Class MouseEvent

java.lang.Object
java.util.EventObject
java.awt.AWTEvent
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
MenuDragMouseEvent,MouseWheelEvent
public non-sealed classMouseEventextendsInputEvent
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-basedEventListener to the component (MouseListener orMouseMotionListener), or by invokingComponent.enableEvents(long) with the appropriate mask parameter (AWTEvent.MOUSE_EVENT_MASK orAWTEvent.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 aMouseListener has been added to a component, orenableEvents(AWTEvent.MOUSE_EVENT_MASK) has been invoked, then all the events defined byMouseListener are dispatched to the component. On the other hand, if aMouseMotionListener has not been added andenableEvents has not been invoked withAWTEvent.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:

  • Mouse Events
    • a mouse button is pressed
    • a mouse button is released
    • a mouse button is clicked (pressed and released)
    • the mouse cursor enters the unobscured part of component's geometry
    • the mouse cursor exits the unobscured part of component's geometry
  • Mouse Motion Events
    • the mouse is moved
    • the mouse is dragged

AMouseEvent object is passed to everyMouseListener orMouseAdapter object which is registered to receive the "interesting" mouse events using the component'saddMouseListener method. (MouseAdapter objects implement theMouseListener interface.) Each such listener object gets aMouseEvent containing the mouse event.

AMouseEvent object is also passed to everyMouseMotionListener orMouseMotionAdapter object which is registered to receive mouse motion events using the component'saddMouseMotionListener method. (MouseMotionAdapter objects implement theMouseMotionListener interface.) Each such listener object gets aMouseEvent containing the mouse motion event.

When a mouse button is clicked, events are generated and sent to the registeredMouseListeners. The state of modal keys can be retrieved usingInputEvent.getModifiers() andInputEvent.getModifiersEx(). The button mask returned byInputEvent.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, useInputEvent.getModifiersEx(). The button which has changed state is returned bygetButton()

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 pressesbutton 1 followed bybutton 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
Ifbutton 2 is released first, theMOUSE_RELEASED/MOUSE_CLICKED pair forBUTTON2_MASK arrives first, followed by the pair forBUTTON1_MASK.

Some extra mouse buttons are added to extend the standard set of buttons represented by the following constants:BUTTON1,BUTTON2, andBUTTON3. Extra buttons have no assignedBUTTONx constants as well as their button masks have no assignedBUTTONx_DOWN_MASK constants. Nevertheless, ordinal numbers starting from 4 may be used as button numbers (button ids). Values obtained by thegetMaskForButton(button) method may be used as button masks.

MOUSE_DRAGGED events are delivered to theComponent in which the mouse button was pressed until the mouse button is released (regardless of whether the mouse position is within the bounds of theComponent). 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 theComponent even if the mouse position is outside the bounds of theGraphicsConfiguration associated with thatComponent. However, the reported position for mouse drag events in this case may differ from the actual mouse position:

  • In a multi-screen environment without a virtual device:
    The reported coordinates for mouse drag events are clipped to fit within the bounds of theGraphicsConfiguration associated with theComponent.
  • In a multi-screen environment with a virtual device:
    The reported coordinates for mouse drag events are clipped to fit within the bounds of the virtual device associated with theComponent.

An unspecified behavior will be caused if theid parameter of any particularMouseEvent instance is not in the range fromMOUSE_FIRST toMOUSE_LAST-1 (MOUSE_WHEEL is not acceptable).

Since:
1.1
See Also:

  • Field Details

    • MOUSE_FIRST

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

    • MOUSE_LAST

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

    • MOUSE_CLICKED

      public static final int MOUSE_CLICKED
      The "mouse clicked" event. ThisMouseEvent occurs when a mouse button is pressed and released.
      See Also:

    • MOUSE_PRESSED

      public static final int MOUSE_PRESSED
      The "mouse pressed" event. ThisMouseEvent occurs when a mouse button is pushed down.
      See Also:

    • MOUSE_RELEASED

      public static final int MOUSE_RELEASED
      The "mouse released" event. ThisMouseEvent occurs when a mouse button is let up.
      See Also:

    • MOUSE_MOVED

      public static final int MOUSE_MOVED
      The "mouse moved" event. ThisMouseEvent occurs when the mouse position changes.
      See Also:

    • MOUSE_ENTERED

      public static final int MOUSE_ENTERED
      The "mouse entered" event. ThisMouseEvent occurs when the mouse cursor enters the unobscured part of component's geometry.
      See Also:

    • MOUSE_EXITED

      public static final int MOUSE_EXITED
      The "mouse exited" event. ThisMouseEvent occurs when the mouse cursor exits the unobscured part of component's geometry.
      See Also:

    • MOUSE_DRAGGED

      public static final int MOUSE_DRAGGED
      The "mouse dragged" event. ThisMouseEvent occurs when the mouse position changes while a mouse button is pressed.
      See Also:

    • MOUSE_WHEEL

      public static final int MOUSE_WHEEL
      The "mouse wheel" event. This is the onlyMouseWheelEvent. It occurs when a mouse equipped with a wheel has its wheel rotated.
      Since:
      1.4
      See Also:

    • NOBUTTON

      public static final int NOBUTTON
      Indicates no mouse buttons; used bygetButton().
      Since:
      1.4
      See Also:

    • BUTTON1

      public static final int BUTTON1
      Indicates mouse button #1; used bygetButton().
      Since:
      1.4
      See Also:

    • BUTTON2

      public static final int BUTTON2
      Indicates mouse button #2; used bygetButton().
      Since:
      1.4
      See Also:

    • BUTTON3

      public static final int BUTTON3
      Indicates mouse button #3; used bygetButton().
      Since:
      1.4
      See Also:

  • Constructor Details

    • MouseEvent

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

      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 formMouseEvent(source, id, when, modifiers, x, y, clickCount, popupTrigger, button) behaves in exactly the same way as the invocationMouseEvent(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 anIllegalArgumentException ifsource isnull.

      Parameters:
      source - TheComponent that originated the event
      id - An integer indicating the type of event. For information on allowable values, see the class description forMouseEvent
      when - A long integer that gives the time the event occurred. Passing negative or zero value is not recommended
      modifiers - a modifier mask describing the modifier keys and mouse buttons (for example, shift, ctrl, alt, and meta) that are down during the event. Only extended modifiers are allowed to be used as a value for this parameter (see theInputEvent.getModifiersEx() class for the description of extended modifiers). Passing negative parameter is not recommended. Zero value means that no modifiers were passed
      x - The horizontal x coordinate for the mouse location. It is allowed to pass negative values
      y - The vertical y coordinate for the mouse location. It is allowed to pass negative values
      clickCount - The number of mouse clicks associated with event. Passing negative value is not recommended
      popupTrigger - A boolean that equalstrue if this event is a trigger for a popup menu
      button - An integer that indicates, which of the mouse buttons has changed its state. The following rules are applied to this parameter:
      • If support for the extended mouse buttons isdisabled by Java then it is allowed to createMouseEvent objects only with the standard buttons:NOBUTTON,BUTTON1,BUTTON2, andBUTTON3.
      • If support for the extended mouse buttons isenabled by Java then it is allowed to createMouseEvent objects with the standard buttons. In case the support for extended mouse buttons isenabled by Java, then in addition to the standard buttons,MouseEvent objects can be created using buttons from the range starting from 4 toMouseInfo.getNumberOfButtons() if the mouse has more than three buttons.
      Throws:
      IllegalArgumentException - ifbutton is less than zero
      IllegalArgumentException - ifsource is null
      IllegalArgumentException - ifbutton is greater than BUTTON3 and the support for extended mouse buttons isdisabled by Java
      IllegalArgumentException - ifbutton is greater than thecurrent number of buttons and the support for extended mouse buttons isenabled by Java
      IllegalArgumentException - if an invalidbutton value is passed in
      IllegalArgumentException - ifsource is null
      Since:
      1.4
      See Also:

    • MouseEvent

      public MouseEvent(Component source, int id, long when, int modifiers, int x, int y, int clickCount, boolean popupTrigger)
      Constructs aMouseEvent object with the specified source component, type, modifiers, coordinates, click count, and popupTrigger flag. An invocation of the formMouseEvent(source, id, when, modifiers, x, y, clickCount, popupTrigger) behaves in exactly the same way as the invocationMouseEvent(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 anIllegalArgumentException ifsource isnull.
      Parameters:
      source - TheComponent that originated the event
      id - An integer indicating the type of event. For information on allowable values, see the class description forMouseEvent
      when - A long integer that gives the time the event occurred. Passing negative or zero value is not recommended
      modifiers - a modifier mask describing the modifier keys and mouse buttons (for example, shift, ctrl, alt, and meta) that are down during the event. Only extended modifiers are allowed to be used as a value for this parameter (see theInputEvent.getModifiersEx() class for the description of extended modifiers). Passing negative parameter is not recommended. Zero value means that no modifiers were passed
      x - The horizontal x coordinate for the mouse location. It is allowed to pass negative values
      y - The vertical y coordinate for the mouse location. It is allowed to pass negative values
      clickCount - The number of mouse clicks associated with event. Passing negative value is not recommended
      popupTrigger - A boolean that equalstrue if this event is a trigger for a popup menu
      Throws:
      IllegalArgumentException - ifsource is null
      See Also:

    • 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 aMouseEvent object with the specified source component, type, time, modifiers, coordinates, absolute coordinates, click count, popupTrigger flag, and button number.

      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 anIllegalArgumentException ifsource isnull.

      Parameters:
      source - TheComponent that originated the event
      id - An integer indicating the type of event. For information on allowable values, see the class description forMouseEvent
      when - A long integer that gives the time the event occurred. Passing negative or zero value is not recommended
      modifiers - a modifier mask describing the modifier keys and mouse buttons (for example, shift, ctrl, alt, and meta) that are down during the event. Only extended modifiers are allowed to be used as a value for this parameter (see theInputEvent.getModifiersEx() class for the description of extended modifiers). Passing negative parameter is not recommended. Zero value means that no modifiers were passed
      x - The horizontal x coordinate for the mouse location. It is allowed to pass negative values
      y - The vertical y coordinate for the mouse location. It is allowed to pass negative values
      xAbs - The absolute horizontal x coordinate for the mouse location It is allowed to pass negative values
      yAbs - The absolute vertical y coordinate for the mouse location It is allowed to pass negative values
      clickCount - The number of mouse clicks associated with event. Passing negative value is not recommended
      popupTrigger - A boolean that equalstrue if this event is a trigger for a popup menu
      button - An integer that indicates, which of the mouse buttons has changed its state. The following rules are applied to this parameter:
      • If support for the extended mouse buttons isdisabled by Java then it is allowed to createMouseEvent objects only with the standard buttons:NOBUTTON,BUTTON1,BUTTON2, andBUTTON3.
      • If support for the extended mouse buttons isenabled by Java then it is allowed to createMouseEvent objects with the standard buttons. In case the support for extended mouse buttons isenabled by Java, then in addition to the standard buttons,MouseEvent objects can be created using buttons from the range starting from 4 toMouseInfo.getNumberOfButtons() if the mouse has more than three buttons.
      Throws:
      IllegalArgumentException - ifbutton is less than zero
      IllegalArgumentException - ifsource is null
      IllegalArgumentException - ifbutton is greater than BUTTON3 and the support for extended mouse buttons isdisabled by Java
      IllegalArgumentException - ifbutton is greater than thecurrent number of buttons and the support for extended mouse buttons isenabled by Java
      IllegalArgumentException - if an invalidbutton value is passed in
      IllegalArgumentException - ifsource is null
      Since:
      1.6
      See Also:

  • Method Details

    • 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:
      aPoint object containing the absolute x and y coordinates.
      Since:
      1.6
      See Also:

    • 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:

    • 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:

    • 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:
      aPoint 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 specifiedx (horizontal) andy (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. The returned value is ranged from 0 to theMouseInfo.getNumberOfButtons() value. The returned value includes at least the following constants:
      • NOBUTTON
      • BUTTON1
      • BUTTON2
      • BUTTON3
      It is allowed to use those constants to compare with the returned button number in the application. For example,
       if (anEvent.getButton() == MouseEvent.BUTTON1) {
      In particular, for a mouse with one, two, or three buttons this method may return the following values:
      • 0 (NOBUTTON)
      • 1 (BUTTON1)
      • 2 (BUTTON2)
      • 3 (BUTTON3)
      Button numbers greater thanBUTTON3 have no constant identifier. So if a mouse with five buttons is installed, this method may return the following values:
      • 0 (NOBUTTON)
      • 1 (BUTTON1)
      • 2 (BUTTON2)
      • 3 (BUTTON3)
      • 4
      • 5

      Note: If support for extended mouse buttons isdisabled by Java then the AWT event subsystem does not produce mouse events for the extended mouse buttons. So it is not expected that this method returns anything exceptNOBUTTON,BUTTON1,BUTTON2,BUTTON3.

      Returns:
      one of the values from 0 toMouseInfo.getNumberOfButtons() if support for the extended mouse buttons isenabled by Java. That range includesNOBUTTON,BUTTON1,BUTTON2,BUTTON3;
      NOBUTTON,BUTTON1,BUTTON2 orBUTTON3 if support for the extended mouse buttons isdisabled by Java
      Since:
      1.4
      See Also:

    • 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 bothmousePressed andmouseReleased 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 aString instance 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 theawt.properties file.

      Note that theInputEvent.ALT_MASK andInputEvent.BUTTON2_MASK have equal values, so the "Alt" string is returned for both modifiers. Likewise, theInputEvent.META_MASK andInputEvent.BUTTON3_MASK have equal values, so the "Meta" string is returned for both modifiers.

      Note that passing negative parameter is incorrect, and will cause the returning an unspecified string. Zero parameter means that no modifiers were passed and will cause the returning an empty string.

      Parameters:
      modifiers - A modifier mask describing the modifier keys and mouse buttons that were down during the event
      Returns:
      string string text description of the combination of modifier keys and mouse buttons that were down during the event
      Since:
      1.4
      See Also:

    • 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