DropDownPreference

Artifact: androidx.preference:preference

Added in 1.0.0

Kotlin |Java

public class DropDownPreference extends ListPreference

java.lang.Object
↳	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(@NonNull Context context)`
`DropDownPreference(@NonNull Context context, @Nullable AttributeSet attrs)`
`DropDownPreference( @NonNull Context context, @Nullable AttributeSet attrs, int defStyle )`
`DropDownPreference( @NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes )`

Public methods
`void`	`onBindViewHolder(@NonNull PreferenceViewHolder holder)` Binds the created View to the data for this preference.
`void`	`setEntries(@NonNull CharSequence[] entries)` Sets the human-readable entries to be shown in the list.
`void`	`setValueIndex(int index)` Sets the value to the given index from the entry values.

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

Inherited Constants

From androidx.preference.Preference

static final int

DEFAULT_ORDER = 2147483647

Specify for setOrder if a specific order is not required.

Inherited methods

From java.lang.Comparable

abstract int

compareTo(T p)

From androidx.preference.DialogPreference

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

From androidx.preference.ListPreference

`int`	`findIndexOfValue(String value)` Returns the index of the given value (in the entry values array).
`CharSequence[]`	`getEntries()` The list of entries to be shown in the list in subsequent dialogs.
`@Nullable CharSequence`	`getEntry()` Returns the entry corresponding to the current value.
`CharSequence[]`	`getEntryValues()` Returns the array of values to be saved for the preference.
`@Nullable CharSequence`	`getSummary()` Returns the summary of this preference.
`String`	`getValue()` Returns the value of the key.
`Object`	`onGetDefaultValue(@NonNull TypedArray a, int index)` Called when a preference is being inflated and the default value attribute needs to be read.
`void`	`onRestoreInstanceState(@Nullable Parcelable state)` Hook allowing a preference to re-apply a representation of its internal state that had previously been generated by `onSaveInstanceState`.
`@Nullable 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.
`void`	`onSetInitialValue(Object defaultValue)` Implement this to set the initial value of the preference.
`void`	`setEntries(@ArrayRes int entriesResId)`
`void`	`setEntryValues(CharSequence[] entryValues)` The array to find the value to save for a preference when an entry from entries is selected.
`void`	`setEntryValues(@ArrayRes int entryValuesResId)`
`void`	`setSummary(@Nullable CharSequence summary)` Sets the summary for this preference with a CharSequence.
`void`	`setValue(String value)` Sets the value of the key.

From androidx.preference.Preference

`boolean`	`callChangeListener(Object newValue)` Call this method after the user changes the preference, but before the internal state is set.
`int`	`compareTo(@NonNull Preference another)` Compares preference objects based on order (if set), otherwise alphabetically on the titles.
`@Nullable T`	`<T extends Preference> findPreferenceInHierarchy(@NonNull String key)` Finds a preference in the entire hierarchy (above or below this preference) with the given key.
`@NonNull Context`	`getContext()` Returns the `Context` of this preference.
`@Nullable String`	`getDependency()` Returns the key of the dependency on this preference.
`@NonNull Bundle`	`getExtras()` Return the extras Bundle object associated with this preference, creating a new Bundle if there currently isn't one.
`@Nullable String`	`getFragment()` Return the fragment class name associated with this preference.
`@Nullable Drawable`	`getIcon()` Returns the icon of this preference.
`@Nullable 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`.
`final int`	`getLayoutResource()` Gets the layout resource that will be shown as the `View` for this preference.
`@Nullable 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).
`@Nullable 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.
`@Nullable 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(boolean defaultReturnValue)` Attempts to get a persisted `Boolean` if this preference is persistent.
`float`	`getPersistedFloat(float defaultReturnValue)` Attempts to get a persisted `Float` if this preference is persistent.
`int`	`getPersistedInt(int defaultReturnValue)` Attempts to get a persisted `Integer` if this preference is persistent.
`long`	`getPersistedLong(long defaultReturnValue)` Attempts to get a persisted `Long` if this preference is persistent.
`String`	`getPersistedString(String defaultReturnValue)` Attempts to get a persisted set of Strings if this preference is persistent.
`Set<String>`	`getPersistedStringSet(Set<String> defaultReturnValue)` Attempts to get a persisted set of Strings if this preference is persistent.
`@Nullable PreferenceDataStore`	`getPreferenceDataStore()` Returns `PreferenceDataStore` used by this preference.
`PreferenceManager`	`getPreferenceManager()` Gets the `PreferenceManager` that manages this preference object's tree.
`@Nullable 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.
`final @Nullable Preference.SummaryProvider`	`getSummaryProvider()` Returns the `SummaryProvider` used to configure the summary of this preference.
`@Nullable CharSequence`	`getTitle()` Returns the title of this preference.
`final 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.
`final 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.
`final boolean`	`isVisible()` Checks whether this preference should be visible to the user.
`void`	`notifyDependencyChange(boolean disableDependents)` Notifies any listening dependents of a change that affects the dependency.
`void`	`notifyHierarchyChanged()` Should be called when a preference has been added/removed from this group, or the ordering should be re-evaluated.
`void`	`onAttached()` Called when the preference hierarchy has been attached to the list of preferences.
`void`	`onAttachedToHierarchy(@NonNull PreferenceManager preferenceManager)` Called when this preference has been attached to a preference hierarchy.
`void`	`onDependencyChanged( @NonNull Preference dependency, boolean disableDependent )` Called when the dependency changes.
`void`	`onDetached()` Called when the preference hierarchy has been detached from the list of preferences.
`void`	`@CallSuper onInitializeAccessibilityNodeInfo(AccessibilityNodeInfoCompat info)` This method is deprecated. Preferences aren't views.
`void`	`onParentChanged(@NonNull Preference parent, boolean disableChild)` Called when the implicit parent dependency changes.
`void`	`onPrepareForRemoval()` Called when this preference is being removed from the hierarchy.
`void`	`onSetInitialValue(@Nullable Object defaultValue)` Implement this to set the initial value of the preference.
`void`	`onSetInitialValue(boolean restorePersistedValue, Object defaultValue)` This method is deprecated. Use `onSetInitialValue` instead.
`@Nullable Bundle`	`peekExtras()` Return the extras Bundle object associated with this preference, returning `null` if there is not currently one.
`boolean`	`persistBoolean(boolean value)` Attempts to persist a `Boolean` if this preference is persistent.
`boolean`	`persistFloat(float value)` Attempts to persist a `Float` if this preference is persistent.
`boolean`	`persistInt(int value)` Attempts to persist an `Integer` if this preference is persistent.
`boolean`	`persistLong(long value)` Attempts to persist a `Long` if this preference is persistent.
`boolean`	`persistString(String value)` Attempts to persist a `String` if this preference is persistent.
`boolean`	`persistStringSet(Set<String> values)` Attempts to persist a set of Strings if this preference is persistent.
`void`	`restoreHierarchyState(@NonNull Bundle container)` Restore this preference hierarchy's previously saved state from the given container.
`void`	`saveHierarchyState(@NonNull Bundle container)` Store this preference hierarchy's frozen state into the given container.
`void`	`setCopyingEnabled(boolean enabled)` Sets whether the summary of this preference can be copied to the clipboard by long pressing on the preference.
`void`	`setDefaultValue(Object defaultValue)` 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.
`void`	`setDependency(@Nullable String dependencyKey)` Sets the key of a preference that this preference will depend on.
`void`	`setEnabled(boolean enabled)` Sets whether this preference is enabled.
`void`	`setFragment(@Nullable String fragment)` Sets the class name of a fragment to be shown when this preference is clicked.
`void`	`setIcon(@Nullable Drawable icon)` Sets the icon for this preference with a Drawable.
`void`	`setIcon(int iconResId)` Sets the icon for this preference with a resource ID.
`void`	`setIconSpaceReserved(boolean iconSpaceReserved)` Sets whether to reserve the space of this preference icon view when no icon is provided.
`void`	`setIntent(@Nullable Intent intent)` Sets an `Intent` to be used for `startActivity` when this preference is clicked.
`void`	`setKey(String key)` Sets the key for this preference, which is used as a key to the `SharedPreferences` or `PreferenceDataStore`.
`void`	`setLayoutResource(int layoutResId)` Sets the layout resource that is inflated as the `View` to be shown for this preference.
`void`	`setOnPreferenceChangeListener( @Nullable Preference.OnPreferenceChangeListener onPreferenceChangeListener )` Sets the callback to be invoked when this preference is changed by the user (but before the internal state has been updated).
`void`	`setOnPreferenceClickListener( @Nullable Preference.OnPreferenceClickListener onPreferenceClickListener )` Sets the callback to be invoked when this preference is clicked.
`void`	`setOrder(int order)` Sets the order of this preference with respect to other preference objects on the same level.
`void`	`setPersistent(boolean persistent)` Sets whether this preference is persistent.
`void`	`setPreferenceDataStore(@Nullable PreferenceDataStore dataStore)` Sets a `PreferenceDataStore` to be used by this preference instead of using `SharedPreferences`.
`void`	`setSelectable(boolean selectable)` Sets whether this preference is selectable.
`void`	`setShouldDisableView(boolean shouldDisableView)` Sets whether this preference should disable its view when it gets disabled.
`void`	`setSingleLineTitle(boolean singleLineTitle)` Sets whether to constrain the title of this preference to a single line instead of letting it wrap onto multiple lines.
`void`	`setSummary(int summaryResId)` Sets the summary for this preference with a resource ID.
`final void`	`setSummaryProvider(@Nullable Preference.SummaryProvider summaryProvider)` Set a `SummaryProvider` that will be invoked whenever the summary of this preference is requested.
`void`	`setTitle(@Nullable CharSequence title)` Sets the title for this preference with a CharSequence.
`void`	`setTitle(int titleResId)` Sets the title for this preference with a resource ID.
`void`	`setViewId(int viewId)` Set the ID that will be assigned to the overall View representing this preference, once bound.
`final void`	`setVisible(boolean visible)` Sets whether this preference should be visible to the user.
`void`	`setWidgetLayoutResource(int widgetLayoutResId)` 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.
`@NonNull String`	`toString()`

Public constructors

DropDownPreference

Added in 1.0.0

public DropDownPreference(@NonNull Context context)

DropDownPreference

Added in 1.0.0

public DropDownPreference(@NonNull Context context, @Nullable AttributeSet attrs)

DropDownPreference

Added in 1.0.0

public DropDownPreference(
    @NonNull Context context,
    @Nullable AttributeSet attrs,
    int defStyle
)

DropDownPreference

Added in 1.0.0

public DropDownPreference(
    @NonNull Context context,
    @Nullable AttributeSet attrs,
    int defStyleAttr,
    int defStyleRes
)

Public methods

onBindViewHolder

public void onBindViewHolder(@NonNull PreferenceViewHolder holder)

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
`@NonNull PreferenceViewHolder holder`	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

public void setEntries(@NonNull CharSequence[] entries)

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
`@NonNull CharSequence[] entries`	The entries

See also
`setEntryValues`

setValueIndex

public void setValueIndex(int index)

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

Parameters
`int index`	The index of the value to set

Protected methods

createAdapter

Added in 1.0.0

protected @NonNull ArrayAdapter createAdapter()

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

notifyChanged

protected void notifyChanged()

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

onClick

protected void onClick()

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.