mouseevent.java

JAVA基本类源代码,大家可以学习学习!

	} else if ((getModifiers() == 0) && 
                   (getModifiersEx() != 0 ||
                    button != NOBUTTON)) 
        {
	    setOldModifiers();
	}
    }

    /**
     * Constructs a <code>MouseEvent</code> object with the
     * specified source component,
     * type, modifiers, coordinates, and click count.
     * <p>Note that passing in an invalid <code>id</code> results in
     * unspecified behavior.
     *
     * @param source       the <code>Component</code> that originated the event
     * @param id           the integer that identifies the event
     * @param when         a long int that gives the time the event occurred
     * @param 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.
     * @param x            the horizontal x coordinate for the mouse location
     * @param y            the vertical y coordinate for the mouse location
     * @param clickCount   the number of mouse clicks associated with event
     * @param popupTrigger a boolean, true if this event is a trigger for a
     *                     popup menu 
     */
    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);
    }

    /**
     * Returns the horizontal x position of the event relative to the 
     * source component.
     *
     * @return x  an integer indicating horizontal position relative to
     *            the component
     */
    public int getX() {
        return x;
    }

    /**
     * Returns the vertical y position of the event relative to the
     * source component.
     *
     * @return y  an integer indicating vertical position relative to
     *            the component
     */
    public int getY() {
        return y;
    }

    /**
     * Returns the x,y position of the event relative to the source component.
     *
     * @return a <code>Point</code> object containing the x and y coordinates 
     *         relative to the source component 
     *
     */
    public Point getPoint() {
	int x;
	int y;
	synchronized (this) {
	    x = this.x;
	    y = this.y;
	}
        return new Point(x, y);
    }

    /**
     * Translates the event's coordinates to a new position
     * by adding specified <code>x</code> (horizontal) and <code>y</code>
     * (vertical) offsets.
     *
     * @param x the horizontal x value to add to the current x
     *          coordinate position
     * @param y the vertical y value to add to the current y
                coordinate position
     */
    public synchronized void translatePoint(int x, int y) {
        this.x += x;
        this.y += y;
    }

    /**
     * Returns the number of mouse clicks associated with this event.
     *
     * @return integer value for the number of clicks
     */
    public int getClickCount() {
        return clickCount;
    }

    /**
     * Returns which, if any, of the mouse buttons has changed state.
     *
     * @return one of the following constants:
     * <code>NOBUTTON</code>,
     * <code>BUTTON1</code>,
     * <code>BUTTON2</code> or
     * <code>BUTTON3</code>.
     * @since 1.4
     */
    public int getButton() {
	return button;
    }

    /**
     * Returns whether or not this mouse event is the popup menu
     * trigger event for the platform.
     * <p><b>Note</b>: Popup menus are triggered differently
     * on different systems. Therefore, <code>isPopupTrigger</code>
     * should be checked in both <code>mousePressed</code>
     * and <code>mouseReleased</code>
     * for proper cross-platform functionality.
     *
     * @return boolean, true if this event is the popup menu trigger
     *         for this platform
     */
    public boolean isPopupTrigger() {
        return popupTrigger;
    }

    /**
     * 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.
     *
     * @param modifiers a modifier mask describing the modifier keys and 
     *                  mouse buttons that were down during the event
     * @return string   a text description of the combination of modifier
     *                  keys and mouse buttons that were down during the event
     * @since 1.4
     */
    public static String getMouseModifiersText(int modifiers) {
        StringBuffer buf = new StringBuffer();
        if ((modifiers & InputEvent.ALT_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.alt", "Alt"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.META_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.meta", "Meta"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.CTRL_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.control", "Ctrl"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.SHIFT_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.shift", "Shift"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.ALT_GRAPH_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.altGraph", "Alt Graph"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.BUTTON1_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.button1", "Button1"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.BUTTON2_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.button2", "Button2"));
            buf.append("+");
        }
        if ((modifiers & InputEvent.BUTTON3_MASK) != 0) {
            buf.append(Toolkit.getProperty("AWT.button3", "Button3"));
            buf.append("+");
        }
        if (buf.length() > 0) {
            buf.setLength(buf.length()-1); // remove trailing '+'
        }
        return buf.toString();
    }

    /**
     * Returns a parameter string identifying this event.
     * This method is useful for event-logging and for debugging.
     *
     * @return a string identifying the event and its attributes
     */
    public String paramString() {
        StringBuffer str = new StringBuffer(80);

        switch(id) {
          case MOUSE_PRESSED:
              str.append("MOUSE_PRESSED");
              break;
          case MOUSE_RELEASED:
              str.append("MOUSE_RELEASED");
              break;
          case MOUSE_CLICKED:
              str.append("MOUSE_CLICKED");
              break;
          case MOUSE_ENTERED:
              str.append("MOUSE_ENTERED");
              break;
          case MOUSE_EXITED:
              str.append("MOUSE_EXITED");
              break;
          case MOUSE_MOVED:
              str.append("MOUSE_MOVED");
              break;
          case MOUSE_DRAGGED:
              str.append("MOUSE_DRAGGED");
              break;
          case MOUSE_WHEEL:
              str.append("MOUSE_WHEEL");
              break;
           default:
              str.append("unknown type");
        }

        // (x,y) coordinates
        str.append(",(").append(x).append(",").append(y).append(")"); 

        str.append(",button=").append(getButton());

        if (getModifiers() != 0) {
            str.append(",modifiers=").append(getMouseModifiersText(modifiers));
        }

        if (getModifiersEx() != 0) {
            str.append(",extModifiers=").append(getModifiersExText(modifiers));
        }

        str.append(",clickCount=").append(clickCount);

        return str.toString(); 
    }

    /**
     * Sets new modifiers by the old ones. 
     * Also sets button.
     */
    private void setNewModifiers() {
    	if ((modifiers & BUTTON1_MASK) != 0) {
	    modifiers |= BUTTON1_DOWN_MASK;
	}
	if ((modifiers & BUTTON2_MASK) != 0) {
	    modifiers |= BUTTON2_DOWN_MASK;
	}
	if ((modifiers & BUTTON3_MASK) != 0) {
	    modifiers |= BUTTON3_DOWN_MASK;
	}	
	if (id == MOUSE_PRESSED 
            || id == MOUSE_RELEASED
	    || id == MOUSE_CLICKED) 
	{
	    if ((modifiers & BUTTON1_MASK) != 0) {
		button = BUTTON1;
		modifiers &= ~BUTTON2_MASK & ~BUTTON3_MASK;
		if (id != MOUSE_PRESSED) {
		    modifiers &= ~BUTTON1_DOWN_MASK;
		}
	    } else if ((modifiers & BUTTON2_MASK) != 0) {
		button = BUTTON2;
		modifiers &= ~BUTTON1_MASK & ~BUTTON3_MASK;
		if (id != MOUSE_PRESSED) {
		    modifiers &= ~BUTTON2_DOWN_MASK;
		}
	    } else if ((modifiers & BUTTON3_MASK) != 0) {
		button = BUTTON3;
		modifiers &= ~BUTTON1_MASK & ~BUTTON2_MASK;
		if (id != MOUSE_PRESSED) {
		    modifiers &= ~BUTTON3_DOWN_MASK;
		}
	    }
	}
	if ((modifiers & InputEvent.ALT_MASK) != 0) {
	    modifiers |= InputEvent.ALT_DOWN_MASK;
	}
	if ((modifiers & InputEvent.META_MASK) != 0) {
	    modifiers |= InputEvent.META_DOWN_MASK;
	}
	if ((modifiers & InputEvent.SHIFT_MASK) != 0) {
	    modifiers |= InputEvent.SHIFT_DOWN_MASK;
	}
	if ((modifiers & InputEvent.CTRL_MASK) != 0) {
	    modifiers |= InputEvent.CTRL_DOWN_MASK;
	}
	if ((modifiers & InputEvent.ALT_GRAPH_MASK) != 0) {
	    modifiers |= InputEvent.ALT_GRAPH_DOWN_MASK;
	}
    }	

    /**
     * Sets old modifiers by the new ones. 
     */
    private void setOldModifiers() {
	if (id == MOUSE_PRESSED 
            || id == MOUSE_RELEASED
	    || id == MOUSE_CLICKED) 
	{	    
	    switch(button) {
	    case BUTTON1:
		modifiers |= BUTTON1_MASK;
		break;
	    case BUTTON2:
		modifiers |= BUTTON2_MASK;
		break;
	    case BUTTON3:
		modifiers |= BUTTON3_MASK;
		break;
	    }
	} else {
	    if ((modifiers & BUTTON1_DOWN_MASK) != 0) {
		modifiers |= BUTTON1_MASK;
	    }
	    if ((modifiers & BUTTON2_DOWN_MASK) != 0) {
		modifiers |= BUTTON2_MASK;
	    }
	    if ((modifiers & BUTTON3_DOWN_MASK) != 0) {
		modifiers |= BUTTON3_MASK;
	    }
	}
	if ((modifiers & ALT_DOWN_MASK) != 0) {
	    modifiers |= ALT_MASK;
	}
	if ((modifiers & META_DOWN_MASK) != 0) {
	    modifiers |= META_MASK;
	}
	if ((modifiers & SHIFT_DOWN_MASK) != 0) {
	    modifiers |= SHIFT_MASK;
	}
	if ((modifiers & CTRL_DOWN_MASK) != 0) {
	    modifiers |= CTRL_MASK;
	}
	if ((modifiers & ALT_GRAPH_DOWN_MASK) != 0) {
	    modifiers |= ALT_GRAPH_MASK;
	}
    }

    /**
     * Sets new modifiers by the old ones.
     * @serial
     */
    private void readObject(ObjectInputStream s)
      throws IOException, ClassNotFoundException {
	s.defaultReadObject();
	if (getModifiers() != 0 && getModifiersEx() == 0) {
	    setNewModifiers();    
	}
    }
}