Android APIs
public abstract class

PreferenceFragment

extends Fragment
java.lang.Object
   ↳ android.app.Fragment
     ↳ android.preference.PreferenceFragment

Class Overview

Shows a hierarchy of Preference objects as lists. These preferences will automatically save to SharedPreferences as the user interacts with them. To retrieve an instance of SharedPreferences that the preference hierarchy in this fragment will use, call getDefaultSharedPreferences(android.content.Context) with a context in the same package as this fragment.

Furthermore, the preferences shown will follow the visual style of system preferences. It is easy to create a hierarchy of preferences (that can be shown on multiple screens) via XML. For these reasons, it is recommended to use this fragment (as a superclass) to deal with preferences in applications.

A PreferenceScreen object should be at the top of the preference hierarchy. Furthermore, subsequent PreferenceScreen in the hierarchy denote a screen break--that is the preferences contained within subsequent PreferenceScreen should be shown on another screen. The preference framework handles showing these other screens from the preference hierarchy.

The preference hierarchy can be formed in multiple ways:

  • From an XML file specifying the hierarchy
  • From different Activities that each specify its own preferences in an XML file via Activity meta-data
  • From an object hierarchy rooted with PreferenceScreen

    To inflate from XML, use the addPreferencesFromResource(int). The root element should be a PreferenceScreen. Subsequent elements can point to actual Preference subclasses. As mentioned above, subsequent PreferenceScreen in the hierarchy will result in the screen break.

    To specify an Intent to query Activities that each have preferences, use addPreferencesFromIntent(Intent). Each Activity can specify meta-data in the manifest (via the key METADATA_KEY_PREFERENCES) that points to an XML resource. These XML resources will be inflated into a single preference hierarchy and shown by this fragment.

    To specify an object hierarchy rooted with PreferenceScreen, use setPreferenceScreen(PreferenceScreen).

    As a convenience, this fragment implements a click listener for any preference in the current hierarchy, see onPreferenceTreeClick(PreferenceScreen, Preference).

    Developer Guides

    For information about using PreferenceFragment, read the Settings guide.

    Sample Code

    The following sample code shows a simple preference fragment that is populated from a resource. The resource it loads is:

    <PreferenceScreen
            xmlns:android="http://schemas.android.com/apk/res/android">
    
        <PreferenceCategory
                android:title="@string/inline_preferences">
    
            <CheckBoxPreference
                    android:key="checkbox_preference"
                    android:title="@string/title_checkbox_preference"
                    android:summary="@string/summary_checkbox_preference" />
    
        </PreferenceCategory>
    
        <PreferenceCategory
                android:title="@string/dialog_based_preferences">
    
            <EditTextPreference
                    android:key="edittext_preference"
                    android:title="@string/title_edittext_preference"
                    android:summary="@string/summary_edittext_preference"
                    android:dialogTitle="@string/dialog_title_edittext_preference" />
    
            <ListPreference
                    android:key="list_preference"
                    android:title="@string/title_list_preference"
                    android:summary="@string/summary_list_preference"
                    android:entries="@array/entries_list_preference"
                    android:entryValues="@array/entryvalues_list_preference"
                    android:dialogTitle="@string/dialog_title_list_preference" />
    
        </PreferenceCategory>
    
        <PreferenceCategory
                android:title="@string/launch_preferences">
    
            <!-- This PreferenceScreen tag serves as a screen break (similar to page break
                 in word processing). Like for other preference types, we assign a key
                 here so it is able to save and restore its instance state. -->
            <PreferenceScreen
                    android:key="screen_preference"
                    android:title="@string/title_screen_preference"
                    android:summary="@string/summary_screen_preference">
    
                <!-- You can place more preferences here that will be shown on the next screen. -->
    
                <CheckBoxPreference
                        android:key="next_screen_checkbox_preference"
                        android:title="@string/title_next_screen_toggle_preference"
                        android:summary="@string/summary_next_screen_toggle_preference" />
    
            </PreferenceScreen>
    
            <PreferenceScreen
                    android:title="@string/title_intent_preference"
                    android:summary="@string/summary_intent_preference">
    
                <intent android:action="android.intent.action.VIEW"
                        android:data="http://www.android.com" />
    
            </PreferenceScreen>
    
        </PreferenceCategory>
    
        <PreferenceCategory
                android:title="@string/preference_attributes">
    
            <CheckBoxPreference
                    android:key="parent_checkbox_preference"
                    android:title="@string/title_parent_preference"
                    android:summary="@string/summary_parent_preference" />
    
            <!-- The visual style of a child is defined by this styled theme attribute. -->
            <CheckBoxPreference
                    android:key="child_checkbox_preference"
                    android:dependency="parent_checkbox_preference"
                    android:layout="?android:attr/preferenceLayoutChild"
                    android:title="@string/title_child_preference"
                    android:summary="@string/summary_child_preference" />
    
        </PreferenceCategory>
    
    </PreferenceScreen>

    The fragment implementation itself simply populates the preferences when created. Note that the preferences framework takes care of loading the current values out of the app preferences and writing them when changed:

    public static class PrefsFragment extends PreferenceFragment {
    
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
    
            // Load the preferences from an XML resource
            addPreferencesFromResource(R.xml.preferences);
        }
    }

  • Summary

    Nested Classes
    interface PreferenceFragment.OnPreferenceStartFragmentCallback Interface that PreferenceFragment's containing activity should implement to be able to process preference items that wish to switch to a new fragment. 
    [Expand]
    Inherited XML Attributes
    From class android.app.Fragment
    [Expand]
    Inherited Constants
    From interface android.content.ComponentCallbacks2
    Public Constructors
    PreferenceFragment()
    Public Methods
    void addPreferencesFromIntent(Intent intent)
    Adds preferences from activities that match the given Intent.
    void addPreferencesFromResource(int preferencesResId)
    Inflates the given XML resource and adds the preference hierarchy to the current preference hierarchy.
    Preference findPreference(CharSequence key)
    Finds a Preference based on its key.
    PreferenceManager getPreferenceManager()
    Returns the PreferenceManager used by this fragment.
    PreferenceScreen getPreferenceScreen()
    Gets the root of the preference hierarchy that this fragment is showing.
    void onActivityCreated(Bundle savedInstanceState)
    Called when the fragment's activity has been created and this fragment's view hierarchy instantiated.
    void onActivityResult(int requestCode, int resultCode, Intent data)
    Receive the result from a previous call to startActivityForResult(Intent, int).
    void onCreate(Bundle savedInstanceState)
    Called to do initial creation of a fragment.
    View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    Called to have the fragment instantiate its user interface view.
    void onDestroy()
    Called when the fragment is no longer in use.
    void onDestroyView()
    Called when the view previously created by onCreateView(LayoutInflater, ViewGroup, Bundle) has been detached from the fragment.
    boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference)
    void onSaveInstanceState(Bundle outState)
    Called to ask the fragment to save its current dynamic state, so it can later be reconstructed in a new instance of its process is restarted.
    void onStart()
    Called when the Fragment is visible to the user.
    void onStop()
    Called when the Fragment is no longer started.
    void setPreferenceScreen(PreferenceScreen preferenceScreen)
    Sets the root of the preference hierarchy that this fragment is showing.
    [Expand]
    Inherited Methods
    From class android.app.Fragment
    From class java.lang.Object
    From interface android.content.ComponentCallbacks2
    From interface android.view.View.OnCreateContextMenuListener
    From interface android.content.ComponentCallbacks

    Public Constructors

    public PreferenceFragment ()

    Added in API level 11

    Public Methods

    public void addPreferencesFromIntent (Intent intent)

    Added in API level 11

    Adds preferences from activities that match the given Intent.

    Parameters
    intent Intent: The Intent to query activities.

    public void addPreferencesFromResource (int preferencesResId)

    Added in API level 11

    Inflates the given XML resource and adds the preference hierarchy to the current preference hierarchy.

    Parameters
    preferencesResId int: The XML resource ID to inflate.

    public Preference findPreference (CharSequence key)

    Added in API level 11

    Finds a Preference based on its key.

    Parameters
    key CharSequence: The key of the preference to retrieve.
    Returns
    Preference The Preference with the key, or null.

    public PreferenceManager getPreferenceManager ()

    Added in API level 11

    Returns the PreferenceManager used by this fragment.

    Returns
    PreferenceManager The PreferenceManager.

    public PreferenceScreen getPreferenceScreen ()

    Added in API level 11

    Gets the root of the preference hierarchy that this fragment is showing.

    Returns
    PreferenceScreen The PreferenceScreen that is the root of the preference hierarchy.

    public void onActivityCreated (Bundle savedInstanceState)

    Added in API level 11

    Called when the fragment's activity has been created and this fragment's view hierarchy instantiated. It can be used to do final initialization once these pieces are in place, such as retrieving views or restoring state. It is also useful for fragments that use setRetainInstance(boolean) to retain their instance, as this callback tells the fragment when it is fully associated with the new activity instance. This is called after onCreateView(LayoutInflater, ViewGroup, Bundle) and before onViewStateRestored(Bundle).

    Parameters
    savedInstanceState Bundle: If the fragment is being re-created from a previous saved state, this is the state.

    public void onActivityResult (int requestCode, int resultCode, Intent data)

    Added in API level 11

    Receive the result from a previous call to startActivityForResult(Intent, int). This follows the related Activity API as described there in onActivityResult(int, int, Intent).

    Parameters
    requestCode int: The integer request code originally supplied to startActivityForResult(), allowing you to identify who this result came from.
    resultCode int: The integer result code returned by the child activity through its setResult().
    data Intent: An Intent, which can return result data to the caller (various data can be attached to Intent "extras").

    public void onCreate (Bundle savedInstanceState)

    Added in API level 11

    Called to do initial creation of a fragment. This is called after onAttach(Activity) and before onCreateView(LayoutInflater, ViewGroup, Bundle).

    Note that this can be called while the fragment's activity is still in the process of being created. As such, you can not rely on things like the activity's content view hierarchy being initialized at this point. If you want to do work once the activity itself is created, see onActivityCreated(Bundle).

    Parameters
    savedInstanceState Bundle: If the fragment is being re-created from a previous saved state, this is the state.

    public View onCreateView (LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)

    Added in API level 11

    Called to have the fragment instantiate its user interface view. This is optional, and non-graphical fragments can return null (which is the default implementation). This will be called between onCreate(Bundle) and onActivityCreated(Bundle).

    If you return a View from here, you will later be called in onDestroyView() when the view is being released.

    Parameters
    inflater LayoutInflater: The LayoutInflater object that can be used to inflate any views in the fragment,
    container ViewGroup: If non-null, this is the parent view that the fragment's UI should be attached to. The fragment should not add the view itself, but this can be used to generate the LayoutParams of the view.
    savedInstanceState Bundle: If non-null, this fragment is being re-constructed from a previous saved state as given here.
    Returns
    View Return the View for the fragment's UI, or null.

    public void onDestroy ()

    Added in API level 11

    Called when the fragment is no longer in use. This is called after onStop() and before onDetach().

    public void onDestroyView ()

    Added in API level 11

    Called when the view previously created by onCreateView(LayoutInflater, ViewGroup, Bundle) has been detached from the fragment. The next time the fragment needs to be displayed, a new view will be created. This is called after onStop() and before onDestroy(). It is called regardless of whether onCreateView(LayoutInflater, ViewGroup, Bundle) returned a non-null view. Internally it is called after the view's state has been saved but before it has been removed from its parent.

    public boolean onPreferenceTreeClick (PreferenceScreen preferenceScreen, Preference preference)

    Added in API level 11

    Parameters
    preferenceScreen PreferenceScreen
    preference Preference
    Returns
    boolean

    public void onSaveInstanceState (Bundle outState)

    Added in API level 11

    Called to ask the fragment to save its current dynamic state, so it can later be reconstructed in a new instance of its process is restarted. If a new instance of the fragment later needs to be created, the data you place in the Bundle here will be available in the Bundle given to onCreate(Bundle), onCreateView(LayoutInflater, ViewGroup, Bundle), and onActivityCreated(Bundle).

    This corresponds to Activity.onSaveInstanceState(Bundle) and most of the discussion there applies here as well. Note however: this method may be called at any time before onDestroy(). There are many situations where a fragment may be mostly torn down (such as when placed on the back stack with no UI showing), but its state will not be saved until its owning activity actually needs to save its state.

    Parameters
    outState Bundle: Bundle in which to place your saved state.

    public void onStart ()

    Added in API level 11

    Called when the Fragment is visible to the user. This is generally tied to Activity.onStart of the containing Activity's lifecycle.

    public void onStop ()

    Added in API level 11

    Called when the Fragment is no longer started. This is generally tied to Activity.onStop of the containing Activity's lifecycle.

    public void setPreferenceScreen (PreferenceScreen preferenceScreen)

    Added in API level 11

    Sets the root of the preference hierarchy that this fragment is showing.

    Parameters
    preferenceScreen PreferenceScreen: The root PreferenceScreen of the preference hierarchy.