Color ComboBox: ComboBoxEditor Demo
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ComboBoxEditor;
import javax.swing.DefaultListCellRenderer;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.ListCellRenderer;
import javax.swing.event.EventListenerList;
public class ColorComboBox {
static class ColorCellRenderer implements ListCellRenderer {
protected DefaultListCellRenderer defaultRenderer = new DefaultListCellRenderer();
// width doesn't matter as combobox will size
private final static Dimension preferredSize = new Dimension(0, 20);
public Component getListCellRendererComponent(JList list, Object value,
int index, boolean isSelected, boolean cellHasFocus) {
JLabel renderer = (JLabel) defaultRenderer
.getListCellRendererComponent(list, value, index,
isSelected, cellHasFocus);
if (value instanceof Color) {
renderer.setBackground((Color) value);
}
renderer.setPreferredSize(preferredSize);
return renderer;
}
}
public static void main(String args[]) {
Color colors[] = { Color.black, Color.blue, Color.cyan, Color.darkGray,
Color.gray, Color.green, Color.lightGray, Color.magenta,
Color.orange, Color.pink, Color.red, Color.white, Color.yellow };
JFrame frame = new JFrame("Color JComboBox");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container contentPane = frame.getContentPane();
final JComboBox comboBox = new JComboBox(colors);
comboBox.setMaximumRowCount(5);
comboBox.setEditable(true);
comboBox.setRenderer(new ColorCellRenderer());
Color color = (Color) comboBox.getSelectedItem();
ComboBoxEditor editor = new ColorComboBoxEditor(color);
comboBox.setEditor(editor);
contentPane.add(comboBox, BorderLayout.NORTH);
final JLabel label = new JLabel();
label.setOpaque(true);
label.setBackground((Color) comboBox.getSelectedItem());
contentPane.add(label, BorderLayout.CENTER);
ActionListener actionListener = new ActionListener() {
public void actionPerformed(ActionEvent actionEvent) {
Color selectedColor = (Color) comboBox.getSelectedItem();
label.setBackground(selectedColor);
}
};
comboBox.addActionListener(actionListener);
frame.setSize(300, 200);
frame.setVisible(true);
}
}
class ColorComboBoxEditor implements ComboBoxEditor {
final protected JButton editor;
transient protected EventListenerList listenerList = new EventListenerList();
public ColorComboBoxEditor(Color initialColor) {
editor = new JButton("");
editor.setBackground(initialColor);
ActionListener actionListener = new ActionListener() {
public void actionPerformed(ActionEvent e) {
Color currentBackground = editor.getBackground();
Color color = JColorChooser.showDialog(editor, "Color Chooser",
currentBackground);
if ((color != null) && (currentBackground != color)) {
editor.setBackground(color);
fireActionEvent(color);
}
}
};
editor.addActionListener(actionListener);
}
public void addActionListener(ActionListener l) {
listenerList.add(ActionListener.class, l);
}
public Component getEditorComponent() {
return editor;
}
public Object getItem() {
return editor.getBackground();
}
public void removeActionListener(ActionListener l) {
listenerList.remove(ActionListener.class, l);
}
public void selectAll() {
// ignore
}
public void setItem(Object newValue) {
if (newValue instanceof Color) {
Color color = (Color) newValue;
editor.setBackground(color);
} else {
// Try to decode
try {
Color color = Color.decode(newValue.toString());
editor.setBackground(color);
} catch (NumberFormatException e) {
// ignore - value unchanged
}
}
}
protected void fireActionEvent(Color color) {
Object listeners[] = listenerList.getListenerList();
for (int i = listeners.length - 2; i >= 0; i -= 2) {
if (listeners[i] == ActionListener.class) {
ActionEvent actionEvent = new ActionEvent(editor,
ActionEvent.ACTION_PERFORMED, color.toString());
((ActionListener) listeners[i + 1])
.actionPerformed(actionEvent);
}
}
}
}
Related examples in the same category
