Question

got some problems.

Built an applet that has to be used step-by-step. After each step, a button is clicked and the next step should be added into the GUI.

Problem: without zooming, the added content doesn’t get visible. in a application you can workaround with scaling the window size, but in an applet I wasn’t able to solve that problem.

Thanks

EDIT:

actually, it looks smth like this:

 Panel cp = new Panel(new GridLayout(0,2));
 Panel Block1 = new Panel(new GridLayout(2,2));
 Panel Block1 = new Panel(new GridLayout(2,2));
  ...

init

 public void init()
  {  

   buildBlock1();
   buildBlock2();


    add(cp);
    cp.setVisible(true);
  }

adding some empty panels here, those who will get filled afterwards

private void buildBlock1()
{
Block1.add(panel1);
Block1.add(panel2);
Block1.add(panel3);
Block1.add(panel4);

cp.add(Block1);
}

button actionlistener

private void generatePanel1()
 {
  //adding some Components to the subpanel of Block1, which is a subpanel of cp.
 Panel1.add(...);
 cp.repaint();
 cp.validate();
 }

Answer 1

Now I don’t have any code that I can check but adding (and removing) components to a container normally often needs to be “validated”. So try

panel.add(...); 
panel.revalidate(); 

---

API docs for JComponent.revalidate():

Validates this container and all of its subcomponents.

Supports deferred automatic layout.

Calls invalidate and then adds this component’s validateRoot to a list of components that need to be validated. Validation will occur after all currently pending events have been dispatched. In other words after this method is called, the first validateRoot (if any) found when walking up the containment hierarchy of this component will be validated. By default, JRootPane, JScrollPane, and JTextField return true from isValidateRoot.

This method will automatically be called on this component when a property value changes such that size, location, or internal layout of this component has been affected. This automatic updating differs from the AWT because programs generally no longer need to invoke validate to get the contents of the GUI to update. The validate method is used to cause a container to lay out its subcomponents again. It should be invoked when this container’s subcomponents are modified (added to or removed from the container, or layout-related information changed) after the container has been displayed.