Container

[Supree]

What can't be added to container?
a.Componet
b.Container
c.panel
d.Applet
e.Frame
f.Container
g.Menu
f.Menu component
I am not clear about this, Could anyone answer pl?

[Tony Alicea]

What don't you understand in particular? It would not serve any purpose just to give the answer. There is something to understand about the AWT Container and MenuComponent hierarchy/relationship and the concept of top-level windows... What does your text on Java say about that?
You may be able to take a hint from the AWT Components hierarchy that I copied to my Java page. It's item (2) here

[Supree]

I know the AWT component hierarchy.
My doubt is whether all sub classes of container can be added to a container or Is there any criteria of what can be added to a container.

[Tony Alicea]

The criteria is that <CODE>Window</CODE>s cannot be added to containers. <CODE>Frame</CODE>, <CODE>Dialog</CODE> and <CODE>FileDialog</CODE> are <CODE>Window</CODE>s.
Neither can <CODE>MenuComponent</CODE>s

[Supree]

What about applet?Applet is not a window. Is it possible to add appllet in a container.

[Tony Alicea]

An Applet is a Panel. So wherever you can add a panel, you can add an applet. Why would you want to do it is another matter. Applets are special purpose Panels for Web pages.
The following compiles and executes:
<PRE> public static void main (String[] args) {
Applet ap = new Applet();
Window w = new Window(new Frame() );
w.add(ap);
}
</PRE>

[Anonymous]

tony,
why can't Windows be added to Containers? the add method of Container takes any Component as argument and Window inherits from Component.

[Tony Alicea]

Yes but it is still illegal. You'll get a runtime IllegalArgumentException if you try to add a Window to a Container.

[deepti_1978]

can anybody please explain
if we can't add a menucomponent to a container then how it is possible to add a menubar to a frame.

[Tony Alicea]

(1) We can't add a MenuComponent to a Container because the Container.add() takes Component objects as arguments not MenuComponent.
(2) We can "add" a MenuComponent (In the form of a MenuBar) to a Frame because the Frame class allows it via the setMenuBar() method.
In my SCPJ2 page I reproduce Sun's inheritance hierarchies for all the AWT component classes. You can get to that page from my main Java page, item (8).