KeyEvent.Callback

public static interface KeyEvent.Callback

android.view.KeyEvent.Callback

Known Indirect Subclasses

AbsListView,AbsSeekBar,AbsSpinner,AbsoluteLayout,AbstractInputMethodService,AccountAuthenticatorActivity,ActionBarActivity,ActionMenuView,Activity,and 161 others.

AbsListView	Base class that can be used to implement virtualized lists of items.
AbsSeekBar	AbsSeekBar extends the capabilities of ProgressBar by adding a draggable thumb.
AbsSpinner	An abstract base class for spinner widgets.
AbsoluteLayout	This class was deprecated in API level 3. Use `FrameLayout`, `RelativeLayout` or a custom layout instead.
AbstractInputMethodService	AbstractInputMethodService provides a abstract base class for input methods.
AccountAuthenticatorActivity	Base class for implementing an Activity that is used to help implement an AbstractAccountAuthenticator.
ActionBarActivity	This class was deprecated in API level 24.2.0. Use `AppCompatActivity` instead.
ActionMenuView	ActionMenuView is a presentation of a series of menu options as a View.
Activity	An activity is a single, focused thing that the user can do.
ActivityGroup	This class was deprecated in API level 13. Use the new `Fragment` and `FragmentManager` APIs instead; these are also available on older platforms through the Android compatibility package.
AdapterView<T extends Adapter>	An AdapterView is a view whose children are determined by an `Adapter`.
AdapterViewAnimator	Base class for a `AdapterView` that will perform animations when switching between its views.
AdapterViewFlipper	Simple `ViewAnimator` that will animate between two or more views that have been added to it.
AlertDialog	A subclass of Dialog that can display one, two or three buttons.
AliasActivity	Stub activity that launches another activity (and then finishes itself) based on information in its component's manifest meta-data.
AnalogClock	This class was deprecated in API level 23. This widget is no longer supported.
AppBarLayout	AppBarLayout is a vertical `LinearLayout` which implements many of the features of material designs app bar concept, namely scrolling gestures.
AppCompatActivity	Base class for activities that use the support library action bar features.
AppCompatAutoCompleteTextView	A `AutoCompleteTextView` which supports compatible features on older version of the platform, including: Supports `textAllCaps` style attribute which works back to `Gingerbread`.
AppCompatButton	A `Button` which supports compatible features on older version of the platform, including: Supports `textAllCaps` style attribute which works back to `Gingerbread`.
AppCompatCheckBox	A `CheckBox` which supports compatible features on older version of the platform, including: Allows dynamic tint of its background via the background tint methods in `CompoundButtonCompat`.
AppCompatCheckedTextView	A `CheckedTextView` which supports compatible features on older version of the platform.
AppCompatDialog	Base class for AppCompat themed `Dialog`s.
AppCompatEditText	A `EditText` which supports compatible features on older version of the platform, including: Supports `textAllCaps` style attribute which works back to `Gingerbread`.
AppCompatImageButton	A `ImageButton` which supports compatible features on older version of the platform, including: Allows dynamic tint of its background via the background tint methods in `ViewCompat`.
AppCompatImageView	A `ImageView` which supports compatible features on older version of the platform, including: Allows dynamic tint of its background via the background tint methods in `ViewCompat`.
AppCompatMultiAutoCompleteTextView	A `MultiAutoCompleteTextView` which supports compatible features on older version of the platform, including: Supports `textAllCaps` style attribute which works back to `Gingerbread`.
AppCompatRadioButton	A `RadioButton` which supports compatible features on older version of the platform, including: Allows dynamic tint of its background via the background tint methods in `CompoundButtonCompat`.
AppCompatRatingBar	A `RatingBar` which supports compatible features on older version of the platform.
AppCompatSeekBar	A `SeekBar` which supports compatible features on older version of the platform.
AppCompatSpinner	A `Spinner` which supports compatible features on older versions of the platform, including: Allows dynamic tint of its background via the background tint methods in `CompoundButtonCompat`.
AppCompatTextView	A `TextView` which supports compatible features on older version of the platform, including: Supports `textAllCaps` style attribute which works back to `Gingerbread`.
AppWidgetHostView	Provides the glue to show AppWidget views.
AutoCompleteTextView	An editable text view that shows completion suggestions automatically while the user is typing.
BaseCardView	A card style layout that responds to certain state changes.
BaseGridView	An abstract base class for vertically and horizontally scrolling lists.
BottomNavigationView	Represents a standard bottom navigation bar for application.
BottomSheetDialog	Base class for `Dialog`s styled as a bottom sheet.
BoxInsetLayout	BoxInsetLayout is a screen shape-aware ViewGroup that can box its children in the center square of a round screen by using the `boxedEdges` attribute.
BrowseFrameLayout	A ViewGroup for managing focus behavior between overlapping views.
Button	A user interface element the user can tap or click to perform an action.
CalendarView	This class is a calendar widget for displaying and selecting dates.
CardView	A FrameLayout with a rounded corner background and shadow.
CharacterPickerDialog	Dialog for choosing accented characters related to a base character.
CheckBox	A checkbox is a specific type of two-states button that can be either checked or unchecked.
CheckedTextView	An extension to `TextView` that supports the `Checkable` interface and displays.
Chronometer	Class that implements a simple timer.
CollapsingToolbarLayout	CollapsingToolbarLayout is a wrapper for `Toolbar` which implements a collapsing app bar.
CompoundButton	A button with two states, checked and unchecked.
ContentLoadingProgressBar	ContentLoadingProgressBar implements a ProgressBar that waits a minimum time to be dismissed before showing.
CoordinatorLayout	CoordinatorLayout is a super-powered `FrameLayout`.
DatePicker	Provides a widget for selecting a date.
DatePickerDialog	A simple dialog containing an `DatePicker`.
DialerFilter	This class was deprecated in API level O. Use a custom view or layout to handle this functionality instead
Dialog	Base class for Dialogs.
DigitalClock	This class was deprecated in API level 17. It is recommended you use `TextClock` instead.
DrawerLayout	DrawerLayout acts as a top-level container for window content that allows for interactive "drawer" views to be pulled out from one or both vertical edges of the window.
EditText	A user interface element for entering and modifying text.
EmojiAppCompatButton	AppCompatButton widget enhanced with emoji capability by using `EmojiTextViewHelper`.
EmojiAppCompatEditText	AppCompatEditText widget enhanced with emoji capability by using `EmojiEditTextHelper`.
EmojiAppCompatTextView	AppCompatTextView widget enhanced with emoji capability by using `EmojiTextViewHelper`.
EmojiButton	Button widget enhanced with emoji capability by using `EmojiTextViewHelper`.
EmojiEditText	EditText widget enhanced with emoji capability by using `EmojiEditTextHelper`.
EmojiTextView	TextView widget enhanced with emoji capability by using `EmojiTextViewHelper`.
ExpandableListActivity	An activity that displays an expandable list of items by binding to a data source implementing the ExpandableListAdapter, and exposes event handlers when the user selects an item.
ExpandableListView	A view that shows items in a vertically scrolling two-level list.
ExtractEditText	Specialization of `EditText` for showing and interacting with the extracted text in a full-screen input method.
FloatingActionButton	Floating action buttons are used for a special type of promoted action.
FragmentActivity	Base class for activities that want to use the support-based `Fragment` and `Loader` APIs.
FragmentBreadCrumbs	This class was deprecated in API level 21. This widget is no longer supported.
FragmentTabHost	Version of `FragmentTabHost` that can be used with the platform `Fragment` APIs.
FrameLayout	FrameLayout is designed to block out an area on the screen to display a single item.
GLSurfaceView	An implementation of SurfaceView that uses the dedicated surface for displaying OpenGL rendering.
Gallery	This class was deprecated in API level 16. This widget is no longer supported. Other horizontally scrolling widgets include `HorizontalScrollView` and `ViewPager` from the support library.
GestureOverlayView	A transparent overlay for gesture input that can be placed on top of other widgets or contain other widgets.
GridLayout	A layout that places its children in a rectangular grid.
GridView	A view that shows items in two-dimensional scrolling grid.
GuidedActionEditText	A custom EditText that satisfies the IME key monitoring requirements of GuidedStepFragment.
HorizontalGridView	A `ViewGroup` that shows items in a horizontal scrolling list.
HorizontalScrollView	Layout container for a view hierarchy that can be scrolled by the user, allowing it to be larger than the physical display.
ImageButton	Displays a button with an image (instead of text) that can be pressed or clicked by the user.
ImageCardView	A subclass of `BaseCardView` with an `ImageView` as its main region.
ImageSwitcher	`ViewSwitcher` that switches between two ImageViews when a new image is set on it.
ImageView	Displays image resources, for example `Bitmap` or `Drawable` resources.
InputMethodService	InputMethodService provides a standard implementation of an InputMethod, which final implementations can derive from and customize.
KeyboardView	A view that renders a virtual `Keyboard`.
LauncherActivity	Displays a list of all activities which can be performed for a given intent.
LinearLayout	A layout that arranges other views either horizontally in a single column or vertically in a single row.
LinearLayoutCompat	A Layout that arranges its children in a single column or a single row.
ListActivity	An activity that displays a list of items by binding to a data source such as an array or Cursor, and exposes event handlers when the user selects an item.
ListRowHoverCardView	ListRowHoverCardView contains a title and description.
ListRowView	ListRowView is a `ViewGroup` which always contains a `HorizontalGridView`, and may optionally include a hover card.
ListView	Displays a vertically-scrollable collection of views, where each view is positioned immediatelybelow the previous view in the list.
MediaController	A view containing controls for a MediaPlayer.
MediaRouteButton
MediaRouteChooserDialog	This class implements the route chooser dialog for `MediaRouter`.
MediaRouteControllerDialog	This class implements the route controller dialog for `MediaRouter`.
MultiAutoCompleteTextView	An editable text view, extending `AutoCompleteTextView`, that can show completion suggestions for the substring of the text where the user is typing instead of necessarily for the entire thing.
NativeActivity	Convenience for implementing an activity that will be implemented purely in native code.
NavigationView	Represents a standard navigation menu for application.
NestedScrollView	NestedScrollView is just like `ScrollView`, but it supports acting as both a nested scrolling parent and child on both new and old versions of Android.
NumberPicker	A widget that enables the user to select a number from a predefined range.
PagerTabStrip	PagerTabStrip is an interactive indicator of the current, next, and previous pages of a `ViewPager`.
PagerTitleStrip	PagerTitleStrip is a non-interactive indicator of the current, next, and previous pages of a `ViewPager`.
PercentFrameLayout	This class is deprecated. consider using ConstraintLayout and associated layouts instead. The following shows how to replicate the functionality of percentage layouts with a ConstraintLayout. The Guidelines are used to define each percentage break point, and then a Button view is stretched to fill the gap: <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent"> <android.support.constraint.Guideline android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/left_guideline" app:layout_constraintGuide_percent=".15" android:orientation="vertical"/> <android.support.constraint.Guideline android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/right_guideline" app:layout_constraintGuide_percent=".85" android:orientation="vertical"/> <android.support.constraint.Guideline android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/top_guideline" app:layout_constraintGuide_percent=".15" android:orientation="horizontal"/> <android.support.constraint.Guideline android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/bottom_guideline" app:layout_constraintGuide_percent=".85" android:orientation="horizontal"/> <Button android:text="Button" android:layout_width="0dp" android:layout_height="0dp" android:id="@+id/button" app:layout_constraintLeft_toLeftOf="@+id/left_guideline" app:layout_constraintRight_toRightOf="@+id/right_guideline" app:layout_constraintTop_toTopOf="@+id/top_guideline" app:layout_constraintBottom_toBottomOf="@+id/bottom_guideline" /> </android.support.constraint.ConstraintLayout>
PercentRelativeLayout	This class is deprecated. consider using ConstraintLayout and associated layouts instead. The following shows how to replicate the functionality of percentage layouts with a ConstraintLayout. The Guidelines are used to define each percentage break point, and then a Button view is stretched to fill the gap: <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent"> <android.support.constraint.Guideline android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/left_guideline" app:layout_constraintGuide_percent=".15" android:orientation="vertical"/> <android.support.constraint.Guideline android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/right_guideline" app:layout_constraintGuide_percent=".85" android:orientation="vertical"/> <android.support.constraint.Guideline android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/top_guideline" app:layout_constraintGuide_percent=".15" android:orientation="horizontal"/> <android.support.constraint.Guideline android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/bottom_guideline" app:layout_constraintGuide_percent=".85" android:orientation="horizontal"/> <Button android:text="Button" android:layout_width="0dp" android:layout_height="0dp" android:id="@+id/button" app:layout_constraintLeft_toLeftOf="@+id/left_guideline" app:layout_constraintRight_toRightOf="@+id/right_guideline" app:layout_constraintTop_toTopOf="@+id/top_guideline" app:layout_constraintBottom_toBottomOf="@+id/bottom_guideline" /> </android.support.constraint.ConstraintLayout>
Picker	Picker is a widget showing multiple customized `PickerColumn`s.
PreferenceActivity	This is the base class for an activity to show a hierarchy of preferences to the user.
Presentation	Base class for presentations.
ProgressBar	A user interface element that indicates the progress of an operation.
ProgressDialog	This class was deprecated in API level O. Use a progress indicator such as ProgressBar inline inside of an activity rather than using this modal dialog.
QuickContactBadge	Widget used to show an image with the standard QuickContact badge and on-click behavior.
RadioButton	A radio button is a two-states button that can be either checked or unchecked.
RadioGroup	This class is used to create a multiple-exclusion scope for a set of radio buttons.
RatingBar	A RatingBar is an extension of SeekBar and ProgressBar that shows a rating in stars.
RecyclerView	A flexible view for providing a limited window into a large data set.
RelativeLayout	A Layout where the positions of the children can be described in relation to each other or to the parent.
RowHeaderView	RowHeaderView is a header text view.
ScrollView	A view group that allows the view hierarchy placed within it to be scrolled.
SearchBar	A search widget containing a search orb and a text entry view.
SearchEditText	EditText widget that monitors keyboard changes.
SearchOrbView	A widget that draws a search affordance, represented by a round background and an icon.
SearchView	A widget that provides a user interface for the user to enter a search query and submit a request to a search provider.
SeekBar	A SeekBar is an extension of ProgressBar that adds a draggable thumb.
ShadowOverlayContainer	Provides an SDK version-independent wrapper to support shadows, color overlays, and rounded corners.
SlidingDrawer	This class was deprecated in API level 17. This class is not supported anymore. It is recommended you base your own implementation on the source code for the Android Open Source Project if you must use it in your application.
SlidingPaneLayout	SlidingPaneLayout provides a horizontal, multi-pane layout for use at the top level of a UI.
Space	Space is a lightweight View subclass that may be used to create gaps between components in general purpose layouts.
SpeechOrbView	A subclass of `SearchOrbView` that visualizes the state of an ongoing speech recognition.
Spinner	A view that displays one child at a time and lets the user pick among them.
StackView
SurfaceView	Provides a dedicated drawing surface embedded inside of a view hierarchy.
SwipeDismissFrameLayout	A layout enabling left-to-right swipe-to-dismiss, intended for use within an activity.
SwipeRefreshLayout	The SwipeRefreshLayout should be used whenever the user can refresh the contents of a view via a vertical swipe gesture.
Switch	A Switch is a two-state toggle switch widget that can select between two options.
SwitchCompat	SwitchCompat is a version of the Switch widget which on devices back to API v7.
TabActivity	This class was deprecated in API level 13. New applications should use Fragments instead of this class; to continue to run on older devices, you can use the v4 support library which provides a version of the Fragment API that is compatible down to `DONUT`.
TabHost	Container for a tabbed window view.
TabItem	TabItem is a special 'view' which allows you to declare tab items for a `TabLayout` within a layout.
TabLayout	TabLayout provides a horizontal layout to display tabs.
TabWidget	Displays a list of tab labels representing each page in the parent's tab collection.
TableLayout	A layout that arranges its children into rows and columns.
TableRow	A layout that arranges its children horizontally.
TextClock	`TextClock` can display the current date and/or time as a formatted string.
TextInputEditText	A special sub-class of `EditText` designed for use as a child of `TextInputLayout`.
TextInputLayout	Layout which wraps an `EditText` (or descendant) to show a floating label when the hint is hidden due to the user inputting text.
TextSwitcher	Specialized `ViewSwitcher` that contains only children of type `TextView`.
TextView	A user interface element that displays text to the user.
TextureView	A TextureView can be used to display a content stream.
TimePicker	A widget for selecting the time of day, in either 24-hour or AM/PM mode.
TimePickerDialog	A dialog that prompts the user for the time of day using a `TimePicker`.
TitleView	Title view for a leanback fragment.
ToggleButton	Displays checked/unchecked states as a button with a "light" indicator and by default accompanied with the text "ON" or "OFF".
Toolbar	A standard toolbar for use within application content.
TvInputService.HardwareSession	Base class for a TV input session which represents an external device connected to a hardware TV input.
TvInputService.Session	Base class for derived classes to implement to provide a TV input session.
TvView	Displays TV contents.
TwoLineListItem	This class was deprecated in API level 17. This class can be implemented easily by apps using a `RelativeLayout` or a `LinearLayout`.
VerticalGridView	A `ViewGroup` that shows items in a vertically scrolling list.
VideoView	Displays a video file.
View	This class represents the basic building block for user interface components.
ViewAnimator	Base class for a `FrameLayout` container that will perform animations when switching between its views.
ViewFlipper	Simple `ViewAnimator` that will animate between two or more views that have been added to it.
ViewGroup	A `ViewGroup` is a special view that can contain other views (called children.) The view group is the base class for layouts and views containers.
ViewPager	Layout manager that allows the user to flip left and right through pages of data.
ViewStub	A ViewStub is an invisible, zero-sized View that can be used to lazily inflate layout resources at runtime.
ViewSwitcher	`ViewAnimator` that switches between two views, and has a factory from which these views are created.
VoiceInteractionSession	An active voice interaction session, providing a facility for the implementation to interact with the user in the voice interaction layer.
WearableActionDrawerView	Ease of use class for creating a Wearable action drawer.
WearableDrawerLayout	Top-level container that allows interactive drawers to be pulled from the top and bottom edge of the window.
WearableDrawerView	View that contains drawer content and a peeking view for use with `WearableDrawerLayout`.
WearableNavigationDrawerView	Ease of use class for creating a Wearable navigation drawer.
WearableRecyclerView	Wearable specific implementation of the `RecyclerView` enabling `setCircularScrollingGestureEnabled(boolean)` circular scrolling} and semi-circular layouts.
WebView	A View that displays web pages.
ZoomButton	This class was deprecated in API level O. Use other means to handle this functionality. This widget is merely a simple wrapper around a long-press handler.
ZoomControls	The `ZoomControls` class displays a simple set of controls used for zooming and provides callbacks to register for events.

Summary

Public methods
`abstract boolean`	`onKeyDown(int keyCode, KeyEvent event)` Called when a key down event has occurred.
`abstract boolean`	`onKeyLongPress(int keyCode, KeyEvent event)` Called when a long press has occurred.
`abstract boolean`	`onKeyMultiple(int keyCode, int count, KeyEvent event)` Called when a user's interaction with an analog control, such as flinging a trackball, generates simulated down/up events for the same key multiple times in quick succession.
`abstract boolean`	`onKeyUp(int keyCode, KeyEvent event)` Called when a key up event has occurred.

Public methods

onKeyDown

added in API level 1

boolean onKeyDown (int keyCode, 
                KeyEvent event)

Called when a key down event has occurred. If you return true, you can first call KeyEvent.startTracking() to have the framework track the event through its onKeyUp(int, KeyEvent) and also call your onKeyLongPress(int, KeyEvent) if it occurs.

Parameters
`keyCode`	`int`: The value in event.getKeyCode().
`event`	`KeyEvent`: Description of the key event.

Returns
`boolean`	If you handled the event, return true. If you want to allow the event to be handled by the next receiver, return false.

onKeyLongPress

added in API level 5

boolean onKeyLongPress (int keyCode, 
                KeyEvent event)

Called when a long press has occurred. If you return true, the final key up will have FLAG_CANCELED and FLAG_CANCELED_LONG_PRESS set. Note that in order to receive this callback, someone in the event change must return true from onKeyDown(int, KeyEvent) and call startTracking() on the event.

Parameters
`keyCode`	`int`: The value in event.getKeyCode().
`event`	`KeyEvent`: Description of the key event.

Returns
`boolean`	If you handled the event, return true. If you want to allow the event to be handled by the next receiver, return false.

onKeyMultiple

added in API level 1

boolean onKeyMultiple (int keyCode, 
                int count, 
                KeyEvent event)

Called when a user's interaction with an analog control, such as flinging a trackball, generates simulated down/up events for the same key multiple times in quick succession.

Parameters
`keyCode`	`int`: The value in event.getKeyCode().
`count`	`int`: Number of pairs as returned by event.getRepeatCount().
`event`	`KeyEvent`: Description of the key event.

Returns
`boolean`	If you handled the event, return true. If you want to allow the event to be handled by the next receiver, return false.

onKeyUp

added in API level 1

boolean onKeyUp (int keyCode, 
                KeyEvent event)

Called when a key up event has occurred.

Parameters
`keyCode`	`int`: The value in event.getKeyCode().
`event`	`KeyEvent`: Description of the key event.

Returns
`boolean`	If you handled the event, return true. If you want to allow the event to be handled by the next receiver, return false.

Jun	JUL	Aug
	18
2016	2017	2018

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KeyEvent.Callback

Summary

Public methods

Public methods

onKeyDown

onKeyLongPress

onKeyMultiple

onKeyUp

Annotations

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Exceptions