MainClass.java Source code

Introduction

Here is the source code for MainClass.java

Source

import java.awt.BorderLayout;

import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.plaf.ComboBoxUI;
import javax.swing.plaf.ComponentUI;
import javax.swing.plaf.basic.BasicArrowButton;
import javax.swing.plaf.basic.BasicComboBoxUI;

public class MainClass {

    public static void main(final String args[]) {
        final String labels[] = { "A", "B", "C", "D", "E" };
        JFrame frame = new JFrame("Popup JComboBox");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JComboBox comboBox = new JComboBox(labels);
        comboBox.setUI((ComboBoxUI) MyComboBoxUI.createUI(comboBox));
        frame.add(comboBox, BorderLayout.NORTH);

        frame.setSize(300, 200);
        frame.setVisible(true);

    }

    static class MyComboBoxUI extends BasicComboBoxUI {
        public static ComponentUI createUI(JComponent c) {
            return new MyComboBoxUI();
        }

        protected JButton createArrowButton() {
            JButton button = new BasicArrowButton(BasicArrowButton.EAST);
            return button;
        }
    }
}