Create Focus Traversal Policy

Description

Demo Code

import java.awt.*;
import java.awt.event.*;

import java.util.Vector;

import javax.swing.*;

/*//  ww w .  ja v a 2s  .  c  om
 * FocusTraversalDemo.java requires no other files.
 */
public class FocusTraversalDemo extends JPanel implements ActionListener {

    static JFrame frame;
    JLabel label;
    JCheckBox togglePolicy;
    static MyOwnFocusTraversalPolicy newPolicy;

    public FocusTraversalDemo() {
        super(new BorderLayout());

        JTextField tf1 = new JTextField("Field 1");
        JTextField tf2 = new JTextField("A Bigger Field 2");
        JTextField tf3 = new JTextField("Field 3");
        JTextField tf4 = new JTextField("A Bigger Field 4");
        JTextField tf5 = new JTextField("Field 5");
        JTextField tf6 = new JTextField("A Bigger Field 6");
        JTable table = new JTable(4, 3);
        togglePolicy = new JCheckBox("Custom FocusTraversalPolicy");
        togglePolicy.setActionCommand("toggle");
        togglePolicy.addActionListener(this);
        togglePolicy.setFocusable(false); //Remove it from the focus cycle.
        //Note that HTML is allowed and will break this run of text
        //across two lines.
        label = new JLabel(
                "<html>Use Tab (or Shift-Tab) to navigate from component to component.<p>Control-Tab (or Control-Shift-Tab) allows you to break out of the JTable.</html>");

        JPanel leftTextPanel = new JPanel(new GridLayout(3, 2));
        leftTextPanel.add(tf1, BorderLayout.PAGE_START);
        leftTextPanel.add(tf3, BorderLayout.CENTER);
        leftTextPanel.add(tf5, BorderLayout.PAGE_END);
        leftTextPanel
                .setBorder(BorderFactory.createEmptyBorder(0, 0, 5, 5));
        JPanel rightTextPanel = new JPanel(new GridLayout(3, 2));
        rightTextPanel.add(tf2, BorderLayout.PAGE_START);
        rightTextPanel.add(tf4, BorderLayout.CENTER);
        rightTextPanel.add(tf6, BorderLayout.PAGE_END);
        rightTextPanel.setBorder(BorderFactory
                .createEmptyBorder(0, 0, 5, 5));
        JPanel tablePanel = new JPanel(new GridLayout(0, 1));
        tablePanel.add(table, BorderLayout.CENTER);
        tablePanel.setBorder(BorderFactory.createEtchedBorder());
        JPanel bottomPanel = new JPanel(new GridLayout(2, 1));
        bottomPanel.add(togglePolicy, BorderLayout.PAGE_START);
        bottomPanel.add(label, BorderLayout.PAGE_END);

        add(leftTextPanel, BorderLayout.LINE_START);
        add(rightTextPanel, BorderLayout.CENTER);
        add(tablePanel, BorderLayout.LINE_END);
        add(bottomPanel, BorderLayout.PAGE_END);
        setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
        Vector<Component> order = new Vector<Component>(7);
        order.add(tf1);
        order.add(tf2);
        order.add(tf3);
        order.add(tf4);
        order.add(tf5);
        order.add(tf6);
        order.add(table);
        newPolicy = new MyOwnFocusTraversalPolicy(order);
    }

    //Turn the custom focus traversal policy on/off,
    //according to the checkbox
    public void actionPerformed(ActionEvent e) {
        if ("toggle".equals(e.getActionCommand())) {
            frame.setFocusTraversalPolicy(togglePolicy.isSelected() ? newPolicy
                    : null);
        }
    }

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        frame = new JFrame("FocusTraversalDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create and set up the content pane.
        JComponent newContentPane = new FocusTraversalDemo();
        newContentPane.setOpaque(true); //content panes must be opaque
        frame.setContentPane(newContentPane);

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        /* Use an appropriate Look and Feel */
        try {
            //UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
            //UIManager.setLookAndFeel("com.sun.java.swing.plaf.gtk.GTKLookAndFeel");
            UIManager
                    .setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
        } catch (UnsupportedLookAndFeelException ex) {
            ex.printStackTrace();
        } catch (IllegalAccessException ex) {
            ex.printStackTrace();
        } catch (InstantiationException ex) {
            ex.printStackTrace();
        } catch (ClassNotFoundException ex) {
            ex.printStackTrace();
        }
        /* Turn off metal's use of bold fonts */
        UIManager.put("swing.boldMetal", Boolean.FALSE);

        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }

    public static class MyOwnFocusTraversalPolicy extends
            FocusTraversalPolicy {
        Vector<Component> order;

        public MyOwnFocusTraversalPolicy(Vector<Component> order) {
            this.order = new Vector<Component>(order.size());
            this.order.addAll(order);
        }

        public Component getComponentAfter(Container focusCycleRoot,
                Component aComponent) {
            int idx = (order.indexOf(aComponent) + 1) % order.size();
            return order.get(idx);
        }

        public Component getComponentBefore(Container focusCycleRoot,
                Component aComponent) {
            int idx = order.indexOf(aComponent) - 1;
            if (idx < 0) {
                idx = order.size() - 1;
            }
            return order.get(idx);
        }

        public Component getDefaultComponent(Container focusCycleRoot) {
            return order.get(0);
        }

        public Component getLastComponent(Container focusCycleRoot) {
            return order.lastElement();
        }

        public Component getFirstComponent(Container focusCycleRoot) {
            return order.get(0);
        }
    }
}

/*
 * Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Oracle or the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
Create Focus Traversal Policy - Java Swing

Description

Demo Code

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