- Swing Programming Examples
- Example - Home
- Example - Environment Setup
- Example - Borders
- Example - Buttons
- Example - CheckBoxes
- Example - Combo Boxes
- Example - Color Choosers
- Example - Dialogs
- Example - Editor Panes
- Example - File Choosers
- Example - Formatted TextFields
- Example - Frames
- Example - Lists
- Example - Layouts
- Example - Menus
- Example - Password Fields
- Example - Progress Bars
- Example - Scroll Panes
- Example - Sliders
- Example - Spinners
- Example - Tables
- Example - Toolbars
- Example - Tree
- Swing Useful Resources
- Swing - Quick Guide
- Swing - Useful Resources
- Swing - Discussion
Swing Examples - Adding Separator to Combobox
Following example showcase how to add a separator to a combobox in swing based application.
We are using the following APIs.
JComboBox − To create a standard combobox.
JCheckBox.setRenderer(renderer); − To set a custom renderer which handles the JSeparator.
ListCellRenderer − To create a custom cell renderer for combo box.
Example
import java.awt.BorderLayout; import java.awt.Component; import java.awt.Dimension; import java.awt.FlowLayout; import java.awt.Font; import java.awt.LayoutManager; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JList; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.JSeparator; import javax.swing.ListCellRenderer; public class SwingTester { public static void main(String[] args) { createWindow(); } private static void createWindow() { JFrame frame = new JFrame("Swing Tester"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); createUI(frame); frame.setSize(560, 200); frame.setLocationRelativeTo(null); frame.setVisible(true); } private static void createUI(final JFrame frame){ JPanel panel = new JPanel(); LayoutManager layout = new FlowLayout(); panel.setLayout(layout); Object[] numbers = {"One", "Two", "Three", new JSeparator(JSeparator.HORIZONTAL), "Four", "Five"}; JComboBox<Object> comboBox = new JComboBox<>(numbers); comboBox.setSelectedIndex(1); ComboBoxRenderer renderer= new ComboBoxRenderer(); renderer.setPreferredSize(new Dimension(100, 20)); comboBox.setRenderer(renderer); comboBox.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { JComboBox combo = (JComboBox)e.getSource(); JOptionPane.showMessageDialog(frame,combo.getSelectedItem()); } }); panel.add(comboBox); frame.getContentPane().add(panel, BorderLayout.CENTER); } } class ComboBoxRenderer extends JLabel implements ListCellRenderer<Object> { public Component getListCellRendererComponent(JList<? extends Object> list, Object value, int index, boolean isSelected, boolean cellHasFocus) { if(value instanceof JSeparator){ return (Component)value; }else{ setText(value.toString()); } return this; } }
Output
swingexamples_comboboxes.htm
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