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Container

Supree
Greenhorn

Joined: Feb 25, 2000
Posts: 27
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
Desperado
Sheriff

Joined: Jan 30, 2000
Posts: 3222
    
    5
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


Tony Alicea
Senior Java Web Application Developer, SCPJ2, SCWCD
Supree
Greenhorn

Joined: Feb 25, 2000
Posts: 27
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
Desperado
Sheriff

Joined: Jan 30, 2000
Posts: 3222
    
    5
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
Greenhorn

Joined: Feb 25, 2000
Posts: 27
What about applet?Applet is not a window. Is it possible to add appllet in a container.
Tony Alicea
Desperado
Sheriff

Joined: Jan 30, 2000
Posts: 3222
    
    5
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
Ranch Hand

Joined: Nov 22, 2008
Posts: 18944
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
Desperado
Sheriff

Joined: Jan 30, 2000
Posts: 3222
    
    5
Yes but it is still illegal. You'll get a runtime IllegalArgumentException if you try to add a Window to a Container.
deepti_1978
Greenhorn

Joined: Feb 24, 2000
Posts: 2
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
Desperado
Sheriff

Joined: Jan 30, 2000
Posts: 3222
    
    5
(1) We can't add a MenuComponent to a Container because the java.awt.Component)" rel="nofollow">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 java.awt.MenuBar)" rel="nofollow">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).
 
Don't get me started about those stupid light bulbs.
 
subject: Container
 
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