MainClass.java Source code

Introduction

Here is the source code for MainClass.java

Source

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.DefaultListCellRenderer;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.ListCellRenderer;

public class MainClass {
    public static void main(String args[]) throws Exception {
        Color colors[] = { Color.GREEN, Color.ORANGE, Color.PINK, Color.RED, Color.WHITE, Color.YELLOW };
        JFrame frame = new JFrame("Color JComboBox");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        final JComboBox comboBox = new JComboBox(colors);
        comboBox.setMaximumRowCount(5);
        comboBox.setEditable(true);
        comboBox.setRenderer(new ColorCellRenderer());
        frame.add(comboBox, BorderLayout.NORTH);

        final JLabel label = new JLabel();
        label.setOpaque(true);
        label.setBackground((Color) comboBox.getSelectedItem());
        frame.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 ColorCellRenderer implements ListCellRenderer {
    protected DefaultListCellRenderer defaultRenderer = new DefaultListCellRenderer();
    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;
    }
}