extends ListCellRenderer to display icons
/*
Definitive Guide to Swing for Java 2, Second Edition
By John Zukowski
ISBN: 1-893115-78-X
Publisher: APress
*/
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Polygon;
import javax.swing.DefaultListCellRenderer;
import javax.swing.Icon;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.ListCellRenderer;
public class ComplexRenderingSample {
public static void main(String args[]) {
Object elements[][] = {
{ new Font("Helvetica", Font.PLAIN, 20), Color.red,
new DiamondIcon(Color.blue), "Help" },
{ new Font("TimesRoman", Font.BOLD, 14), Color.blue,
new DiamondIcon(Color.green), "Me" },
{ new Font("Courier", Font.ITALIC, 18), Color.green,
new DiamondIcon(Color.black), "I'm" },
{ new Font("Helvetica", Font.BOLD | Font.ITALIC, 12),
Color.gray, new DiamondIcon(Color.magenta), "Trapped" },
{ new Font("TimesRoman", Font.PLAIN, 32), Color.pink,
new DiamondIcon(Color.yellow), "Inside" },
{ new Font("Courier", Font.BOLD, 16), Color.yellow,
new DiamondIcon(Color.red), "This" },
{ new Font("Helvetica", Font.ITALIC, 8), Color.darkGray,
new DiamondIcon(Color.pink), "Computer" } };
JFrame frame = new JFrame("Complex Renderer");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container contentPane = frame.getContentPane();
JList jlist = new JList(elements);
ListCellRenderer renderer = new ComplexCellRenderer();
jlist.setCellRenderer(renderer);
JScrollPane scrollPane = new JScrollPane(jlist);
contentPane.add(scrollPane, BorderLayout.CENTER);
JComboBox comboBox = new JComboBox(elements);
comboBox.setRenderer(renderer);
contentPane.add(comboBox, BorderLayout.NORTH);
frame.setSize(300, 300);
frame.setVisible(true);
}
}
class DiamondIcon implements Icon {
private Color color;
private boolean selected;
private int width;
private int height;
private Polygon poly;
private static final int DEFAULT_WIDTH = 10;
private static final int DEFAULT_HEIGHT = 10;
public DiamondIcon(Color color) {
this(color, true, DEFAULT_WIDTH, DEFAULT_HEIGHT);
}
public DiamondIcon(Color color, boolean selected) {
this(color, selected, DEFAULT_WIDTH, DEFAULT_HEIGHT);
}
public DiamondIcon(Color color, boolean selected, int width, int height) {
this.color = color;
this.selected = selected;
this.width = width;
this.height = height;
initPolygon();
}
private void initPolygon() {
poly = new Polygon();
int halfWidth = width / 2;
int halfHeight = height / 2;
poly.addPoint(0, halfHeight);
poly.addPoint(halfWidth, 0);
poly.addPoint(width, halfHeight);
poly.addPoint(halfWidth, height);
}
public int getIconHeight() {
return height;
}
public int getIconWidth() {
return width;
}
public void paintIcon(Component c, Graphics g, int x, int y) {
g.setColor(color);
g.translate(x, y);
if (selected) {
g.fillPolygon(poly);
} else {
g.drawPolygon(poly);
}
g.translate(-x, -y);
}
}
class ComplexCellRenderer implements ListCellRenderer {
protected DefaultListCellRenderer defaultRenderer = new DefaultListCellRenderer();
public Component getListCellRendererComponent(JList list, Object value,
int index, boolean isSelected, boolean cellHasFocus) {
Font theFont = null;
Color theForeground = null;
Icon theIcon = null;
String theText = null;
JLabel renderer = (JLabel) defaultRenderer
.getListCellRendererComponent(list, value, index, isSelected,
cellHasFocus);
if (value instanceof Object[]) {
Object values[] = (Object[]) value;
theFont = (Font) values[0];
theForeground = (Color) values[1];
theIcon = (Icon) values[2];
theText = (String) values[3];
} else {
theFont = list.getFont();
theForeground = list.getForeground();
theText = "";
}
if (!isSelected) {
renderer.setForeground(theForeground);
}
if (theIcon != null) {
renderer.setIcon(theIcon);
}
renderer.setText(theText);
renderer.setFont(theFont);
return renderer;
}
}
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