Toolbar is hidden in nested PreferenceScreen

Toolbar is hidden in nested PreferenceScreen - android

I use PreferenceFragment in ActionBarActivity from support-v7 library.
In the Activity I have Toolbar. Everything goes okay, until I open a nested PreferenceScreen.
In the opened screen the Toolbar is hidden.
Maybe somebody know a workaround for this issue?
Preferences xml-file:
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<PreferenceCategory android:title="Main category" >
<EditTextPreference
android:defaultValue="defaultValue"
android:key="key_global_setting"
android:title="Global title" />
</PreferenceCategory>
<PreferenceCategory android:title="Nested screens" >
<PreferenceScreen
android:persistent="false"
android:title="#string/settings_facility_title" >
<CheckBoxPreference
android:defaultValue="false"
android:key="nested_screen_1_1"
android:title="Nested screen 1.1 check box" />
<CheckBoxPreference
android:defaultValue="true"
android:key="nested_screen_1_2"
android:title="Nested screen 1.2 check box" />
</PreferenceScreen>
<PreferenceScreen
android:persistent="false"
android:title="#string/settings_menu_screen_title" >
<CheckBoxPreference
android:defaultValue="true"
android:key="nested_screen2"
android:title="Nested screen 2 check box" />
</PreferenceScreen>
</PreferenceCategory>
</PreferenceScreen>
Activity layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".SettingsScreen" >
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
style="#style/Toolbar" />
<FrameLayout
android:id="#+id/contentSettings"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>

I found the solution on my own. I used a small work-around of all this nested PreferenceScreen's. I simply made a separation to different xml-preference files, created an additional Fragment which extends PreferenceFragment and there I show an appropriate nested preference screen.
Maybe somebody would found this useful.
Github sources link.
Some code examples below:
main_preferences.xml
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<PreferenceCategory android:title="Main category" >
<EditTextPreference
android:defaultValue="defaultValue"
android:key="key_global_setting"
android:title="Global title" />
</PreferenceCategory>
<PreferenceCategory android:title="Nested screens" >
<Preference
android:key="NESTED_KEY1"
android:persistent="false"
android:title="Nested screen #1" />
<Preference
android:key="NESTED_KEY2"
android:persistent="false"
android:title="Nested screen #2" />
</PreferenceCategory>
</PreferenceScreen>
nested_screen1_preferences.xml
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
android:title="Nested screen #1" >
<CheckBoxPreference
android:defaultValue="false"
android:key="nested_screen_1_1"
android:title="Nested screen 1.1 check box" />
<CheckBoxPreference
android:defaultValue="true"
android:key="nested_screen_1_2"
android:title="Nested screen 1.2 check box" />
</PreferenceScreen>
nested_screen2_preferences.xml
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
android:title="Nested screen #2">
<CheckBoxPreference
android:defaultValue="true"
android:key="nested_screen2"
android:title="Nested screen 2 check box" />
</PreferenceScreen>
SettingsActivity.java
public class SettingsActivity extends ActionBarActivity implements MyPreferenceFragment.Callback {
private static final String TAG_NESTED = "TAG_NESTED";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_settings);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
if (toolbar != null) {
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.contentSettings, new MyPreferenceFragment())
.commit();
}
}
#Override
public void onBackPressed() {
// this if statement is necessary to navigate through nested and main fragments
if (getFragmentManager().getBackStackEntryCount() == 0) {
super.onBackPressed();
} else {
getFragmentManager().popBackStack();
}
}
#Override
public void onNestedPreferenceSelected(int key) {
getFragmentManager().beginTransaction().replace(R.id.contentSettings, NestedPreferenceFragment.newInstance(key), TAG_NESTED).addToBackStack(TAG_NESTED).commit();
}
}
MyPreferenceFragment.java
// The main preference fragment class
public class MyPreferenceFragment extends PreferenceFragment implements Preference.OnPreferenceClickListener {
private Callback mCallback;
private static final String KEY_1 = "NESTED_KEY1";
private static final String KEY_2 = "NESTED_KEY2";
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
if (activity instanceof Callback) {
mCallback = (Callback) activity;
} else {
throw new IllegalStateException("Owner must implement Callback interface");
}
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Load the preferences from an XML resource
addPreferencesFromResource(R.xml.main_preferences);
// add listeners for non-default actions
Preference preference = findPreference(KEY_1);
preference.setOnPreferenceClickListener(this);
preference = findPreference(KEY_2);
preference.setOnPreferenceClickListener(this);
}
#Override
public boolean onPreferenceClick(Preference preference) {
// here you should use the same keys as you used in the xml-file
if (preference.getKey().equals(KEY_1)) {
mCallback.onNestedPreferenceSelected(NestedPreferenceFragment.NESTED_SCREEN_1_KEY);
}
if (preference.getKey().equals(KEY_2)) {
mCallback.onNestedPreferenceSelected(NestedPreferenceFragment.NESTED_SCREEN_2_KEY);
}
return false;
}
public interface Callback {
public void onNestedPreferenceSelected(int key);
}
}
NestedPreferencesFragment.java
public class NestedPreferenceFragment extends PreferenceFragment {
public static final int NESTED_SCREEN_1_KEY = 1;
public static final int NESTED_SCREEN_2_KEY = 2;
private static final String TAG_KEY = "NESTED_KEY";
public static NestedPreferenceFragment newInstance(int key) {
NestedPreferenceFragment fragment = new NestedPreferenceFragment();
// supply arguments to bundle.
Bundle args = new Bundle();
args.putInt(TAG_KEY, key);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
checkPreferenceResource();
}
private void checkPreferenceResource() {
int key = getArguments().getInt(TAG_KEY);
// Load the preferences from an XML resource
switch (key) {
case NESTED_SCREEN_1_KEY:
addPreferencesFromResource(R.xml.nested_screen1_preferences);
break;
case NESTED_SCREEN_2_KEY:
addPreferencesFromResource(R.xml.nested_screen2_preferences);
break;
default:
break;
}
}
}

Here comes my solution, which is inspired by the original answer but not that complicated. Maybe it'll help someone...
layout/settings.xml:
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<include
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
layout="#layout/toolbar" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/content"
android:layout_below="#+id/toolbar"/>
</RelativeLayout>
Classes:
public class SettingsActivity extends ActionBarActivity {
#Override
protected void onCreate( Bundle savedInstanceState ) {
setContentView( R.layout.settings );
super.onCreate( savedInstanceState );
initializeSupportActionBar();
getFragmentManager().beginTransaction().replace( R.id.content, new MainFragment() ).commit();
}
#Override
public void onBackPressed() {
if( !getFragmentManager().popBackStackImmediate() ) super.onBackPressed();
}
}
public class MainFragment extends PreferenceFragment {
public MainFragment() {}
#Override
public void onCreate( Bundle savedInstanceState ) {
super.onCreate( savedInstanceState );
addPreferencesFromResource( R.xml.pref_main );
// "nested" is the <Preference android:key="nested" android:persistent="false"/>`
findPreference( "nested" ).setOnPreferenceClickListener( new OnPreferenceClickListener() {
#Override public boolean onPreferenceClick( Preference preference ) {
getFragmentManager().beginTransaction().replace( R.id.content, new NestedFragment() ).addToBackStack( NestedFragment.class.getSimpleName() ).commit();
return true;
}
} );
}
public class NestedFragment extends PreferenceFragment {
...
}
I tested it on 4.3 and 5.0.2 and no limitation on nesting levels applies

In my solution you only need one AppCompatActivity and one PreferenceFragement, but several XML files, each having only one level of PreferenceScreens.
XML file list
top level PreferenceScreen
second level PreferenceScreen 0
second level PreferenceScreen 1
second level PreferenceScreen 2
...
This code is for one sub-level (for simplicity and to get the idea), but you can easily extend it to have arbitrary sub-levels of PreferenceScreens.
SettingsFragment.java
public class SettingsFragment extends PreferenceFragment
{
private int xmlId;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
xmlId = R.xml.preferences;
addPreferencesFromResource(xmlId);
}
public void changePrefScreen(int xmlId, int titleId)
{
this.xmlId = xmlId;
((AppCompatActivity)getActivity()).getSupportActionBar().setTitle(getActivity().getResources().getString(titleId));
getPreferenceScreen().removeAll();
addPreferencesFromResource(xmlId);
}
// will be called by SettingsActivity (Host Activity)
public void onUpButton()
{
if(xmlId == R.xml.preferences) // in top-level
{
// Switch to MainActivity
Intent intent = new Intent(getActivity(), MainActivity.class);
startActivity(intent);
}
else // in sub-level
{
changePrefScreen(R.xml.preferences, R.string.settings);
}
}
#Override
public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference)
{
String key = preference.getKey();
//
// Top level PreferenceScreen
//
if(key.equals("top_key_0"))
{
changePrefScreen(R.xml.download_preference_screen, R.string.download_database); // descend into second level
}
// ...
//
// Second level PreferenceScreens
//
if (key.equals("second_level_key_0"))
{
// do something...
}
// ...
}
SettingsActivity.java
public class SettingsActivity extends AppCompatActivity
{
SettingsFragment settingsFragment;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
settingsFragment = new SettingsFragment();
// Display the fragment as the main content.
getFragmentManager().beginTransaction()
.replace(android.R.id.content, settingsFragment)
.commit();
}
//
// Handle what happens on up button
//
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId())
{
case android.R.id.home:
settingsFragment.onUpButton();
return true;
}
return true;
}
// ...
}
Technically it should work for all Android versions for which the PreferenceFragment is available.

As the issue comes from the part that you are still in the same activity/fragment and the nested pref screen is just a dialog you can do the following:
You can set preference click listener
Get the root view from the dialog:
(PreferenceScreen)preference).getDialog().getWindow()
.getDecorView().getRootView());
Recursively search until find a stub view (there is one, unfortunately I do not know the android.R.id.xxxxx) and set what layout you need as title which will look like the toolbar(You can inflate toolbar):
private Toolbar toolbar;
public void findViewStub(ViewGroup viewGroup) {
int childCount = viewGroup.getChildCount();
for (int i = 0; i < childCount; i++) {
View childView = viewGroup.getChildAt(i);
if( childView instanceof ViewStub){
((ViewStub)childView).setLayoutResource(R.layout.your_title_layout);
toolbar = ((ViewStub)childView).inflate();
}
if (childView instanceof ViewGroup) {
findViewStub((ViewGroup) childView);
}
}
}
toolbar.setNavigationIcon();
toolbar.setNavigationOnClickListener();
toolbar.setTitle();
In the layout you can put only a toolbar. And set the back icon. Register for click on it and having reference to the fragment, on click you can dismiss the dialog. You have set title and etc.

Related

Android - Setting activity inside a fragment is empty

I'm creating an app that contains 5 tabs in the bottom navigation menu. One of these tabs contains a default settings activity that I created with Android Studio. The onClick event on every tab displays a different fragment. When I click on the "Settings" button the fragment for the settings activity is loaded with no errors, however it is empty. I've looked elsewhere, but still haven't found an answer. My problem is not about displaying a group of settings in a different fragment, rather generating for the first time the Settings fragment itself.
I listen for the click event in the main activity. Then I load the right fragment class, this class calls the .SettingsActivity class that generates the view using settings_activity.xml and loads the "settings" from root_parameters.xml. I've changed nothing from the default activity created by Android Studio. And I'm loading it the same way I load the other fragments and they all work, including a Google Maps fragment.
This is my .MainActivity
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
setTheme(R.style.AppTheme);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
BottomNavigationView bottomNav = findViewById(R.id.bottom_navigation);
bottomNav.setOnNavigationItemSelectedListener(navListener);
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, new HomeFragment()).commit();
}
private BottomNavigationView.OnNavigationItemSelectedListener navListener =
new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem item) {
Fragment selectedFragment = null;
switch (item.getItemId()) {
case R.id.map_nav:
selectedFragment = new MapFragment();
break;
case R.id.settings_nav:
selectedFragment = new OldSettingsFragment();
break;
case R.id.user_nav:
selectedFragment = new UserFragment();
break;
case R.id.test_settings_nav:
selectedFragment = new SettingsFragment();
break;
default:
selectedFragment = new HomeFragment();
break;
}
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, selectedFragment).commit();
return true;
}
};
}
Here is my .SettingsFragment
public class SettingsFragment extends Fragment {
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.settings_activity, container, false);
}
}
This is the .SettingsActivity as created by Android Studio
public class SettingsActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.settings_activity);
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.settings, new SettingsFragment())
.commit();
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.setDisplayHomeAsUpEnabled(true);
}
}
public static class SettingsFragment extends PreferenceFragmentCompat {
#Override
public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
setPreferencesFromResource(R.xml.root_preferences, rootKey);
}
}
}
This is settings_activity.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:tools="http://schemas.android.com/tools"
tools:context=".TestSettings.SettingsActivity">
<FrameLayout
android:id="#+id/settings"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
And finally this is my root_preferences.xml
<PreferenceScreen xmlns:app="http://schemas.android.com/apk/res-auto">
<PreferenceCategory app:title="#string/app_name">
<EditTextPreference
app:key="signature"
app:title="#string/signature_title"
app:useSimpleSummaryProvider="true" />
<ListPreference
app:defaultValue="reply"
app:entries="#array/reply_entries"
app:entryValues="#array/reply_values"
app:key="reply"
app:title="#string/reply_title"
app:useSimpleSummaryProvider="true" />
</PreferenceCategory>
<PreferenceCategory app:title="#string/sync_header">
<SwitchPreferenceCompat
app:key="sync"
app:title="#string/sync_title" />
<SwitchPreferenceCompat
app:dependency="sync"
app:key="attachment"
app:summaryOff="#string/attachment_summary_off"
app:summaryOn="#string/attachment_summary_on"
app:title="#string/attachment_title" />
</PreferenceCategory>
PLEASE HELP.

You can not set an Activity in one of BottomNavigationView tabs instead of a fragment.
So, you need to replace SettingsActivity with a Fragment, I will name it as PreferenceFragment as you already has an inner SettingsFragment.
So modify your SettingsActivity with:
public class PreferenceFragment extends Fragment {
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_settings, container, false);
ActionBar actionBar = requireActivity().getSupportActionBar();
if (actionBar != null) {
actionBar.setDisplayHomeAsUpEnabled(true);
}
return view;
}
public static class SettingsFragment extends PreferenceFragmentCompat {
#Override
public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
setPreferencesFromResource(R.xml.root_preferences, rootKey);
}
}
}
So, now delete settings_activity.xml and you need to create fragment_settings.xml instead to have a static fragment for the inner SettingsActivity Fragment
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:id="#+id/settings_root"
android:layout_height="match_parent">
<fragment
android:id="#+id/settingsFragment"
class="com.xx.PreferenceFragment$SettingsFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</androidx.constraintlayout.widget.ConstraintLayout>
Note: replace the com.xx with your package name that holds the PreferenceFragment

You are loading the SettingsFragment on test_settings_nav click which inflate R.layout.settings_activity and the entire layout has a FrameLayout under a LinerLayout and you don't load anything in that FrameLayout so its Empty. Load something on that frame layout will appear in screen.

Cannot access preferences when specicying preference file

I'm quite new to Android development, and I've looked at the similar posts but I still can't get this to work. I can't retrieve SharedPreferences when specifying a preference file, which I try to do in PrefFragment and that's where SharedPreferences.getAll().size() returns 0.
src/main/res/xml/things.xml
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory app:title="things_category">
<SwitchPreference
app:key="thing"
app:title="thing"
/>
<Preference
app:fragment="org.thing.appo.PrefFragment2"
app:key="more_things_menu"
android:title="more things menu"/>
</PreferenceCategory>
</PreferenceScreen>
src/main/res/xml/more_things.xml
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android">
<SwitchPreference
app:key="more_things"
app:title="more things"
/>
</PreferenceScreen>
src/main/res/values/strings.xml
<resources>
<string name="app_name">appo</string>
<string name="things">things</string>
<string name="more_things">more_things</string>
</resources>
MainActivity
public class MainActivity extends AppCompatActivity implements
PreferenceFragmentCompat.OnPreferenceStartFragmentCallback {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (findViewById(R.id.fragment_container) != null) {
if (savedInstanceState != null) {
return;
}
getSupportFragmentManager()
.beginTransaction()
.add(R.id.fragment_container, new PrefFragment())
.commit();
}
}
#Override
public boolean onPreferenceStartFragment(PreferenceFragmentCompat caller, Preference pref) {
final Fragment fragment = getSupportFragmentManager().getFragmentFactory().instantiate(
getClassLoader(),
pref.getFragment());
getSupportFragmentManager().beginTransaction()
.replace(R.id.fragment_container, fragment)
.addToBackStack(null)
.commit();
return true;
}
}
PrefFragment
public class PrefFragment extends PreferenceFragmentCompat {
#Override
public void onCreatePreferences(Bundle savedInstanceState, String key) {
setPreferencesFromResource(R.xml.things, key);
Map<String, ?> things = getActivity().getSharedPreferences(getString(R.string.things), Context.MODE_PRIVATE).getAll();
System.out.println("things.size() = " + things.size()); // returns 0
Map<String, ?> moreThings = getActivity().getSharedPreferences(getString(R.string.more_things), Context.MODE_PRIVATE).getAll();
System.out.println("moreThings = " + moreThings.size()); // returns 0
Map<String, ?> all = PreferenceManager.getDefaultSharedPreferences(getActivity()).getAll();
System.out.println("all.size() = " + all.size()); // But here it returns 2
}
}
PrefFragment2
public class PrefFragment2 extends PreferenceFragmentCompat {
#Override
public void onCreatePreferences(Bundle savedInstanceState, String key) {
setPreferencesFromResource(R.xml.more_things, key);
}
}

With help from the comments, I googled a bit and found this https://stackoverflow.com/a/27872280/8120495. Problem solved. :)
EDIT:
Finally got it working by being able to access preferences from the child PreferencesScreen. Also, I had not really understood how SharedPreferences differs from Preferences and what Preferences gets saved to ShardPreferences. To get only the prefs from the child PreferenceScreen:
PreferenceScreen preferenceScreen = getPreferenceManager().inflateFromResource(getActivity(), R.xml.more_things.xml, null);
int count = preferenceScreen.getPreferenceCount();
for (int i = 0; i < count; i++) {
String key = preferenceScreen.getPreference(i).getKey();
//In this case, the child PreferenceScreen only has a single SwitchPreference, so now that we have its key, we can check its value
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getActivity());
boolean switchValue = sharedPreferences.getBoolean(key, false);
}

Load Preferences Settings in Swipable Tabs with Fragment

I have searched the web but didnt find any proper solution.
I am trying to load some preference Settings in Tab Fragments.
In the first Image, When I use menu Inflator, I get those 3 dotted buttons, I dont need those, insted I want the menu to load in my Tab Fragment.
Below is the code of my
SettingPrefActivity.java
public class SettingsPrefActivity extends AppPreferenceActivity {
private static final String TAG = SettingsPrefActivity.class.getSimpleName();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
// load settings fragment
getFragmentManager().beginTransaction().replace(android.R.id.content, new MainPreferenceFragment()).commit();
}
public static class MainPreferenceFragment extends PreferenceFragment {
#Override
public void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.pref_main);
// gallery EditText change listener
bindPreferenceSummaryToValue(findPreference(getString(R.string.key_gallery_name)));
// notification preference change listener
bindPreferenceSummaryToValue(findPreference(getString(R.string.key_notifications_new_message_ringtone)));
// feedback preference click listener
Preference myPref = findPreference(getString(R.string.key_send_feedback));
myPref.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
public boolean onPreferenceClick(Preference preference) {
sendFeedback(getActivity());
return true;
}
});
}
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == android.R.id.home) {
onBackPressed();
}
return super.onOptionsItemSelected(item);
}
private static void bindPreferenceSummaryToValue(Preference preference) {
preference.setOnPreferenceChangeListener(sBindPreferenceSummaryToValueListener);
sBindPreferenceSummaryToValueListener.onPreferenceChange(preference,
PreferenceManager
.getDefaultSharedPreferences(preference.getContext())
.getString(preference.getKey(), ""));
}
/**
* A preference value change listener that updates the preference's summary
* to reflect its new value.
*/
private static Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener() {
#Override
public boolean onPreferenceChange(Preference preference, Object newValue) {
String stringValue = newValue.toString();
if (preference instanceof ListPreference) {
// For list preferences, look up the correct display value in
// the preference's 'entries' list.
ListPreference listPreference = (ListPreference) preference;
int index = listPreference.findIndexOfValue(stringValue);
// Set the summary to reflect the new value.
preference.setSummary(
index >= 0
? listPreference.getEntries()[index]
: null);
} else if (preference instanceof RingtonePreference) {
// For ringtone preferences, look up the correct display value
// using RingtoneManager.
if (TextUtils.isEmpty(stringValue)) {
// Empty values correspond to 'silent' (no ringtone).
preference.setSummary(R.string.pref_ringtone_silent);
} else {
Ringtone ringtone = RingtoneManager.getRingtone(
preference.getContext(), Uri.parse(stringValue));
if (ringtone == null) {
// Clear the summary if there was a lookup error.
preference.setSummary(R.string.summary_choose_ringtone);
} else {
// Set the summary to reflect the new ringtone display
// name.
String name = ringtone.getTitle(preference.getContext());
preference.setSummary(name);
}
}
} else if (preference instanceof EditTextPreference) {
if (preference.getKey().equals("key_gallery_name")) {
// update the changed gallery name to summary filed
preference.setSummary(stringValue);
}
} else {
preference.setSummary(stringValue);
}
return true;
}
};
/**
* Email client intent to send support mail
* Appends the necessary device information to email body
* useful when providing support
*/
public static void sendFeedback(Context context) {
String body = null;
try {
body = context.getPackageManager().getPackageInfo(context.getPackageName(), 0).versionName;
body = "\n\n-----------------------------\nPlease don't remove this information\n Device OS: Android \n Device OS version: " +
Build.VERSION.RELEASE + "\n App Version: " + body + "\n Device Brand: " + Build.BRAND +
"\n Device Model: " + Build.MODEL + "\n Device Manufacturer: " + Build.MANUFACTURER;
} catch (PackageManager.NameNotFoundException e) {
}
Intent intent = new Intent(Intent.ACTION_SEND);
intent.setType("message/rfc822");
intent.putExtra(Intent.EXTRA_EMAIL, new String[]{"contact#androidhive.info"});
intent.putExtra(Intent.EXTRA_SUBJECT, "Query from android app");
intent.putExtra(Intent.EXTRA_TEXT, body);
context.startActivity(Intent.createChooser(intent, context.getString(R.string.choose_email_client)));
}}
SettingsActivity.java
public class SettingsActivity extends Fragment {
private static final String TAG = SettingsPrefActivity.class.getSimpleName();
/*public SettingsActivity() {
// Required empty public constructor
}*/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.setting_layout, container, false);
}
/*public boolean onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
// launch settings activity
startActivity(new Intent(SettingsActivity.this, SettingsPrefActivity.class));
return true;
}
return super.onOptionsItemSelected(item);
}*/
}
pref_main.xml
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory android:title="General">
<EditTextPreference
android:defaultValue="#string/default_gallery_storage"
android:key="#string/key_gallery_name"
android:summary="#string/default_gallery_storage"
android:title="#string/title_gallery_storage" />
<CheckBoxPreference
android:defaultValue="true"
android:key="#string/key_upload_over_wifi"
android:summary="#string/summary_upload_over_wifi"
android:title="#string/title_auto_upload" />
<ListPreference
android:defaultValue="3"
android:dialogTitle="#string/title_upload_quality"
android:entries="#array/pref_upload_quality_entries"
android:entryValues="#array/pref_upload_quality_values"
android:key="#string/key_upload_quality"
android:summary="#string/summary_upload_video_quality"
android:title="#string/title_upload_quality" />
</PreferenceCategory>
<PreferenceCategory android:title="#string/pref_title_notifications">
<SwitchPreference
android:defaultValue="true"
android:key="#string/notifications_new_message"
android:title="#string/title_new_notification_sound" />
<RingtonePreference
android:defaultValue="content://settings/system/notification_sound"
android:dependency="notifications_new_message"
android:key="#string/key_notifications_new_message_ringtone"
android:ringtoneType="notification"
android:summary="#string/summary_choose_ringtone"
android:title="#string/pref_title_ringtone" />
<SwitchPreference
android:defaultValue="true"
android:key="#string/key_vibrate"
android:summary="#string/summary_vibrate"
android:title="#string/title_vibrate" />
</PreferenceCategory>
<PreferenceCategory android:title="#string/pref_header_about">
<Preference
android:selectable="false"
android:summary="#string/summary_about" />
<Preference
android:summary="#string/app_version"
android:title="#string/title_version" />
<Preference
android:key="#string/key_send_feedback"
android:summary="#string/summary_support"
android:title="#string/title_send_feedback" />
<!-- preference opens url in browser -->
<Preference
android:summary="#string/summary_faq"
android:title="#string/title_faq">
<intent
android:action="android.intent.action.VIEW"
android:data="#string/url_faq" />
</Preference>
<Preference android:title="#string/privacy_policy">
<intent
android:action="android.intent.action.VIEW"
android:data="#string/url_privacy" />
</Preference>
<Preference android:title="#string/title_terms">
<intent
android:action="android.intent.action.VIEW"
android:data="#string/url_terms" />
</Preference>
</PreferenceCategory>
</PreferenceScreen>
menu_main.xml
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="settings.MainActivity">
<item
android:id="#+id/action_settings"
android:orderInCategory="100"
android:title="#string/action_settings"
app:showAsAction="never" />
</menu>
settings_layout.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="This is Settings Page!! Coming Soon!"
android:textSize="30dp"
android:textStyle="bold"
android:layout_centerInParent="true"/>
</RelativeLayout>
MainActivity.java
public class MainActivity extends AppCompatActivity {
private Toolbar toolbar;
private TabLayout tabLayout;
private ViewPager viewPager;
private int[] tabIcons = {R.drawable.ic_action_name};
String[] tabTitle={"","All"};
int[] unreadCount={0,5,3,0,12,3,9,0};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
viewPager = (ViewPager) findViewById(R.id.viewpager);
setupViewPager(viewPager);
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
viewPager.setCurrentItem(1);
setupTabIcons();
}
private View prepareTabView(int pos) {
View view = getLayoutInflater().inflate(R.layout.custom_tab,null);
TextView tv_title = (TextView) view.findViewById(R.id.tv_title);
TextView tv_count = (TextView) view.findViewById(R.id.tv_count);
tv_title.setText(tabTitle[pos]);
if(unreadCount[pos]>0)
{
tv_count.setVisibility(View.VISIBLE);
tv_count.setText(""+unreadCount[pos]);
}
else
tv_count.setVisibility(View.GONE);
return view;
}
private void setupTabIcons() {
tabLayout.getTabAt(0).setIcon(tabIcons[0]);
/*TabLayout.Tab tabitem = tabLayout.newTab();
tabitem.setCustomView(prepareTabView(i));
tabLayout.addTab(tabitem);*/
for(int i = 1; i < unreadCount.length; i++)
{
/*TabLayout.Tab tabitem = tabLayout.newTab();
tabitem.setCustomView(prepareTabView(i));
tabLayout.addTab(tabitem);*/
tabLayout.getTabAt(i).setCustomView(prepareTabView(i));
}
}
private TabLayout.OnTabSelectedListener onTabSelectedListener(final
ViewPager viewPager) {
return new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
};
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new
ViewPagerAdapter(getSupportFragmentManager());
adapter.addFragment(new SettingsActivity(), "");
adapter.addFragment(new AllTab(), "All");
viewPager.setAdapter(adapter);
}
class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
#Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
#Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="inc.apperz.passmanager.MainActivity">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light" />
<android.support.design.widget.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabMode="scrollable"
app:tabSelectedTextColor="#color/colorGreen"
app:tabTextColor="#color/colorWhite"
app:tabIndicatorColor="#color/colorWhite"
app:tabGravity="fill"/>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</android.support.constraint.ConstraintLayout>
Is there any possibility that I can include my main_menu.xml into my setting_layout.xml? such that it will get bind to my SettingsActivity.java?
If its possible, that would be great, but I tried that way and didn't find appropriate way to include it.
Can someone guide me to how to achieve this..

Try adding this to your fragment:
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
MenuItem item= menu.findItem(R.id.action_settings);
item.setVisible(false);
super.onPrepareOptionsMenu(menu);
return true;
}

Preference sub-screen not opening when using support.v7.preference

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

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);
}
}

One extremely important thing you need you remember:
Your PreferenceScreen must contain :
android:key="name_a_unique_key"
Otherwise, it will not work. I've spent hours with thí

Overriding PreferenceFragmentCompat.OnPreferenceStartScreenCallback
and adding the following to my preference fragment saved my day
#Override
public Fragment getCallbackFragment() {
return this;
}
#Override
public boolean onPreferenceStartScreen(PreferenceFragmentCompat caller, PreferenceScreen pref) {
caller.setPreferenceScreen(pref);
return true;
}
My preference version is
compile 'com.android.support:preference-v7:25.0.0'

It seems Google finally decides to support this in the newly released AndroidX preference 1.1.0-alpha.
This video from Android Dev Summit covers something about preference sub screen.

Inner PreferenceScreen does not open with PreferenceFragmentCompat

My inner PreferenceScreen of PreferenceFragmentCompat is not showing, or seems to ignore tapping events.
I created MyPreferenceFragment that extends PreferenceFragmentCompat
public class MyPreferenceFragment extends PreferenceFragmentCompat {
#Override
public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
addPreferencesFromResource(R.xml.preferences);
}
}
then I changed my theme at styles.xml like
<style name="AppTheme" parent="#style/Theme.AppCompat.Light">
<item name="preferenceTheme">#style/PreferenceThemeOverlay</item>
</style>
And finally create my preferences.xml file like
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<CheckBoxPreference android:title="Check Me"/>
<PreferenceScreen android:title="My Screen"> <!-- This is not opening -->
<EditTextPreference android:title="Edit text" />
</PreferenceScreen>
</PreferenceScreen>
At the build.gradle I have added both:
compile 'com.android.support:appcompat-v7:23.0.1'
compile 'com.android.support:preference-v7:23.0.1'
code of the Activity
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
activity_main.xml
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fragment"
android:name="com.mando.preferenceapp.MyPreferenceFragment"
android:layout_width="match_parent"
android:layout_height="match_parent" />
Testing the above code I cannot open / get into the preference screen. Am I missing something? Why this isn't working?

After spending many many hours with tries, searching and thankfully with some assistance from the creators of the support library. I've managed to make it work.
Step 1. Activity
public class MyActivity extends AppCompatActivity implements
PreferenceFragmentCompat.OnPreferenceStartScreenCallback {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
// Create the fragment only when the activity is created for the first time.
// ie. not after orientation changes
Fragment fragment = getSupportFragmentManager().findFragmentByTag(MyPreferenceFragment.FRAGMENT_TAG);
if (fragment == null) {
fragment = new MyPreferenceFragment();
}
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.fragment_container, fragment, MyPreferenceFragment.FRAGMENT_TAG);
ft.commit();
}
}
#Override
public boolean onPreferenceStartScreen(PreferenceFragmentCompat preferenceFragmentCompat,
PreferenceScreen preferenceScreen) {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
MyPreferenceFragment fragment = new MyPreferenceFragment();
Bundle args = new Bundle();
args.putString(PreferenceFragmentCompat.ARG_PREFERENCE_ROOT, preferenceScreen.getKey());
fragment.setArguments(args);
ft.replace(R.id.fragment_container, fragment, preferenceScreen.getKey());
ft.addToBackStack(preferenceScreen.getKey());
ft.commit();
return true;
}
}
Tips.
Do not add the fragment by xml you will have crashes on orientation changes.
Handle the recreations of activity / fragment add in onCreate so as to avoid losing your fragment when inside a preference screen.
The host activity of the fragment should implement the PreferenceFragmentCompat.OnPreferenceStartScreenCallback and recreate fragments of the same instance.
Step 2. PreferenceFragment
public class MyPreferenceFragment extends PreferenceFragmentCompat {
public static final String FRAGMENT_TAG = "my_preference_fragment";
public MyPreferenceFragment() {
}
#Override
public void onCreatePreferences(Bundle bundle, String rootKey) {
setPreferencesFromResource(R.xml.preferences, rootKey);
}
}
Tips.
Use the method setPreferencesFromResource and take advantage of the rootKey of each screen. This way your code will be reused properly.
Keep in mind that if you have code like findPreference in your fragment it should have null checks as when you were in inner screens this will give you nothing.
The thing that is missing now is the implementation of the back arrow in the actionbar (home action) but this never works by itself ;-)
I' also created a demo app wrapping all this code you can find it on github.

Solution is to start another fragment of the same class but with different root key. No Activity actions involved.
#Override
public void onCreatePreferences(Bundle savedInstanceState, String rootKey){
if(getArguments() != null){
String key = getArguments().getString("rootKey");
setPreferencesFromResource(R.xml.preferences, key);
}else{
setPreferencesFromResource(R.xml.preferences, rootKey);
}
}
#Override
public void onNavigateToScreen(PreferenceScreen preferenceScreen){
ApplicationPreferencesFragment applicationPreferencesFragment = new ApplicationPreferencesFragment();
Bundle args = new Bundle();
args.putString("rootKey", preferenceScreen.getKey());
applicationPreferencesFragment.setArguments(args);
getFragmentManager()
.beginTransaction()
.replace(getId(), applicationPreferencesFragment)
.addToBackStack(null)
.commit();
}

I did it slightly differently, I'm launching a new activity for each screen. This seems to require less hacks: no need to mess with swapping fragments and background colors. You also get activity change animation as a bonus!
public class PreferencesActivity extends AppCompatActivity implements PreferenceFragmentCompat.OnPreferenceStartScreenCallback {
final static private String KEY = "key";
#Override protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.preferences);
setSupportActionBar((Toolbar) findViewById(R.id.toolbar));
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) actionBar.setDisplayHomeAsUpEnabled(true);
if (savedInstanceState != null)
return;
Fragment p = new PreferencesFragment();
String key = getIntent().getStringExtra(KEY);
if (key != null) {
Bundle args = new Bundle();
args.putString(PreferenceFragmentCompat.ARG_PREFERENCE_ROOT, key);
p.setArguments(args);
}
getSupportFragmentManager().beginTransaction()
.add(R.id.preferences, p, null)
.commit();
}
#Override public boolean onPreferenceStartScreen(PreferenceFragmentCompat preferenceFragmentCompat, PreferenceScreen preferenceScreen) {
Intent intent = new Intent(PreferencesActivity.this, PreferencesActivity.class);
intent.putExtra(KEY, preferenceScreen.getKey());
startActivity(intent);
return true;
}
#Override public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == android.R.id.home) {
onBackPressed();
return true;
}
return super.onOptionsItemSelected(item);
}
public static class PreferencesFragment extends PreferenceFragmentCompat implements ... {
private static final String FRAGMENT_DIALOG_TAG = "android.support.v7.preference.PreferenceFragment.DIALOG";
private String key;
#Override public void onCreatePreferences(Bundle bundle, String key) {
setPreferencesFromResource(R.xml.preferences, this.key = key);
}
// this only sets the title of the action bar
#Override public void onActivityCreated(Bundle savedInstanceState) {
ActionBar actionBar = ((AppCompatActivity) getActivity()).getSupportActionBar();
if (actionBar != null) actionBar.setTitle((key == null) ? "Settings" : findPreference(key).getTitle());
super.onActivityCreated(savedInstanceState);
}
}
}
xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="0dp"
android:orientation="vertical"
android:padding="0dp"
android:id="#+id/preferences">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary" />
<!-- preference fragment will be inserted here programmatically -->
</LinearLayout>

Another solution is to track the preference screens yourself and use the PreferenceFragmentCompat api
Here's the basic solution. (It doesn't cover all the edge cases, see advanced solution below)
Ensure you have configChanges="orientation" to prevent create/destroy
<activity
android:name=".MyPreferencesActivity"
android:configChanges="orientation" />
In the Activity you want to keep a Stack of PreferenceScreens and push/pop as needed
/* track the screens as a Stack */
private Stack<PreferenceScreen> preferenceScreens = new Stack<>();
// ensure your Activity implements PreferenceFragmentCompat.OnPreferenceStartScreenCallback
#Override
public boolean onPreferenceStartScreen(PreferenceFragmentCompat preferenceFragmentCompat, PreferenceScreen preferenceScreen) {
preferenceScreens.push(preferenceFragmentCompat.getPreferenceScreen());
preferenceFragmentCompat.setPreferenceScreen(preferenceScreen);
return true;
}
#Override
public void onBackPressed() {
if (preferenceScreens.empty()) {
super.onBackPressed();
} else {
prefsFragment.setPreferenceScreen(preferenceScreens.pop());
}
}
Optional: In your Fragment that extends PreferenceFragmentCompat, add setRetainInstance(true). (Note that without
this it will likely work also, but it 'could' break occasionally. If you set 'Don't keep Activities' to true, and
you'll see that it will get collected)
#Override
public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
setRetainInstance(true);
// Load the preferences from an XML resource
setPreferencesFromResource(R.xml.preferences, rootKey);
...
That's it! Except that if you want to cover edge cases...
Advanced Solution (If you set 'Don't Keep Activities to True, you'll need to ensure you can rebuild everything from savedInstanceState)
Note that the accepted answer doesn't actually preserve state.
set 'Don't Keep Activities' to True
navigate to a nested PreferenceScreen
Press home and then navigate back to the app
It 'should' still be on the Nested PreferenceScreen, but it's actually on the root one
Full Advanced Solution using PreferenceFragmentCompat api and preserving the PreferenceScreen stack
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.preference.PreferenceFragmentCompat;
import android.support.v7.preference.PreferenceScreen;
import java.util.ArrayList;
import java.util.Objects;
import java.util.Stack;
/**
* Class to Show the preference screen with Activity keeping state
* #author Aaron Vargas
*/
public class MyPreferencesActivityStateful extends AppCompatActivity implements PreferenceFragmentCompat.OnPreferenceStartScreenCallback {
private static final String PREFERENCE_SCREENS = "PREFERENCE_SCREENS";
private PrefsFragment prefsFragment;
private Stack<PreferenceScreen> preferenceScreens = new Stack<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Display the fragment as the main content. Re-Use if possible
String tag = PrefsFragment.class.getName();
prefsFragment = (PrefsFragment) getSupportFragmentManager().findFragmentByTag(tag);
if (prefsFragment == null) prefsFragment = new PrefsFragment();
getSupportFragmentManager().beginTransaction().replace(android.R.id.content,
prefsFragment, tag).commit();
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
// rebuild preferenceScreen stack
for (String screenKey : Objects.requireNonNull(savedInstanceState.getStringArrayList(PREFERENCE_SCREENS))) {
preferenceScreens.push((PreferenceScreen) prefsFragment.findPreference(screenKey));
}
PreferenceScreen preferenceScreen = preferenceScreens.pop();
if (preferenceScreen != prefsFragment.getPreferenceScreen()) { // optimize if same
prefsFragment.setPreferenceScreen(preferenceScreen);
}
}
#Override
public boolean onPreferenceStartScreen(PreferenceFragmentCompat preferenceFragmentCompat, PreferenceScreen preferenceScreen) {
preferenceScreens.push(preferenceFragmentCompat.getPreferenceScreen());
preferenceFragmentCompat.setPreferenceScreen(preferenceScreen);
return true;
}
#Override
public void onBackPressed() {
// account for onRestore not getting called equally to onSave
while (preferenceScreens.contains(prefsFragment.getPreferenceScreen())) {
preferenceScreens.remove(prefsFragment.getPreferenceScreen());
}
if (preferenceScreens.empty()) {
super.onBackPressed();
} else {
prefsFragment.setPreferenceScreen(preferenceScreens.pop());
}
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
preferenceScreens.push(prefsFragment.getPreferenceScreen());
ArrayList<String> keys = new ArrayList<>(preferenceScreens.size());
for (PreferenceScreen screen : preferenceScreens) {
keys.add(screen.getKey());
}
outState.putStringArrayList(PREFERENCE_SCREENS, keys);
}
public static class PrefsFragment extends PreferenceFragmentCompat {
#Override
public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
setRetainInstance(true); // ensure in manifest - android:configChanges="orientation"
// Load the preferences from an XML resource
setPreferencesFromResource(R.xml.preferences, rootKey);
}
}
}
You can also handle all this in your Fragment instead of the Activity. Here's a gist of that https://gist.github.com/aaronvargas/0f210ad8643b512efda4acfd524e1232

Using Navigation Component (Android Jetpack) and Kotlin it's very easy now:
class PrefsFragment : PreferenceFragmentCompat() {
private val args: PrefsFragmentArgs by navArgs()
override fun onCreatePreferences(state: Bundle?, rootKey: String?) {
setPreferencesFromResource(R.xml.prefs, args.rootKey)
}
override fun onNavigateToScreen(preferenceScreen: PreferenceScreen?) {
findNavController().navigate(
PrefsFragmentDirections.changeRoot(preferenceScreen!!.key)
)
}
}

Based on #squirrel Intent solution, I made it work this way. It requires even less hacking.
Activity:
import android.support.v7.app.AppCompatActivity;
public class SettingsActivity extends AppCompatActivity {
public static final String TARGET_SETTING_PAGE = "target";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
SettingsFragment settingsFragment = new SettingsFragment();
Intent intent = getIntent();
if (intent != null) {
String rootKey = intent.getStringExtra(TARGET_SETTING_PAGE);
if (rootKey != null) {
settingsFragment.setArguments(Bundler.single(TARGET_SETTING_PAGE, rootKey));
}
}
getFragmentManager().beginTransaction()
.replace(android.R.id.content, settingsFragment)
.commit();
}
}
Fragment:
import android.support.v14.preference.PreferenceFragment;
public class SettingsFragment extends PreferenceFragment {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle arguments = getArguments();
if (arguments != null && arguments.getString(TARGET_SETTING_PAGE) != null) {
setPreferencesFromResource(R.xml.preferences, arguments.getString(TARGET_SETTING_PAGE));
} else {
addPreferencesFromResource(R.xml.preferences);
}
}
#Override
public void onNavigateToScreen(PreferenceScreen preferenceScreen) {
Intent intent = new Intent(getActivity(), SettingsActivity.class)
.putExtra(TARGET_SETTING_PAGE, preferenceScreen.getKey());
startActivity(intent);
super.onNavigateToScreen(preferenceScreen);
}
}
It is sad you need so much hacks in the support appcompat libraries for something that works flawlessly out-of-the-box in standard android.

Alternative using Navigation component + androidx.appcomat:
https://stackoverflow.com/a/59732509/5437789
With this, you wont loose the back stack and go back to main page settings when you press back button.

Here is a simple solution from android documentation. To implement inner preference screen navigation with PreferenceFragmentCompact all you have to do is add fragment attribute to the embedded preference screen giving the fragment full path to navigate to eg. com.example.FragmentName.
Sample code:
<PreferenceCategory app:title="#string/choose_theme"
android:icon="#drawable/ic_baseline_color_lens_24">
<SwitchPreference
android:title="#string/apply_night_mode"
android:key="#string/key_enable_night_mode"/>
<PreferenceScreen
android:fragment="com.example.simbokeyboard.BlankFragment"
android:title="Custom Theme"
android:summary="#string/theme_summary">
<Preference
android:key="#string/choose_theme"
android:title="#string/choose_theme"
android:layout="#layout/theme_chooser"/>
</PreferenceScreen>
</PreferenceCategory>

Develop Reference

The Android operating system is a mobile operating system that was developed by Google (GOOGL?) to be primarily used for touchscreen devices, cell phones, and tablets.

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