/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2009, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* This library 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 library 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ----------------------
* MouseWheelHandler.java
* ----------------------
* (C) Copyright 2009, by Object Refinery Limited and Contributors.
*
* Original Author: David Gilbert (for Object Refinery Limited);
* Contributor(s): Ulrich Voigt - patch 2686040;
*
* Changes
* -------
* 18-Mar-2009 : Version 1, based on ideas by UV in patch 2686040 (DG);
* 26-Mar-2009 : Implemented Serializable (DG);
*
*/
package org.jfree.chart;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.geom.Point2D;
import java.io.Serializable;
import org.jfree.chart.plot.Plot;
import org.jfree.chart.plot.PlotRenderingInfo;
import org.jfree.chart.plot.Zoomable;
/**
* A class that handles mouse wheel events for the {@link ChartPanel} class.
* Mouse wheel event support was added in JDK 1.4, so this class will be omitted
* from JFreeChart if you build it using JDK 1.3.
*
* @since 1.0.13
*/
class MouseWheelHandler implements MouseWheelListener, Serializable {
/** The chart panel. */
private ChartPanel chartPanel;
/** The zoom factor. */
double zoomFactor;
/**
* Creates a new instance.
*
* @param chartPanel the chart panel (<code>null</code> not permitted).
*/
public MouseWheelHandler(ChartPanel chartPanel) {
this.chartPanel = chartPanel;
this.zoomFactor = 0.10;
this.chartPanel.addMouseWheelListener(this);
}
/**
* Returns the current zoom factor. The default value is 0.10 (ten
* percent).
*
* @return The zoom factor.
*
* @see #setZoomFactor(double)
*/
public double getZoomFactor() {
return this.zoomFactor;
}
/**
* Sets the zoom factor.
*
* @param zoomFactor the zoom factor.
*
* @see #getZoomFactor()
*/
public void setZoomFactor(double zoomFactor) {
this.zoomFactor = zoomFactor;
}
/**
* Handles a mouse wheel event from the underlying chart panel.
*
* @param e the event.
*/
public void mouseWheelMoved(MouseWheelEvent e) {
JFreeChart chart = this.chartPanel.getChart();
if (chart == null) {
return;
}
Plot plot = chart.getPlot();
if (plot instanceof Zoomable) {
Zoomable zoomable = (Zoomable) plot;
handleZoomable(zoomable, e);
}
// TODO: here we could handle non-zoomable plots in interesting
// ways (for example, the wheel could rotate a PiePlot or just zoom
// in on the whole panel).
}
/**
* Handle the case where a plot implements the {@link Zoomable} interface.
*
* @param zoomable the zoomable plot.
* @param e the mouse wheel event.
*/
private void handleZoomable(Zoomable zoomable, MouseWheelEvent e) {
Plot plot = (Plot) zoomable;
ChartRenderingInfo info = this.chartPanel.getChartRenderingInfo();
PlotRenderingInfo pinfo = info.getPlotInfo();
Point2D p = this.chartPanel.translateScreenToJava2D(e.getPoint());
if (!pinfo.getDataArea().contains(p)) {
return;
}
int clicks = e.getWheelRotation();
int direction = 0;
if (clicks < 0) {
direction = -1;
}
else if (clicks > 0) {
direction = 1;
}
boolean old = plot.isNotify();
// do not notify while zooming each axis
plot.setNotify(false);
double increment = 1.0 + this.zoomFactor;
if (direction > 0) {
zoomable.zoomDomainAxes(increment, pinfo, p, true);
zoomable.zoomRangeAxes(increment, pinfo, p, true);
}
else if (direction < 0) {
zoomable.zoomDomainAxes(1.0 / increment, pinfo, p, true);
zoomable.zoomRangeAxes(1.0 / increment, pinfo, p, true);
}
// set the old notify status
plot.setNotify(old);
}
}