Question

I have class main extends jframe, it has a button that calls /shows another class that extends jdialog.

If the button from jdialog is triggered, it will dispose that dialog and will remove all component of jframe, then add it to a new jpanel.

What should I do?

Here’s my new broken code:

public class mainz extends JFrame{
mainz(){
    setVisible(true);
    setDefaultCloseOperation(DISPOSE_ON_CLOSE);

    JToolBar r = new JToolBar();
    r.add(Box.createHorizontalGlue());
    add(r, BorderLayout.NORTH);

    JButton n = new JButton();
    r.add(n, BorderLayout.EAST);

    n.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent ae){
            show();
        }
    });
}

public void  show(){
    dialogz d = new dialogz(this);
    d.setVisible(true);
}

public void lastHope(){
    getContentPane().removeAll();
    getContentPane().validate();
    getContentPane().repaint();
}

public static void main (String[]args){
    new mainz().setExtendedState(MAXIMIZED_BOTH);
}

}

public class dialogz extends JDialog{
public dialogz(final mainz owner) {
    setSize(300, 300);
    JButton n = new JButton("execute");
    add(n);

    final JFrame ew = (JFrame)super.getOwner();// <<

    n.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent ae){
            dispose();
            //owner.lastHope;
            ew.removeAll();// <<
            ew.validate();// <<
            ew.repaint();// <<
        }
    });
}

void yes(){
    getOwner().removeAll();

    getOwner().validate();
    getOwner().repaint();
}

}

I know I can prevent my main class from extending jframe, and call it from main instead, but I want to do it like that…

Please help me … T-T

Sorry for my English, I from a far away country ~,~”

update:
the error is

java.lang.ClassCastException: javax.swing.SwingUtilities$SharedOwnerFrame cannot be cast to javax.swing.JFrame

it will be done with delete the line that contain
// <<
then call lastHope();

but i think there’s a another way to get that existing jframe to removeall
(by casting it first or something ~,~” )

Answer 1

You are calling getParent() but you never set the parent (or owner). That should happen in the constructor as already pointed out. Also, be mindful that getParent() returns a Container object and getOwner() returns a Window object. Both of these refer to the JFrame which is the parent and owner. If you want to use it as a JFrame, you’ll have to cast the output as (JFrame). But removeAll() is in Container class so if that’s all you want, there’ll be no need for casting.

Update:

JFrame frame = new JFrame();
JDialog dialog = new JDialog(frame);//frame is owner

JFrame parentOfDialog = (JFrame)(dialog.getParent());
//OR
//JFrame parentOfDialog = (JFrame)(dialog.getOwner());
parentOfDialog.removeAll();

If you are using your custom class, pass JFrame in the constructor and call super.

Please read the javadoc on JDialog before you try to use it. Also, read more about inheritance.