Module javafx.graphics
Package javafx.scene.input

Class KeyEvent

  • All Implemented Interfaces:
    Serializable, Cloneable
    public final class KeyEvent
extends InputEvent
    An event which indicates that a keystroke occurred in a Node.

    This event is generated when a key is pressed, released, or typed. Depending on the type of the event it is passed to onKeyPressed, onKeyTyped or onKeyReleased function.

    "Key typed" events are higher-level and generally do not depend on the platform or keyboard layout. They are generated when a Unicode character is entered, and are the preferred way to find out about character input. In the simplest case, a key typed event is produced by a single key press (e.g., 'a'). Often, however, characters are produced by series of key presses (e.g., SHIFT + 'a'), and the mapping from key pressed events to key typed events may be many-to-one or many-to-many. Key releases are not usually necessary to generate a key typed event, but there are some cases where the key typed event is not generated until a key is released (e.g., entering ASCII sequences via the Alt-Numpad method in Windows). No key typed events are generated for keys that don't generate Unicode characters (e.g., action keys, modifier keys, etc.).

    The character variable always contains a valid Unicode character(s) or CHAR_UNDEFINED. Character input is reported by key typed events; key pressed and key released events are not necessarily associated with character input. Therefore, the character variable is guaranteed to be meaningful only for key typed events.

    For key pressed and key released events, the code variable contains the event's key code. For key typed events, the code variable always contains KeyCode.UNDEFINED.

    "Key pressed" and "key released" events are lower-level and depend on the platform and keyboard layout. They are generated whenever a key is pressed or released, and are the only way to find out about keys that don't generate character input (e.g., action keys, modifier keys, etc.). The key being pressed or released is indicated by the code variable, which contains a virtual key code.

    For triggering context menus see the ContextMenuEvent.

    Since:
    JavaFX 2.0
    See Also:
    Serialized Form

    • Field Detail

      • ANY

        public static final EventType<KeyEvent> ANY
        Common supertype for all key event types.

      • KEY_PRESSED

        public static final EventType<KeyEvent> KEY_PRESSED
        This event occurs when a key has been pressed.

      • KEY_RELEASED

        public static final EventType<KeyEvent> KEY_RELEASED
        This event occurs when a key has been released.

      • KEY_TYPED

        public static final EventType<KeyEvent> KEY_TYPED
        This event occurs when a character-generating key was typed (pressed and released). The event contains the character field containing the typed string, the code and text fields are not used.

      • CHAR_UNDEFINED

        public static final String CHAR_UNDEFINED
        KEY_PRESSED and KEY_RELEASED events which do not map to a valid Unicode character use this for the keyChar value.

    • Constructor Detail

      • KeyEvent

        public KeyEvent​(Object source,
                EventTarget target,
                EventType<KeyEvent> eventType,
                String character,
                String text,
                KeyCode code,
                boolean shiftDown,
                boolean controlDown,
                boolean altDown,
                boolean metaDown)
        Constructs a new KeyEvent event from the specified parameters.
        Parameters:
        source - the source of the event. Can be null.
        target - the target of the event. Can be null.
        eventType - The type of the event.
        character - The character or sequence of characters associated with the event
        text - A String describing the key code
        code - The integer key code
        shiftDown - true if shift modifier was pressed.
        controlDown - true if control modifier was pressed.
        altDown - true if alt modifier was pressed.
        metaDown - true if meta modifier was pressed.
        Since:
        JavaFX 8.0

      • KeyEvent

        public KeyEvent​(EventType<KeyEvent> eventType,
                String character,
                String text,
                KeyCode code,
                boolean shiftDown,
                boolean controlDown,
                boolean altDown,
                boolean metaDown)
        Constructs a new KeyEvent event from the specified parameters, with a null source and target.
        Parameters:
        eventType - The type of the event.
        character - The character or sequence of characters associated with the event
        text - A String describing the key code
        code - The integer key code
        shiftDown - true if shift modifier was pressed.
        controlDown - true if control modifier was pressed.
        altDown - true if alt modifier was pressed.
        metaDown - true if meta modifier was pressed.
        Since:
        JavaFX 8.0

    • Method Detail

      • getCharacter

        public final String getCharacter()
        The Unicode character or sequence of characters associated with the key typed event. Contains multiple elements if the key produced a single Unicode character from outside of the Basic Multilingual Plane which needs to be encoded by the corresponding surrogate pair in Java or if the key produced multiple Unicode characters itself.

        For example, character will have the value "A" for a key typed event generated by pressing SHIFT + 'a'. For key pressed and key released events, character is always CHAR_UNDEFINED.

        Returns:
        The Unicode character(s) associated with the key typed event

      • getText

        public final String getText()
        A String describing the key code, such as "HOME", "F1" or "A", for key pressed and key released events. For key typed events, text is always the empty string.
        Returns:
        A String describing the key code

      • getCode

        public final KeyCode getCode()
        The key code associated with the key in this key pressed or key released event. For key typed events, code is always KeyCode.UNDEFINED.
        Returns:
        The key code associated with the key in this event, KeyCode.UNDEFINED for key typed event

      • isShiftDown

        public final boolean isShiftDown()
        Returns whether or not the Shift modifier is down on this event.
        Returns:
        whether or not the Shift modifier is down on this event.

      • isControlDown

        public final boolean isControlDown()
        Returns whether or not the Control modifier is down on this event.
        Returns:
        whether or not the Control modifier is down on this event.

      • isAltDown

        public final boolean isAltDown()
        Returns whether or not the Alt modifier is down on this event.
        Returns:
        whether or not the Alt modifier is down on this event.

      • isMetaDown

        public final boolean isMetaDown()
        Returns whether or not the Meta modifier is down on this event.
        Returns:
        whether or not the Meta modifier is down on this event.

      • isShortcutDown

        public final boolean isShortcutDown()
        Returns whether or not the host platform common shortcut modifier is down on this event. This common shortcut modifier is a modifier key which is used commonly in shortcuts on the host platform. It is for example control on Windows and meta (command key) on Mac.
        Returns:
        true if the shortcut modifier is down, false otherwise

      • toString

        public String toString()
        Returns a string representation of this KeyEvent object.
        Overrides:
        toString in class EventObject
        Returns:
        a string representation of this KeyEvent object.

      • copyFor

        public KeyEvent copyFor​(Object source,
                        EventTarget target,
                        EventType<KeyEvent> type)
        Creates a copy of the given event with the given fields substituted.
        Parameters:
        source - the new source of the copied event
        target - the new target of the copied event
        type - the new event type.
        Returns:
        the event copy with the fields substituted
        Since:
        JavaFX 8.0