Bug with KeyListener?
Create a component, make it focusable and add a key listener. then remove it from it's parent and add it back again. It doesn't respond to key events and there doesn't seem to be a way to switch this back on.
Is this a bug? If so, is it a known bug? Can anyone suggest a workaround?
package tjacobs.ui;
import java.awt.Component;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
publicclass Deletableimplements KeyListener{
private Component mComponent;
public Deletable(Component c){
mComponent = c;
c.addKeyListener(this);
c.setFocusable(true);
}
publicvoid keyPressed(KeyEvent ev){
if (ev.getKeyCode() == ev.VK_DELETE){
setDeleted(mComponent.getParent());
}
}
publicvoid setDeleted(Container c){
SimpleJavaBeanUndoManager man = SimpleJavaBeanUndoManager.getGlobalManager();
if (man !=null){
man.recordEvent(this,"Deleted", mComponent.getParent());
}
c.remove(mComponent);
c.invalidate();
c.validate();
c.repaint();
}
public Container getDeleted(){
return mComponent.getParent();
}
publicvoid undoDeleted(Container c){
if (c ==null){
//System.out.println("c == null!");
c = mComponent.getParent();
c.remove(mComponent);
}else{
c.add(mComponent);
mComponent.addKeyListener(this);
mComponent.setFocusable(true);
}
//mComponent.setFocusable(true);
c.invalidate();
c.validate();
c.repaint();
}
publicvoid keyReleased(KeyEvent arg0){
// TODO Auto-generated method stub
}
publicvoid keyTyped(KeyEvent arg0){
// TODO Auto-generated method stub
}
/**
* @param args
*/
publicstaticvoid main(String[] args){
//SimpleJavaBeanUndoManager man = SimpleJavaBeanUndoManager.createGlobalManager();
final JLabel l =new JLabel("Hello World");
final KeyAdapter ke =new KeyAdapter(){
publicvoid keyPressed(KeyEvent ke){
System.out.println("hit!");
}
};
l.addKeyListener(ke);
l.setFocusable(true);
new Deletable(l);
//new Draggable(l);
final JFrame f =new JFrame("Deletable");
f.add(l);
JMenuBar bar =new JMenuBar();
//JMenu undo = man.getMenu();
JMenu menu =new JMenu("Hello");
final JMenuItem item =new JMenuItem("remove");
final JMenuItem item2 =new JMenuItem("add");
ActionListener al =new ActionListener(){
publicvoid actionPerformed(ActionEvent ae){
if (ae.getSource() == item){
f.getContentPane().remove(l);
}
else{
f.getContentPane().add(l);
}
l.setFocusable(true);
l.addKeyListener(ke);
f.getContentPane().invalidate();
f.getContentPane().validate();
f.getContentPane().repaint();
}
};
item.addActionListener(al);
item2.addActionListener(al);
menu.add(item);
menu.add(item2);
bar.add(menu);
f.setJMenuBar(bar);
f.setBounds(100,100,200,200);
f.setVisible(true);
//WindowUtilities.visualize(f);
//WindowUtilities.visualize(l);
}
}
