/*
* Copyright 1998-2003 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package sun.awt.windows;
import java.awt.Toolkit;
import java.awt.Component;
import java.awt.Point;
import java.awt.dnd.DnDConstants;
import java.awt.dnd.DragSource;
import java.awt.dnd.MouseDragGestureRecognizer;
import java.awt.dnd.DragGestureListener;
import java.awt.event.InputEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.lang.reflect.*;
import sun.awt.dnd.SunDragSourceContextPeer;
/**
* <p>
* This subclass of MouseDragGestureRecognizer defines a DragGestureRecognizer
* for Mouse based gestures on Win32.
* </p>
*
* @author Laurence P. G. Cable
*
* @see java.awt.dnd.DragGestureListener
* @see java.awt.dnd.DragGestureEvent
* @see java.awt.dnd.DragSource
*/
class WMouseDragGestureRecognizer extends MouseDragGestureRecognizer {
private static final long serialVersionUID = -3527844310018033570L;
/*
* constant for number of pixels hysterisis before drag is determined
* to have started
*/
protected static int motionThreshold;
protected static final int ButtonMask = InputEvent.BUTTON1_DOWN_MASK |
InputEvent.BUTTON2_DOWN_MASK |
InputEvent.BUTTON3_DOWN_MASK;
/**
* construct a new WMouseDragGestureRecognizer
*
* @param ds The DragSource for the Component c
* @param c The Component to observe
* @param act The actions permitted for this Drag
* @param dgl The DragGestureRecognizer to notify when a gesture is detected
*
*/
protected WMouseDragGestureRecognizer(DragSource ds, Component c, int act, DragGestureListener dgl) {
super(ds, c, act, dgl);
}
/**
* construct a new WMouseDragGestureRecognizer
*
* @param ds The DragSource for the Component c
* @param c The Component to observe
* @param act The actions permitted for this Drag
*/
protected WMouseDragGestureRecognizer(DragSource ds, Component c, int act) {
this(ds, c, act, null);
}
/**
* construct a new WMouseDragGestureRecognizer
*
* @param ds The DragSource for the Component c
* @param c The Component to observe
*/
protected WMouseDragGestureRecognizer(DragSource ds, Component c) {
this(ds, c, DnDConstants.ACTION_NONE);
}
/**
* construct a new WMouseDragGestureRecognizer
*
* @param ds The DragSource for the Component c
*/
protected WMouseDragGestureRecognizer(DragSource ds) {
this(ds, null);
}
/**
* determine the drop action from the event
*/
protected int mapDragOperationFromModifiers(MouseEvent e) {
int mods = e.getModifiersEx();
int btns = mods & ButtonMask;
// Prohibit multi-button drags.
if (!(btns == InputEvent.BUTTON1_DOWN_MASK ||
btns == InputEvent.BUTTON2_DOWN_MASK ||
btns == InputEvent.BUTTON3_DOWN_MASK)) {
return DnDConstants.ACTION_NONE;
}
return
SunDragSourceContextPeer.convertModifiersToDropAction(mods,
getSourceActions());
}
/**
* Invoked when the mouse has been clicked on a component.
*/
public void mouseClicked(MouseEvent e) {
// do nothing
}
/**
* Invoked when a mouse button has been pressed on a component.
*/
public void mousePressed(MouseEvent e) {
events.clear();
if (mapDragOperationFromModifiers(e) != DnDConstants.ACTION_NONE) {
try {
motionThreshold = DragSource.getDragThreshold();
} catch (Exception exc) {
motionThreshold = 5;
}
appendEvent(e);
}
}
/**
* Invoked when a mouse button has been released on a component.
*/
public void mouseReleased(MouseEvent e) {
events.clear();
}
/**
* Invoked when the mouse enters a component.
*/
public void mouseEntered(MouseEvent e) {
events.clear();
}
/**
* Invoked when the mouse exits a component.
*/
public void mouseExited(MouseEvent e) {
if (!events.isEmpty()) { // gesture pending
int dragAction = mapDragOperationFromModifiers(e);
if (dragAction == DnDConstants.ACTION_NONE) {
events.clear();
}
}
}
/**
* Invoked when a mouse button is pressed on a component.
*/
public void mouseDragged(MouseEvent e) {
if (!events.isEmpty()) { // gesture pending
int dop = mapDragOperationFromModifiers(e);
if (dop == DnDConstants.ACTION_NONE) {
return;
}
MouseEvent trigger = (MouseEvent)events.get(0);
Point origin = trigger.getPoint();
Point current = e.getPoint();
int dx = Math.abs(origin.x - current.x);
int dy = Math.abs(origin.y - current.y);
if (dx > motionThreshold || dy > motionThreshold) {
fireDragGestureRecognized(dop, ((MouseEvent)getTriggerEvent()).getPoint());
} else
appendEvent(e);
}
}
/**
* Invoked when the mouse button has been moved on a component
* (with no buttons no down).
*/
public void mouseMoved(MouseEvent e) {
// do nothing
}
}