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Flying Saucer is a CSS 2.1 renderer written in Java. This artifact contains the core rendering and layout code as well as Java2D output.
/*
* {{{ header & license
* Copyright (c) 2007 Sean Bright
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* of the License, or (at your option) any later version.
*
* This program 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* }}}
*/
package org.xhtmlrenderer.swing;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import javax.swing.event.MouseInputAdapter;
import org.xhtmlrenderer.render.Box;
/**
* A MouseTracker is used to delegate mouse events to the {@link org.xhtmlrenderer.swing.FSMouseListener} instances
* associated with a {@link org.xhtmlrenderer.swing.BasicPanel}. The tracker will start receiving events as soon
* as the first listener is added (via {@link #addListener(FSMouseListener)} and will stop receiving events as soon
* as the last listener is removed via {@link #removeListener(FSMouseListener)}. This binding is handled automatically
* via the add and remove methods and the tracker will remain active as long as the tracker has at least one listener.
* The MouseTracker is also responsible for using MouseEvent coordinates to located the Box on which the mouse is
* acting.
*/
public class MouseTracker extends MouseInputAdapter {
private BasicPanel _panel;
private Map _handlers;
private Box _last;
private boolean _enabled;
/**
* Instantiates a MouseTracker to listen to mouse events for the given panel.
* @param panel the panel for which mouse events should be delegated.
*/
public MouseTracker(BasicPanel panel) {
_panel = panel;
_handlers = new LinkedHashMap();
}
/**
* Adds a listener to receive callbacks on mouse events.
*
* @param l the listener
*/
public void addListener(FSMouseListener l) {
if (l == null) {
return;
}
if (!_handlers.containsKey(l)) {
_handlers.put(l, l);
}
if (!_enabled && _handlers.size() > 0) {
_panel.addMouseListener(this);
_panel.addMouseMotionListener(this);
_enabled = true;
}
}
/**
* Removes the given listener, after which it will no longer receive callbacks on mouse events.
*
* @param l the listener to remove
*/
public void removeListener(FSMouseListener l) {
if (l == null) {
return;
}
if (_handlers.containsKey(l)) {
_handlers.remove(l);
}
if (_enabled && _handlers.size() == 0) {
_panel.removeMouseListener(this);
_panel.removeMouseMotionListener(this);
_enabled = false;
}
}
/**
* Returns a (new) list of all listeners currently tracked for receiving events.
* @return a (new) list of all listeners currently tracked for receiving events.
*/
public List getListeners() {
return new ArrayList(_handlers.keySet());
}
/**
* {@inheritDoc}
*/
public void mouseEntered(MouseEvent e) {
handleMouseMotion(_panel.find(e));
}
/**
* {@inheritDoc}
*/
public void mouseExited(MouseEvent e) {
handleMouseMotion(_panel.find(e));
}
/**
* {@inheritDoc}
*/
public void mouseMoved(MouseEvent e) {
handleMouseMotion(_panel.find(e));
}
/**
* {@inheritDoc}
*/
public void mouseReleased(MouseEvent e) {
handleMouseUp(_panel.find(e));
}
/**
* {@inheritDoc}
*/
public void mousePressed(MouseEvent e) {
fireMousePressed(e);
}
/**
* {@inheritDoc}
*/
public void mouseDragged(MouseEvent e) {
fireMouseDragged(e);
}
/**
* Utility method; calls {@link FSMouseListener#reset()} for all listeners currently being tracked.
*/
public void reset() {
_last = null;
Iterator iterator = _handlers.keySet().iterator();
while (iterator.hasNext()) {
((FSMouseListener) iterator.next()).reset();
}
}
// handles delegation of mouse events to listeners
private void handleMouseMotion(Box box) {
if (box == null || box.equals(_last)) {
return;
}
if (_last != null) {
fireMouseOut(_last);
}
fireMouseOver(box);
_last = box;
}
private void handleMouseUp(Box box) {
if (box == null) {
return;
}
fireMouseUp(box);
}
// delegates onMouseOver() to all listeners
private void fireMouseOver(Box box) {
Iterator iterator = _handlers.keySet().iterator();
while (iterator.hasNext()) {
((FSMouseListener) iterator.next()).onMouseOver(_panel, box);
}
}
// delegates onMouseOut() to all listeners
private void fireMouseOut(Box box) {
Iterator iterator = _handlers.keySet().iterator();
while (iterator.hasNext()) {
((FSMouseListener) iterator.next()).onMouseOut(_panel, box);
}
}
// delegates onMouseUp() to all listeners
private void fireMouseUp(Box box) {
Iterator iterator = _handlers.keySet().iterator();
while (iterator.hasNext()) {
((FSMouseListener) iterator.next()).onMouseUp(_panel, box);
}
}
// delegates onMousePressed() to all listeners
private void fireMousePressed(MouseEvent e) {
Iterator iterator = _handlers.keySet().iterator();
while (iterator.hasNext()) {
((FSMouseListener) iterator.next()).onMousePressed(_panel, e);
}
}
// delegates onMouseDragged() to all listeners
private void fireMouseDragged(MouseEvent e) {
Iterator iterator = _handlers.keySet().iterator();
while (iterator.hasNext()) {
((FSMouseListener) iterator.next()).onMouseDragged(_panel, e);
}
}
}