Stepped ComboBox Example : ComboBox « Swing Components « Java
Stepped ComboBox Example
// Example from http://www.crionics.com/products/opensource/faq/swing_ex/SwingExamples.html
/* (swing1.1) */
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Rectangle;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.Vector;
import javax.swing.ComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.UIManager;
import javax.swing.plaf.basic.BasicComboPopup;
import javax.swing.plaf.basic.ComboPopup;
import javax.swing.plaf.metal.MetalComboBoxUI;
/**
* @version 1.0 12/12/98
*/
public class SteppedComboBoxExample extends JFrame {
public SteppedComboBoxExample() {
super("SteppedComboBox Example");
String[] str = { "A", "abcdefghijklmnopqrstuvwxyz",
"ABCDEFGHIJKLMNOPQRSTUVWXYZ", "0123456789" };
SteppedComboBox combo = new SteppedComboBox(str);
Dimension d = combo.getPreferredSize();
combo.setPreferredSize(new Dimension(50, d.height));
combo.setPopupWidth(d.width);
getContentPane().setLayout(new FlowLayout());
getContentPane().add(combo);
}
public static void main(String args[]) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
} catch (Exception evt) {}
SteppedComboBoxExample f = new SteppedComboBoxExample();
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
f.setSize(300, 100);
f.show();
}
}
class SteppedComboBoxUI extends MetalComboBoxUI {
protected ComboPopup createPopup() {
BasicComboPopup popup = new BasicComboPopup(comboBox) {
public void show() {
Dimension popupSize = ((SteppedComboBox) comboBox)
.getPopupSize();
popupSize
.setSize(popupSize.width,
getPopupHeightForRowCount(comboBox
.getMaximumRowCount()));
Rectangle popupBounds = computePopupBounds(0, comboBox
.getBounds().height, popupSize.width, popupSize.height);
scroller.setMaximumSize(popupBounds.getSize());
scroller.setPreferredSize(popupBounds.getSize());
scroller.setMinimumSize(popupBounds.getSize());
list.invalidate();
int selectedIndex = comboBox.getSelectedIndex();
if (selectedIndex == -1) {
list.clearSelection();
} else {
list.setSelectedIndex(selectedIndex);
}
list.ensureIndexIsVisible(list.getSelectedIndex());
setLightWeightPopupEnabled(comboBox.isLightWeightPopupEnabled());
show(comboBox, popupBounds.x, popupBounds.y);
}
};
popup.getAccessibleContext().setAccessibleParent(comboBox);
return popup;
}
}
class SteppedComboBox extends JComboBox {
protected int popupWidth;
public SteppedComboBox(ComboBoxModel aModel) {
super(aModel);
setUI(new SteppedComboBoxUI());
popupWidth = 0;
}
public SteppedComboBox(final Object[] items) {
super(items);
setUI(new SteppedComboBoxUI());
popupWidth = 0;
}
public SteppedComboBox(Vector items) {
super(items);
setUI(new SteppedComboBoxUI());
popupWidth = 0;
}
public void setPopupWidth(int width) {
popupWidth = width;
}
public Dimension getPopupSize() {
Dimension size = getSize();
if (popupWidth < 1)
popupWidth = size.width;
return new Dimension(popupWidth, size.height);
}
}
