PreferenceGroup

Kotlin |Java

abstract class PreferenceGroup : Preference

kotlin.Any
↳	androidx.preference.Preference
	↳	androidx.preference.PreferenceGroup

Known Direct Subclasses

PreferenceCategory, PreferenceScreen

PreferenceCategory	A container that is used to group similar `Preference`s.
PreferenceScreen	A top-level container that represents a settings screen.

A container for multiple Preferences. It is a base class for preference objects that are parents, such as PreferenceCategory and PreferenceScreen.

Summary

Nested classes
abstract	`PreferencePositionCallback` Interface for PreferenceGroup adapters to implement so that `PreferenceFragmentCompat#scrollToPreference(String)` and `PreferenceFragmentCompat#scrollToPreference(Preference)` can determine the correct scroll position to request.

Inherited constants

From class Preference

Int

DEFAULT_ORDER

Specify for setOrder(int) if a specific order is not required.

Public constructors
`<init>(context: Context!, attrs: AttributeSet!, defStyleAttr: Int, defStyleRes: Int)`
`<init>(context: Context!, attrs: AttributeSet!, defStyleAttr: Int)`
`<init>(context: Context!, attrs: AttributeSet!)`

Public methods
open Unit	`addItemFromInflater(preference: Preference!)` Called by the inflater to add an item to this group.
open Boolean	`addPreference(preference: Preference!)` Adds a `Preference` at the correct position based on the preference's order.
open T?	`findPreference(@NonNull key: CharSequence)` Finds a `Preference` based on its key.
open Int	`getInitialExpandedChildrenCount()` Gets the maximal number of children that are initially shown.
open Preference!	`getPreference(index: Int)` Returns the `Preference` at a particular index.
open Int	`getPreferenceCount()` Returns the number of children `Preference`s.
open Boolean	`isOrderingAsAdded()` Whether this group is ordering preferences in the order they are added.
open Unit	`notifyDependencyChange(disableDependents: Boolean)`
open Unit	`onAttached()`
open Unit	`onDetached()`
open Unit	`removeAll()` Removes all `Preference`s from this group.
open Boolean	`removePreference(preference: Preference!)` Removes a `Preference` from this group.
open Boolean	`removePreferenceRecursively(@NonNull key: CharSequence)` Recursively finds and removes a `Preference` from this group or a nested group lower down in the hierarchy.
open Unit	`setInitialExpandedChildrenCount(expandedCount: Int)` Sets the maximal number of children that are shown when the preference group is launched where the rest of the children will be hidden.
open Unit	`setOrderingAsAdded(orderingAsAdded: Boolean)` Whether to order the `Preference` children of this group as they are added.

Protected methods
open Unit	`dispatchRestoreInstanceState(container: Bundle!)`
open Unit	`dispatchSaveInstanceState(container: Bundle!)`
open Boolean	`isOnSameScreenAsChildren()` Whether this preference group should be shown on the same screen as its contained preferences.
open Boolean	`onPrepareAddPreference(preference: Preference!)` Prepares a `Preference` to be added to the group.
open Unit	`onRestoreInstanceState(state: Parcelable!)`
open Parcelable!	`onSaveInstanceState()`

Inherited functions

From class Preference

`Boolean`	`callChangeListener(newValue: Any!)` Call this method after the user changes the preference, but before the internal state is set. This allows the client to ignore the user value.
`Int`	`compareTo(@NonNull other: Preference)` Compares preference objects based on order (if set), otherwise alphabetically on the titles.
`T?`	`findPreferenceInHierarchy(@NonNull key: String)` Finds a preference in the entire hierarchy (above or below this preference) with the given key. Returns `null` if no preference could be found with the given key. This only works after this preference has been attached to a hierarchy.
`Context!`	`getContext()` Returns the `Context` of this preference. Each preference in a preference hierarchy can be from different Context (for example, if multiple activities provide preferences into a single `PreferenceFragmentCompat`). This Context will be used to save the preference values.
`String!`	`getDependency()` Returns the key of the dependency on this preference.
`Bundle!`	`getExtras()` Return the extras Bundle object associated with this preference, creating a new Bundle if there currently isn't one. You can use this to get and set individual extra key/value pairs.
`String!`	`getFragment()` Return the fragment class name associated with this preference.
`Drawable!`	`getIcon()` Returns the icon of this preference.
`Intent!`	`getIntent()` Return the `Intent` associated with this preference.
`String!`	`getKey()` Gets the key for this preference, which is also the key used for storing values into `SharedPreferences` or `PreferenceDataStore`.
`Int`	`getLayoutResource()` Gets the layout resource that will be shown as the `View` for this preference.
`Preference.OnPreferenceChangeListener!`	`getOnPreferenceChangeListener()` Returns the callback to be invoked when this preference is changed by the user (but before the internal state has been updated).
`Preference.OnPreferenceClickListener!`	`getOnPreferenceClickListener()` Returns the callback to be invoked when this preference is clicked.
`Int`	`getOrder()` Gets the order of this preference with respect to other preference objects on the same level.
`PreferenceGroup?`	`getParent()` Returns the `PreferenceGroup` which is this preference assigned to or `null` if this preference is not assigned to any group or is a root preference.
`Boolean`	`getPersistedBoolean(defaultReturnValue: Boolean)` Attempts to get a persisted `Boolean` if this preference is persistent.
`Float`	`getPersistedFloat(defaultReturnValue: Float)` Attempts to get a persisted `Float` if this preference is persistent.
`Int`	`getPersistedInt(defaultReturnValue: Int)` Attempts to get a persisted `Integer` if this preference is persistent.
`Long`	`getPersistedLong(defaultReturnValue: Long)` Attempts to get a persisted `Long` if this preference is persistent.
`String!`	`getPersistedString(defaultReturnValue: String!)` Attempts to get a persisted set of Strings if this preference is persistent.
`MutableSet<String!>!`	`getPersistedStringSet(defaultReturnValue: MutableSet<String!>!)` Attempts to get a persisted set of Strings if this preference is persistent.
`PreferenceDataStore?`	`getPreferenceDataStore()` Returns `PreferenceDataStore` used by this preference. Returns `null` if `SharedPreferences` is used instead. By default preferences always use `SharedPreferences`. To make this preference to use the `PreferenceDataStore` you need to assign your implementation to the preference itself via `setPreferenceDataStore(PreferenceDataStore)` or to its `PreferenceManager` via `PreferenceManager#setPreferenceDataStore(PreferenceDataStore)`.
`PreferenceManager!`	`getPreferenceManager()` Gets the `PreferenceManager` that manages this preference object's tree.
`SharedPreferences!`	`getSharedPreferences()` Returns the `SharedPreferences` where this preference can read its value(s). Usually, it's easier to use one of the helper read methods: `getPersistedBoolean(boolean)`, `getPersistedFloat(float)`, `getPersistedInt(int)`, `getPersistedLong(long)`, `getPersistedString(String)`.
`Boolean`	`getShouldDisableView()` Checks whether this preference should disable its view when it's action is disabled.
`CharSequence!`	`getSummary()` Returns the summary of this preference. If a `SummaryProvider` has been set for this preference, it will be used to provide the summary returned by this method.
`Preference.SummaryProvider<Preference!>?`	`getSummaryProvider()` Returns the `SummaryProvider` used to configure the summary of this preference.
`CharSequence!`	`getTitle()` Returns the title of this preference.
`Int`	`getWidgetLayoutResource()` Gets the layout resource for the controllable widget portion of this preference.
`Boolean`	`hasKey()` Checks whether this preference has a valid key.
`Boolean`	`isCopyingEnabled()` Returns whether the summary of this preference can be copied to the clipboard by long pressing on the preference.
`Boolean`	`isEnabled()` Checks whether this preference should be enabled in the list.
`Boolean`	`isIconSpaceReserved()` Returns whether the space of this preference icon view is reserved.
`Boolean`	`isPersistent()` Checks whether this preference is persistent. If it is, it stores its value(s) into the persistent `SharedPreferences` storage by default or into `PreferenceDataStore` if assigned.
`Boolean`	`isSelectable()` Checks whether this preference should be selectable in the list.
`Boolean`	`isShown()` Checks whether this preference is shown to the user in the hierarchy. For a preference to be shown in the hierarchy, it and all of its ancestors must be visible and attached to the root `PreferenceScreen`.
`Boolean`	`isSingleLineTitle()` Gets whether the title of this preference is constrained to a single line.
`Boolean`	`isVisible()` Checks whether this preference should be visible to the user. If this preference is visible, but one or more of its ancestors are not visible, then this preference will not be shown until its ancestors are all visible.
`Unit`	`notifyChanged()` Should be called when the data of this `Preference` has changed.
`Unit`	`notifyHierarchyChanged()` Should be called when a preference has been added/removed from this group, or the ordering should be re-evaluated.
`Unit`	`onAttachedToHierarchy(preferenceManager: PreferenceManager!)` Called when this preference has been attached to a preference hierarchy. Make sure to call the super implementation.
`Unit`	`onBindViewHolder(holder: PreferenceViewHolder!)` Binds the created View to the data for this preference. This is a good place to grab references to custom Views in the layout and set properties on them. Make sure to call through to the superclass's implementation.
`Unit`	`onClick()` Processes a click on the preference. This includes saving the value to the `SharedPreferences`. However, the overridden method should call `callChangeListener(Object)` to make sure the client wants to update the preference's state with the new value.
`Unit`	`onDependencyChanged(dependency: Preference!, disableDependent: Boolean)` Called when the dependency changes.
`Any!`	`onGetDefaultValue(a: TypedArray!, index: Int)` Called when a preference is being inflated and the default value attribute needs to be read. Since different preference types have different value types, the subclass should get and return the default value which will be its value type. For example, if the value type is String, the body of the method would proxy to `TypedArray#getString(int)`.
`Unit`	`onInitializeAccessibilityNodeInfo(info: AccessibilityNodeInfoCompat!)` Initializes an `android.view.accessibility.AccessibilityNodeInfo` with information about the View for this preference.
`Unit`	`onParentChanged(parent: Preference!, disableChild: Boolean)` Called when the implicit parent dependency changes.
`Unit`	`onPrepareForRemoval()` Called when this preference is being removed from the hierarchy. You should remove any references to this preference that you know about. Make sure to call through to the superclass implementation.
`Unit`	`onSetInitialValue(restorePersistedValue: Boolean, defaultValue: Any!)` Implement this to set the initial value of the preference. If restorePersistedValue is true, you should restore the preference value from the `SharedPreferences`. If restorePersistedValue is false, you should set the preference value to defaultValue that is given (and possibly store to SharedPreferences if `shouldPersist()` is true). In case of using `PreferenceDataStore`, the restorePersistedValue is always `true` but the default value (if provided) is set. This may not always be called. One example is if it should not persist but there is no default value given.
`Unit`	`onSetInitialValue(@Nullable defaultValue: Any?)` Implement this to set the initial value of the preference. If you are persisting values to `SharedPreferences` or a `PreferenceDataStore` you should restore the saved value for the preference. If you are not persisting values, or there is no value saved for the preference, you should set the value of the preference to defaultValue.
`Bundle!`	`peekExtras()` Return the extras Bundle object associated with this preference, returning `null` if there is not currently one.
`Boolean`	`persistBoolean(value: Boolean)` Attempts to persist a `Boolean` if this preference is persistent. The returned value doesn't reflect whether the given value was persisted, since we may not necessarily commit if there will be a batch commit later.
`Boolean`	`persistFloat(value: Float)` Attempts to persist a `Float` if this preference is persistent. The returned value doesn't reflect whether the given value was persisted, since we may not necessarily commit if there will be a batch commit later.
`Boolean`	`persistInt(value: Int)` Attempts to persist an `Integer` if this preference is persistent. The returned value doesn't reflect whether the given value was persisted, since we may not necessarily commit if there will be a batch commit later.
`Boolean`	`persistLong(value: Long)` Attempts to persist a `Long` if this preference is persistent. The returned value doesn't reflect whether the given value was persisted, since we may not necessarily commit if there will be a batch commit later.
`Boolean`	`persistString(value: String!)` Attempts to persist a `String` if this preference is persistent. The returned value doesn't reflect whether the given value was persisted, since we may not necessarily commit if there will be a batch commit later.
`Boolean`	`persistStringSet(values: MutableSet<String!>!)` Attempts to persist a set of Strings if this preference is persistent. The returned value doesn't reflect whether the given value was persisted, since we may not necessarily commit if there will be a batch commit later.
`Unit`	`restoreHierarchyState(container: Bundle!)` Restore this preference hierarchy's previously saved state from the given container.
`Unit`	`saveHierarchyState(container: Bundle!)` Store this preference hierarchy's frozen state into the given container.
`Unit`	`setCopyingEnabled(enabled: Boolean)` Sets whether the summary of this preference can be copied to the clipboard by long pressing on the preference.
`Unit`	`setDefaultValue(defaultValue: Any!)` Sets the default value for this preference, which will be set either if persistence is off or persistence is on and the preference is not found in the persistent storage.
`Unit`	`setDependency(dependencyKey: String!)` Sets the key of a preference that this preference will depend on. If that preference is not set or is off, this preference will be disabled.
`Unit`	`setEnabled(enabled: Boolean)` Sets whether this preference is enabled. If disabled, it will not handle clicks.
`Unit`	`setFragment(fragment: String!)` Sets the class name of a fragment to be shown when this preference is clicked.
`Unit`	`setIcon(icon: Drawable!)` Sets the icon for this preference with a Drawable. This icon will be placed into the ID `android.R.id#icon` within the View created by `onBindViewHolder(PreferenceViewHolder)`.
`Unit`	`setIcon(iconResId: Int)` Sets the icon for this preference with a resource ID.
`Unit`	`setIconSpaceReserved(iconSpaceReserved: Boolean)` Sets whether to reserve the space of this preference icon view when no icon is provided. If set to true, the preference will be offset as if it would have the icon and thus aligned with other preferences having icons.
`Unit`	`setIntent(intent: Intent!)` Sets an `Intent` to be used for `Context#startActivity(Intent)` when this preference is clicked.
`Unit`	`setKey(key: String!)` Sets the key for this preference, which is used as a key to the `SharedPreferences` or `PreferenceDataStore`. This should be unique for the package.
`Unit`	`setLayoutResource(layoutResId: Int)` Sets the layout resource that is inflated as the `View` to be shown for this preference. In most cases, the default layout is sufficient for custom preference objects and only the widget layout needs to be changed. This layout should contain a `ViewGroup` with ID `android.R.id#widget_frame` to be the parent of the specific widget for this preference. It should similarly contain `android.R.id#title` and `android.R.id#summary`. It is an error to change the layout after adding the preference to a `PreferenceGroup`.
`Unit`	`setOnPreferenceChangeListener(onPreferenceChangeListener: Preference.OnPreferenceChangeListener!)` Sets the callback to be invoked when this preference is changed by the user (but before the internal state has been updated).
`Unit`	`setOnPreferenceClickListener(onPreferenceClickListener: Preference.OnPreferenceClickListener!)` Sets the callback to be invoked when this preference is clicked.
`Unit`	`setOrder(order: Int)` Sets the order of this preference with respect to other preference objects on the same level. If this is not specified, the default behavior is to sort alphabetically. The `PreferenceGroup#setOrderingAsAdded(boolean)` can be used to order preference objects based on the order they appear in the XML.
`Unit`	`setPersistent(persistent: Boolean)` Sets whether this preference is persistent. When persistent, it stores its value(s) into the persistent `SharedPreferences` storage by default or into `PreferenceDataStore` if assigned.
`Unit`	`setPreferenceDataStore(dataStore: PreferenceDataStore!)` Sets a `PreferenceDataStore` to be used by this preference instead of using `SharedPreferences`. The data store will remain assigned even if the preference is moved around the preference hierarchy. It will also override a data store propagated from the `PreferenceManager` that owns this preference.
`Unit`	`setSelectable(selectable: Boolean)` Sets whether this preference is selectable.
`Unit`	`setShouldDisableView(shouldDisableView: Boolean)` Sets whether this preference should disable its view when it gets disabled. For example, set this and `setEnabled(boolean)` to false for preferences that are only displaying information and 1) should not be clickable 2) should not have the view set to the disabled state.
`Unit`	`setSingleLineTitle(singleLineTitle: Boolean)` Sets whether to constrain the title of this preference to a single line instead of letting it wrap onto multiple lines.
`Unit`	`setSummary(summary: CharSequence!)` Sets the summary for this preference with a CharSequence. You can also use a `SummaryProvider` to dynamically configure the summary of this preference.
`Unit`	`setSummary(summaryResId: Int)` Sets the summary for this preference with a resource ID. You can also use a `SummaryProvider` to dynamically configure the summary of this preference.
`Unit`	`setSummaryProvider(@Nullable summaryProvider: Preference.SummaryProvider<Preference!>?)` Set a `SummaryProvider` that will be invoked whenever the summary of this preference is requested. Set `null` to remove the existing SummaryProvider.
`Unit`	`setTitle(title: CharSequence!)` Sets the title for this preference with a CharSequence. This title will be placed into the ID `android.R.id#title` within the View bound by `onBindViewHolder(PreferenceViewHolder)`.
`Unit`	`setTitle(titleResId: Int)` Sets the title for this preference with a resource ID.
`Unit`	`setViewId(viewId: Int)` Set the ID that will be assigned to the overall View representing this preference, once bound.
`Unit`	`setVisible(visible: Boolean)` Sets whether this preference should be visible to the user. If false, it is excluded from the adapter, but can still be retrieved using `PreferenceFragmentCompat#findPreference(CharSequence)`. To show this preference to the user, its ancestors must also all be visible. If you make a `PreferenceGroup` invisible, none of its children will be shown to the user until the group is visible.
`Unit`	`setWidgetLayoutResource(widgetLayoutResId: Int)` Sets the layout for the controllable widget portion of this preference. This is inflated into the main layout. For example, a `CheckBoxPreference` would specify a custom layout (consisting of just the CheckBox) here, instead of creating its own main layout. It is an error to change the layout after adding the preference to a `PreferenceGroup`.
`Boolean`	`shouldDisableDependents()` Checks whether this preference's dependents should currently be disabled.
`Boolean`	`shouldPersist()` Checks whether, at the given time this method is called, this preference should store/restore its value(s) into the `SharedPreferences` or into `PreferenceDataStore` if assigned. This, at minimum, checks whether this preference is persistent and it currently has a key. Before you save/restore from the storage, check this first.
`String`	`toString()`

Extension functions

From androidx.preference

operator Boolean	`PreferenceGroup.contains(preference: Preference)` Returns `true` if `preference` is found in this preference group.
Unit	`PreferenceGroup.forEach(action: (preference: Preference) -> Unit)` Performs the given action on each preference in this preference group.
Unit	`PreferenceGroup.forEachIndexed(action: (index: Int, preference: Preference) -> Unit)` Performs the given action on each preference in this preference group, providing its sequential index.
operator T?	`PreferenceGroup.get(key: CharSequence)` Returns the preference with `key`, or `null` if no preference with `key` is found.
operator Preference	`PreferenceGroup.get(index: Int)` Returns the preference at `index`.
Boolean	`PreferenceGroup.isEmpty()` Returns true if this preference group contains no preferences.
Boolean	`PreferenceGroup.isNotEmpty()` Returns true if this preference group contains one or more preferences.
operator MutableIterator<Preference>	`PreferenceGroup.iterator()` Returns a MutableIterator over the preferences in this preference group.
operator Unit	`PreferenceGroup.minusAssign(preference: Preference)` Removes `preference` from this preference group.
operator Unit	`PreferenceGroup.plusAssign(preference: Preference)` Adds `preference` to this preference group.

Extension properties

From androidx.preference

Sequence<Preference>	`children` Returns a Sequence over the preferences in this preference group.
Int	`size` Returns the number of preferences in this preference group.

Public constructors

<init>

PreferenceGroup(
    context: Context!, 
    attrs: AttributeSet!, 
    defStyleAttr: Int, 
    defStyleRes: Int)

<init>

PreferenceGroup(
    context: Context!, 
    attrs: AttributeSet!, 
    defStyleAttr: Int)

<init>

PreferenceGroup(
    context: Context!, 
    attrs: AttributeSet!)

Public methods

addItemFromInflater

open fun addItemFromInflater(preference: Preference!): Unit

Called by the inflater to add an item to this group.

addPreference

open fun addPreference(preference: Preference!): Boolean

Adds a Preference at the correct position based on the preference's order.

Parameters
`preference`	Preference!: The preference to add

Return
`Boolean`	Whether the preference is now in this group

findPreference

@Nullable open fun <T : Preference!> findPreference(@NonNull key: CharSequence): T?

Finds a Preference based on its key. If two Preferences share the same key (not recommended), the first to appear will be returned.

This will recursively search for the Preference in any children that are also PreferenceGroups.

Parameters
`key`	CharSequence: The key of the `Preference` to retrieve

Return
`T?`	The `Preference` with the key, or `null`

getInitialExpandedChildrenCount

open fun getInitialExpandedChildrenCount(): Int

Gets the maximal number of children that are initially shown.

Return
`Int`	The maximal number of children that are initially shown androidx.preference.R.attr#initialExpandedChildrenCount

getPreference

open fun getPreference(index: Int): Preference!

Returns the Preference at a particular index.

Parameters
`index`	Int: The index of the `Preference` to retrieve

Return
`Preference!`	The `Preference`

getPreferenceCount

open fun getPreferenceCount(): Int

Returns the number of children Preferences.

Return
`Int`	The number of preference children in this group

isOrderingAsAdded

open fun isOrderingAsAdded(): Boolean

Whether this group is ordering preferences in the order they are added.

Return
`Boolean`	Whether this group orders based on the order the children are added

See Also

#setOrderingAsAdded(boolean)

notifyDependencyChange

open fun notifyDependencyChange(disableDependents: Boolean): Unit

onAttached

open fun onAttached(): Unit

onDetached

open fun onDetached(): Unit

removeAll

open fun removeAll(): Unit

Removes all Preferences from this group.

removePreference

open fun removePreference(preference: Preference!): Boolean

Removes a Preference from this group.

Note: This action is not recursive, and will only remove a preference if it exists in this group, ignoring preferences found in nested groups. Use removePreferenceRecursively(CharSequence) to recursively find and remove a preference.

Parameters
`preference`	Preference!: The preference to remove

Return
`Boolean`	Whether the preference was found and removed

See Also

#removePreferenceRecursively(CharSequence)

removePreferenceRecursively

open fun removePreferenceRecursively(@NonNull key: CharSequence): Boolean

Recursively finds and removes a Preference from this group or a nested group lower down in the hierarchy. If two Preferences share the same key (not recommended), the first to appear will be removed.

Parameters
`key`	CharSequence: The key of the preference to remove

Return
`Boolean`	Whether the preference was found and removed

See Also

#findPreference(CharSequence)

setInitialExpandedChildrenCount

open fun setInitialExpandedChildrenCount(expandedCount: Int): Unit

Sets the maximal number of children that are shown when the preference group is launched where the rest of the children will be hidden. If some children are hidden an expand button will be provided to show all the hidden children. Any child in any level of the hierarchy that is also a preference group (e.g. preference category) will not be counted towards the limit. But instead the children of such group will be counted. By default, all children will be shown, so the default value of this attribute is equal to Integer.MAX_VALUE.

Note: The group should have a key defined if an expandable preference is present to correctly persist state.

Parameters
`expandedCount`	Int: The number of children that is initially shown androidx.preference.R.attr#initialExpandedChildrenCount

setOrderingAsAdded

open fun setOrderingAsAdded(orderingAsAdded: Boolean): Unit

Whether to order the Preference children of this group as they are added. If this is false, the ordering will follow each Preference order and default to alphabetic for those without an order.

If this is called after preferences are added, they will not be re-ordered in the order they were added, hence call this method early on.

Parameters
`orderingAsAdded`	Boolean: Whether to order according to the order added

See Also

Preference#setOrder(int)

Protected methods

dispatchRestoreInstanceState

protected open fun dispatchRestoreInstanceState(container: Bundle!): Unit

dispatchSaveInstanceState

protected open fun dispatchSaveInstanceState(container: Bundle!): Unit

isOnSameScreenAsChildren

protected open fun isOnSameScreenAsChildren(): Boolean

Whether this preference group should be shown on the same screen as its contained preferences.

Return
`Boolean`	`true` if the contained preferences should be shown on the same screen as this preference.

onPrepareAddPreference

protected open fun onPrepareAddPreference(preference: Preference!): Boolean

Prepares a Preference to be added to the group.

Parameters
`preference`	Preference!: The preference to add

Return
`Boolean`	Whether to allow adding the preference (`true`), or not (`false`)

onRestoreInstanceState

protected open fun onRestoreInstanceState(state: Parcelable!): Unit

onSaveInstanceState

protected open fun onSaveInstanceState(): Parcelable!