Module java.desktop
Package java.awt.event

Class KeyEvent

  • All Implemented Interfaces:
    Serializable
    Direct Known Subclasses:
    MenuKeyEvent
    public class KeyEvent
extends InputEvent
    An event which indicates that a keystroke occurred in a component.

    This low-level event is generated by a component object (such as a text field) when a key is pressed, released, or typed. The event is passed to every KeyListener or KeyAdapter object which registered to receive such events using the component's addKeyListener method. (KeyAdapter objects implement the KeyListener interface.) Each such listener object gets this KeyEvent when the event occurs.

    "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 getKeyChar method always returns a valid Unicode character 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 result of the getKeyChar method is guaranteed to be meaningful only for KEY_TYPED events.

    For key pressed and key released events, the getKeyCode method returns the event's keyCode. For key typed events, the getKeyCode method always returns VK_UNDEFINED. The getExtendedKeyCode method may also be used with many international keyboard layouts.

    "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 getKeyCode and getExtendedKeyCode methods, which return a virtual key code.

    Virtual key codes are used to report which keyboard key has been pressed, rather than a character generated by the combination of one or more keystrokes (such as "A", which comes from shift and "a").

    For example, pressing the Shift key will cause a KEY_PRESSED event with a VK_SHIFT keyCode, while pressing the 'a' key will result in a VK_A keyCode. After the 'a' key is released, a KEY_RELEASED event will be fired with VK_A. Separately, a KEY_TYPED event with a keyChar value of 'A' is generated.

    Pressing and releasing a key on the keyboard results in the generating the following key events (in order): 

        KEY_PRESSED
    KEY_TYPED (is only generated if a valid Unicode character could be generated.)
    KEY_RELEASED
    But in some cases (e.g. auto-repeat or input method is activated) the order could be different (and platform dependent).

    Notes:

    • Key combinations which do not result in Unicode characters, such as action keys like F1 and the HELP key, do not generate KEY_TYPED events.
    • Not all keyboards or systems are capable of generating all virtual key codes. No attempt is made in Java to generate these keys artificially.
    • Virtual key codes do not identify a physical key: they depend on the platform and keyboard layout. For example, the key that generates VK_Q when using a U.S. keyboard layout will generate VK_A when using a French keyboard layout.
    • The key that generates VK_Q when using a U.S. keyboard layout also generates a unique code for Russian or Hebrew layout. There is no a VK_ constant for these and many other codes in various layouts. These codes may be obtained by using getExtendedKeyCode and are used whenever a VK_ constant is used.
    • Not all characters have a keycode associated with them. For example, there is no keycode for the question mark because there is no keyboard for which it appears on the primary layer.
    • In order to support the platform-independent handling of action keys, the Java platform uses a few additional virtual key constants for functions that would otherwise have to be recognized by interpreting virtual key codes and modifiers. For example, for Japanese Windows keyboards, VK_ALL_CANDIDATES is returned instead of VK_CONVERT with the ALT modifier.
    • As specified in Focus Specification key events are dispatched to the focus owner by default.

    WARNING: Aside from those keys that are defined by the Java language (VK_ENTER, VK_BACK_SPACE, and VK_TAB), do not rely on the values of the VK_ constants. The platform steward reserves the right to change these values as needed to accommodate a wider range of keyboards in the future.

    An unspecified behavior will be caused if the id parameter of any particular KeyEvent instance is not in the range from KEY_FIRST to KEY_LAST.

    Since:
    1.1
    See Also:
    KeyAdapter, KeyListener, Tutorial: Writing a Key Listener, Serialized Form

    • Field Detail

      • KEY_FIRST

        public static final int KEY_FIRST
        The first number in the range of ids used for key events.
        See Also:
        Constant Field Values

      • KEY_LAST

        public static final int KEY_LAST
        The last number in the range of ids used for key events.
        See Also:
        Constant Field Values

      • KEY_TYPED

        public static final int KEY_TYPED
        The "key typed" event. This event is generated when a character is entered. In the simplest case, it is produced by a single key press. Often, however, characters are produced by series of key presses, and the mapping from key pressed events to key typed events may be many-to-one or many-to-many.
        See Also:
        Constant Field Values

      • KEY_PRESSED

        public static final int KEY_PRESSED
        The "key pressed" event. This event is generated when a key is pushed down.
        See Also:
        Constant Field Values

      • KEY_RELEASED

        public static final int KEY_RELEASED
        The "key released" event. This event is generated when a key is let up.
        See Also:
        Constant Field Values

      • VK_ENTER

        public static final int VK_ENTER
        Constant for the ENTER virtual key.
        See Also:
        Constant Field Values

      • VK_BACK_SPACE

        public static final int VK_BACK_SPACE
        Constant for the BACK_SPACE virtual key.
        See Also:
        Constant Field Values

      • VK_TAB

        public static final int VK_TAB
        Constant for the TAB virtual key.
        See Also:
        Constant Field Values

      • VK_CANCEL

        public static final int VK_CANCEL
        Constant for the CANCEL virtual key.
        See Also:
        Constant Field Values

      • VK_CLEAR

        public static final int VK_CLEAR
        Constant for the CLEAR virtual key.
        See Also:
        Constant Field Values

      • VK_SHIFT

        public static final int VK_SHIFT
        Constant for the SHIFT virtual key.
        See Also:
        Constant Field Values

      • VK_CONTROL

        public static final int VK_CONTROL
        Constant for the CONTROL virtual key.
        See Also:
        Constant Field Values

      • VK_ALT

        public static final int VK_ALT
        Constant for the ALT virtual key.
        See Also:
        Constant Field Values

      • VK_PAUSE

        public static final int VK_PAUSE
        Constant for the PAUSE virtual key.
        See Also:
        Constant Field Values

      • VK_CAPS_LOCK

        public static final int VK_CAPS_LOCK
        Constant for the CAPS_LOCK virtual key.
        See Also:
        Constant Field Values

      • VK_ESCAPE

        public static final int VK_ESCAPE
        Constant for the ESCAPE virtual key.
        See Also:
        Constant Field Values

      • VK_SPACE

        public static final int VK_SPACE
        Constant for the SPACE virtual key.
        See Also:
        Constant Field Values

      • VK_PAGE_UP

        public static final int VK_PAGE_UP
        Constant for the PAGE_UP virtual key.
        See Also:
        Constant Field Values

      • VK_PAGE_DOWN

        public static final int VK_PAGE_DOWN
        Constant for the PAGE_DOWN virtual key.
        See Also:
        Constant Field Values

      • VK_END

        public static final int VK_END
        Constant for the END virtual key.
        See Also:
        Constant Field Values

      • VK_HOME

        public static final int VK_HOME
        Constant for the HOME virtual key.
        See Also:
        Constant Field Values

      • VK_COMMA

        public static final int VK_COMMA
        Constant for the comma key, ","
        See Also:
        Constant Field Values

      • VK_MINUS

        public static final int VK_MINUS
        Constant for the minus key, "-"
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_PERIOD

        public static final int VK_PERIOD
        Constant for the period key, "."
        See Also:
        Constant Field Values

      • VK_SLASH

        public static final int VK_SLASH
        Constant for the forward slash key, "/"
        See Also:
        Constant Field Values

      • VK_SEMICOLON

        public static final int VK_SEMICOLON
        Constant for the semicolon key, ";"
        See Also:
        Constant Field Values

      • VK_EQUALS

        public static final int VK_EQUALS
        Constant for the equals key, "="
        See Also:
        Constant Field Values

      • VK_OPEN_BRACKET

        public static final int VK_OPEN_BRACKET
        Constant for the open bracket key, "["
        See Also:
        Constant Field Values

      • VK_BACK_SLASH

        public static final int VK_BACK_SLASH
        Constant for the back slash key, "\"
        See Also:
        Constant Field Values

      • VK_CLOSE_BRACKET

        public static final int VK_CLOSE_BRACKET
        Constant for the close bracket key, "]"
        See Also:
        Constant Field Values

      • VK_NUMPAD0

        public static final int VK_NUMPAD0
        Constant for the number pad "0" key.
        See Also:
        Constant Field Values

      • VK_NUMPAD1

        public static final int VK_NUMPAD1
        Constant for the number pad "1" key.
        See Also:
        Constant Field Values

      • VK_NUMPAD2

        public static final int VK_NUMPAD2
        Constant for the number pad "2" key.
        See Also:
        Constant Field Values

      • VK_NUMPAD3

        public static final int VK_NUMPAD3
        Constant for the number pad "3" key.
        See Also:
        Constant Field Values

      • VK_NUMPAD4

        public static final int VK_NUMPAD4
        Constant for the number pad "4" key.
        See Also:
        Constant Field Values

      • VK_NUMPAD5

        public static final int VK_NUMPAD5
        Constant for the number pad "5" key.
        See Also:
        Constant Field Values

      • VK_NUMPAD6

        public static final int VK_NUMPAD6
        Constant for the number pad "6" key.
        See Also:
        Constant Field Values

      • VK_NUMPAD7

        public static final int VK_NUMPAD7
        Constant for the number pad "7" key.
        See Also:
        Constant Field Values

      • VK_NUMPAD8

        public static final int VK_NUMPAD8
        Constant for the number pad "8" key.
        See Also:
        Constant Field Values

      • VK_NUMPAD9

        public static final int VK_NUMPAD9
        Constant for the number pad "9" key.
        See Also:
        Constant Field Values

      • VK_MULTIPLY

        public static final int VK_MULTIPLY
        Constant for the number pad multiply key.
        See Also:
        Constant Field Values

      • VK_ADD

        public static final int VK_ADD
        Constant for the number pad add key.
        See Also:
        Constant Field Values

      • VK_SEPARATER

        public static final int VK_SEPARATER
        This constant is obsolete, and is included only for backwards compatibility.
        See Also:
        VK_SEPARATOR, Constant Field Values

      • VK_SEPARATOR

        public static final int VK_SEPARATOR
        Constant for the Numpad Separator key.
        Since:
        1.4
        See Also:
        Constant Field Values

      • VK_SUBTRACT

        public static final int VK_SUBTRACT
        Constant for the number pad subtract key.
        See Also:
        Constant Field Values

      • VK_DECIMAL

        public static final int VK_DECIMAL
        Constant for the number pad decimal point key.
        See Also:
        Constant Field Values

      • VK_DIVIDE

        public static final int VK_DIVIDE
        Constant for the number pad divide key.
        See Also:
        Constant Field Values

      • VK_DELETE

        public static final int VK_DELETE
        Constant for the delete key.
        See Also:
        Constant Field Values

      • VK_NUM_LOCK

        public static final int VK_NUM_LOCK
        Constant for the NUM_LOCK key.
        See Also:
        Constant Field Values

      • VK_SCROLL_LOCK

        public static final int VK_SCROLL_LOCK
        Constant for the SCROLL_LOCK key.
        See Also:
        Constant Field Values

      • VK_F10

        public static final int VK_F10
        Constant for the F10 function key.
        See Also:
        Constant Field Values

      • VK_F11

        public static final int VK_F11
        Constant for the F11 function key.
        See Also:
        Constant Field Values

      • VK_F12

        public static final int VK_F12
        Constant for the F12 function key.
        See Also:
        Constant Field Values

      • VK_F13

        public static final int VK_F13
        Constant for the F13 function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_F14

        public static final int VK_F14
        Constant for the F14 function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_F15

        public static final int VK_F15
        Constant for the F15 function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_F16

        public static final int VK_F16
        Constant for the F16 function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_F17

        public static final int VK_F17
        Constant for the F17 function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_F18

        public static final int VK_F18
        Constant for the F18 function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_F19

        public static final int VK_F19
        Constant for the F19 function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_F20

        public static final int VK_F20
        Constant for the F20 function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_F21

        public static final int VK_F21
        Constant for the F21 function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_F22

        public static final int VK_F22
        Constant for the F22 function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_F23

        public static final int VK_F23
        Constant for the F23 function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_F24

        public static final int VK_F24
        Constant for the F24 function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_PRINTSCREEN

        public static final int VK_PRINTSCREEN
        Constant for the PRINTSCREEN key.
        See Also:
        Constant Field Values

      • VK_INSERT

        public static final int VK_INSERT
        Constant for the INSERT key.
        See Also:
        Constant Field Values

      • VK_BACK_QUOTE

        public static final int VK_BACK_QUOTE
        Constant for the BACK_QUOTE key.
        See Also:
        Constant Field Values

      • VK_KP_UP

        public static final int VK_KP_UP
        Constant for the numeric keypad up arrow key.
        Since:
        1.2
        See Also:
        VK_UP, Constant Field Values

      • VK_KP_DOWN

        public static final int VK_KP_DOWN
        Constant for the numeric keypad down arrow key.
        Since:
        1.2
        See Also:
        VK_DOWN, Constant Field Values

      • VK_KP_LEFT

        public static final int VK_KP_LEFT
        Constant for the numeric keypad left arrow key.
        Since:
        1.2
        See Also:
        VK_LEFT, Constant Field Values

      • VK_KP_RIGHT

        public static final int VK_KP_RIGHT
        Constant for the numeric keypad right arrow key.
        Since:
        1.2
        See Also:
        VK_RIGHT, Constant Field Values

      • VK_DEAD_CIRCUMFLEX

        public static final int VK_DEAD_CIRCUMFLEX
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_DEAD_DIAERESIS

        public static final int VK_DEAD_DIAERESIS
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_DEAD_ABOVERING

        public static final int VK_DEAD_ABOVERING
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_DEAD_DOUBLEACUTE

        public static final int VK_DEAD_DOUBLEACUTE
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_DEAD_VOICED_SOUND

        public static final int VK_DEAD_VOICED_SOUND
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_DEAD_SEMIVOICED_SOUND

        public static final int VK_DEAD_SEMIVOICED_SOUND
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_AT

        public static final int VK_AT
        Constant for the "@" key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_COLON

        public static final int VK_COLON
        Constant for the ":" key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_CIRCUMFLEX

        public static final int VK_CIRCUMFLEX
        Constant for the "^" key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_DOLLAR

        public static final int VK_DOLLAR
        Constant for the "$" key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_EURO_SIGN

        public static final int VK_EURO_SIGN
        Constant for the Euro currency sign key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_EXCLAMATION_MARK

        public static final int VK_EXCLAMATION_MARK
        Constant for the "!" key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_INVERTED_EXCLAMATION_MARK

        public static final int VK_INVERTED_EXCLAMATION_MARK
        Constant for the inverted exclamation mark key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_LEFT_PARENTHESIS

        public static final int VK_LEFT_PARENTHESIS
        Constant for the "(" key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_NUMBER_SIGN

        public static final int VK_NUMBER_SIGN
        Constant for the "#" key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_PLUS

        public static final int VK_PLUS
        Constant for the "+" key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_RIGHT_PARENTHESIS

        public static final int VK_RIGHT_PARENTHESIS
        Constant for the ")" key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_UNDERSCORE

        public static final int VK_UNDERSCORE
        Constant for the "_" key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_WINDOWS

        public static final int VK_WINDOWS
        Constant for the Microsoft Windows "Windows" key. It is used for both the left and right version of the key.
        Since:
        1.5
        See Also:
        getKeyLocation(), Constant Field Values

      • VK_CONTEXT_MENU

        public static final int VK_CONTEXT_MENU
        Constant for the Microsoft Windows Context Menu key.
        Since:
        1.5
        See Also:
        Constant Field Values

      • VK_CONVERT

        public static final int VK_CONVERT
        Constant for the Convert function key.
        See Also:
        Constant Field Values

      • VK_NONCONVERT

        public static final int VK_NONCONVERT
        Constant for the Don't Convert function key.
        See Also:
        Constant Field Values

      • VK_ACCEPT

        public static final int VK_ACCEPT
        Constant for the Accept or Commit function key.
        See Also:
        Constant Field Values

      • VK_MODECHANGE

        public static final int VK_MODECHANGE
        Constant for the MODECHANGE key.
        See Also:
        Constant Field Values

      • VK_ALPHANUMERIC

        public static final int VK_ALPHANUMERIC
        Constant for the Alphanumeric function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_KATAKANA

        public static final int VK_KATAKANA
        Constant for the Katakana function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_HIRAGANA

        public static final int VK_HIRAGANA
        Constant for the Hiragana function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_FULL_WIDTH

        public static final int VK_FULL_WIDTH
        Constant for the Full-Width Characters function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_HALF_WIDTH

        public static final int VK_HALF_WIDTH
        Constant for the Half-Width Characters function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_ROMAN_CHARACTERS

        public static final int VK_ROMAN_CHARACTERS
        Constant for the Roman Characters function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_ALL_CANDIDATES

        public static final int VK_ALL_CANDIDATES
        Constant for the All Candidates function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_PREVIOUS_CANDIDATE

        public static final int VK_PREVIOUS_CANDIDATE
        Constant for the Previous Candidate function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_CODE_INPUT

        public static final int VK_CODE_INPUT
        Constant for the Code Input function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_JAPANESE_KATAKANA

        public static final int VK_JAPANESE_KATAKANA
        Constant for the Japanese-Katakana function key. This key switches to a Japanese input method and selects its Katakana input mode.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_JAPANESE_HIRAGANA

        public static final int VK_JAPANESE_HIRAGANA
        Constant for the Japanese-Hiragana function key. This key switches to a Japanese input method and selects its Hiragana input mode.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_JAPANESE_ROMAN

        public static final int VK_JAPANESE_ROMAN
        Constant for the Japanese-Roman function key. This key switches to a Japanese input method and selects its Roman-Direct input mode.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_KANA_LOCK

        public static final int VK_KANA_LOCK
        Constant for the locking Kana function key. This key locks the keyboard into a Kana layout.
        Since:
        1.3
        See Also:
        Constant Field Values

      • VK_INPUT_METHOD_ON_OFF

        public static final int VK_INPUT_METHOD_ON_OFF
        Constant for the input method on/off key.
        Since:
        1.3
        See Also:
        Constant Field Values

      • VK_COMPOSE

        public static final int VK_COMPOSE
        Constant for the Compose function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_ALT_GRAPH

        public static final int VK_ALT_GRAPH
        Constant for the AltGraph function key.
        Since:
        1.2
        See Also:
        Constant Field Values

      • VK_BEGIN

        public static final int VK_BEGIN
        Constant for the Begin key.
        Since:
        1.5
        See Also:
        Constant Field Values

      • VK_UNDEFINED

        public static final int VK_UNDEFINED
        This value is used to indicate that the keyCode is unknown. KEY_TYPED events do not have a keyCode value; this value is used instead.
        See Also:
        Constant Field Values

      • CHAR_UNDEFINED

        public static final char CHAR_UNDEFINED
        KEY_PRESSED and KEY_RELEASED events which do not map to a valid Unicode character use this for the keyChar value.
        See Also:
        Constant Field Values

      • KEY_LOCATION_UNKNOWN

        public static final int KEY_LOCATION_UNKNOWN
        A constant indicating that the keyLocation is indeterminate or not relevant. KEY_TYPED events do not have a keyLocation; this value is used instead.
        Since:
        1.4
        See Also:
        Constant Field Values

      • KEY_LOCATION_STANDARD

        public static final int KEY_LOCATION_STANDARD
        A constant indicating that the key pressed or released is not distinguished as the left or right version of a key, and did not originate on the numeric keypad (or did not originate with a virtual key corresponding to the numeric keypad).
        Since:
        1.4
        See Also:
        Constant Field Values

      • KEY_LOCATION_LEFT

        public static final int KEY_LOCATION_LEFT
        A constant indicating that the key pressed or released is in the left key location (there is more than one possible location for this key). Example: the left shift key.
        Since:
        1.4
        See Also:
        Constant Field Values

      • KEY_LOCATION_RIGHT

        public static final int KEY_LOCATION_RIGHT
        A constant indicating that the key pressed or released is in the right key location (there is more than one possible location for this key). Example: the right shift key.
        Since:
        1.4
        See Also:
        Constant Field Values

      • KEY_LOCATION_NUMPAD

        public static final int KEY_LOCATION_NUMPAD
        A constant indicating that the key event originated on the numeric keypad or with a virtual key corresponding to the numeric keypad.
        Since:
        1.4
        See Also:
        Constant Field Values

    • Constructor Detail

      • KeyEvent

        public KeyEvent​(Component source,
                int id,
                long when,
                int modifiers,
                int keyCode,
                char keyChar,
                int keyLocation)
        Constructs a KeyEvent object.

        This method throws an IllegalArgumentException if source is null.

        Parameters:
        source - The Component that originated the event
        id - An integer indicating the type of event. For information on allowable values, see the class description for KeyEvent
        when - A long integer that specifies the time the event occurred. Passing negative or zero value is not recommended
        modifiers - The modifier keys down during event (shift, ctrl, alt, meta). Passing negative value is not recommended. Zero value means that no modifiers were passed. Use either an extended _DOWN_MASK or old _MASK modifiers, however do not mix models in the one event. The extended modifiers are preferred for using
        keyCode - The integer code for an actual key, or VK_UNDEFINED (for a key-typed event)
        keyChar - The Unicode character generated by this event, or CHAR_UNDEFINED (for key-pressed and key-released events which do not map to a valid Unicode character)
        keyLocation - Identifies the key location. The only legal values are KEY_LOCATION_UNKNOWN, KEY_LOCATION_STANDARD, KEY_LOCATION_LEFT, KEY_LOCATION_RIGHT, and KEY_LOCATION_NUMPAD.
        Throws:
        IllegalArgumentException - if id is KEY_TYPED and keyChar is CHAR_UNDEFINED; or if id is KEY_TYPED and keyCode is not VK_UNDEFINED; or if id is KEY_TYPED and keyLocation is not KEY_LOCATION_UNKNOWN; or if keyLocation is not one of the legal values enumerated above.
        IllegalArgumentException - if source is null
        Since:
        1.4
        See Also:
        EventObject.getSource(), AWTEvent.getID(), InputEvent.getWhen(), InputEvent.getModifiers(), getKeyCode(), getKeyChar(), getKeyLocation()

      • KeyEvent

        public KeyEvent​(Component source,
                int id,
                long when,
                int modifiers,
                int keyCode,
                char keyChar)
        Constructs a KeyEvent object.

        This method throws an IllegalArgumentException if source is null.

        Parameters:
        source - The Component that originated the event
        id - An integer indicating the type of event. For information on allowable values, see the class description for KeyEvent
        when - A long integer that specifies the time the event occurred. Passing negative or zero value is not recommended
        modifiers - The modifier keys down during event (shift, ctrl, alt, meta). Passing negative value is not recommended. Zero value means that no modifiers were passed. Use either an extended _DOWN_MASK or old _MASK modifiers, however do not mix models in the one event. The extended modifiers are preferred for using
        keyCode - The integer code for an actual key, or VK_UNDEFINED (for a key-typed event)
        keyChar - The Unicode character generated by this event, or CHAR_UNDEFINED (for key-pressed and key-released events which do not map to a valid Unicode character)
        Throws:
        IllegalArgumentException - if id is KEY_TYPED and keyChar is CHAR_UNDEFINED; or if id is KEY_TYPED and keyCode is not VK_UNDEFINED
        IllegalArgumentException - if source is null
        See Also:
        EventObject.getSource(), AWTEvent.getID(), InputEvent.getWhen(), InputEvent.getModifiers(), getKeyCode(), getKeyChar()

      • KeyEvent

        @Deprecated
public KeyEvent​(Component source,
                int id,
                long when,
                int modifiers,
                int keyCode)
        Deprecated.
        as of JDK1.1; use KeyEvent(Component, int, long, int, int, char) instead
        Parameters:
        source - The Component that originated the event
        id - An integer indicating the type of event. For information on allowable values, see the class description for KeyEvent
        when - A long integer that specifies the time the event occurred. Passing negative or zero value is not recommended
        modifiers - The modifier keys down during event (shift, ctrl, alt, meta). Passing negative value is not recommended. Zero value means that no modifiers were passed. Use either an extended _DOWN_MASK or old _MASK modifiers, however do not mix models in the one event. The extended modifiers are preferred for using
        keyCode - The integer code for an actual key, or VK_UNDEFINED (for a key-typed event)

    • Method Detail

      • getKeyCode

        public int getKeyCode()
        Returns the integer keyCode associated with the key in this event.
        Returns:
        the integer code for an actual key on the keyboard. (For KEY_TYPED events, the keyCode is VK_UNDEFINED.)

      • setKeyCode

        public void setKeyCode​(int keyCode)
        Set the keyCode value to indicate a physical key.
        Parameters:
        keyCode - an integer corresponding to an actual key on the keyboard.

      • getKeyChar

        public char getKeyChar()
        Returns the character associated with the key in this event. For example, the KEY_TYPED event for shift + "a" returns the value for "A".

        KEY_PRESSED and KEY_RELEASED events are not intended for reporting of character input. Therefore, the values returned by this method are guaranteed to be meaningful only for KEY_TYPED events.

        Returns:
        the Unicode character defined for this key event. If no valid Unicode character exists for this key event, CHAR_UNDEFINED is returned.

      • setKeyChar

        public void setKeyChar​(char keyChar)
        Set the keyChar value to indicate a logical character.
        Parameters:
        keyChar - a char corresponding to the combination of keystrokes that make up this event.

      • setModifiers

        @Deprecated
public void setModifiers​(int modifiers)
        Deprecated.
        as of JDK1.1.4
        Set the modifiers to indicate additional keys that were held down (e.g. shift, ctrl, alt, meta) defined as part of InputEvent.

        NOTE: use of this method is not recommended, because many AWT implementations do not recognize modifier changes. This is especially true for KEY_TYPED events where the shift modifier is changed.

        Parameters:
        modifiers - an integer combination of the modifier constants.
        See Also:
        InputEvent

      • getKeyLocation

        public int getKeyLocation()
        Returns the location of the key that originated this key event. Some keys occur more than once on a keyboard, e.g. the left and right shift keys. Additionally, some keys occur on the numeric keypad. This provides a way of distinguishing such keys.
        Returns:
        the location of the key that was pressed or released. Always returns KEY_LOCATION_UNKNOWN for KEY_TYPED events.
        Since:
        1.4

      • getKeyText

        public static String getKeyText​(int keyCode)
        Returns a String describing the keyCode, such as "HOME", "F1" or "A". These strings can be localized by changing the awt.properties file.
        Parameters:
        keyCode - the key whose description is to be returned
        Returns:
        a string containing a text description for a physical key, identified by its keyCode

      • getKeyModifiersText

        @Deprecated(since="9")
public static String getKeyModifiersText​(int modifiers)
        Deprecated.
        It is recommended that extended modifier keys and InputEvent.getModifiersExText(int) be used instead
        Returns a String describing the modifier key(s), such as "Shift", or "Ctrl+Shift". These strings can be localized by changing the awt.properties file.

        Note that InputEvent.ALT_MASK and InputEvent.BUTTON2_MASK have the same value, so the string "Alt" is returned for both modifiers. Likewise, InputEvent.META_MASK and InputEvent.BUTTON3_MASK have the same value, so the string "Meta" is returned for both modifiers.

        Parameters:
        modifiers - the modifier mask to be processed
        Returns:
        string a text description of the combination of modifier keys that were held down during the event
        See Also:
        InputEvent.getModifiersExText(int)

      • isActionKey

        public boolean isActionKey()
        Returns whether the key in this event is an "action" key. Typically an action key does not fire a unicode character and is not a modifier key.
        Returns:
        true if the key is an "action" key, false otherwise

      • paramString

        public String paramString()
        Returns a parameter string identifying this event. This method is useful for event logging and for debugging.
        Overrides:
        paramString in class ComponentEvent
        Returns:
        a string identifying the event and its attributes

      • getExtendedKeyCode

        public int getExtendedKeyCode()
        Returns an extended key code for the event. The extended key code is a unique id assigned to a key on the keyboard just like keyCode. However, unlike keyCode, this value depends on the current keyboard layout. For instance, pressing the left topmost letter key in a common English layout produces the same value as keyCode, VK_Q. Pressing the same key in a regular Russian layout gives another code, unique for the letter "Cyrillic I short".
        Returns:
        an extended key code for the event
        Since:
        1.7

      • getExtendedKeyCodeForChar

        public static int getExtendedKeyCodeForChar​(int c)
        Returns an extended key code for a unicode character.
        Parameters:
        c - the unicode character to be processed
        Returns:
        for a unicode character with a corresponding VK_ constant -- this VK_ constant; for a character appearing on the primary level of a known keyboard layout -- a unique integer. If a character does not appear on the primary level of a known keyboard, VK_UNDEFINED is returned.
        Since:
        1.7