/*
* 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.Image;
import java.util.ArrayList;
import java.util.Iterator;
/**
* A DrawableBuffer contains an image of drawable objects. This image is displayed
* on a drawing panel whenever when the draw method is invoked.
*
* A drawble buffer should be used to render complex drawable objects that change infrequently.
* Use the updateImage method to generate a new image when the properties of
* the drawable objects change.
*
* @author Wolfgang Christian
* @version 1.0
*/
public class DrawableBuffer implements Drawable, Measurable {
Image image;
boolean invalid = true;
ArrayList<Drawable> drawableList = new ArrayList<Drawable>(); // list of Drawable objects
Color background = Color.white;
boolean measured = false;
double xmin, xmax, ymin, ymax;
boolean visible = true;
/**
* Constructor DrawableBuffer
*
*/
public DrawableBuffer() {}
/**
* Constructor DrawableBuffer
*
* @param drawable
*/
public DrawableBuffer(Drawable drawable) {
addDrawable(drawable);
}
/**
* Adds a drawable object to the drawing buffer.
* @param drawable
*/
public synchronized void addDrawable(Drawable drawable) {
if(!drawableList.contains(drawable)) {
drawableList.add(drawable);
}
invalidateImage();
}
/**
* Method setBackground
*
* @param color
*/
public void setBackground(Color color) {
background = color;
}
/**
* Sets the bufferrer's visible flag.
* @param vis boolean
*/
public void setVisible(boolean vis) {
visible = vis;
}
/**
* Reads the visible flag.
* @return boolean
*/
public boolean isVisible() {
return visible;
}
/**
* Remove all drawable objects from the drawing buffer.
*/
public synchronized void clear() {
drawableList.clear();
invalidateImage();
}
/**
* Invalidates the image so that it is redrawn during the next repaint operation.
*
*/
public void invalidateImage() {
measured = false;
ArrayList<Drawable> tempList = new ArrayList<Drawable>(drawableList);
Iterator<Drawable> it = tempList.iterator();
xmin = Double.MAX_VALUE;
xmax = -Double.MAX_VALUE;
ymin = Double.MAX_VALUE;
ymax = -Double.MAX_VALUE;
while(it.hasNext()) {
Drawable drawable = it.next();
if((drawable instanceof Measurable)&&((Measurable) drawable).isMeasured()) {
xmin = Math.min(xmin, ((Measurable) drawable).getXMin());
xmax = Math.max(xmax, ((Measurable) drawable).getXMax());
ymin = Math.min(ymin, ((Measurable) drawable).getYMin());
ymax = Math.max(ymax, ((Measurable) drawable).getYMax());
measured = true;
}
}
invalid = true;
}
/**
* Updates the image using the given drawing panel to set the dimension.
*
* @param drawingPanel
*/
public void updateImage(DrawingPanel drawingPanel) {
invalid = false;
Image newImage = image;
int iw = drawingPanel.getWidth();
int ih = drawingPanel.getHeight();
if((image==null)||(image.getWidth(drawingPanel)!=iw)||(image.getHeight(drawingPanel)!=ih)) {
newImage = drawingPanel.createImage(iw, ih);
}
if(newImage==null) {
return;
}
Graphics g = newImage.getGraphics();
if(g!=null) {
if(background==null) {
g.clearRect(0, 0, iw, ih);
} else {
g.setColor(background);
g.fillRect(0, 0, iw, ih);
}
paintMyDrawableList(drawingPanel, g);
g.dispose();
}
image = newImage;
}
/**
* Method draw
*
* @param drawingPanel
* @param g
*/
public void draw(DrawingPanel drawingPanel, Graphics g) {
if(!visible) {
return;
}
if(invalid||(image==null)||(image.getWidth(drawingPanel)!=drawingPanel.getWidth())||(image.getHeight(drawingPanel)!=drawingPanel.getHeight())) {
updateImage(drawingPanel);
}
if(image!=null) {
g.drawImage(image, 0, 0, drawingPanel);
}
}
/**
* Method getXMin
*
*
* @return x min
*/
public double getXMin() {
return xmin;
}
/**
* Method getXMax
*
*
* @return x max
*/
public double getXMax() {
return xmax;
}
/**
* Method getYMin
*
*
* @return ymin
*/
public double getYMin() {
return ymin;
}
/**
* Method getYMax
*
*
* @return ymax
*/
public double getYMax() {
return ymax;
}
/**
* Tests to see if the buffer has an object with a valid measure.
*
* @return true if any object in the drawable list is measured
*/
public boolean isMeasured() {
return measured;
}
/**
* Paints the drawable objects onto the image.
* @param g
*/
private void paintMyDrawableList(DrawingPanel drawingPanel, Graphics g) {
ArrayList<Drawable> tempList = new ArrayList<Drawable>(drawableList);
Iterator<Drawable> it = tempList.iterator();
while(it.hasNext()) {
Drawable drawable = it.next();
drawable.draw(drawingPanel, g);
}
}
}
/*
* 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
*/