LeanbackSettingsFragmentCompat


abstract class LeanbackSettingsFragmentCompat : Fragment, PreferenceFragmentCompat.OnPreferenceStartFragmentCallback, PreferenceFragmentCompat.OnPreferenceStartScreenCallback, PreferenceFragmentCompat.OnPreferenceDisplayDialogCallback


This fragment provides a container for displaying a LeanbackPreferenceFragmentCompat

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

<PreferenceScreen
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto">

    <PreferenceCategory
            android:title="@string/basic_preferences">

        <Preference
                android:key="preference"
                android:title="@string/title_basic_preference"
                android:summary="@string/summary_basic_preference"/>

        <Preference
                android:key="stylized"
                android:title="@string/title_stylish_preference"
                android:summary="@string/summary_stylish_preference"/>

        <Preference
                android:key="icon"
                android:title="@string/title_icon_preference"
                android:summary="@string/summary_icon_preference"
                android:icon="@android:drawable/ic_menu_camera"/>

        <Preference
                android:key="single_line_title"
                android:title="@string/title_single_line_title_preference"
                android:summary="@string/summary_single_line_title_preference"
                app:singleLineTitle="true"/>
    </PreferenceCategory>

    <PreferenceCategory
            android:title="@string/widgets">

        <CheckBoxPreference
                android:key="checkbox"
                android:title="@string/title_checkbox_preference"
                android:summary="@string/summary_checkbox_preference"/>

        <SwitchPreferenceCompat
                android:key="switch"
                android:title="@string/title_switch_preference"
                android:summary="@string/summary_switch_preference"/>

        <DropDownPreference
                android:key="dropdown"
                android:title="@string/title_dropdown_preference"
                android:entries="@array/entries"
                app:useSimpleSummaryProvider="true"
                android:entryValues="@array/entry_values"/>

        <SeekBarPreference
                android:key="seekbar"
                android:title="@string/title_seekbar_preference"
                android:max="10"
                android:defaultValue="5"/>
    </PreferenceCategory>

    <PreferenceCategory
            android:title="@string/dialogs">

        <EditTextPreference
                android:key="edittext"
                android:title="@string/title_edittext_preference"
                app:useSimpleSummaryProvider="true"
                android:dialogTitle="@string/dialog_title_edittext_preference"/>

        <ListPreference
                android:key="list"
                android:title="@string/title_list_preference"
                app:useSimpleSummaryProvider="true"
                android:entries="@array/entries"
                android:entryValues="@array/entry_values"
                android:dialogTitle="@string/dialog_title_list_preference"/>

        <MultiSelectListPreference
                android:key="multi_select_list"
                android:title="@string/title_multi_list_preference"
                android:summary="@string/summary_multi_list_preference"
                android:entries="@array/entries"
                android:entryValues="@array/entry_values"
                android:dialogTitle="@string/dialog_title_multi_list_preference"/>
    </PreferenceCategory>

    <PreferenceCategory
            android:key="advanced"
            android:title="@string/advanced_attributes"
            app:initialExpandedChildrenCount="1">

        <Preference
                android:key="expandable"
                android:title="@string/title_expandable_preference"
                android:summary="@string/summary_expandable_preference"/>

        <Preference
                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"/>

        </Preference>

        <SwitchPreferenceCompat
                android:key="parent"
                android:title="@string/title_parent_preference"
                android:summary="@string/summary_parent_preference"/>

        <SwitchPreferenceCompat
                android:key="child"
                android:dependency="parent"
                android:title="@string/title_child_preference"
                android:summary="@string/summary_child_preference"/>

        <SwitchPreferenceCompat
                android:key="toggle_summary"
                android:title="@string/title_toggle_summary_preference"
                android:summaryOn="@string/summary_on_toggle_summary_preference"
                android:summaryOff="@string/summary_off_toggle_summary_preference"/>

        <Preference
                android:key="copyable"
                android:title="@string/title_copyable_preference"
                android:summary="@string/summary_copyable_preference"
                android:selectable="false"
                app:enableCopying="true"/>
    </PreferenceCategory>

</PreferenceScreen>

The sample implements onPreferenceStartFragment, onPreferenceStartScreen, and onPreferenceStartInitialScreen:

public static class SettingsFragment extends LeanbackSettingsFragmentCompat {
    @Override
    public void onPreferenceStartInitialScreen() {
        startPreferenceFragment(new DemoFragment());
    }

    @Override
    public boolean onPreferenceStartFragment(PreferenceFragmentCompat caller, Preference pref) {
        final Bundle args = pref.getExtras();
        final Fragment f = getChildFragmentManager().getFragmentFactory().instantiate(
                requireActivity().getClassLoader(), pref.getFragment());
        f.setArguments(args);
        f.setTargetFragment(caller, 0);
        if (f instanceof PreferenceFragmentCompat
                || f instanceof PreferenceDialogFragmentCompat) {
            startPreferenceFragment(f);
        } else {
            startImmersiveFragment(f);
        }
        return true;
    }

    @Override
    public boolean onPreferenceStartScreen(PreferenceFragmentCompat caller,
            PreferenceScreen pref) {
        final Fragment fragment = new DemoFragment();
        final Bundle args = new Bundle(1);
        args.putString(PreferenceFragmentCompat.ARG_PREFERENCE_ROOT, pref.getKey());
        fragment.setArguments(args);
        startPreferenceFragment(fragment);
        return true;
    }
}

/**
 * The fragment that is embedded in SettingsFragment
 */
public static class DemoFragment extends LeanbackPreferenceFragmentCompat {

    @Override
    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
        // Load the preferences from an XML resource
        setPreferencesFromResource(R.xml.preferences, rootKey);
    }
}

Summary

Public constructors

Public functions

View!
onCreateView(
    inflater: LayoutInflater,
    container: ViewGroup!,
    savedInstanceState: Bundle!
)

Called to have the fragment instantiate its user interface view.

Unit

Called when the Fragment is no longer resumed.

Boolean
abstract Unit

Called to instantiate the initial PreferenceFragment to be shown in this fragment.

Unit

Called when the fragment is visible to the user and actively running.

Unit
onViewCreated(view: View, savedInstanceState: Bundle!)

Called immediately after onCreateView has returned, but before any saved state has been restored in to the view.

Unit

Displays a fragment to the user, temporarily replacing the contents of this fragment.

Unit

Displays a preference fragment to the user.

Inherited functions

From androidx.activity.result.ActivityResultCaller
abstract ActivityResultLauncher<I!>!
<I, O> registerForActivityResult(
    contract: ActivityResultContract<I!, O!>!,
    callback: ActivityResultCallback<O!>!
)

Register a request to start an activity for result, designated by the given contract.

From android.content.ComponentCallbacks
From androidx.fragment.app.Fragment
Unit
dump(
    prefix: String,
    fd: FileDescriptor?,
    writer: PrintWriter,
    args: Array<String!>?
)

Print the Fragments's state into the given stream.

Boolean
equals(o: Any?)

Subclasses can not override equals().

FragmentActivity?

Return the FragmentActivity this fragment is currently associated with.

Boolean

Returns whether the the exit transition and enter transition overlap or not.

Boolean

Returns whether the the return transition and reenter transition overlap or not.

Bundle?

Return the arguments supplied when the fragment was instantiated, if any.

FragmentManager

Return a private FragmentManager for placing and managing Fragments inside of this Fragment.

Context?

Return the Context this fragment is currently associated with.

CreationExtras

The Fragment's arguments when this is first called will be used as the defaults to any androidx.lifecycle.SavedStateHandle passed to a view model created using this extra.

ViewModelProvider.Factory
Any?

Returns the Transition that will be used to move Views into the initial scene.

Any?

Returns the Transition that will be used to move Views out of the scene when the fragment is removed, hidden, or detached when not popping the back stack.

FragmentManager?

This function is deprecated.

This has been removed in favor of getParentFragmentManager() which throws an IllegalStateException if the FragmentManager is null.

Any?

Return the host object of this fragment.

Int

Return the identifier this fragment is known by.

LayoutInflater

Returns the cached LayoutInflater used to inflate Views of this Fragment.

Lifecycle

Overriding this method is no longer supported and this method will be made final in a future version of Fragment.

LoaderManager

This function is deprecated.

Use LoaderManager.getInstance(this).

Fragment?

Returns the parent Fragment containing this Fragment.

FragmentManager

Return the FragmentManager for interacting with fragments associated with this fragment's activity.

Any?

Returns the Transition that will be used to move Views in to the scene when returning due to popping a back stack.

Resources

Return requireActivity().getResources().

Boolean

This function is deprecated.

Instead of retaining the Fragment itself, use a non-retained Fragment and keep retained state in a ViewModel attached to that Fragment.

Any?

Returns the Transition that will be used to move Views out of the scene when the Fragment is preparing to be removed, hidden, or detached because of popping the back stack.

SavedStateRegistry
Any?

Returns the Transition that will be used for shared elements transferred into the content Scene.

Any?

Return the Transition that will be used for shared elements transferred back during a pop of the back stack.

String

Return a localized string from the application's package's default string table.

String
getString(resId: @StringRes Int, formatArgs: Array<Any!>?)

Return a localized formatted string from the application's package's default string table, substituting the format arguments as defined in java.util.Formatter and format.

String?

Get the tag name of the fragment, if specified.

Fragment?

This function is deprecated.

Instead of using a target fragment to pass results, use setFragmentResult to deliver results to FragmentResultListener instances registered by other fragments via setFragmentResultListener.

Int

This function is deprecated.

When using the target fragment replacement of setFragmentResultListener and setFragmentResult, consider using setArguments to pass a requestKey if you need to support dynamic request keys.

CharSequence

Return a localized, styled CharSequence from the application's package's default string table.

Boolean

This function is deprecated.

Use setMaxLifecycle instead.

View?

Get the root view for the fragment's layout (the one returned by onCreateView), if provided.

LifecycleOwner

Get a LifecycleOwner that represents the Fragment's View lifecycle.

LiveData<LifecycleOwner!>

Retrieve a LiveData which allows you to observe the lifecycle of the Fragment's View.

ViewModelStore

Returns the ViewModelStore associated with this Fragment

Int

Subclasses can not override hashCode().

java-static Fragment
instantiate(context: Context, fname: String)

This function is deprecated.

Use getFragmentFactory and instantiate

java-static Fragment
instantiate(context: Context, fname: String, args: Bundle?)

This function is deprecated.

Use getFragmentFactory and instantiate, manually calling setArguments on the returned Fragment.

Boolean

Return true if the fragment is currently added to its activity.

Boolean

Return true if the fragment has been explicitly detached from the UI.

Boolean

Return true if the fragment has been hidden.

Boolean

Return true if the layout is included as part of an activity view hierarchy via the tag.

Boolean

Return true if this fragment is currently being removed from its activity.

Boolean

Return true if the fragment is in the resumed state.

Boolean

Returns true if this fragment is added and its state has already been saved by its host.

Boolean

Return true if the fragment is currently visible to the user.

Unit

This function is deprecated.

use onViewCreated for code touching the view created by onCreateView and onCreate for other initialization.

Unit
onActivityResult(requestCode: Int, resultCode: Int, data: Intent?)

This function is deprecated.

This method has been deprecated in favor of using the Activity Result API which brings increased type safety via an ActivityResultContract and the prebuilt contracts for common intents available in androidx.activity.result.contract.ActivityResultContracts, provides hooks for testing, and allow receiving results in separate, testable classes independent from your fragment.

Unit

This function is deprecated.

See onAttach.

Unit

Called when a fragment is first attached to its context.

Unit

This function is deprecated.

The responsibility for listening for fragments being attached has been moved to FragmentManager.

Unit
Boolean

This hook is called whenever an item in a context menu is selected.

Unit
@MainThread
@CallSuper
onCreate(savedInstanceState: Bundle?)

Called to do initial creation of a fragment.

Animation?
@MainThread
onCreateAnimation(transit: Int, enter: Boolean, nextAnim: Int)

Called when a fragment loads an animation.

Animator?
@MainThread
onCreateAnimator(transit: Int, enter: Boolean, nextAnim: Int)

Called when a fragment loads an animator.

Unit
@MainThread
onCreateContextMenu(
    menu: ContextMenu,
    v: View,
    menuInfo: ContextMenu.ContextMenuInfo?
)

Called when a context menu for the view is about to be shown.

Unit

This function is deprecated.

androidx.activity.ComponentActivity now implements MenuHost, an interface that allows any component, including your activity itself, to add menu items by calling addMenuProvider without forcing all components through this single method override.

Unit

Called when the fragment is no longer in use.

Unit

This function is deprecated.

androidx.activity.ComponentActivity now implements MenuHost, an interface that allows any component, including your activity itself, to add menu items by calling addMenuProvider without forcing all components through this single method override.

Unit

Called when the view previously created by onCreateView has been detached from the fragment.

Unit

Called when the fragment is no longer attached to its activity.

LayoutInflater
onGetLayoutInflater(savedInstanceState: Bundle?)

Returns the LayoutInflater used to inflate Views of this Fragment.

Unit

Called when the hidden state (as returned by isHidden of the fragment or another fragment in its hierarchy has changed.

Unit
@UiThread
@CallSuper
onInflate(
    activity: Activity,
    attrs: AttributeSet,
    savedInstanceState: Bundle?
)

This function is deprecated.

See onInflate.

Unit
@UiThread
@CallSuper
onInflate(
    context: Context,
    attrs: AttributeSet,
    savedInstanceState: Bundle?
)

Called when a fragment is being created as part of a view layout inflation, typically from setting the content view of an activity.

Unit
Unit
onMultiWindowModeChanged(isInMultiWindowMode: Boolean)

Called when the Fragment's activity changes from fullscreen mode to multi-window mode and visa-versa.

Boolean

This function is deprecated.

androidx.activity.ComponentActivity now implements MenuHost, an interface that allows any component, including your activity itself, to add menu items by calling addMenuProvider without forcing all components through this single method override.

Unit

This function is deprecated.

androidx.activity.ComponentActivity now implements MenuHost, an interface that allows any component, including your activity itself, to add menu items by calling addMenuProvider without forcing all components through this single method override.

Unit
onPictureInPictureModeChanged(isInPictureInPictureMode: Boolean)

Called by the system when the activity changes to and from picture-in-picture mode.

Unit

This function is deprecated.

androidx.activity.ComponentActivity now implements MenuHost, an interface that allows any component, including your activity itself, to add menu items by calling addMenuProvider without forcing all components through this single method override.

Unit
@MainThread
onPrimaryNavigationFragmentChanged(
    isPrimaryNavigationFragment: Boolean
)

Callback for when the primary navigation state of this Fragment has changed.

Unit
onRequestPermissionsResult(
    requestCode: Int,
    permissions: Array<String!>,
    grantResults: IntArray
)

This function is deprecated.

This method has been deprecated in favor of using the Activity Result API which brings increased type safety via an ActivityResultContract and the prebuilt contracts for common intents available in androidx.activity.result.contract.ActivityResultContracts, provides hooks for testing, and allow receiving results in separate, testable classes independent from your fragment.

Unit

Called to ask the fragment to save its current dynamic state, so it can later be reconstructed in a new instance if its process is restarted.

Unit

Called when the Fragment is visible to the user.

Unit

Called when the Fragment is no longer started.

Unit

Called when all saved state has been restored into the view hierarchy of the fragment.

Unit

Postpone the entering Fragment transition until startPostponedEnterTransition or executePendingTransactions has been called.

Unit
postponeEnterTransition(duration: Long, timeUnit: TimeUnit)

Postpone the entering Fragment transition for a given amount of time and then call startPostponedEnterTransition.

ActivityResultLauncher<I!>
@MainThread
<I, O> registerForActivityResult(
    contract: ActivityResultContract<I!, O!>,
    callback: ActivityResultCallback<O!>
)

Register a request to start an activity for result, designated by the given contract.

ActivityResultLauncher<I!>
@MainThread
<I, O> registerForActivityResult(
    contract: ActivityResultContract<I!, O!>,
    registry: ActivityResultRegistry,
    callback: ActivityResultCallback<O!>
)

Register a request to start an activity for result, designated by the given contract.

Unit

Registers a context menu to be shown for the given view (multiple views can show the context menu).

Unit
requestPermissions(permissions: Array<String!>, requestCode: Int)

This function is deprecated.

This method has been deprecated in favor of using the Activity Result API which brings increased type safety via an ActivityResultContract and the prebuilt contracts for common intents available in androidx.activity.result.contract.ActivityResultContracts, provides hooks for testing, and allow receiving results in separate, testable classes independent from your fragment.

FragmentActivity

Return the FragmentActivity this fragment is currently associated with.

Bundle

Return the arguments supplied when the fragment was instantiated.

Context

Return the Context this fragment is currently associated with.

FragmentManager

This function is deprecated.

This has been renamed to getParentFragmentManager() to make it clear that you are accessing the FragmentManager that contains this Fragment and not the FragmentManager associated with child Fragments.

Any

Return the host object of this fragment.

Fragment

Returns the parent Fragment containing this Fragment.

View

Get the root view for the fragment's layout (the one returned by onCreateView).

Unit

Sets whether the the exit transition and enter transition overlap or not.

Unit

Sets whether the the return transition and reenter transition overlap or not.

Unit

Supply the construction arguments for this fragment.

Unit

When custom transitions are used with Fragments, the enter transition callback is called when this Fragment is attached or detached when not popping the back stack.

Unit
setEnterTransition(transition: Any?)

Sets the Transition that will be used to move Views into the initial scene.

Unit

When custom transitions are used with Fragments, the exit transition callback is called when this Fragment is attached or detached when popping the back stack.

Unit
setExitTransition(transition: Any?)

Sets the Transition that will be used to move Views out of the scene when the fragment is removed, hidden, or detached when not popping the back stack.

Unit

This function is deprecated.

This method is no longer needed when using a MenuProvider to provide a Menu to your activity, which replaces onCreateOptionsMenu as the recommended way to provide a consistent, optionally Lifecycle-aware, and modular way to handle menu creation and item selection.

Unit

Set the initial saved state that this Fragment should restore itself from when first being constructed, as returned by FragmentManager.saveFragmentInstanceState.

Unit
setMenuVisibility(menuVisible: Boolean)

Set a hint for whether this fragment's menu should be visible.

Unit
setReenterTransition(transition: Any?)

Sets the Transition that will be used to move Views in to the scene when returning due to popping a back stack.

Unit

This function is deprecated.

Instead of retaining the Fragment itself, use a non-retained Fragment and keep retained state in a ViewModel attached to that Fragment.

Unit
setReturnTransition(transition: Any?)

Sets the Transition that will be used to move Views out of the scene when the Fragment is preparing to be removed, hidden, or detached because of popping the back stack.

Unit

Sets the Transition that will be used for shared elements transferred into the content Scene.

Unit

Sets the Transition that will be used for shared elements transferred back during a pop of the back stack.

Unit
setTargetFragment(fragment: Fragment?, requestCode: Int)

This function is deprecated.

Instead of using a target fragment to pass results, the fragment requesting a result should use setFragmentResultListener to register a FragmentResultListener with a requestKey using its parent fragment manager.

Unit
setUserVisibleHint(isVisibleToUser: Boolean)

This function is deprecated.

If you are manually calling this method, use setMaxLifecycle instead.

Boolean

Gets whether you should show UI with rationale before requesting a permission.

Unit

Call startActivity from the fragment's containing Activity.

Unit
startActivity(intent: Intent, options: Bundle?)

Call startActivity from the fragment's containing Activity.

Unit
startActivityForResult(intent: Intent, requestCode: Int)

This function is deprecated.

This method has been deprecated in favor of using the Activity Result API which brings increased type safety via an ActivityResultContract and the prebuilt contracts for common intents available in androidx.activity.result.contract.ActivityResultContracts, provides hooks for testing, and allow receiving results in separate, testable classes independent from your fragment.

Unit
startActivityForResult(intent: Intent, requestCode: Int, options: Bundle?)

This function is deprecated.

This method has been deprecated in favor of using the Activity Result API which brings increased type safety via an ActivityResultContract and the prebuilt contracts for common intents available in androidx.activity.result.contract.ActivityResultContracts, provides hooks for testing, and allow receiving results in separate, testable classes independent from your fragment.

Unit
startIntentSenderForResult(
    intent: IntentSender,
    requestCode: Int,
    fillInIntent: Intent?,
    flagsMask: Int,
    flagsValues: Int,
    extraFlags: Int,
    options: Bundle?
)

This function is deprecated.

This method has been deprecated in favor of using the Activity Result API which brings increased type safety via an ActivityResultContract and the prebuilt contracts for common intents available in androidx.activity.result.contract.ActivityResultContracts, provides hooks for testing, and allow receiving results in separate, testable classes independent from your fragment.

Unit

Begin postponed transitions after postponeEnterTransition was called.

String
Unit

Prevents a context menu to be shown for the given view.

From androidx.lifecycle.HasDefaultViewModelProviderFactory
From androidx.lifecycle.LifecycleOwner
abstract Lifecycle!
From androidx.preference.PreferenceFragmentCompat.OnPreferenceStartFragmentCallback
abstract Boolean

Called when the user has clicked on a preference that has a fragment class name associated with it.

From androidx.preference.PreferenceFragmentCompat.OnPreferenceStartScreenCallback
abstract Boolean

Called when the user has clicked on a PreferenceScreen in order to navigate to a new screen of preferences.

From androidx.savedstate.SavedStateRegistryOwner
From android.view.View.OnCreateContextMenuListener
abstract Unit
onCreateContextMenu(
    p: ContextMenu!,
    p1: View!,
    p2: ContextMenu.ContextMenuInfo!
)
From androidx.lifecycle.ViewModelStoreOwner

Public constructors

LeanbackSettingsFragmentCompat

Added in 1.1.0
LeanbackSettingsFragmentCompat()

Public functions

onCreateView

fun onCreateView(
    inflater: LayoutInflater,
    container: ViewGroup!,
    savedInstanceState: Bundle!
): View!

Called to have the fragment instantiate its user interface view. This is optional, and non-graphical fragments can return null. This will be called between onCreate and onViewCreated.

A default View can be returned by calling Fragment in your constructor. Otherwise, this method returns null.

It is recommended to only inflate the layout in this method and move logic that operates on the returned View to onViewCreated.

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.

onPause

fun onPause(): Unit

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

onPreferenceDisplayDialog

Added in 1.1.0
fun onPreferenceDisplayDialog(
    caller: PreferenceFragmentCompat,
    pref: Preference!
): Boolean
Parameters
caller: PreferenceFragmentCompat

The fragment containing the preference requesting the dialog

pref: Preference!

The preference requesting the dialog

Returns
Boolean

true if the dialog creation has been handled

onPreferenceStartInitialScreen

Added in 1.1.0
abstract fun onPreferenceStartInitialScreen(): Unit

Called to instantiate the initial PreferenceFragment to be shown in this fragment. Implementations are expected to call startPreferenceFragment.

onResume

fun onResume(): Unit

Called when the fragment is visible to the user and actively running. This is generally tied to Activity.onResume of the containing Activity's lifecycle.

onViewCreated

fun onViewCreated(view: View, savedInstanceState: Bundle!): Unit

Called immediately after onCreateView has returned, but before any saved state has been restored in to the view. This gives subclasses a chance to initialize themselves once they know their view hierarchy has been completely created. The fragment's view hierarchy is not however attached to its parent at this point.

Parameters
view: View

The View returned by onCreateView.

savedInstanceState: Bundle!

If non-null, this fragment is being re-constructed from a previous saved state as given here.

startImmersiveFragment

Added in 1.1.0
fun startImmersiveFragment(fragment: Fragment): Unit

Displays a fragment to the user, temporarily replacing the contents of this fragment.

Parameters
fragment: Fragment

Fragment instance to be added.

startPreferenceFragment

Added in 1.1.0
fun startPreferenceFragment(fragment: Fragment): Unit

Displays a preference fragment to the user. This method can also be used to display list-style fragments on top of the stack of preference fragments.

Parameters
fragment: Fragment

Fragment instance to be added.