Java™ Platform
Standard Ed. 6

java.awt.event
Class MouseEvent

java.lang.Object
  extended by java.util.EventObject
      extended by java.awt.AWTEvent
          extended by java.awt.event.ComponentEvent
              extended by java.awt.event.InputEvent
                  extended by java.awt.event.MouseEvent
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
MenuDragMouseEvent, MouseWheelEvent

public class MouseEvent
extends InputEvent

An event which indicates that a mouse action occurred in a component. A mouse action is considered to occur in a particular component if and only if the mouse cursor is over the unobscured part of the component's bounds when the action happens. For lightweight components, such as Swing's components, mouse events are only dispatched to the component if the mouse event type has been enabled on the component. A mouse event type is enabled by adding the appropriate mouse-based EventListener to the component (MouseListener or MouseMotionListener), or by invoking Component.enableEvents(long) with the appropriate mask parameter (AWTEvent.MOUSE_EVENT_MASK or AWTEvent.MOUSE_MOTION_EVENT_MASK). If the mouse event type has not been enabled on the component, the corresponding mouse events are dispatched to the first ancestor that has enabled the mouse event type.

For example, if a MouseListener has been added to a component, or enableEvents(AWTEvent.MOUSE_EVENT_MASK) has been invoked, then all the events defined by MouseListener are dispatched to the component. On the other hand, if a MouseMotionListener has not been added and enableEvents has not been invoked with AWTEvent.MOUSE_MOTION_EVENT_MASK, then mouse motion events are not dispatched to the component. Instead the mouse motion events are dispatched to the first ancestors that has enabled mouse motion events.

This low-level event is generated by a component object for:

A MouseEvent object is passed to every MouseListener or MouseAdapter object which is registered to receive the "interesting" mouse events using the component's addMouseListener method. (MouseAdapter objects implement the MouseListener interface.) Each such listener object gets a MouseEvent containing the mouse event.

A MouseEvent object is also passed to every MouseMotionListener or MouseMotionAdapter object which is registered to receive mouse motion events using the component's addMouseMotionListener method. (MouseMotionAdapter objects implement the MouseMotionListener interface.) Each such listener object gets a MouseEvent containing the mouse motion event.

When a mouse button is clicked, events are generated and sent to the registered MouseListeners. The state of modal keys can be retrieved using InputEvent.getModifiers() and InputEvent.getModifiersEx(). The button mask returned by InputEvent.getModifiers() reflects only the button that changed state, not the current state of all buttons. (Note: Due to overlap in the values of ALT_MASK/BUTTON2_MASK and META_MASK/BUTTON3_MASK, this is not always true for mouse events involving modifier keys). To get the state of all buttons and modifier keys, use InputEvent.getModifiersEx(). The button which has changed state is returned by getButton()

For example, if the first mouse button is pressed, events are sent in the following order:

    id              modifiers    button           
    MOUSE_PRESSED:  BUTTON1_MASK BUTTON1
    MOUSE_RELEASED: BUTTON1_MASK BUTTON1
    MOUSE_CLICKED:  BUTTON1_MASK BUTTON1
 
When multiple mouse buttons are pressed, each press, release, and click results in a separate event.

For example, if the user presses button 1 followed by button 2, and then releases them in the same order, the following sequence of events is generated:

    id              modifiers    button           
    MOUSE_PRESSED:  BUTTON1_MASK BUTTON1
    MOUSE_PRESSED:  BUTTON2_MASK BUTTON2
    MOUSE_RELEASED: BUTTON1_MASK BUTTON1
    MOUSE_CLICKED:  BUTTON1_MASK BUTTON1
    MOUSE_RELEASED: BUTTON2_MASK BUTTON2
    MOUSE_CLICKED:  BUTTON2_MASK BUTTON2
 
If button 2 is released first, the MOUSE_RELEASED/MOUSE_CLICKED pair for BUTTON2_MASK arrives first, followed by the pair for BUTTON1_MASK.

MOUSE_DRAGGED events are delivered to the Component in which the mouse button was pressed until the mouse button is released (regardless of whether the mouse position is within the bounds of the Component). Due to platform-dependent Drag&Drop implementations, MOUSE_DRAGGED events may not be delivered during a native Drag&Drop operation. In a multi-screen environment mouse drag events are delivered to the Component even if the mouse position is outside the bounds of the GraphicsConfiguration associated with that Component. However, the reported position for mouse drag events in this case may differ from the actual mouse position:

Since:
1.1
See Also:
MouseAdapter, MouseListener, MouseMotionAdapter, MouseMotionListener, MouseWheelListener, Tutorial: Writing a Mouse Listener, Tutorial: Writing a Mouse Motion Listener, Serialized Form

Field Summary
static int BUTTON1
          Indicates mouse button #1; used by getButton().
static int BUTTON2
          Indicates mouse button #2; used by getButton().
static int BUTTON3
          Indicates mouse button #3; used by getButton().
static int MOUSE_CLICKED
          The "mouse clicked" event.
static int MOUSE_DRAGGED
          The "mouse dragged" event.
static int MOUSE_ENTERED
          The "mouse entered" event.
static int MOUSE_EXITED
          The "mouse exited" event.
static int MOUSE_FIRST
          The first number in the range of ids used for mouse events.
static int MOUSE_LAST
          The last number in the range of ids used for mouse events.
static int MOUSE_MOVED
          The "mouse moved" event.
static int MOUSE_PRESSED
          The "mouse pressed" event.
static int MOUSE_RELEASED
          The "mouse released" event.
static int MOUSE_WHEEL
          The "mouse wheel" event.
static int NOBUTTON
          Indicates no mouse buttons; used by getButton().
 
Fields inherited from class java.awt.event.InputEvent
ALT_DOWN_MASK, ALT_GRAPH_DOWN_MASK, ALT_GRAPH_MASK, ALT_MASK, BUTTON1_DOWN_MASK, BUTTON1_MASK, BUTTON2_DOWN_MASK, BUTTON2_MASK, BUTTON3_DOWN_MASK, BUTTON3_MASK, CTRL_DOWN_MASK, CTRL_MASK, META_DOWN_MASK, META_MASK, SHIFT_DOWN_MASK, SHIFT_MASK
 
Fields inherited from class java.awt.event.ComponentEvent
COMPONENT_FIRST, COMPONENT_HIDDEN, COMPONENT_LAST, COMPONENT_MOVED, COMPONENT_RESIZED, COMPONENT_SHOWN
 
Fields inherited from class java.awt.AWTEvent
ACTION_EVENT_MASK, ADJUSTMENT_EVENT_MASK, COMPONENT_EVENT_MASK, consumed, CONTAINER_EVENT_MASK, FOCUS_EVENT_MASK, HIERARCHY_BOUNDS_EVENT_MASK, HIERARCHY_EVENT_MASK, id, INPUT_METHOD_EVENT_MASK, INVOCATION_EVENT_MASK, ITEM_EVENT_MASK, KEY_EVENT_MASK, MOUSE_EVENT_MASK, MOUSE_MOTION_EVENT_MASK, MOUSE_WHEEL_EVENT_MASK, PAINT_EVENT_MASK, RESERVED_ID_MAX, TEXT_EVENT_MASK, WINDOW_EVENT_MASK, WINDOW_FOCUS_EVENT_MASK, WINDOW_STATE_EVENT_MASK
 
Fields inherited from class java.util.EventObject
source
 
Constructor Summary
MouseEvent(Component source, int id, long when, int modifiers, int x, int y, int clickCount, boolean popupTrigger)
          Constructs a MouseEvent object with the specified source component, type, modifiers, coordinates, and click count.
MouseEvent(Component source, int id, long when, int modifiers, int x, int y, int clickCount, boolean popupTrigger, int button)
          Constructs a MouseEvent object with the specified source component, type, modifiers, coordinates, and click count.
MouseEvent(Component source, int id, long when, int modifiers, int x, int y, int xAbs, int yAbs, int clickCount, boolean popupTrigger, int button)
          Constructs a MouseEvent object with the specified source component, type, modifiers, coordinates, absolute coordinates, and click count.
 
Method Summary
 int getButton()
          Returns which, if any, of the mouse buttons has changed state.
 int getClickCount()
          Returns the number of mouse clicks associated with this event.
 Point getLocationOnScreen()
          Returns the absolute x, y position of the event.
static String getMouseModifiersText(int modifiers)
          Returns a String describing the modifier keys and mouse buttons that were down during the event, such as "Shift", or "Ctrl+Shift".
 Point getPoint()
          Returns the x,y position of the event relative to the source component.
 int getX()
          Returns the horizontal x position of the event relative to the source component.
 int getXOnScreen()
          Returns the absolute horizontal x position of the event.
 int getY()
          Returns the vertical y position of the event relative to the source component.
 int getYOnScreen()
          Returns the absolute vertical y position of the event.
 boolean isPopupTrigger()
          Returns whether or not this mouse event is the popup menu trigger event for the platform.
 String paramString()
          Returns a parameter string identifying this event.
 void translatePoint(int x, int y)
          Translates the event's coordinates to a new position by adding specified x (horizontal) and y (vertical) offsets.
 
Methods inherited from class java.awt.event.InputEvent
consume, getModifiers, getModifiersEx, getModifiersExText, getWhen, isAltDown, isAltGraphDown, isConsumed, isControlDown, isMetaDown, isShiftDown
 
Methods inherited from class java.awt.event.ComponentEvent
getComponent
 
Methods inherited from class java.awt.AWTEvent
getID, setSource, toString
 
Methods inherited from class java.util.EventObject
getSource
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

MOUSE_FIRST

public static final int MOUSE_FIRST
The first number in the range of ids used for mouse events.

See Also:
Constant Field Values

MOUSE_LAST

public static final int MOUSE_LAST
The last number in the range of ids used for mouse events.

See Also:
Constant Field Values

MOUSE_CLICKED

public static final int MOUSE_CLICKED
The "mouse clicked" event. This MouseEvent occurs when a mouse button is pressed and released.

See Also:
Constant Field Values

MOUSE_PRESSED

public static final int MOUSE_PRESSED
The "mouse pressed" event. This MouseEvent occurs when a mouse button is pushed down.

See Also:
Constant Field Values

MOUSE_RELEASED

public static final int MOUSE_RELEASED
The "mouse released" event. This MouseEvent occurs when a mouse button is let up.

See Also:
Constant Field Values

MOUSE_MOVED

public static final int MOUSE_MOVED
The "mouse moved" event. This MouseEvent occurs when the mouse position changes.

See Also:
Constant Field Values

MOUSE_ENTERED

public static final int MOUSE_ENTERED
The "mouse entered" event. This MouseEvent occurs when the mouse cursor enters the unobscured part of component's geometry.

See Also:
Constant Field Values

MOUSE_EXITED

public static final int MOUSE_EXITED
The "mouse exited" event. This MouseEvent occurs when the mouse cursor exits the unobscured part of component's geometry.

See Also:
Constant Field Values

MOUSE_DRAGGED

public static final int MOUSE_DRAGGED
The "mouse dragged" event. This MouseEvent occurs when the mouse position changes while a mouse button is pressed.

See Also:
Constant Field Values

MOUSE_WHEEL

public static final int MOUSE_WHEEL
The "mouse wheel" event. This is the only MouseWheelEvent. It occurs when a mouse equipped with a wheel has its wheel rotated.

Since:
1.4
See Also:
Constant Field Values

NOBUTTON

public static final int NOBUTTON
Indicates no mouse buttons; used by getButton().

Since:
1.4
See Also:
Constant Field Values

BUTTON1

public static final int BUTTON1
Indicates mouse button #1; used by getButton().

Since:
1.4
See Also:
Constant Field Values

BUTTON2

public static final int BUTTON2
Indicates mouse button #2; used by getButton().

Since:
1.4
See Also:
Constant Field Values

BUTTON3

public static final int BUTTON3
Indicates mouse button #3; used by getButton().

Since:
1.4
See Also:
Constant Field Values
Constructor Detail

MouseEvent

public MouseEvent(Component source,
                  int id,
                  long when,
                  int modifiers,
                  int x,
                  int y,
                  int clickCount,
                  boolean popupTrigger,
                  int button)
Constructs a MouseEvent object with the specified source component, type, modifiers, coordinates, and click count.

Note that passing in an invalid id results in unspecified behavior. Creating an invalid event (such as by using more than one of the old _MASKs, or modifier/button values which don't match) results in unspecified behavior. An invocation of the form MouseEvent(source, id, when, modifiers, x, y, clickCount, popupTrigger, button) behaves in exactly the same way as the invocation MouseEvent(source, id, when, modifiers, x, y, xAbs, yAbs, clickCount, popupTrigger, button) where xAbs and yAbs defines as source's location on screen plus relative coordinates x and y. xAbs and yAbs are set to zero if the source is not showing. This method throws an IllegalArgumentException if source is null.

Parameters:
source - the Component that originated the event
id - the integer that identifies the event
when - a long int that gives the time the event occurred
modifiers - the modifier keys down during event (e.g. shift, ctrl, alt, meta) Either extended _DOWN_MASK or old _MASK modifiers should be used, but both models should not be mixed in one event. Use of the extended modifiers is preferred.
x - the horizontal x coordinate for the mouse location
y - the vertical y coordinate for the mouse location
clickCount - the number of mouse clicks associated with event
popupTrigger - a boolean, true if this event is a trigger for a popup menu
button - which of the mouse buttons has changed state. NOBUTTON, BUTTON1, BUTTON2 or BUTTON3.
Throws:
IllegalArgumentException - if an invalid button value is passed in
IllegalArgumentException - if source is null
Since:
1.4

MouseEvent

public MouseEvent(Component source,
                  int id,
                  long when,
                  int modifiers,
                  int x,
                  int y,
                  int clickCount,
                  boolean popupTrigger)
Constructs a MouseEvent object with the specified source component, type, modifiers, coordinates, and click count.

Note that passing in an invalid id results in unspecified behavior. An invocation of the form MouseEvent(source, id, when, modifiers, x, y, clickCount, popupTrigger) behaves in exactly the same way as the invocation MouseEvent(source, id, when, modifiers, x, y, xAbs, yAbs, clickCount, popupTrigger, MouseEvent.NOBUTTON) where xAbs and yAbs defines as source's location on screen plus relative coordinates x and y. xAbs and yAbs are set to zero if the source is not showing. This method throws an IllegalArgumentException if source is null.

Parameters:
source - the Component that originated the event
id - the integer that identifies the event
when - a long int that gives the time the event occurred
modifiers - the modifier keys down during event (e.g. shift, ctrl, alt, meta) Either extended _DOWN_MASK or old _MASK modifiers should be used, but both models should not be mixed in one event. Use of the extended modifiers is preferred.
x - the horizontal x coordinate for the mouse location
y - the vertical y coordinate for the mouse location
clickCount - the number of mouse clicks associated with event
popupTrigger - a boolean, true if this event is a trigger for a popup menu
Throws:
IllegalArgumentException - if source is null

MouseEvent

public MouseEvent(Component source,
                  int id,
                  long when,
                  int modifiers,
                  int x,
                  int y,
                  int xAbs,
                  int yAbs,
                  int clickCount,
                  boolean popupTrigger,
                  int button)
Constructs a MouseEvent object with the specified source component, type, modifiers, coordinates, absolute coordinates, and click count.

Note that passing in an invalid id results in unspecified behavior. Creating an invalid event (such as by using more than one of the old _MASKs, or modifier/button values which don't match) results in unspecified behavior. Even if inconsistent values for relative and absolute coordinates are passed to the constructor, the mouse event instance is still created and no exception is thrown. This method throws an IllegalArgumentException if source is null.

Parameters:
source - the Component that originated the event
id - the integer that identifies the event
when - a long int that gives the time the event occurred
modifiers - the modifier keys down during event (e.g. shift, ctrl, alt, meta) Either extended _DOWN_MASK or old _MASK modifiers should be used, but both models should not be mixed in one event. Use of the extended modifiers is preferred.
x - the horizontal x coordinate for the mouse location
y - the vertical y coordinate for the mouse location
xAbs - the absolute horizontal x coordinate for the mouse location
yAbs - the absolute vertical y coordinate for the mouse location
clickCount - the number of mouse clicks associated with event
popupTrigger - a boolean, true if this event is a trigger for a popup menu
button - which of the mouse buttons has changed state. NOBUTTON, BUTTON1, BUTTON2 or BUTTON3.
Throws:
IllegalArgumentException - if an invalid button value is passed in
IllegalArgumentException - if source is null
Since:
1.6
Method Detail

getLocationOnScreen

public Point getLocationOnScreen()
Returns the absolute x, y position of the event. In a virtual device multi-screen environment in which the desktop area could span multiple physical screen devices, these coordinates are relative to the virtual coordinate system. Otherwise, these coordinates are relative to the coordinate system associated with the Component's GraphicsConfiguration.

Returns:
a Point object containing the absolute x and y coordinates.
Since:
1.6
See Also:
GraphicsConfiguration

getXOnScreen

public int getXOnScreen()
Returns the absolute horizontal x position of the event. In a virtual device multi-screen environment in which the desktop area could span multiple physical screen devices, this coordinate is relative to the virtual coordinate system. Otherwise, this coordinate is relative to the coordinate system associated with the Component's GraphicsConfiguration.

Returns:
x an integer indicating absolute horizontal position.
Since:
1.6
See Also:
GraphicsConfiguration

getYOnScreen

public int getYOnScreen()
Returns the absolute vertical y position of the event. In a virtual device multi-screen environment in which the desktop area could span multiple physical screen devices, this coordinate is relative to the virtual coordinate system. Otherwise, this coordinate is relative to the coordinate system associated with the Component's GraphicsConfiguration.

Returns:
y an integer indicating absolute vertical position.
Since:
1.6
See Also:
GraphicsConfiguration

getX

public int getX()
Returns the horizontal x position of the event relative to the source component.

Returns:
x an integer indicating horizontal position relative to the component

getY

public int getY()
Returns the vertical y position of the event relative to the source component.

Returns:
y an integer indicating vertical position relative to the component

getPoint

public Point getPoint()
Returns the x,y position of the event relative to the source component.

Returns:
a Point object containing the x and y coordinates relative to the source component

translatePoint

public void translatePoint(int x,
                           int y)
Translates the event's coordinates to a new position by adding specified x (horizontal) and y (vertical) offsets.

Parameters:
x - the horizontal x value to add to the current x coordinate position
y - the vertical y value to add to the current y coordinate position

getClickCount

public int getClickCount()
Returns the number of mouse clicks associated with this event.

Returns:
integer value for the number of clicks

getButton

public int getButton()
Returns which, if any, of the mouse buttons has changed state.

Returns:
one of the following constants: NOBUTTON, BUTTON1, BUTTON2 or BUTTON3.
Since:
1.4

isPopupTrigger

public boolean isPopupTrigger()
Returns whether or not this mouse event is the popup menu trigger event for the platform.

Note: Popup menus are triggered differently on different systems. Therefore, isPopupTrigger should be checked in both mousePressed and mouseReleased for proper cross-platform functionality.

Returns:
boolean, true if this event is the popup menu trigger for this platform

getMouseModifiersText

public static String getMouseModifiersText(int modifiers)
Returns a String describing the modifier keys and mouse buttons that were down during the event, 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 - a modifier mask describing the modifier keys and mouse buttons that were down during the event
Returns:
string a text description of the combination of modifier keys and mouse buttons that were down during the event
Since:
1.4
See Also:
InputEvent.getModifiersExText(int)

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

Java™ Platform
Standard Ed. 6

Submit a bug or feature
For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright © 1993, 2011, Oracle and/or its affiliates. All rights reserved.

Scripting on this page tracks web page traffic, but does not change the content in any way.