Question

I am trying to maximize JFrame from within JMenuBar, I can not pass a reference to the frame. Is it possible to get a reference to the frame that it is used in?

i can get to the top level component but it does not have a way to maximize and minimize frame.

    public Container getApplicationFrame(ActionEvent event){
         JMenuItem menuItem = (JMenuItem) event.getSource();  
         JPopupMenu popupMenu = (JPopupMenu) menuItem.getParent();  
         Component invoker = popupMenu.getInvoker(); 
         JComponent invokerAsJComponent = (JComponent) invoker;  
         Container topLevel = invokerAsJComponent.getTopLevelAncestor();  
         return topLevel;
    }

Answer 1

You can get the Window that contains the JPanel via

Window window = SwingUtilities.getWindowAncestor(popupMenu);

You can then either maximise it using window.setSize() — or, since you seem to know that it’s a JFrame, cast it to Frame and use the setExtendedState method that Kevin mentions. Example code from the Java Developers’ Almanac for that:

// This method minimizes a frame; the iconified bit is not affected
public void maximize(Frame frame) {
    int state = frame.getExtendedState();

    // Set the maximized bits
    state |= Frame.MAXIMIZED_BOTH;

    // Maximize the frame
    frame.setExtendedState(state);
}