A mouse event is tied to the unobstructed visible component that the
* mouse cursor was over at the time of the action. The button that was
* most recently pressed is the only one that shows up in
* getModifiers, and is returned by getButton,
* while all buttons that are down show up in getModifiersEx.
*
*
Drag events may be cut short if native drag-and-drop operations steal
* the event. Likewise, if a mouse drag exceeds the bounds of a window or
* virtual device, some platforms may clip the path to fit in the bounds of
* the component.
*
* @author Aaron M. Renn (arenn@urbanophile.com)
* @author Eric Blake (ebb9@email.byu.edu)
* @see MouseAdapter
* @see MouseListener
* @see MouseMotionAdapter
* @see MouseMotionListener
* @see MouseWheelListener
* @since 1.1
* @status updated to 1.4
*/
public class MouseEvent extends InputEvent
{
/**
* Compatible with JDK 1.1+.
*/
private static final long serialVersionUID = -991214153494842848L;
/** This is the first id in the range of event ids used by this class. */
public static final int MOUSE_FIRST = 500;
/** This is the last id in the range of event ids used by this class. */
public static final int MOUSE_LAST = 507;
/** This event id indicates that the mouse was clicked. */
public static final int MOUSE_CLICKED = 500;
/** This event id indicates that the mouse was pressed. */
public static final int MOUSE_PRESSED = 501;
/** This event id indicates that the mouse was released. */
public static final int MOUSE_RELEASED = 502;
/** This event id indicates that the mouse was moved. */
public static final int MOUSE_MOVED = 503;
/** This event id indicates that the mouse entered a component. */
public static final int MOUSE_ENTERED = 504;
/** This event id indicates that the mouse exited a component. */
public static final int MOUSE_EXITED = 505;
/**
* This indicates that no button changed state.
*
* @see #getButton()
* @since 1.4
*/
public static final int NOBUTTON = 0;
/**
* This indicates that button 1 changed state.
*
* @see #getButton()
* @since 1.4
*/
public static final int BUTTON1 = 1;
/**
* This indicates that button 2 changed state.
*
* @see #getButton()
* @since 1.4
*/
public static final int BUTTON2 = 2;
/**
* This indicates that button 3 changed state.
*
* @see #getButton()
* @since 1.4
*/
public static final int BUTTON3 = 3;
/** This event id indicates that the mouse was dragged over a component. */
public static final int MOUSE_DRAGGED = 506;
/**
* This event id indicates that the mouse wheel was rotated.
*
* @since 1.4
*/
public static final int MOUSE_WHEEL = 507;
/**
* The X coordinate of the mouse cursor at the time of the event.
*
* @see #getX()
* @serial the x coordinate
*/
private int x;
/**
* The Y coordinate of the mouse cursor at the time of the event.
*
* @see #getY()
* @serial the y coordinate
*/
private int y;
/**
* The number of clicks that took place. For MOUSE_CLICKED, MOUSE_PRESSED,
* and MOUSE_RELEASED, this will be at least 1; otherwise it is 0.
*
* see #getClickCount()
* @serial the number of clicks
*/
private final int clickCount;
/**
* Indicates which mouse button changed state. Can only be one of
* {@link #NOBUTTON}, {@link #BUTTON1}, {@link #BUTTON2}, or
* {@link #BUTTON3}.
*
* @see #getButton()
* @since 1.4
*/
private int button;
/**
* Whether or not this event should trigger a popup menu.
*
* @see PopupMenu
* @see #isPopupTrigger()
* @serial true if this is a popup trigger
*/
private final boolean popupTrigger;
/**
* Initializes a new instance of MouseEvent with the specified
* information. Note that an invalid id leads to unspecified results.
*
* @param source the source of the event
* @param id the event id
* @param when the timestamp of when the event occurred
* @param modifiers the modifier keys during the event, in old or new style
* @param x the X coordinate of the mouse point
* @param y the Y coordinate of the mouse point
* @param clickCount the number of mouse clicks for this event
* @param popupTrigger true if this event triggers a popup menu
* @param button the most recent mouse button to change state
* @throws IllegalArgumentException if source is null or button is invalid
* @since 1.4
*/
public MouseEvent(Component source, int id, long when, int modifiers,
int x, int y, int clickCount, boolean popupTrigger,
int button)
{
super(source, id, when, modifiers);
this.x = x;
this.y = y;
this.clickCount = clickCount;
this.popupTrigger = popupTrigger;
this.button = button;
if (button < NOBUTTON || button > BUTTON3)
throw new IllegalArgumentException();
if ((modifiers & EventModifier.OLD_MASK) != 0)
{
if ((modifiers & BUTTON1_MASK) != 0)
this.button = BUTTON1;
else if ((modifiers & BUTTON2_MASK) != 0)
this.button = BUTTON2;
else if ((modifiers & BUTTON3_MASK) != 0)
this.button = BUTTON3;
}
// clear the mouse button modifier masks if this is a button
// release event.
if (id == MOUSE_RELEASED)
this.modifiersEx &= ~(BUTTON1_DOWN_MASK
| BUTTON2_DOWN_MASK
| BUTTON3_DOWN_MASK);
}
/**
* Initializes a new instance of MouseEvent with the specified
* information. Note that an invalid id leads to unspecified results.
*
* @param source the source of the event
* @param id the event id
* @param when the timestamp of when the event occurred
* @param modifiers the modifier keys during the event, in old or new style
* @param x the X coordinate of the mouse point
* @param y the Y coordinate of the mouse point
* @param clickCount the number of mouse clicks for this event
* @param popupTrigger true if this event triggers a popup menu
* @throws IllegalArgumentException if source is null
*/
public MouseEvent(Component source, int id, long when, int modifiers,
int x, int y, int clickCount, boolean popupTrigger)
{
this(source, id, when, modifiers, x, y, clickCount, popupTrigger,
NOBUTTON);
}
/**
* This method returns the X coordinate of the mouse position. This is
* relative to the source component.
*
* @return the x coordinate
*/
public int getX()
{
return x;
}
/**
* This method returns the Y coordinate of the mouse position. This is
* relative to the source component.
*
* @return the y coordinate
*/
public int getY()
{
return y;
}
/**
* This method returns a Point for the x,y position of
* the mouse pointer. This is relative to the source component.
*
* @return a Point for the event position
*/
public Point getPoint()
{
return new Point(x, y);
}
/**
* Translates the event coordinates by the specified x and y offsets.
*
* @param dx the value to add to the X coordinate of this event
* @param dy the value to add to the Y coordiante of this event
*/
public void translatePoint(int dx, int dy)
{
x += dx;
y += dy;
}
/**
* This method returns the number of mouse clicks associated with this
* event.
*
* @return the number of mouse clicks for this event
*/
public int getClickCount()
{
return clickCount;
}
/**
* Returns which button, if any, was the most recent to change state. This
* will be one of {@link #NOBUTTON}, {@link #BUTTON1}, {@link #BUTTON2}, or
* {@link #BUTTON3}.
*
* @return the button that changed state
* @since 1.4
*/
public int getButton()
{
return button;
}
/**
* This method tests whether or not the event is a popup menu trigger. This
* should be checked in both MousePressed and MouseReleased to be
* cross-platform compatible, as different systems have different popup
* triggers.
*
* @return true if the event is a popup menu trigger
*/
public boolean isPopupTrigger()
{
return popupTrigger;
}
/**
* Returns a string describing the modifiers, such as "Shift" or
* "Ctrl+Button1".
*
* XXX Sun claims this can be localized via the awt.properties file - how
* do we implement that?
*
* @param modifiers the old-style modifiers to convert to text
* @return a string representation of the modifiers in this bitmask
*/
public static String getMouseModifiersText(int modifiers)
{
modifiers &= EventModifier.OLD_MASK;
if ((modifiers & BUTTON2_MASK) != 0)
modifiers |= BUTTON2_DOWN_MASK;
if ((modifiers & BUTTON3_MASK) != 0)
modifiers |= BUTTON3_DOWN_MASK;
return getModifiersExText(EventModifier.extend(modifiers));
}
/**
* Returns a string identifying this event. This is formatted as the field
* name of the id type, followed by the (x,y) point, the most recent button
* changed, modifiers (if any), extModifiers (if any), and clickCount.
*
* @return a string identifying this event
*/
public String paramString()
{
StringBuffer s = new StringBuffer();
switch (id)
{
case MOUSE_CLICKED:
s.append("MOUSE_CLICKED,(");
break;
case MOUSE_PRESSED:
s.append("MOUSE_PRESSED,(");
break;
case MOUSE_RELEASED:
s.append("MOUSE_RELEASED,(");
break;
case MOUSE_MOVED:
s.append("MOUSE_MOVED,(");
break;
case MOUSE_ENTERED:
s.append("MOUSE_ENTERED,(");
break;
case MOUSE_EXITED:
s.append("MOUSE_EXITED,(");
break;
case MOUSE_DRAGGED:
s.append("MOUSE_DRAGGED,(");
break;
case MOUSE_WHEEL:
s.append("MOUSE_WHEEL,(");
break;
default:
s.append("unknown type,(");
}
s.append(x).append(',').append(y).append("),button=").append(button);
// FIXME: need a mauve test for this method
if (modifiersEx != 0)
s.append(",extModifiers=").append(getModifiersExText(modifiersEx));
return s.append(",clickCount=").append(clickCount).toString();
}
/**
* Reads in the object from a serial stream.
*
* @param s the stream to read from
* @throws IOException if deserialization fails
* @throws ClassNotFoundException if deserialization fails
* @serialData default, except that the modifiers are converted to new style
*/
private void readObject(ObjectInputStream s)
throws IOException, ClassNotFoundException
{
s.defaultReadObject();
if ((modifiers & EventModifier.OLD_MASK) != 0)
{
if ((modifiers & BUTTON1_MASK) != 0)
button = BUTTON1;
else if ((modifiers & BUTTON2_MASK) != 0)
button = BUTTON2;
else if ((modifiers & BUTTON3_MASK) != 0)
button = BUTTON3;
modifiersEx = EventModifier.extend(modifiers) & EventModifier.NEW_MASK;
}
}
} // class MouseEvent