CODEWITHSUNDEEP
javawindowawtcontainersframe
Kumar Chetan
Kumar Chetan

Reputation: 49

What is a top-level window in java awt?

I found this line on the java docs tutorial site- "A Frame is a top-level window with a title and a border". Here, what is the meaning of "top-level window"?

Upvotes: 1

Views: 2494

Answers (4)

Andrew Thompson
Andrew Thompson

Reputation: 168845

A 'top-level window' or 'top level container' is something that can be shown on screen without having to add it to another component. We would start a GUI with a top level container, and then add panels and components to that TLC. E.G. of top level containers..

See also this answer for many good reasons to abandon AWT components in favor of Swing. As to abandoning Swing for Java-FX, I'll be unwilling to do so until Java-FX is promoted to the Java API's Java docs, and makes it into the official Java Tutorial. Sun, then Oracle, has a bad habit of hyping many technologies only to later quietly drop support & development for them.

Upvotes: 3

Puce
Puce

Reputation: 38142

In GUI toolkits such as AWT, a top-level window is a window which is usually known to the OS (heavy-weight components).

Side note: AWT (and even Swing) is a pretty old technology. I recommend to use JavaFX where possible.

Upvotes: 1

Pratik Ambani
Pratik Ambani

Reputation: 2570

Observe difference among these classes.

Frame is top level window because it has border and title. An instance of frame can have a menubar. Without those it is mere is an instance of java.awt.Window class.

Window class: It has neither border not title. Window class is not attached to nor embedded within another container.

Dialog: It has border and title. An instance of the Dialog class cannot exist without an associated instance of the Frame class.

Panel: just a generic container to hold components. Its instance provides a container to which to add components.

Note: Revert me back if further clarification is required.

Upvotes: -1

Daij-Djan
Daij-Djan

Reputation: 50119

a window without a parent.

a window can have child windows alright and they have a parent then

Upvotes: -1

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