It has method onNavigateToScreen which is called when you click on PreferenceScreen item.
But method getCallbackFragment() returns null by default, so you need override it in your fragment to return this. Also you need to implement PreferenceFragmentCompat.OnPreferenceStartScreenCallback.
public class SettingsFragment extends PreferenceFragmentCompat implements PreferenceFragmentCompat.OnPreferenceStartScreenCallback { public static SettingsFragment newInstance() { return new SettingsFragment(); } @Override public void onCreatePreferences(Bundle savedInstanceState, String rootKey) { addPreferencesFromResource(R.xml.news_settings); } @Override public Fragment getCallbackFragment() { return this; } @Override public boolean onPreferenceStartScreen(PreferenceFragmentCompat preferenceFragmentCompat, PreferenceScreen preferenceScreen) { preferenceFragmentCompat.setPreferenceScreen(preferenceScreen); return true; } }
But it leads to another problem when you can't get back to your initial PreferenceScreen,
Another way is to replace fragment which is described here How to move back from Preferences subscreen to main screen in PreferenceFragmentCompat?
This is complete working example, I hope this will be helpful to someone.It covers opening the preference subscreen and moving back to main Settings screen.
I followed this issue in Android open source issue tracker --here
The official documentation is missing the documentation for loading preference subscreen—Refer here for official documentation--
The main advanced settings screen has 2 checkboxes and a disabled subscreen title(custom Pattern Settings):-
Once we check the Custom checkbox, the subscreen title is enabled.
On click of Custom pattern settings, the subscreen opens in new screen
Here is the example code with documentation:--
In res/xml/preferences.xml file:--
<?xml version="1.0" encoding="utf-8"?> <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" android:summary="Trying intro text"> <PreferenceCategory android:title="Settings"> <CheckBoxPreference android:defaultValue="true" android:key="defaultPress" android:title="Default settings" /> <CheckBoxPreference android:defaultValue="false" android:key="customKey" android:title="Custom" /> <PreferenceScreen android:key="customPrefKey" android:title="Custom Pattern Settings"> <PreferenceCategory android:key="customSettingsKey" android:title="Custom Settings"> <ListPreference android:defaultValue="4" android:entries="@array/initialClickArray" android:entryValues="@array/initialClickValues" android:key="initialClicks" android:summary="initialClicksSummary" android:title="No. Of Clicks" /> <ListPreference android:defaultValue="5" android:entries="@array/initialTimeArray" android:entryValues="@array/initialTimeValues" android:key="initialTimeKey" android:summary="Time to complete clicks" android:title="Time to complete" /> </PreferenceCategory> </PreferenceScreen> </PreferenceCategory> </PreferenceScreen>
MainActivity.java should implement interface PreferenceFragmentCompat.OnPreferenceStartScreenCallback
and then override the method-- onPreferenceStartScreen
public class MainActivity extends AppCompatActivity implements PreferenceFragmentCompat.OnPreferenceStartScreenCallback { private static final String TAG = MainActivity.class.getName(); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); FragmentManager fragmentManager = getSupportFragmentManager(); Fragment fragment = null; if (savedInstanceState == null) { FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction(); fragment = new AdvancedSettingsFragment().newInstance("Advanced Setting"); fragmentTransaction.add(R.id.fragment_container, fragment); fragmentTransaction.commit(); } } @Override public boolean onPreferenceStartScreen(PreferenceFragmentCompat preferenceFragmentCompat, PreferenceScreen preferenceScreen) { Log.d(TAG, "callback called to attach the preference sub screen"); FragmentTransaction ft = getSupportFragmentManager().beginTransaction(); AdvancedSettingsSubScreenFragment fragment = AdvancedSettingsSubScreenFragment.newInstance("Advanced Settings Subscreen"); Bundle args = new Bundle(); //Defining the sub screen as new root for the subscreen args.putString(PreferenceFragmentCompat.ARG_PREFERENCE_ROOT, preferenceScreen.getKey()); fragment.setArguments(args); ft.replace(R.id.fragment_container, fragment, preferenceScreen.getKey()); ft.addToBackStack(null); ft.commit(); return true; }
For the main Settings screen(fragment):-
public class AdvancedSettingsFragment extends PreferenceFragmentCompat { private static final String TAG = AdvancedSettingsFragment.class.getName(); public static final String PAGE_ID = "page_id"; public static AdvancedSettingsFragment newInstance(String pageId) { AdvancedSettingsFragment f = new AdvancedSettingsFragment(); Bundle args = new Bundle(); args.putString(PAGE_ID, pageId); f.setArguments(args); return (f); } @Override public void onCreatePreferences(Bundle savedInstanceState, String rootKey) { // Load the preferences from an XML resource addPreferencesFromResource(R.xml.preferences); final CheckBoxPreference customPreference = (CheckBoxPreference) findPreference("customKey"); final Preference customSettings = (Preference) findPreference("customPrefKey"); // First time loading the preference screen, we check the saved settings and enable/disable the custom settings, based on the custom check box //get the customSettings value from shared preferences if (getCustomSettings(getActivity())) { customPreference.setChecked(true); customSettings.setEnabled(true); } else { customPreference.setChecked(false); customSettings.setEnabled(false); } customPreference.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() { @Override public boolean onPreferenceChange(Preference preference, Object selectedValue) { Log.d(TAG, "Inside on preference change of custom checkbox selection " + selectedValue.getClass()); if ((Boolean) selectedValue) { customSettings.setEnabled(true); }else{ customSettings.setEnabled(false); } return true; } }); } private boolean getCustomSettings(Context context) { return PreferenceManager.getDefaultSharedPreferences(getActivity()).getBoolean("customKey", false); } }
and finally for the loading of subscreen:
public class AdvancedSettingsSubScreenFragment extends PreferenceFragmentCompat { private static final String TAG = AdvancedSettingsSubScreenFragment.class.getName(); public static final String PAGE_ID = "page_id"; public static AdvancedSettingsSubScreenFragment newInstance(String pageId) { AdvancedSettingsSubScreenFragment f = new AdvancedSettingsSubScreenFragment(); Bundle args = new Bundle(); args.putString(PAGE_ID, pageId); f.setArguments(args); return (f); } @Override public void onCreatePreferences(Bundle savedInstanceState, String rootKey) { // rootKey is the name of preference sub screen key name , here--customPrefKey setPreferencesFromResource(R.xml.preferences, rootKey); Log.d(TAG, "onCreatePreferences of the sub screen " + rootKey); } }
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