Home key

[Stephen Douglas]

I want the frame to respond when the home key is pressed.. Whenever I try pressing "Home Key" while the program is under execution some error is generated.

please suggest. thnx:)

[JosAH]

I want the frame to respond when the home key is pressed.. Whenever I try pressing "Home Key" while the program is under execution some error is generated.

please suggest. thnx:)

Great, all the information you're giving us is "some error"; how are we supposed to know what you have in mind and what your program actually does?

kind regards,

Jos

[Stephen Douglas]

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;

public class MyFrame extends JFrame {

    KeyboardFocusManager manager = KeyboardFocusManager.getCurrentKeyboardFocusManager();

    public MyFrame() {
        add(new JTextField());
        add(new JButton());
        manager.addKeyEventDispatcher(new KeyEventDispatcher() {

            @Override
            public boolean dispatchKeyEvent(KeyEvent e) {
                if (e.getID() == KeyEvent.KEY_TYPED) {
                        System.out.println(e.getSource());
                        System.out.println(e.getKeyChar());
                }
                return false;
            }
        });
    }

    public static void main(String[] args) {
        MyFrame f = new MyFrame();
        f.setBounds(100, 100, 500, 500);
        f.setVisible(true);
    }
}

Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: bad position: -1
at javax.swing.text.JTextComponent.setCaretPosition(J TextComponent.java:1650)
at javax.swing.text.DefaultEditorKit$BeginLineAction. actionPerformed(DefaultEditorKit.java:1935)
at javax.swing.SwingUtilities.notifyAction(SwingUtili ties.java:1636)
at javax.swing.JComponent.processKeyBinding(JComponen t.java:2844)
at javax.swing.JComponent.processKeyBindings(JCompone nt.java:2879)
at javax.swing.JComponent.processKeyEvent(JComponent. java:2807)
at java.awt.Component.processEvent(Component.java:581 5)
at java.awt.Container.processEvent(Container.java:205 8)
at java.awt.Component.dispatchEventImpl(Component.jav a:4410)
at java.awt.Container.dispatchEventImpl(Container.jav a:2116)
at java.awt.Component.dispatchEvent(Component.java:42 40)
at java.awt.KeyboardFocusManager.redispatchEvent(Keyb oardFocusManager.java:1848)
at java.awt.DefaultKeyboardFocusManager.dispatchKeyEv ent(DefaultKeyboardFocusManager.java:693)
at java.awt.DefaultKeyboardFocusManager.preDispatchKe yEvent(DefaultKeyboardFocusManager.java:958)
at java.awt.DefaultKeyboardFocusManager.typeAheadAsse rtions(DefaultKeyboardFocusManager.java:830)
at java.awt.DefaultKeyboardFocusManager.dispatchEvent (DefaultKeyboardFocusManager.java:657)
at java.awt.Component.dispatchEventImpl(Component.jav a:4282)
at java.awt.Container.dispatchEventImpl(Container.jav a:2116)
at java.awt.Window.dispatchEventImpl(Window.java:2429 )
at java.awt.Component.dispatchEvent(Component.java:42 40)
at java.awt.EventQueue.dispatchEvent(EventQueue.java: 599)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(EventDispatchThread.java:273)
at java.awt.EventDispatchThread.pumpEventsForFilter(E ventDispatchThread.java:183)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(EventDispatchThread.java:173)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:168)
at java.awt.EventDispatchThread.pumpEvents(EventDispa tchThread.java:160)
at java.awt.EventDispatchThread.run(EventDispatchThre ad.java:121)

[JosAH]

Yes, now what? I ran your code (after setting those components in the north and center positions respectively) and I didn't get those exceptions; what do you have in mind? You at least have to give some information, don't just dump your code here and wait for us to consult our crystal balls and fix your (unknown) problem.

kind regards,

Jos

[Stephen Douglas]

While this code is under execution... I pressed the "Home" and "End" key the specified error was generated.:(
I am working on NetBeans.

[JosAH]

While this code is under execution... I pressed the "Home" and "End" key the specified error was generated.:(
I am working on NetBeans.

I don't have that behaviour when I run your code, either a key code of 36 (the home key) or 35 (the end key) is returned for both the buton and the text field. Even when I try to press them both at the same time one is always first and after a roll over the other key shows up. No exceptions thrown here. What Java version are you running?

kind regards,

Jos

[Stephen Douglas]

I am actually willing to move from one frame to another when the user presses the "page up" or similar keys... while the frame contains multiple components.. irrespective of the focus being on any component.

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

public class test_backspace extends javax.swing.JFrame {

    KeyboardFocusManager manager = KeyboardFocusManager.getCurrentKeyboardFocusManager();

    public test_backspace() {
        initComponents();
        manager.addKeyEventDispatcher(new KeyEventDispatcher() {

            @Override
            public boolean dispatchKeyEvent(KeyEvent e) {
                if (e.getID() == KeyEvent.KEY_TYPED) {
                        System.out.println((int) e.getKeyChar());
                }
                return false;
            }
        });
    }
    private void initComponents() {

        jTextField1 = new javax.swing.JTextField();
        jButton1 = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jTextField1.setText("jTextField1");

        jButton1.setText("jButton1");

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(65, 65, 65)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 81, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 138, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap(197, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(46, 46, 46)
                .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(29, 29, 29)
                .addComponent(jButton1)
                .addContainerGap(182, Short.MAX_VALUE))
        );

        pack();
    }

    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                new test_backspace().setVisible(true);
            }
        });
    }                  
    private javax.swing.JButton jButton1;
    private javax.swing.JTextField jTextField1;
}

In the above code when I press keys such as "HOme", "End", "Page Up", "Page Down" I don't get any response.

I am using jdk1.6.0.

[JosAH]

In the above code when I press keys such as "HOme", "End", "Page Up", "Page Down" I don't get any response.

I don't think the home, end, pgup etc. keys send "KEY_TYPED" events because they don't have an ASII code equivalent. Check the KEY_PRESSED, KEY_RELEASED parts instead.

kind regards,

Jos

[Stephen Douglas]

Yup it worked.. But how can I distinguish between these keys?????????

public boolean dispatchKeyEvent(KeyEvent e) {
if (e.getID() == KeyEvent.KEY_PRESSED) {
if((int)e.getKeyChar()==36)
System.out.println("mo");
}
return false;
}

from the above code I hoped that the response will be generated when the "Home" key is pressed. But didn't received any response.. please help.

[Stephen Douglas]

i would prefer........ "page up"................... so
if((int)e.getKeyChar()==33)

the focus is on the textfield in my code.. but i want the program to respond irrespective of the focus being set at any component.

[JosAH]

Yup it worked.. But how can I distinguish between these keys?????????

public boolean dispatchKeyEvent(KeyEvent e) {
if (e.getID() == KeyEvent.KEY_PRESSED) {
if((int)e.getKeyChar()==36)
System.out.println("mo");
}
return false;
}

from the above code I hoped that the response will be generated when the "Home" key is pressed. But didn't received any response.. please help.

Don't check for the getKeyChar(), check for the getKeyCode().

kind regards,

Jos

[Stephen Douglas]

thanks buddy it worked.

[JosAH]

thanks buddy it worked.

I still find it a strange way to navigate between windows/frames, what if I move the windows/frames to other locations and the PgUp key moves the focus to the window visually below the current window/frame? I would be a bit surprised ...

kind regards,

Jos

[Stephen Douglas]

what if I move the windows/frames to other locations and the PgUp key moves the focus to the window visually below the current window/frame?

I didn't get it !! Please elaborate.

[JosAH]

I didn't get it !! Please elaborate.

I associate the PgUp key with moving something upward and the PgDown key with moving something downwards; you want to move the focus from window to window with those keys; what if the window that loses the focus is positioned above the window that receives the focus when I press, say, the PgUp key? It looks a bit unnatural to me ...

kind regards,

Jos