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Class java.awt.event.KeyEvent

java.lang.Object
    |
    +----java.util.EventObject
            |
            +----java.awt.AWTEvent
                    |
                    +----java.awt.event.ComponentEvent
                            |
                            +----java.awt.event.InputEvent
                                    |
                                    +----java.awt.event.KeyEvent

public class KeyEvent

extends InputEvent

This low-level event is generated by a component object (such as a text field) when a key is pressed, released, or typed (pressed and released). 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.

See Also:

KeyAdapter, KeyListener, Tutorial: Writing a Key Listener, Reference: The Java Class Libraries (update file)

CHAR_UNDEFINED

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

KEY_FIRST

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

KEY_LAST

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

KEY_PRESSED

The "key pressed" event.

KEY_RELEASED

The "key released" event.

KEY_TYPED

The "key typed" event.

VK_0

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

VK_1

VK_2

VK_3

VK_4

VK_5

VK_6

VK_7

VK_8

VK_9

VK_A

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

VK_ACCEPT

VK_ADD

VK_ALT

VK_AMPERSAND

VK_ASTERISK

VK_B

VK_BACK_QUOTE

VK_BACK_SLASH

VK_BACK_SPACE

VK_BRACELEFT

VK_BRACERIGHT

VK_C

VK_CANCEL

VK_CAPS_LOCK

VK_CLEAR

VK_CLOSE_BRACKET

VK_COMMA

VK_CONTROL

VK_CONVERT

VK_D

VK_DEAD_ABOVEDOT

VK_DEAD_ABOVERING

VK_DEAD_ACUTE

VK_DEAD_BREVE

VK_DEAD_CARON

VK_DEAD_CEDILLA

VK_DEAD_CIRCUMFLEX

VK_DEAD_DIAERESIS

VK_DEAD_DOUBLEACUTE

VK_DEAD_GRAVE

VK_DEAD_IOTA

VK_DEAD_MACRON

VK_DEAD_OGONEK

VK_DEAD_SEMIVOICED_SOUND

VK_DEAD_TILDE

VK_DEAD_VOICED_SOUND

VK_DECIMAL

VK_DELETE

VK_DIVIDE

VK_DOWN

VK_E

VK_END

VK_ENTER

Virtual key codes.

VK_EQUALS

VK_ESCAPE

VK_F

VK_F1

VK_F10

VK_F11

VK_F12

VK_F2

VK_F3

VK_F4

VK_F5

VK_F6

VK_F7

VK_F8

VK_F9

VK_FINAL

VK_G

VK_GREATER

VK_H

VK_HELP

VK_HOME

VK_I

VK_INSERT

VK_J

VK_K

VK_KANA

VK_KANJI

VK_KP_DOWN

VK_KP_LEFT

VK_KP_RIGHT

VK_KP_UP

for KeyPad cursor arrow keys

VK_L

VK_LEFT

VK_LESS

VK_M

VK_META

VK_MODECHANGE

VK_MULTIPLY

VK_N

VK_NONCONVERT

VK_NUM_LOCK

VK_NUMPAD0

VK_NUMPAD1

VK_NUMPAD2

VK_NUMPAD3

VK_NUMPAD4

VK_NUMPAD5

VK_NUMPAD6

VK_NUMPAD7

VK_NUMPAD8

VK_NUMPAD9

VK_O

VK_OPEN_BRACKET

VK_P

VK_PAGE_DOWN

VK_PAGE_UP

VK_PAUSE

VK_PERIOD

VK_PRINTSCREEN

VK_Q

VK_QUOTE

VK_QUOTEDBL

VK_R

VK_RIGHT

VK_S

VK_SCROLL_LOCK

VK_SEMICOLON

VK_SEPARATER

VK_SHIFT

VK_SLASH

VK_SPACE

VK_SUBTRACT

VK_T

VK_TAB

VK_U

VK_UNDEFINED

KEY_TYPED events do not have a keyCode value.

VK_UP

VK_V

VK_W

VK_X

VK_Y

VK_Z

KeyEvent(Component, int, long, int, int)

KeyEvent(Component, int, long, int, int, char)

Constructs a KeyEvent object.

getKeyChar()

Returns the character associated with the key in this event.

getKeyCode()

Returns the integer key-code associated with the key in this event.

getKeyModifiersText(int)

Returns a String describing the modifier key(s), such as "Shift", or "Ctrl+Shift".

getKeyText(int)

Returns a String describing the keyCode, such as "HOME", "F1" or "A".

isActionKey()

Returns whether or not the key in this event is an "action" key, as defined in Event.java.

paramString()

Returns a parameter string identifying this event.

setKeyChar(char)

Set the keyChar value to indicate a logical character.

setKeyCode(int)

Set the keyCode value to indicate a physical key.

setModifiers(int)

Set the modifiers to indicate additional keys that were held down (shift, ctrl, alt, meta) defined as part of InputEvent.

public static final int KEY_FIRST

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

public static final int KEY_LAST

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

public static final int KEY_TYPED

The "key typed" event. This event is generated by a combination of a key press followed by a key release.

public static final int KEY_PRESSED

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

public static final int KEY_RELEASED

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

public static final int VK_ENTER

Virtual key codes. These codes report which keyboard key has been pressed, rather than a character generated by the combination of one or more keystrokes (like "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, followed by a KEY_TYPED event with a keyChar value of 'A'.

Note: Key combinations which do not result in characters, such as action keys like F1, do not generate KEY_TYPED events.

Note: not all keyboards or systems are capable of generating all virtual key codes. No attempt is made in Java to artificially generate these keys.

WARNING: aside from those keys where are defined by the Java language (VK_ENTER, VK_BACK_SPACE, and VK_TAB), do not rely on the values of these constants. Sun reserves the right to change these values as needed to accomodate a wider range of keyboards in the future.

public static final int VK_BACK_SPACE

public static final int VK_TAB

public static final int VK_CANCEL

public static final int VK_CLEAR

public static final int VK_SHIFT

public static final int VK_CONTROL

public static final int VK_ALT

public static final int VK_PAUSE

public static final int VK_CAPS_LOCK

public static final int VK_ESCAPE

public static final int VK_SPACE

public static final int VK_PAGE_UP

public static final int VK_PAGE_DOWN

public static final int VK_END

public static final int VK_HOME

public static final int VK_LEFT

public static final int VK_UP

public static final int VK_RIGHT

public static final int VK_DOWN

public static final int VK_COMMA

public static final int VK_PERIOD

public static final int VK_SLASH

public static final int VK_0

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

public static final int VK_1

public static final int VK_2

public static final int VK_3

public static final int VK_4

public static final int VK_5

public static final int VK_6

public static final int VK_7

public static final int VK_8

public static final int VK_9

public static final int VK_SEMICOLON

public static final int VK_EQUALS

public static final int VK_A

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

public static final int VK_B

public static final int VK_C

public static final int VK_D

public static final int VK_E

public static final int VK_F

public static final int VK_G

public static final int VK_H

public static final int VK_I

public static final int VK_J

public static final int VK_K

public static final int VK_L

public static final int VK_M

public static final int VK_N

public static final int VK_O

public static final int VK_P

public static final int VK_Q

public static final int VK_R

public static final int VK_S

public static final int VK_T

public static final int VK_U

public static final int VK_V

public static final int VK_W

public static final int VK_X

public static final int VK_Y

public static final int VK_Z

public static final int VK_OPEN_BRACKET

public static final int VK_BACK_SLASH

public static final int VK_CLOSE_BRACKET

public static final int VK_NUMPAD0

public static final int VK_NUMPAD1

public static final int VK_NUMPAD2

public static final int VK_NUMPAD3

public static final int VK_NUMPAD4

public static final int VK_NUMPAD5

public static final int VK_NUMPAD6

public static final int VK_NUMPAD7

public static final int VK_NUMPAD8

public static final int VK_NUMPAD9

public static final int VK_MULTIPLY

public static final int VK_ADD

public static final int VK_SEPARATER

public static final int VK_SUBTRACT

public static final int VK_DECIMAL

public static final int VK_DIVIDE

public static final int VK_F1

public static final int VK_F2

public static final int VK_F3

public static final int VK_F4

public static final int VK_F5

public static final int VK_F6

public static final int VK_F7

public static final int VK_F8

public static final int VK_F9

public static final int VK_F10

public static final int VK_F11

public static final int VK_F12

public static final int VK_DELETE

public static final int VK_NUM_LOCK

public static final int VK_SCROLL_LOCK

public static final int VK_PRINTSCREEN

public static final int VK_INSERT

public static final int VK_HELP

public static final int VK_META

public static final int VK_BACK_QUOTE

public static final int VK_QUOTE

public static final int VK_KP_UP

for KeyPad cursor arrow keys

public static final int VK_KP_DOWN

public static final int VK_KP_LEFT

public static final int VK_KP_RIGHT

public static final int VK_DEAD_GRAVE

public static final int VK_DEAD_ACUTE

public static final int VK_DEAD_CIRCUMFLEX

public static final int VK_DEAD_TILDE

public static final int VK_DEAD_MACRON

public static final int VK_DEAD_BREVE

public static final int VK_DEAD_ABOVEDOT

public static final int VK_DEAD_DIAERESIS

public static final int VK_DEAD_ABOVERING

public static final int VK_DEAD_DOUBLEACUTE

public static final int VK_DEAD_CARON

public static final int VK_DEAD_CEDILLA

public static final int VK_DEAD_OGONEK

public static final int VK_DEAD_IOTA

public static final int VK_DEAD_VOICED_SOUND

public static final int VK_DEAD_SEMIVOICED_SOUND

public static final int VK_AMPERSAND

public static final int VK_ASTERISK

public static final int VK_QUOTEDBL

public static final int VK_LESS

public static final int VK_GREATER

public static final int VK_BRACELEFT

public static final int VK_BRACERIGHT

public static final int VK_FINAL

public static final int VK_CONVERT

public static final int VK_NONCONVERT

public static final int VK_ACCEPT

public static final int VK_MODECHANGE

public static final int VK_KANA

public static final int VK_KANJI

public static final int VK_UNDEFINED

KEY_TYPED events do not have a keyCode value. This value is used, instead.

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.

public KeyEvent(Component source,
                int id,
                long when,
                int modifiers,
                int keyCode,
                char keyChar)

Constructs a KeyEvent object.

Parameters:

source - the Component that originated the event

id - an integer identifying the type of event

when - a long integer that specifys the time the event occurred

modifiers - the modifier keys down during event (shift, ctrl, alt, meta)

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)

public KeyEvent(Component source,
                int id,
                long when,
                int modifiers,
                int keyCode)

public int getKeyCode()

Returns the integer key-code associated with the key in this event.

Returns:

the integer code for an actual key on the keyboard. (For KEY_TYPED events, keyCode is VK_UNDEFINED.)

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.

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.

public void setModifiers(int modifiers)

Set the modifiers to indicate additional keys that were held down (shift, ctrl, alt, meta) defined as part of InputEvent.

Parameters:

modifiers - an integer combination of the modifier constants.

See Also:

InputEvent

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".

Returns:

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

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:

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

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.

Returns:

string a text description of the combination of modifier keys that were held down during the event

public boolean isActionKey()

Returns whether or not the key in this event is an "action" key, as defined in Event.java.

Returns:

boolean value, true if the key is an "action" key

See Also:

Event

public String paramString()

Returns a parameter string identifying this event. This method is useful for event-logging and for debugging.

Returns:

a string identifying the event and its attributes

Overrides:

paramString in class ComponentEvent

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