W3cubDocs

Class KeyEvent

java.lang.Object
- java.util.EventObject
- - java.awt.AWTEvent
  - - java.awt.event.ComponentEvent
    - - java.awt.event.InputEvent
      - java.awt.event.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. Sun 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

Fields

KEY_FIRST

public static final int KEY_FIRST

The first number in the range of ids used for key events.

KEY_LAST

public static final int KEY_LAST

The last number in the range of ids used for key events.

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.

KEY_PRESSED

public static final int KEY_PRESSED

The "key pressed" event. This event is generated when a key is pushed down.

KEY_RELEASED

public static final int KEY_RELEASED

The "key released" event. This event is generated when a key is let up.

VK_ENTER

public static final int VK_ENTER

VK_BACK_SPACE

public static final int VK_BACK_SPACE

VK_TAB

public static final int VK_TAB

VK_CANCEL

public static final int VK_CANCEL

VK_CLEAR

public static final int VK_CLEAR

VK_SHIFT

public static final int VK_SHIFT

VK_CONTROL

public static final int VK_CONTROL

VK_ALT

public static final int VK_ALT

VK_PAUSE

public static final int VK_PAUSE

VK_CAPS_LOCK

public static final int VK_CAPS_LOCK

VK_ESCAPE

public static final int VK_ESCAPE

VK_SPACE

public static final int VK_SPACE

VK_PAGE_UP

public static final int VK_PAGE_UP

VK_PAGE_DOWN

public static final int VK_PAGE_DOWN

VK_END

public static final int VK_END

VK_HOME

public static final int VK_HOME

VK_LEFT

public static final int VK_LEFT

Constant for the non-numpad left arrow key.

See Also:: VK_KP_LEFT, Constant Field Values

VK_UP

public static final int VK_UP

Constant for the non-numpad up arrow key.

See Also:: VK_KP_UP, Constant Field Values

VK_RIGHT

public static final int VK_RIGHT

Constant for the non-numpad right arrow key.

See Also:: VK_KP_RIGHT, Constant Field Values

VK_DOWN

public static final int VK_DOWN

Constant for the non-numpad down arrow key.

See Also:: VK_KP_DOWN, Constant Field Values

VK_COMMA

public static final int VK_COMMA

Constant for the comma key, ","

VK_MINUS

public static final int VK_MINUS

Constant for the minus key, "-"

Since:: 1.2

VK_PERIOD

public static final int VK_PERIOD

Constant for the period key, "."

VK_SLASH

public static final int VK_SLASH

Constant for the forward slash key, "/"

VK_0

public static final int VK_0

VK_0 thru VK_9 are the same as ASCII '0' thru '9' (0x30 - 0x39)

VK_1

public static final int VK_1

VK_2

public static final int VK_2

VK_3

public static final int VK_3

VK_4

public static final int VK_4

VK_5

public static final int VK_5

VK_6

public static final int VK_6

VK_7

public static final int VK_7

VK_8

public static final int VK_8

VK_9

public static final int VK_9

VK_SEMICOLON

public static final int VK_SEMICOLON

Constant for the semicolon key, ";"

VK_EQUALS

public static final int VK_EQUALS

Constant for the equals key, "="

VK_A

public static final int VK_A

VK_A thru VK_Z are the same as ASCII 'A' thru 'Z' (0x41 - 0x5A)

VK_B

public static final int VK_B

VK_C

public static final int VK_C

VK_D

public static final int VK_D

VK_E

public static final int VK_E

VK_F

public static final int VK_F

VK_G

public static final int VK_G

VK_H

public static final int VK_H

VK_I

public static final int VK_I

VK_J

public static final int VK_J

VK_K

public static final int VK_K

VK_L

public static final int VK_L

VK_M

public static final int VK_M

VK_N

public static final int VK_N

VK_O

public static final int VK_O

VK_P

public static final int VK_P

VK_Q

public static final int VK_Q

VK_R

public static final int VK_R

VK_S

public static final int VK_S

VK_T

public static final int VK_T

VK_U

public static final int VK_U

VK_V

public static final int VK_V

VK_W

public static final int VK_W

VK_X

public static final int VK_X

VK_Y

public static final int VK_Y

VK_Z

public static final int VK_Z

VK_OPEN_BRACKET

public static final int VK_OPEN_BRACKET

Constant for the open bracket key, "["

VK_BACK_SLASH

public static final int VK_BACK_SLASH

Constant for the back slash key, "\"

VK_CLOSE_BRACKET

public static final int VK_CLOSE_BRACKET

Constant for the close bracket key, "]"

VK_NUMPAD0

public static final int VK_NUMPAD0

VK_NUMPAD1

public static final int VK_NUMPAD1

VK_NUMPAD2

public static final int VK_NUMPAD2

VK_NUMPAD3

public static final int VK_NUMPAD3

VK_NUMPAD4

public static final int VK_NUMPAD4

VK_NUMPAD5

public static final int VK_NUMPAD5

VK_NUMPAD6

public static final int VK_NUMPAD6

VK_NUMPAD7

public static final int VK_NUMPAD7

VK_NUMPAD8

public static final int VK_NUMPAD8

VK_NUMPAD9

public static final int VK_NUMPAD9

VK_MULTIPLY

public static final int VK_MULTIPLY

VK_ADD

public static final int VK_ADD

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

VK_SUBTRACT

public static final int VK_SUBTRACT

VK_DECIMAL

public static final int VK_DECIMAL

VK_DIVIDE

public static final int VK_DIVIDE

VK_DELETE

public static final int VK_DELETE

VK_NUM_LOCK

public static final int VK_NUM_LOCK

VK_SCROLL_LOCK

public static final int VK_SCROLL_LOCK

VK_F1

public static final int VK_F1

Constant for the F1 function key.

VK_F2

public static final int VK_F2

Constant for the F2 function key.

VK_F3

public static final int VK_F3

Constant for the F3 function key.

VK_F4

public static final int VK_F4

Constant for the F4 function key.

VK_F5

public static final int VK_F5

Constant for the F5 function key.

VK_F6

public static final int VK_F6

Constant for the F6 function key.

VK_F7

public static final int VK_F7

Constant for the F7 function key.

VK_F8

public static final int VK_F8

Constant for the F8 function key.

VK_F9

public static final int VK_F9

Constant for the F9 function key.

VK_F10

public static final int VK_F10

Constant for the F10 function key.

VK_F11

public static final int VK_F11

Constant for the F11 function key.

VK_F12

public static final int VK_F12

Constant for the F12 function key.

VK_F13

public static final int VK_F13

Constant for the F13 function key.

Since:: 1.2

VK_F14

public static final int VK_F14

Constant for the F14 function key.

Since:: 1.2

VK_F15

public static final int VK_F15

Constant for the F15 function key.

Since:: 1.2

VK_F16

public static final int VK_F16

Constant for the F16 function key.

Since:: 1.2

VK_F17

public static final int VK_F17

Constant for the F17 function key.

Since:: 1.2

VK_F18

public static final int VK_F18

Constant for the F18 function key.

Since:: 1.2

VK_F19

public static final int VK_F19

Constant for the F19 function key.

Since:: 1.2

VK_F20

public static final int VK_F20

Constant for the F20 function key.

Since:: 1.2

VK_F21

public static final int VK_F21

Constant for the F21 function key.

Since:: 1.2

VK_F22

public static final int VK_F22

Constant for the F22 function key.

Since:: 1.2

VK_F23

public static final int VK_F23

Constant for the F23 function key.

Since:: 1.2

VK_F24

public static final int VK_F24

Constant for the F24 function key.

Since:: 1.2

VK_PRINTSCREEN

public static final int VK_PRINTSCREEN

VK_INSERT

public static final int VK_INSERT

VK_HELP

public static final int VK_HELP

VK_META

public static final int VK_META

VK_BACK_QUOTE

public static final int VK_BACK_QUOTE

VK_QUOTE

public static final int VK_QUOTE

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_GRAVE

public static final int VK_DEAD_GRAVE

Since:: 1.2

VK_DEAD_ACUTE

public static final int VK_DEAD_ACUTE

Since:: 1.2

VK_DEAD_CIRCUMFLEX

public static final int VK_DEAD_CIRCUMFLEX

Since:: 1.2

VK_DEAD_TILDE

public static final int VK_DEAD_TILDE

Since:: 1.2

VK_DEAD_MACRON

public static final int VK_DEAD_MACRON

Since:: 1.2

VK_DEAD_BREVE

public static final int VK_DEAD_BREVE

Since:: 1.2

VK_DEAD_ABOVEDOT

public static final int VK_DEAD_ABOVEDOT

Since:: 1.2

VK_DEAD_DIAERESIS

public static final int VK_DEAD_DIAERESIS

Since:: 1.2

VK_DEAD_ABOVERING

public static final int VK_DEAD_ABOVERING

Since:: 1.2

VK_DEAD_DOUBLEACUTE

public static final int VK_DEAD_DOUBLEACUTE

Since:: 1.2

VK_DEAD_CARON

public static final int VK_DEAD_CARON

Since:: 1.2

VK_DEAD_CEDILLA

public static final int VK_DEAD_CEDILLA

Since:: 1.2

VK_DEAD_OGONEK

public static final int VK_DEAD_OGONEK

Since:: 1.2

VK_DEAD_IOTA

public static final int VK_DEAD_IOTA

Since:: 1.2

VK_DEAD_VOICED_SOUND

public static final int VK_DEAD_VOICED_SOUND

Since:: 1.2

VK_DEAD_SEMIVOICED_SOUND

public static final int VK_DEAD_SEMIVOICED_SOUND

Since:: 1.2

VK_AMPERSAND

public static final int VK_AMPERSAND

Since:: 1.2

VK_ASTERISK

public static final int VK_ASTERISK

Since:: 1.2

VK_QUOTEDBL

public static final int VK_QUOTEDBL

Since:: 1.2

VK_LESS

public static final int VK_LESS

Since:: 1.2

VK_GREATER

public static final int VK_GREATER

Since:: 1.2

VK_BRACELEFT

public static final int VK_BRACELEFT

Since:: 1.2

VK_BRACERIGHT

public static final int VK_BRACERIGHT

Since:: 1.2

VK_AT

public static final int VK_AT

Constant for the "@" key.

Since:: 1.2

VK_COLON

public static final int VK_COLON

Constant for the ":" key.

Since:: 1.2

VK_CIRCUMFLEX

public static final int VK_CIRCUMFLEX

Constant for the "^" key.

Since:: 1.2

VK_DOLLAR

public static final int VK_DOLLAR

Constant for the "$" key.

Since:: 1.2

VK_EURO_SIGN

public static final int VK_EURO_SIGN

Constant for the Euro currency sign key.

Since:: 1.2

VK_EXCLAMATION_MARK

public static final int VK_EXCLAMATION_MARK

Constant for the "!" key.

Since:: 1.2

VK_INVERTED_EXCLAMATION_MARK

public static final int VK_INVERTED_EXCLAMATION_MARK

Constant for the inverted exclamation mark key.

Since:: 1.2

VK_LEFT_PARENTHESIS

public static final int VK_LEFT_PARENTHESIS

Constant for the "(" key.

Since:: 1.2

VK_NUMBER_SIGN

public static final int VK_NUMBER_SIGN

Constant for the "#" key.

Since:: 1.2

VK_PLUS

public static final int VK_PLUS

Constant for the "+" key.

Since:: 1.2

VK_RIGHT_PARENTHESIS

public static final int VK_RIGHT_PARENTHESIS

Constant for the ")" key.

Since:: 1.2

VK_UNDERSCORE

public static final int VK_UNDERSCORE

Constant for the "_" key.

Since:: 1.2

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

VK_FINAL

public static final int VK_FINAL

VK_CONVERT

public static final int VK_CONVERT

Constant for the Convert function key.

VK_NONCONVERT

public static final int VK_NONCONVERT

Constant for the Don't Convert function key.

VK_ACCEPT

public static final int VK_ACCEPT

Constant for the Accept or Commit function key.

VK_MODECHANGE

public static final int VK_MODECHANGE

VK_KANA

public static final int VK_KANA

VK_KANJI

public static final int VK_KANJI

VK_ALPHANUMERIC

public static final int VK_ALPHANUMERIC

Constant for the Alphanumeric function key.

Since:: 1.2

VK_KATAKANA

public static final int VK_KATAKANA

Constant for the Katakana function key.

Since:: 1.2

VK_HIRAGANA

public static final int VK_HIRAGANA

Constant for the Hiragana function key.

Since:: 1.2

VK_FULL_WIDTH

public static final int VK_FULL_WIDTH

Constant for the Full-Width Characters function key.

Since:: 1.2

VK_HALF_WIDTH

public static final int VK_HALF_WIDTH

Constant for the Half-Width Characters function key.

Since:: 1.2

VK_ROMAN_CHARACTERS

public static final int VK_ROMAN_CHARACTERS

Constant for the Roman Characters function key.

Since:: 1.2

VK_ALL_CANDIDATES

public static final int VK_ALL_CANDIDATES

Constant for the All Candidates function key.

Since:: 1.2

VK_PREVIOUS_CANDIDATE

public static final int VK_PREVIOUS_CANDIDATE

Constant for the Previous Candidate function key.

Since:: 1.2

VK_CODE_INPUT

public static final int VK_CODE_INPUT

Constant for the Code Input function key.

Since:: 1.2

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

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

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

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

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

VK_CUT

public static final int VK_CUT

Since:: 1.2

VK_COPY

public static final int VK_COPY

Since:: 1.2

VK_PASTE

public static final int VK_PASTE

Since:: 1.2

VK_UNDO

public static final int VK_UNDO

Since:: 1.2

VK_AGAIN

public static final int VK_AGAIN

Since:: 1.2

VK_FIND

public static final int VK_FIND

Since:: 1.2

VK_PROPS

public static final int VK_PROPS

Since:: 1.2

VK_STOP

public static final int VK_STOP

Since:: 1.2

VK_COMPOSE

public static final int VK_COMPOSE

Constant for the Compose function key.

Since:: 1.2

VK_ALT_GRAPH

public static final int VK_ALT_GRAPH

Constant for the AltGraph function key.

Since:: 1.2

VK_BEGIN

public static final int VK_BEGIN

Constant for the Begin key.

Since:: 1.5

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.

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.

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

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

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

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

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

Constructors

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

Methods

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 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.

Returns:: a string containing a text description for a physical key, identified by its keyCode

getKeyModifiersText

public static String getKeyModifiersText(int modifiers)

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.

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".

Since:: 1.7

getExtendedKeyCodeForChar

public static int getExtendedKeyCodeForChar(int c)

Returns an extended key code for a unicode character.

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

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