DropDownPreference

Artifact: androidx.preference:preference

Added in 1.0.0

Kotlin |Java

class DropDownPreference : ListPreference

kotlin.Any
↳	androidx.preference.Preference
	↳	androidx.preference.DialogPreference
		↳	androidx.preference.ListPreference
			↳	androidx.preference.DropDownPreference

A ListPreference that presents the options in a drop down menu rather than a dialog.

Summary

Public constructors
`DropDownPreference(context: Context)`
`DropDownPreference(context: Context, attrs: AttributeSet?)`
`DropDownPreference(context: Context, attrs: AttributeSet?, defStyle: Int)`
`DropDownPreference( context: Context, attrs: AttributeSet?, defStyleAttr: Int, defStyleRes: Int )`

Public functions
`Unit`	`onBindViewHolder(holder: PreferenceViewHolder)` Binds the created View to the data for this preference.
`Unit`	`setEntries(entries: Array<CharSequence!>)` Sets the human-readable entries to be shown in the list.
`Unit`	`setValueIndex(index: Int)` Sets the value to the given index from the entry values.

Protected functions
`ArrayAdapter`	`createAdapter()` By default, this class uses a simple `ArrayAdapter`.
`Unit`	`notifyChanged()` Should be called when the data of this `Preference` has changed.
`Unit`	`onClick()` Processes a click on the preference.

Inherited Constants

From androidx.preference.Preference

const Int

DEFAULT_ORDER = 2147483647

Specify for setOrder if a specific order is not required.

Inherited functions

From java.lang.Comparable

abstract Int

compareTo(p: T!)

From androidx.preference.DialogPreference

`Drawable?`	`getDialogIcon()` Returns the icon to be shown on subsequent dialogs.
`Int`	`getDialogLayoutResource()` Returns the layout resource that is used as the content view for subsequent dialogs.
`CharSequence?`	`getDialogMessage()` Returns the message to be shown on subsequent dialogs.
`CharSequence?`	`getDialogTitle()` Returns the title to be shown on subsequent dialogs.
`CharSequence?`	`getNegativeButtonText()` Returns the text of the negative button to be shown on subsequent dialogs.
`CharSequence?`	`getPositiveButtonText()` Returns the text of the positive button to be shown on subsequent dialogs.
`Unit`	`setDialogIcon(dialogIcon: Drawable?)` Sets the icon of the dialog.
`Unit`	`setDialogIcon(dialogIconRes: Int)` Sets the icon (resource ID) of the dialog.
`Unit`	`setDialogLayoutResource(dialogLayoutResId: Int)` Sets the layout resource that is inflated as the `View` to be shown as the content view of subsequent dialogs.
`Unit`	`setDialogMessage(dialogMessage: CharSequence?)` Sets the message of the dialog.
`Unit`	`setDialogMessage(dialogMessageResId: Int)`
`Unit`	`setDialogTitle(dialogTitle: CharSequence?)` Sets the title of the dialog.
`Unit`	`setDialogTitle(dialogTitleResId: Int)`
`Unit`	`setNegativeButtonText(negativeButtonText: CharSequence?)` Sets the text of the negative button of the dialog.
`Unit`	`setNegativeButtonText(negativeButtonTextResId: Int)`
`Unit`	`setPositiveButtonText(positiveButtonText: CharSequence?)` Sets the text of the positive button of the dialog.
`Unit`	`setPositiveButtonText(positiveButtonTextResId: Int)`

From androidx.preference.ListPreference

`Int`	`findIndexOfValue(value: String!)` Returns the index of the given value (in the entry values array).
`Array<CharSequence!>!`	`getEntries()` The list of entries to be shown in the list in subsequent dialogs.
`CharSequence?`	`getEntry()` Returns the entry corresponding to the current value.
`Array<CharSequence!>!`	`getEntryValues()` Returns the array of values to be saved for the preference.
`CharSequence?`	`getSummary()` Returns the summary of this preference.
`String!`	`getValue()` Returns the value of the key.
`Any!`	`onGetDefaultValue(a: TypedArray, index: Int)` Called when a preference is being inflated and the default value attribute needs to be read.
`Unit`	`onRestoreInstanceState(state: Parcelable?)` Hook allowing a preference to re-apply a representation of its internal state that had previously been generated by `onSaveInstanceState`.
`Parcelable?`	`onSaveInstanceState()` Hook allowing a preference to generate a representation of its internal state that can later be used to create a new instance with that same state.
`Unit`	`onSetInitialValue(defaultValue: Any!)` Implement this to set the initial value of the preference.
`Unit`	`setEntries(entriesResId: @ArrayRes Int)`
`Unit`	`setEntryValues(entryValues: Array<CharSequence!>!)` The array to find the value to save for a preference when an entry from entries is selected.
`Unit`	`setEntryValues(entryValuesResId: @ArrayRes Int)`
`Unit`	`setSummary(summary: CharSequence?)` Sets the summary for this preference with a CharSequence.
`Unit`	`setValue(value: String!)` Sets the value of the key.

From androidx.preference.Preference

`Boolean`	`callChangeListener(newValue: Any!)` Call this method after the user changes the preference, but before the internal state is set.
`Int`	`compareTo(another: Preference)` Compares preference objects based on order (if set), otherwise alphabetically on the titles.
`T?`	`<T : Preference?> findPreferenceInHierarchy(key: String)` Finds a preference in the entire hierarchy (above or below this preference) with the given key.
`Context`	`getContext()` Returns the `Context` of this preference.
`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.
`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.
`(Mutable)Set<String!>!`	`getPersistedStringSet(defaultReturnValue: (Mutable)Set<String!>!)` Attempts to get a persisted set of Strings if this preference is persistent.
`PreferenceDataStore?`	`getPreferenceDataStore()` Returns `PreferenceDataStore` used by this preference.
`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).
`Boolean`	`getShouldDisableView()` Checks whether this preference should disable its view when it's action is disabled.
`Preference.SummaryProvider?`	`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.
`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.
`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.
`Unit`	`notifyDependencyChange(disableDependents: Boolean)` Notifies any listening dependents of a change that affects the dependency.
`Unit`	`notifyHierarchyChanged()` Should be called when a preference has been added/removed from this group, or the ordering should be re-evaluated.
`Unit`	`onAttached()` Called when the preference hierarchy has been attached to the list of preferences.
`Unit`	`onAttachedToHierarchy(preferenceManager: PreferenceManager)` Called when this preference has been attached to a preference hierarchy.
`Unit`	`onDependencyChanged(dependency: Preference, disableDependent: Boolean)` Called when the dependency changes.
`Unit`	`onDetached()` Called when the preference hierarchy has been detached from the list of preferences.
`Unit`	`@CallSuper onInitializeAccessibilityNodeInfo(info: AccessibilityNodeInfoCompat!)` This function is deprecated. Preferences aren't views.
`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.
`Unit`	`onSetInitialValue(defaultValue: Any?)` Implement this to set the initial value of the preference.
`Unit`	`onSetInitialValue(restorePersistedValue: Boolean, defaultValue: Any!)` This function is deprecated. Use `onSetInitialValue` instead.
`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.
`Boolean`	`persistFloat(value: Float)` Attempts to persist a `Float` if this preference is persistent.
`Boolean`	`persistInt(value: Int)` Attempts to persist an `Integer` if this preference is persistent.
`Boolean`	`persistLong(value: Long)` Attempts to persist a `Long` if this preference is persistent.
`Boolean`	`persistString(value: String!)` Attempts to persist a `String` if this preference is persistent.
`Boolean`	`persistStringSet(values: (Mutable)Set<String!>!)` Attempts to persist a set of Strings if this preference is persistent.
`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.
`Unit`	`setEnabled(enabled: Boolean)` Sets whether this preference is enabled.
`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.
`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.
`Unit`	`setIntent(intent: Intent?)` Sets an `Intent` to be used for `startActivity` 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`.
`Unit`	`setLayoutResource(layoutResId: Int)` Sets the layout resource that is inflated as the `View` to be shown for this preference.
`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.
`Unit`	`setPersistent(persistent: Boolean)` Sets whether this preference is persistent.
`Unit`	`setPreferenceDataStore(dataStore: PreferenceDataStore?)` Sets a `PreferenceDataStore` to be used by this preference instead of using `SharedPreferences`.
`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.
`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(summaryResId: Int)` Sets the summary for this preference with a resource ID.
`Unit`	`setSummaryProvider(summaryProvider: Preference.SummaryProvider?)` Set a `SummaryProvider` that will be invoked whenever the summary of this preference is requested.
`Unit`	`setTitle(title: CharSequence?)` Sets the title for this preference with a CharSequence.
`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.
`Unit`	`setWidgetLayoutResource(widgetLayoutResId: Int)` Sets the layout for the controllable widget portion of this preference.
`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.
`String`	`toString()`

Public constructors

DropDownPreference

Added in 1.0.0

DropDownPreference(context: Context)

DropDownPreference

Added in 1.0.0

DropDownPreference(context: Context, attrs: AttributeSet?)

DropDownPreference

Added in 1.0.0

DropDownPreference(context: Context, attrs: AttributeSet?, defStyle: Int)

DropDownPreference

Added in 1.0.0

DropDownPreference(
    context: Context,
    attrs: AttributeSet?,
    defStyleAttr: Int,
    defStyleRes: Int
)

Public functions

onBindViewHolder

fun onBindViewHolder(holder: PreferenceViewHolder): Unit

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.

Parameters
`holder: PreferenceViewHolder`	The ViewHolder that provides references to the views to fill in. These views will be recycled, so you should not hold a reference to them after this method returns.

setEntries

fun setEntries(entries: Array<CharSequence!>): Unit

Sets the human-readable entries to be shown in the list. This will be shown in subsequent dialogs.

Each entry must have a corresponding index in setEntryValues.

Parameters
`entries: Array<CharSequence!>`	The entries

See also
`setEntryValues`

setValueIndex

fun setValueIndex(index: Int): Unit

Sets the value to the given index from the entry values.

Parameters
`index: Int`	The index of the value to set

Protected functions

createAdapter

Added in 1.0.0

protected fun createAdapter(): ArrayAdapter

By default, this class uses a simple ArrayAdapter. But if you need a more complicated adapter, this method can be overridden to create a custom one.

Note: This method is called from the constructor. Overridden methods will get called before any subclass initialization.

Returns
`ArrayAdapter`	The custom `ArrayAdapter` that needs to be used with this class

notifyChanged

protected fun notifyChanged(): Unit

Should be called when the data of this Preference has changed.

onClick

protected fun onClick(): Unit

Processes a click on the preference. This includes saving the value to the SharedPreferences. However, the overridden method should call callChangeListener to make sure the client wants to update the preference's state with the new value.