Develop Reference

How to create Settings page on Android?

I am trying to add a page in "Settings" menu option on top of the android app. The app by default had the 3 dots on top right corner and when I click on it, it doesn't go anywhere and now I am trying to implement settings to my app. What I have done so far is following,
Created xml file in /res/xml folder called preferences.xml with following content;
<?xml version="1.0" encoding="utf-8"?>
<preferencescreen xmlns:android="http://schemas.android.com/apk/res/android">
<preference android:key="sample"
android:summary="can open other activity"
android:title="click here">
</preference>
<edittextpreference android:key="Name"
android:summary="Add user Name."
android:title="Your Name">
</edittextpreference>
</preferencescreen>
Then I have created a new java class called Preferences in /src/main/java/package/ with following content;
package com.domain.mobile.tipcalculator.app;
import android.preference.PreferenceFragment;
import android.os.Bundle;
public class Preferences extends PreferenceFragment {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.preferences);
}
}
Then to my understanding this is all I need. I m not getting any errors on compilation time but when I click on the 3 dots on top right and click on "Settings" I still don't see the page come up. Any ideas? Thank you.
P.S. I am using PreferenceFragment because my min sdk requirement is 11.

To use menus like that, you have to create a menu xml file then inflate it and then switch between the menu item ids so that you can handle click events like the following:
#Override
public boolean onCreateOptionsMenu(Menu menu)
{
MenuInflater menuInflater = getMenuInflater();
menuInflater.inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId())
{
case R.id.preferences:
startActivity(new Intent(this, PreferenceActivity.class));
return true;
case R.id.settings:
startActivity(new Intent(this, SettingsActivity.class));
return true;
default:
return super.onOptionsItemSelected(item);
}
}
You should be able to achieve what you need this way and I hope this helped.

Programmatically close Preference Header

In my application I am displaying Preference Headers in the recommended way.
I extend PreferenceActivity and add the headers from the XML resource as so:
#Override
public void onBuildHeaders(List<Header> target) {
loadHeadersFromResource(R.xml.preference_headers, target);
}
One such Header is:
<header
android:fragment="com.example.FragmentSettings"
android:summary="Tap to configure"
android:title="General Settings" />
Which launches the main Preference Fragment which extends PreferenceFragment
A particular Setting allows a user to wipe all of the data the application has access to and deauthorise their account.
If the user selects this option, I wipe everything, cache, shared preferences etc etc and I would then like to return them to the initial authorisation screen.
The problem is that the Preference Header Screen persists, even when all Activities call finish(); and even if I call System.exit(0);
How can I make the damn thing close!?
Help!

Given the small amount of detail you've given, I'll try to provide an answer assuming you want the activity backstack cleared when you open the authorisation screen.
MyPreferenceActivity - only 'onBuildHeaders' as an example (also, the activity is opened when a button is clicked)
preference-headers - only 'FragmentSettings'
FragmentSettings:
public class FragmentSettings extends PreferenceFragment {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.preference_settings);
Preference myPref = (Preference) findPreference("pref_clearAllData");
myPref.setOnPreferenceClickListener(new OnPreferenceClickListener() {
public boolean onPreferenceClick(Preference preference) {
Intent intent = new Intent(FragmentSettings.this.getActivity(), AuthActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
return true;
}
});
}
}
preference_settings (I'm assuming you're not using a checkbox, but it works as an example):
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<PreferenceCategory android:title="General Settings" >
<CheckBoxPreference
android:key="pref_clearAllData"
android:title="Clear all data"
android:summary="Clears all data and shows the authorisation screen"
android:defaultValue="false" />
</PreferenceCategory>

please try this:
protected void onListItemClick (ListView l, View v, int position, long id)
{
super.onListItemClick(l, v, position, id);
finish();
}

Show up-Button in actionBar in subscreen preferences

I've implemented my preferences like shown in the official guidelines.
I have a PreferenceActivity which creates the PreferenceFragment like this:
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
Bundle extras = getIntent().getExtras();
if (extras != null)
{
Bundle bundle = new Bundle();
_widgetID = extras.getInt(GlobalSettings.EXTRA_WIDGET_ID);
bundle.putInt(GlobalSettings.EXTRA_WIDGET_ID, _widgetID);
WidgetSettingsFragment fragment = new WidgetSettingsFragment();
fragment.setArguments(bundle);
getFragmentManager().beginTransaction().replace(android.R.id.content,
fragment).commit();
}
}
The PreferenceFragment loads the preferences from the resources and they contain a preference subscreen like this:
<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 well so far, but now I'd like to have an up-Button in the actionBar when the preferences subscreen is shown. Any idea how to accomplish that?
I have tried to set setDisplayHomeAsUpEnabled(true) in my activity but then the up-Button is only shown in the main preferences (where it should not) and not in the subscreen.
I'm wondering that even in the official docs the subscreen is shown without an active up-Button:
Link to the docs: Settings
Any help is really welcome

I finally got it to work :D. It's quite hacky but it works.
The problem is, that using subscreens in xml-layouts results in some 'code magic'.
A new activity/dialog is started for the subscreen and you don't have direct access to it.
To get access to the actionbar and the OnClickListener of the home/up-button you need to get a reference to your PreferenceScreen and get its parent Dialog in order to access the actionbar and its home/up button.
This is how it is done inside my PreferenceFragment:
#Override
public void onCreate(Bundle savedInstanceState)
{
...
final PreferenceScreen preferenceScreen = (PreferenceScreen) findPreference(getString(R.string.keyPrefScreenDynamicWidgetDetails));
preferenceScreen.setOnPreferenceClickListener(new OnPreferenceClickListener()
{
public boolean onPreferenceClick(Preference preference)
{
preferenceScreen.getDialog().getActionBar().setDisplayHomeAsUpEnabled(true);
final Dialog dialog = preferenceScreen.getDialog();
View homeBtn = dialog.findViewById(android.R.id.home);
if (homeBtn != null)
{
OnClickListener dismissDialogClickListener = new OnClickListener()
{
#Override
public void onClick(View v)
{
dialog.dismiss();
}
};
// Prepare yourselves for some hacky programming
ViewParent homeBtnContainer = homeBtn.getParent();
// The home button is an ImageView inside a FrameLayout
if (homeBtnContainer instanceof FrameLayout) {
ViewGroup containerParent = (ViewGroup) homeBtnContainer.getParent();
if (containerParent instanceof LinearLayout) {
// This view also contains the title text, set the whole view as clickable
((LinearLayout) containerParent).setOnClickListener(dismissDialogClickListener);
} else {
// Just set it on the home button
((FrameLayout) homeBtnContainer).setOnClickListener(dismissDialogClickListener);
}
} else {
// The 'If all else fails' default case
homeBtn.setOnClickListener(dismissDialogClickListener);
}
}
return true;
}
});
...
}
Following link gave me the final hints and code to solve my problem:
Action Bar Home Button not functional with nested PreferenceScreen

I do this per the Android docs in the "Supporting older versions with preference headers" section http://developer.android.com/guide/topics/ui/settings.html#BackCompatHeaders. Using the legacy PreferenceActivity, you specify a Preference in the xml that launches an intent to the same preference activity class. The activity checks the intent action and determines if it is nested or not (to show the up button) and which preference xml to inflate in the screen.
Of course, I intend to support older devices as well. I have found that the PreferenceFragment is only useful for large tablets that use preference headers.
To reuse preferences between phones and tablets I came up with this solution https://stackoverflow.com/a/20806812/1139784

To enable the up action do the following:
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayUseLogoEnabled(true);
this will give you the icon.
then add
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
// Respond to the action bar's Up/Home button
case android.R.id.home:
finish();
return true;
}
return super.onOptionsItemSelected(item);
}
you can alter this to go where you need to. As another option you can use the navigateUpTo(Intent intent) and the onSupportNavigateUpTo(Intent intent) methods and specify the intent you want to return to.

Can't accesses setting activity (SharedPreferences)

When I run my application there is no menu button to go to the settings activity.
I have a settings activity which uses shared preferences. I call in the Main Activity like this:
private SharedPreferences settings;
private OnSharedPreferenceChangeListener listener;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
settings = PreferenceManager.getDefaultSharedPreferences(this);
listener = new OnSharedPreferenceChangeListener() {
#Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
String key) {
}
};
settings.registerOnSharedPreferenceChangeListener(listener);
And this is my settings activity:
public class SettingsActivity extends PreferenceActivity {
#SuppressWarnings("deprecation")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.settings);
}
}
And my settings.xml is in XML folder and its very simple at the moment. I just want to be able to open settings in my application. The XML is like this:
<?xml version="1.0" encoding="utf-8"?>
<PreferenceCategory android:title="General settings" >
<EditTextPreference
android:key="pref_username"
android:title="User name" />
<CheckBoxPreference
android:key="pref_viewimages"
android:summary="Determines whether lists are shown with thumbnail photo"
android:title="View images"/>
</PreferenceCategory>
I've also added the settings activity to the Manifest file:
<activity
android:name=".SettingsActivity"></activity>
so far it eclipse doesn't show me any errors. But when I run my application there is no menu to go to the settings page! I was under the impression that when I create a settings activity, Android will automatically create a settings menu. But there is no menu button or anything. How can I fix this?

The menu and sharedpreferences are not directly linked. Shared preferences store values inside storage. Menu would be the graphical layout bringing you to PreferenceActivity that allow you to used shared preferences to store the settings.
You have to first inflate the menu like this in your activity :
#Override
public boolean onCreateOptionsMenu(Menu menu)
{
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
where menu contains the menu details like these (res/menu/main.xml):
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
<<item android:id="#+id/item1" android:title="Your setting name"></item>
</menu>
This would add "Your setting name" as an option when you click the menu button. Now to make the menu button do something use this (put it in your mainactivity) :
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
// Handle item selection
switch (item.getItemId())
{
case R.id.item1:
//Do something here like in my case launch intent to my new settings menu
Intent options1 = new Intent(MainActivity.this, SettingsActivity.class);
startActivity(options1);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
Now the menu button called "Your setting name" will launch your settings activity.

I don't think it's created by default. I had to do it myself. Anyway, check the menu file for your activity and check if this menu is used in your activity.

PreferenceScreen android:summary update !

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?

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.

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;
}
});

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

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

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;
}
});

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.