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Class java.awt.Event

java.lang.Object
   |
   +----java.awt.Event

public class Event
extends Object
implements Serializable

Event is a platform-independent class that encapsulates events from the platform's Graphical User Interface in the Java 1.0 event model. In Java 1.1 and later versions, the Event class is maintained only for backwards compatibilty. The information in this class description is provided to assist programmers in converting Java 1.0 programs to the new event model.

In the Java 1.0 event model, an event contains an id field that indicates what type of event it is and which other Event variables are relevant for the event.

For keyboard events, key contains a value indicating which key was activated, and modifiers contains the modifiers for that event. For the KEY_PRESS and KEY_RELEASE event ids, the value of key is the unicode character code for the key. For KEY_ACTION and KEY_ACTION_RELEASE, the value of key is one of the defined action-key identifiers in the Event class (PGUP, PGDN, F1, F2, etc).

ACTION_EVENT: This event indicates that the user wants some action to occur.
ALT_MASK: This flag indicates that the Alt key was down when the event occurred.
arg: An arbitrary argument of the event.
BACK_SPACE: The BackSpace key.
CAPS_LOCK: The Caps Lock key, a non-ASCII action key.
clickCount: For MOUSE_DOWN events, this field indicates the number of consecutive clicks.
CTRL_MASK: This flag indicates that the Control key was down when the event occurred.
DELETE: The Delete key.
DOWN: The Down Arrow key, a non-ASCII action key.
END: The End key, a non-ASCII action key.
ENTER: The Enter key.
ESCAPE: The Escape key.
evt: The next event.
F1: The F1 function key, a non-ASCII action key.
F10: The F10 function key, a non-ASCII action key.
F11: The F11 function key, a non-ASCII action key.
F12: The F12 function key, a non-ASCII action key.
F2: The F2 function key, a non-ASCII action key.
F3: The F3 function key, a non-ASCII action key.
F4: The F4 function key, a non-ASCII action key.
F5: The F5 function key, a non-ASCII action key.
F6: The F6 function key, a non-ASCII action key.
F7: The F7 function key, a non-ASCII action key.
F8: The F8 function key, a non-ASCII action key.
F9: The F9 function key, a non-ASCII action key.
GOT_FOCUS: A component gained the focus.
HOME: The Home key, a non-ASCII action key.
id: Indicates which type of event the event is, and which other Event variables are relevant for the event.
INSERT: The Insert key, a non-ASCII action key.
key: The key code of the key that was pressed in a keyboard event.
KEY_ACTION: The user has pressed a non-ASCII action key.
KEY_ACTION_RELEASE: The user has released a non-ASCII action key.
KEY_PRESS: The user has pressed a normal key.
KEY_RELEASE: The user has released a normal key.
LEFT: The Left Arrow key, a non-ASCII action key.
LIST_DESELECT: An item in a list has been deselected.
LIST_SELECT: An item in a list has been selected.
LOAD_FILE: A file loading event.
LOST_FOCUS: A component lost the focus.
META_MASK: This flag indicates that the Meta key was down when the event occurred.
modifiers: The state of the modifier keys.
MOUSE_DOWN: The user has pressed the mouse button.
MOUSE_DRAG: The user has moved the mouse with a button pressed.
MOUSE_ENTER: The mouse has entered a component.
MOUSE_EXIT: The mouse has exited a component.
MOUSE_MOVE: The mouse has moved with no button pressed.
MOUSE_UP: The user has released the mouse button.
NUM_LOCK: The Num Lock key, a non-ASCII action key.
PAUSE: The Pause key, a non-ASCII action key.
PGDN: The Page Down key, a non-ASCII action key.
PGUP: The Page Up key, a non-ASCII action key.
PRINT_SCREEN: The Print Screen key, a non-ASCII action key.
RIGHT: The Right Arrow key, a non-ASCII action key.
SAVE_FILE: A file saving event.
SCROLL_ABSOLUTE: The user has moved the bubble (thumb) in a scroll bar, moving to an "absolute" position, rather than to an offset from the last postion.
SCROLL_BEGIN: The scroll begin event.
SCROLL_END: The scroll end event.
SCROLL_LINE_DOWN: The user has activated the line down area of a scroll bar.
SCROLL_LINE_UP: The user has activated the line up area of a scroll bar.
SCROLL_LOCK: The Scroll Lock key, a non-ASCII action key.
SCROLL_PAGE_DOWN: The user has activated the page down area of a scroll bar.
SCROLL_PAGE_UP: The user has activated the page up area of a scroll bar.
SHIFT_MASK: This flag indicates that the Shift key was down when the event occurred.
TAB: The Tab key.
target: The target component.
UP: The Up Arrow key, a non-ASCII action key.
when: The time stamp.
WINDOW_DEICONIFY: The user has asked the window manager to de-iconify the window.
WINDOW_DESTROY: The user has asked the window manager to kill the window.
WINDOW_EXPOSE: The user has asked the window manager to expose the window.
WINDOW_ICONIFY: The user has asked the window manager to iconify the window.
WINDOW_MOVED: The user has asked the window manager to move the window.
x: The x coordinate of the event.
y: The y coordinate of the event.

Event(Object, int, Object): Creates an instance of Event with the specified target component, event type, and argument.
Event(Object, long, int, int, int, int, int): Creates an instance of Event, with the specified target component, time stamp, event type, x and y coordinates, keyboard key, state of the modifier keys, and an argument set to null.
Event(Object, long, int, int, int, int, int, Object): Creates an instance of Event with the specified target component, time stamp, event type, x and y coordinates, keyboard key, state of the modifier keys, and argument.

controlDown(): Checks if the Control key is down.
metaDown(): Checks if the Meta key is down.
paramString(): Returns the parameter string representing this event.
shiftDown(): Checks if the Shift key is down.
toString(): Returns a representation of this event's values as a string.
translate(int, int): Translates this event so that its x and y coordinates are increased by dx and dy, respectively.

SHIFT_MASK

 public static final int SHIFT_MASK

This flag indicates that the Shift key was down when the event occurred.

CTRL_MASK

 public static final int CTRL_MASK

This flag indicates that the Control key was down when the event occurred.

META_MASK

 public static final int META_MASK

This flag indicates that the Meta key was down when the event occurred. For mouse events, this flag indicates that the right button was pressed or released.

ALT_MASK

 public static final int ALT_MASK

This flag indicates that the Alt key was down when the event occurred. For mouse events, this flag indicates that the middle mouse button was pressed or released.

HOME

 public static final int HOME

The Home key, a non-ASCII action key.

END

 public static final int END

The End key, a non-ASCII action key.

PGUP

 public static final int PGUP

The Page Up key, a non-ASCII action key.

PGDN

 public static final int PGDN

The Page Down key, a non-ASCII action key.

 public static final int UP

The Up Arrow key, a non-ASCII action key.

DOWN

 public static final int DOWN

The Down Arrow key, a non-ASCII action key.

LEFT

 public static final int LEFT

The Left Arrow key, a non-ASCII action key.

RIGHT

 public static final int RIGHT

The Right Arrow key, a non-ASCII action key.

 public static final int F1

The F1 function key, a non-ASCII action key.

 public static final int F2

The F2 function key, a non-ASCII action key.

 public static final int F3

The F3 function key, a non-ASCII action key.

 public static final int F4

The F4 function key, a non-ASCII action key.

 public static final int F5

The F5 function key, a non-ASCII action key.

 public static final int F6

The F6 function key, a non-ASCII action key.

 public static final int F7

The F7 function key, a non-ASCII action key.

 public static final int F8

The F8 function key, a non-ASCII action key.

 public static final int F9

The F9 function key, a non-ASCII action key.

F10

 public static final int F10

The F10 function key, a non-ASCII action key.

F11

 public static final int F11

The F11 function key, a non-ASCII action key.

F12

 public static final int F12

The F12 function key, a non-ASCII action key.

PRINT_SCREEN

 public static final int PRINT_SCREEN

The Print Screen key, a non-ASCII action key.

SCROLL_LOCK

 public static final int SCROLL_LOCK

The Scroll Lock key, a non-ASCII action key.

CAPS_LOCK

 public static final int CAPS_LOCK

The Caps Lock key, a non-ASCII action key.

NUM_LOCK

 public static final int NUM_LOCK

The Num Lock key, a non-ASCII action key.

PAUSE

 public static final int PAUSE

The Pause key, a non-ASCII action key.

INSERT

 public static final int INSERT

The Insert key, a non-ASCII action key.

ENTER

 public static final int ENTER

The Enter key.

BACK_SPACE

 public static final int BACK_SPACE

The BackSpace key.

TAB

 public static final int TAB

The Tab key.

ESCAPE

 public static final int ESCAPE

The Escape key.

DELETE

 public static final int DELETE

The Delete key.

WINDOW_DESTROY

 public static final int WINDOW_DESTROY

The user has asked the window manager to kill the window.

WINDOW_EXPOSE

 public static final int WINDOW_EXPOSE

The user has asked the window manager to expose the window.

WINDOW_ICONIFY

 public static final int WINDOW_ICONIFY

The user has asked the window manager to iconify the window.

WINDOW_DEICONIFY

 public static final int WINDOW_DEICONIFY

The user has asked the window manager to de-iconify the window.

WINDOW_MOVED

 public static final int WINDOW_MOVED

The user has asked the window manager to move the window.

KEY_PRESS

 public static final int KEY_PRESS

The user has pressed a normal key.

KEY_RELEASE

 public static final int KEY_RELEASE

The user has released a normal key.

KEY_ACTION

 public static final int KEY_ACTION

The user has pressed a non-ASCII action key. The key field contains a value that indicates that the event occurred on one of the action keys, which comprise the 12 function keys, the arrow (cursor) keys, Page Up, Page Down, Home, End, Print Screen, Scroll Lock, Caps Lock, Num Lock, Pause, and Insert.

KEY_ACTION_RELEASE

 public static final int KEY_ACTION_RELEASE

The user has released a non-ASCII action key. The key field contains a value that indicates that the event occurred on one of the action keys, which comprise the 12 function keys, the arrow (cursor) keys, Page Up, Page Down, Home, End, Print Screen, Scroll Lock, Caps Lock, Num Lock, Pause, and Insert.

MOUSE_DOWN

 public static final int MOUSE_DOWN

The user has pressed the mouse button. The ALT_MASK flag indicates that the middle button has been pressed. The META_MASKflag indicates that the right button has been pressed.

See Also:: ALT_MASK, META_MASK

MOUSE_UP

 public static final int MOUSE_UP

The user has released the mouse button. The ALT_MASK flag indicates that the middle button has been released. The META_MASKflag indicates that the right button has been released.

See Also:: ALT_MASK, META_MASK

MOUSE_MOVE

 public static final int MOUSE_MOVE

The mouse has moved with no button pressed.

MOUSE_ENTER

 public static final int MOUSE_ENTER

The mouse has entered a component.

MOUSE_EXIT

 public static final int MOUSE_EXIT

The mouse has exited a component.

MOUSE_DRAG

 public static final int MOUSE_DRAG

The user has moved the mouse with a button pressed. The ALT_MASK flag indicates that the middle button is being pressed. The META_MASK flag indicates that the right button is being pressed.

See Also:: ALT_MASK, META_MASK

SCROLL_LINE_UP

 public static final int SCROLL_LINE_UP

The user has activated the line up area of a scroll bar.

SCROLL_LINE_DOWN

 public static final int SCROLL_LINE_DOWN

The user has activated the line down area of a scroll bar.

SCROLL_PAGE_UP

 public static final int SCROLL_PAGE_UP

The user has activated the page up area of a scroll bar.

SCROLL_PAGE_DOWN

 public static final int SCROLL_PAGE_DOWN

The user has activated the page down area of a scroll bar.

SCROLL_ABSOLUTE

 public static final int SCROLL_ABSOLUTE

The user has moved the bubble (thumb) in a scroll bar, moving to an "absolute" position, rather than to an offset from the last postion.

SCROLL_BEGIN

 public static final int SCROLL_BEGIN

The scroll begin event.

SCROLL_END

 public static final int SCROLL_END

The scroll end event.

LIST_SELECT

 public static final int LIST_SELECT

An item in a list has been selected.

LIST_DESELECT

 public static final int LIST_DESELECT

An item in a list has been deselected.

ACTION_EVENT

 public static final int ACTION_EVENT

This event indicates that the user wants some action to occur.

LOAD_FILE

 public static final int LOAD_FILE

A file loading event.

SAVE_FILE

 public static final int SAVE_FILE

A file saving event.

GOT_FOCUS

 public static final int GOT_FOCUS

A component gained the focus.

LOST_FOCUS

 public static final int LOST_FOCUS

A component lost the focus.

target

 public Object target

The target component. This indicates the component over which the event occurred or with which the event is associated.

when

 public long when

The time stamp.

 public int id

Indicates which type of event the event is, and which other Event variables are relevant for the event.

 public int x

The x coordinate of the event.

 public int y

The y coordinate of the event.

key

 public int key

The key code of the key that was pressed in a keyboard event.

modifiers

 public int modifiers

The state of the modifier keys.

NOTE: changing the modifier keys is not recommended, because many native implementations do not recognize modifier changes. This is especially true when the shift modifier is changed.

clickCount

 public int clickCount

For MOUSE_DOWN events, this field indicates the number of consecutive clicks. For other events, its value is 0.

arg

 public Object arg

An arbitrary argument of the event. The value of this field depends on the type of event.

evt

 public Event evt

The next event. This field is set when putting events into a linked list.

Event

 public Event(Object target,
              long when,
              int id,
              int x,
              int y,
              int key,
              int modifiers,
              Object arg)

Creates an instance of Event with the specified target component, time stamp, event type, x and y coordinates, keyboard key, state of the modifier keys, and argument.

Parameters:: target - the target component.; when - the time stamp.; id - the event type.; x - the x coordinate.; y - the y coordinate.; key - the key pressed in a keyboard event.; modifiers - the state of the modifier keys.; arg - the specified argument.

Event

 public Event(Object target,
              long when,
              int id,
              int x,
              int y,
              int key,
              int modifiers)

Creates an instance of Event, with the specified target component, time stamp, event type, x and y coordinates, keyboard key, state of the modifier keys, and an argument set to null.

Parameters:: target - the target component.; when - the time stamp.; id - the event type.; x - the x coordinate.; y - the y coordinate.; key - the key pressed in a keyboard event.; modifiers - the state of the modifier keys.

Event

 public Event(Object target,
              int id,
              Object arg)

Creates an instance of Event with the specified target component, event type, and argument.

Parameters:: target - the target component.; id - the event type.; arg - the specified argument.

translate

 public void translate(int x,
                       int y)

Translates this event so that its x and y coordinates are increased by dx and dy, respectively.

This method translates an event relative to the given component. This involves, at a minimum, translating the coordinates into the local coordinate system of the given component. It may also involve translating a region in the case of an expose event.

Parameters:: dx - the distance to translate the x coordinate.; dy - the distance to translate the y coordinate.

shiftDown

 public boolean shiftDown()

Checks if the Shift key is down.

Returns:: true if the key is down; false otherwise.
See Also:: modifiers, controlDown, metaDown

controlDown

 public boolean controlDown()

Checks if the Control key is down.

Returns:: true if the key is down; false otherwise.
See Also:: modifiers, shiftDown, metaDown

metaDown

 public boolean metaDown()

Checks if the Meta key is down.

Returns:: true if the key is down; false otherwise.
See Also:: modifiers, shiftDown, controlDown

paramString

 protected String paramString()

Returns the parameter string representing this event. This string is useful for debugging.

Returns:: the parameter string of this event.

toString

 public String toString()

Returns a representation of this event's values as a string.

Returns:: a string that represents the event and the values of its member fields.
Overrides:: toString in class Object
See Also:: paramString

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