Java Platform 1.2

java.awt
Class 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).

Since:
JDK1.0
See Also:
Serialized Form

Field Summary
static int ACTION_EVENT
          This event indicates that the user wants some action to occur.
static int ALT_MASK
          This flag indicates that the Alt key was down when the event occurred.
 Object arg
          An arbitrary argument of the event.
static int BACK_SPACE
          The BackSpace key.
static int CAPS_LOCK
          The Caps Lock key, a non-ASCII action key.
 int clickCount
          For MOUSE_DOWN events, this field indicates the number of consecutive clicks.
static int CTRL_MASK
          This flag indicates that the Control key was down when the event occurred.
static int DELETE
          The Delete key.
static int DOWN
          The Down Arrow key, a non-ASCII action key.
static int END
          The End key, a non-ASCII action key.
static int ENTER
          The Enter key.
static int ESCAPE
          The Escape key.
 Event evt
          The next event.
static int F1
          The F1 function key, a non-ASCII action key.
static int F10
          The F10 function key, a non-ASCII action key.
static int F11
          The F11 function key, a non-ASCII action key.
static int F12
          The F12 function key, a non-ASCII action key.
static int F2
          The F2 function key, a non-ASCII action key.
static int F3
          The F3 function key, a non-ASCII action key.
static int F4
          The F4 function key, a non-ASCII action key.
static int F5
          The F5 function key, a non-ASCII action key.
static int F6
          The F6 function key, a non-ASCII action key.
static int F7
          The F7 function key, a non-ASCII action key.
static int F8
          The F8 function key, a non-ASCII action key.
static int F9
          The F9 function key, a non-ASCII action key.
static int GOT_FOCUS
          A component gained the focus.
static int HOME
          The Home key, a non-ASCII action key.
 int id
          Indicates which type of event the event is, and which other Event variables are relevant for the event.
static int INSERT
          The Insert key, a non-ASCII action key.
 int key
          The key code of the key that was pressed in a keyboard event.
static int KEY_ACTION
          The user has pressed a non-ASCII action key.
static int KEY_ACTION_RELEASE
          The user has released a non-ASCII action key.
static int KEY_PRESS
          The user has pressed a normal key.
static int KEY_RELEASE
          The user has released a normal key.
static int LEFT
          The Left Arrow key, a non-ASCII action key.
static int LIST_DESELECT
          An item in a list has been deselected.
static int LIST_SELECT
          An item in a list has been selected.
static int LOAD_FILE
          A file loading event.
static int LOST_FOCUS
          A component lost the focus.
static int META_MASK
          This flag indicates that the Meta key was down when the event occurred.
 int modifiers
          The state of the modifier keys.
static int MOUSE_DOWN
          The user has pressed the mouse button.
static int MOUSE_DRAG
          The user has moved the mouse with a button pressed.
static int MOUSE_ENTER
          The mouse has entered a component.
static int MOUSE_EXIT
          The mouse has exited a component.
static int MOUSE_MOVE
          The mouse has moved with no button pressed.
static int MOUSE_UP
          The user has released the mouse button.
static int NUM_LOCK
          The Num Lock key, a non-ASCII action key.
static int PAUSE
          The Pause key, a non-ASCII action key.
static int PGDN
          The Page Down key, a non-ASCII action key.
static int PGUP
          The Page Up key, a non-ASCII action key.
static int PRINT_SCREEN
          The Print Screen key, a non-ASCII action key.
static int RIGHT
          The Right Arrow key, a non-ASCII action key.
static int SAVE_FILE
          A file saving event.
static 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.
static int SCROLL_BEGIN
          The scroll begin event.
static int SCROLL_END
          The scroll end event.
static int SCROLL_LINE_DOWN
          The user has activated the line down area of a scroll bar.
static int SCROLL_LINE_UP
          The user has activated the line up area of a scroll bar.
static int SCROLL_LOCK
          The Scroll Lock key, a non-ASCII action key.
static int SCROLL_PAGE_DOWN
          The user has activated the page down area of a scroll bar.
static int SCROLL_PAGE_UP
          The user has activated the page up area of a scroll bar.
static int SHIFT_MASK
          This flag indicates that the Shift key was down when the event occurred.
static int TAB
          The Tab key.
 Object target
          The target component.
static int UP
          The Up Arrow key, a non-ASCII action key.
 long when
          The time stamp.
static int WINDOW_DEICONIFY
          The user has asked the window manager to de-iconify the window.
static int WINDOW_DESTROY
          The user has asked the window manager to kill the window.
static int WINDOW_EXPOSE
          The user has asked the window manager to expose the window.
static int WINDOW_ICONIFY
          The user has asked the window manager to iconify the window.
static int WINDOW_MOVED
          The user has asked the window manager to move the window.
 int x
          The x coordinate of the event.
 int y
          The y coordinate of the event.
 
Constructor Summary
Event(Object target, int id, Object arg)
          Creates an instance of Event with the specified target component, event type, and argument.
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.
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.
 
Method Summary
 boolean controlDown()
          Checks if the Control key is down.
 boolean metaDown()
          Checks if the Meta key is down.
protected  String paramString()
          Returns the parameter string representing this event.
 boolean shiftDown()
          Checks if the Shift key is down.
 String toString()
          Returns a representation of this event's values as a string.
 void translate(int x, int y)
          Translates this event so that its x and y coordinates are increased by dx and dy, respectively.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

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.

UP

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.

F1

public static final int F1
The F1 function key, a non-ASCII action key.

F2

public static final int F2
The F2 function key, a non-ASCII action key.

F3

public static final int F3
The F3 function key, a non-ASCII action key.

F4

public static final int F4
The F4 function key, a non-ASCII action key.

F5

public static final int F5
The F5 function key, a non-ASCII action key.

F6

public static final int F6
The F6 function key, a non-ASCII action key.

F7

public static final int F7
The F7 function key, a non-ASCII action key.

F8

public static final int F8
The F8 function key, a non-ASCII action key.

F9

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. This object has been replaced by AWTEvent.getSource()
See Also:
EventObject.getSource()

when

public long when
The time stamp. Replaced by InputEvent.getWhen().
See Also:
java.awt.InputEvent#getWhen()

id

public int id
Indicates which type of event the event is, and which other Event variables are relevant for the event. This has been replaced by AWTEvent.getID()
See Also:
java.awt.AWTEvent.getID()

x

public int x
The x coordinate of the event. Replaced by MouseEvent.getX()
See Also:
java.awt.MouseEvent#getX()

y

public int y
The y coordinate of the event. Replaced by MouseEvent.getY()
See Also:
java.awt.MouseEvent#getY()

key

public int key
The key code of the key that was pressed in a keyboard event. This has been replaced by KeyEvent.getKeyCode()
See Also:
java.awt.KeyEvent#getKeyCode()

modifiers

public int modifiers
The state of the modifier keys. This is replaced with InputEvent.getModifiers() In java 1.1 MouseEvent and KeyEvent are subclasses of InputEvent.
See Also:
java.awt.InputEvent#getModifiers()

clickCount

public int clickCount
For MOUSE_DOWN events, this field indicates the number of consecutive clicks. For other events, its value is 0. This field has been replaced by MouseEvent.getClickCount().
See Also:
java.awt.MouseEvent.getClickCount().

arg

public Object arg
An arbitrary argument of the event. The value of this field depends on the type of event. arg has been replaced b event specific property.

evt

public Event evt
The next event. This field is set when putting events into a linked list. This has been replaced by EventQueue.
See Also:
EventQueue
Constructor Detail

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.
Method Detail

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
Since:
JDK1.1
See Also:
paramString()

Java Platform 1.2

Submit a bug or feature Version 1.2 of Java Platform API Specification
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