/*
* Open Source Physics software is free software as described near the bottom of this code file.
*
* For additional information and documentation on Open Source Physics please see:
* <http://www.opensourcephysics.org/>
*/
package org.opensourcephysics.display;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.geom.GeneralPath;
import org.opensourcephysics.controls.XML;
import org.opensourcephysics.controls.XMLControl;
import org.opensourcephysics.controls.XMLLoader;
/**
* Title: Trail
* Description: A trail of pixels on the screen. This object is often used to
* show the path of a moving object.
*
* @author Wolfgang Christian
* @version 1.0
*/
public class Trail extends AbstractTrail implements LogMeasurable {
GeneralPath generalPath = new GeneralPath();
boolean connected = true;
/**
* Adds a point to the trail.
* @param x double
* @param y double
*/
public synchronized void addPoint(double x, double y) {
if(closed) {
throw new IllegalStateException("Cannot add points to a closed trail."); //$NON-NLS-1$
}
if(!connected||(numpts==0)) {
generalPath.moveTo((float) x, (float) y);
}
generalPath.lineTo((float) x, (float) y);
xmin = Math.min(xmin, x);
xmax = Math.max(xmax, x);
if(x>0) {
xminLogscale = Math.min(xminLogscale, x);
xmaxLogscale = Math.max(xmaxLogscale, x);
}
ymin = Math.min(ymin, y);
ymax = Math.max(ymax, y);
if(y>0) {
yminLogscale = Math.min(yminLogscale, y);
ymaxLogscale = Math.max(ymaxLogscale, y);
}
numpts++;
}
/**
* Starts a new trail segment by moving to a new point without drawing.
* @param x double
* @param y double
*/
public synchronized void moveToPoint(double x, double y) {
generalPath.moveTo((float) x, (float) y);
xmin = Math.min(xmin, x);
xmax = Math.max(xmax, x);
if(x>0) {
xminLogscale = Math.min(xminLogscale, x);
xmaxLogscale = Math.max(xmaxLogscale, x);
}
ymin = Math.min(ymin, y);
ymax = Math.max(ymax, y);
if(y>0) {
yminLogscale = Math.min(yminLogscale, y);
ymaxLogscale = Math.max(ymaxLogscale, y);
}
numpts++;
}
/**
* Closes the path by connecting the first point to the last point.
* Points cannot be added to a closed path;
*/
public void closeTrail() {
closed = true;
generalPath.closePath();
}
/**
* Sets the connectd flag.
*
* Successive points are connetected by straight lines.
* Each point is marked as a colored pixel if the trail is not connected.
*
* @param connected boolean
*/
public void setConnected(boolean connected) {
this.connected = connected;
}
/**
* Gets the connected flag.
*
* @param connected boolean
*/
public boolean isConnected() {
return connected;
}
/**
* Clears all points from the trail.
*/
public synchronized void clear() {
closed = false;
numpts = 0;
xmax = xmaxLogscale = -Double.MAX_VALUE;
ymax = ymaxLogscale = -Double.MAX_VALUE;
xmin = xminLogscale = Double.MAX_VALUE;
ymin = yminLogscale = Double.MAX_VALUE;
generalPath.reset();
}
/**
* Draws the trail on the panel.
* @param g
*/
public void draw(DrawingPanel panel, Graphics g) {
if(numpts==0) {
return;
}
Graphics2D g2 = (Graphics2D) g;
g2.setColor(color);
// transform from world to pixel coordinates
Shape s = generalPath.createTransformedShape(panel.getPixelTransform());
if(drawingStroke!=null) {
Stroke stroke = g2.getStroke();
g2.setStroke(drawingStroke);
g2.draw(s);
g2.setStroke(stroke);
} else {
g2.draw(s);
}
}
/**
* Returns the XML.ObjectLoader for this class.
*
* @return the object loader
*/
public static XML.ObjectLoader getLoader() {
return new Loader();
}
/**
* A class to save and load Dataset data in an XMLControl.
*/
private static class Loader extends XMLLoader {
public void saveObject(XMLControl control, Object obj) {
Trail trail = (Trail) obj;
control.setValue("connected", trail.connected); //$NON-NLS-1$
control.setValue("color", trail.color); //$NON-NLS-1$
control.setValue("number of pts", trail.numpts); //$NON-NLS-1$
control.setValue("general path", trail.generalPath); //$NON-NLS-1$
}
public Object createObject(XMLControl control) {
return new Trail();
}
public Object loadObject(XMLControl control, Object obj) {
Trail trail = (Trail) obj;
trail.connected = control.getBoolean("connected"); //$NON-NLS-1$
trail.color = (Color) control.getObject("color"); //$NON-NLS-1$
trail.numpts = control.getInt("number of pts"); //$NON-NLS-1$
trail.generalPath = (GeneralPath) control.getObject("general path"); //$NON-NLS-1$
return obj;
}
}
}
/*
* Open Source Physics software is free software; you can redistribute
* it and/or modify it under the terms of the GNU General Public License (GPL) as
* published by the Free Software Foundation; either version 2 of the License,
* or(at your option) any later version.
*
* Code that uses any portion of the code in the org.opensourcephysics package
* or any subpackage (subdirectory) of this package must must also be be released
* under the GNU GPL license.
*
* This software 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with this; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston MA 02111-1307 USA
* or view the license online at http://www.gnu.org/copyleft/gpl.html
*
* Copyright (c) 2007 The Open Source Physics project
* http://www.opensourcephysics.org
*/