Mega Code Archive
Renders an ellipse overlapping a rectangle with the compositing rule and alpha value selected by the user
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/*
* Copyright (c) 1995 - 2008 Sun Microsystems, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Sun Microsystems nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import javax.swing.JApplet;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
/*
* This applet renders an ellipse overlapping a rectangle with the compositing
* rule and alpha value selected by the user.
*/
public class Composite extends JApplet implements ItemListener {
CompPanel comp;
JLabel alphaLabel, rulesLabel;
JComboBox alphas, rules;
String alpha = "1.0";
int rule = 0;
// Initializes the layout of the components.
public void init() {
GridBagLayout layOut = new GridBagLayout();
getContentPane().setLayout(layOut);
GridBagConstraints l = new GridBagConstraints();
l.weightx = 1.0;
l.fill = GridBagConstraints.BOTH;
l.gridwidth = GridBagConstraints.RELATIVE;
alphaLabel = new JLabel();
alphaLabel.setText("Alphas");
Font newFont = getFont().deriveFont(1);
alphaLabel.setFont(newFont);
alphaLabel.setHorizontalAlignment(JLabel.CENTER);
layOut.setConstraints(alphaLabel, l);
getContentPane().add(alphaLabel);
GridBagConstraints c = new GridBagConstraints();
getContentPane().setLayout(layOut);
l.gridwidth = GridBagConstraints.REMAINDER;
rulesLabel = new JLabel();
rulesLabel.setText("Rules");
newFont = getFont().deriveFont(1);
rulesLabel.setFont(newFont);
rulesLabel.setHorizontalAlignment(JLabel.CENTER);
layOut.setConstraints(rulesLabel, l);
getContentPane().add(rulesLabel);
GridBagConstraints a = new GridBagConstraints();
a.gridwidth = GridBagConstraints.RELATIVE;
a.weightx = 1.0;
a.fill = GridBagConstraints.BOTH;
alphas = new JComboBox();
layOut.setConstraints(alphas, a);
alphas.addItem("1.0");
alphas.addItem("0.75");
alphas.addItem("0.50");
alphas.addItem("0.25");
alphas.addItem("0.0");
alphas.addItemListener(this);
getContentPane().add(alphas);
a.gridwidth = GridBagConstraints.REMAINDER;
rules = new JComboBox();
layOut.setConstraints(rules, a);
rules.addItem("SRC");
rules.addItem("DST_IN");
rules.addItem("DST_OUT");
rules.addItem("DST_OVER");
rules.addItem("SRC_IN");
rules.addItem("SRC_OVER");
rules.addItem("SRC_OUT");
rules.addItem("CLEAR");
rules.addItemListener(this);
getContentPane().add(rules);
GridBagConstraints fC = new GridBagConstraints();
fC.fill = GridBagConstraints.BOTH;
fC.weightx = 1.0;
fC.weighty = 1.0;
fC.gridwidth = GridBagConstraints.REMAINDER;
comp = new CompPanel();
layOut.setConstraints(comp, fC);
getContentPane().add(comp);
validate();
}
/*
* Detects a change in either of the Choice components. Resets the variable
* corresponding to the Choice whose state is changed. Invokes changeRule in
* CompPanel with the current alpha and composite rules.
*/
public void itemStateChanged(ItemEvent e) {
if (e.getStateChange() != ItemEvent.SELECTED) {
return;
}
Object choice = e.getSource();
if (choice == alphas) {
alpha = (String) alphas.getSelectedItem();
} else {
rule = rules.getSelectedIndex();
}
comp.changeRule(alpha, rule);
}
public static void main(String s[]) {
JFrame f = new JFrame("Composite");
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
JApplet applet = new Composite();
f.getContentPane().add("Center", applet);
applet.init();
f.pack();
f.setSize(new Dimension(300, 300));
f.setVisible(true);
}
}
class CompPanel extends JPanel {
AlphaComposite ac = AlphaComposite.getInstance(AlphaComposite.SRC);
float alpha = 1.0f;
public CompPanel() {
}
// Resets the alpha and composite rules with selected items.
public void changeRule(String a, int rule) {
alpha = Float.valueOf(a).floatValue();
ac = AlphaComposite.getInstance(getRule(rule), alpha);
repaint();
}
// Gets the requested compositing rule.
public int getRule(int rule) {
int alphaComp = 0;
switch (rule) {
case 0:
alphaComp = AlphaComposite.SRC;
break;
case 1:
alphaComp = AlphaComposite.DST_IN;
break;
case 2:
alphaComp = AlphaComposite.DST_OUT;
break;
case 3:
alphaComp = AlphaComposite.DST_OVER;
break;
case 4:
alphaComp = AlphaComposite.SRC_IN;
break;
case 5:
alphaComp = AlphaComposite.SRC_OVER;
break;
case 6:
alphaComp = AlphaComposite.SRC_OUT;
break;
case 7:
alphaComp = AlphaComposite.CLEAR;
break;
}
return alphaComp;
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
Dimension d = getSize();
int w = d.width;
int h = d.height;
// Creates the buffered image.
BufferedImage buffImg = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
Graphics2D gbi = buffImg.createGraphics();
// Clears the previously drawn image.
g2.setColor(Color.white);
g2.fillRect(0, 0, d.width, d.height);
int rectx = w / 4;
int recty = h / 4;
// Draws the rectangle and ellipse into the buffered image.
gbi.setColor(new Color(0.0f, 0.0f, 1.0f, 1.0f));
gbi.fill(new Rectangle2D.Double(rectx, recty, 150, 100));
gbi.setColor(new Color(1.0f, 0.0f, 0.0f, 1.0f));
gbi.setComposite(ac);
gbi.fill(new Ellipse2D.Double(rectx + rectx / 2, recty + recty / 2, 150,
100));
// Draws the buffered image.
g2.drawImage(buffImg, null, 0, 0);
}
}
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