Question

I am coding MVC. In my controller i am listening to the action and if the user clicks a “SHOW-LIST” button i am making an instance of my view class which extends from JFrame and therein the view class i create a new JFrame. My problem is that if i click on SHOW-LIST button multiple times, i have the frame opened multiple time. Can somebody please tell me how can i do so so that once a new frame is about to open the old frame closes..

Controller

public void actionPerformed(ActionEvent event) {
  String viewAction = event.getActionCommand();
  ...
    if (viewAction.equals("SHOW-LIST")) {
      showListUI = new ShowListDialogUI(displayedCustomerList);
    }
}

View

class ShowListDialogUI extends JFrame{
  public ShowListDialogUI (List<Customer> customerList) {
    ..
    // I am drawing it here
    ..
  }
}

Answer 1

Can somebody please tell me how can i do so so that once a new frame
is about to open the old frame closes..

• use CardLayout, then there no reason to playing with Top-Level Containers, put there required number of JPanels, then just to switch betweens JPanel views

• as @trashgod notified, really not good idea, way

• otherwise have to clean-up (remove all contents) uselless container, because Top-Level Containers never will be GC’ed