Can JFrame be added to a container?

[Igor Mechnikov]

Please explain.

Thank you.

[Matthew Brown]

Have you tried it? What happens?

[Igor Mechnikov]

Matthew Brown wrote:Have you tried it? What happens?

Have not tried.
Just wanted to verify an answer from a self-quiz.

[Campbell Ritchie]

Go through the documentation for Container and see what parameters its add methods take.

And I shall move you to our GUIs forum.

[Matthew Brown]

Ilya Mechnikov wrote:Have not tried.
Just wanted to verify an answer from a self-quiz.

Well, the easiest, and most reliable, way to verify it is to try it. Try compiling and running the following, see what happens:

import java.awt.Color;
import javax.swing.JFrame;

public class JFrameInAContainerTest {
    public static void main(String[] args) {
        JFrame innerFrame = new JFrame("Inner frame");
        innerFrame.setBackground(Color.red);
        innerFrame.setSize(200, 200);

        JFrame outerFrame = new JFrame("Outer frame");
        outerFrame.getContentPane().add(innerFrame);
        // note that getContentPane() returns a Container
        outerFrame.setSize(400, 300);
        outerFrame.setVisible(true);
    }
}

[Campbell Ritchie]

So, I went into the API and could find nothing in add() which explained that behaviour. There was a link in add() to something else which does explain that behaviour, but I think the documentation could be improved a bit there.

[Darryl Burke]

I think the documentation could be improved

I agree. I also feel it's counter-intuitive that the last component added goes to the bottom, and not the top, of the stacking order.

[Igor Mechnikov]

Matthew Brown wrote:

Ilya Mechnikov wrote:Have not tried.
Just wanted to verify an answer from a self-quiz.

Well, the easiest, and most reliable, way to verify it is to try it. Try compiling and running the following, see what happens:

import java.awt.Color;
import javax.swing.JFrame;

public class JFrameInAContainerTest {
    public static void main(String[] args) {
        JFrame innerFrame = new JFrame("Inner frame");
        innerFrame.setBackground(Color.red);
        innerFrame.setSize(200, 200);

        JFrame outerFrame = new JFrame("Outer frame");
        outerFrame.getContentPane().add(innerFrame);
        // note that getContentPane() returns a Container
        outerFrame.setSize(400, 300);
        outerFrame.setVisible(true);
    }
}

Thank you much.
I look forward to being able to produce code snippets for testing purposes, until then I must rely on the kindness of strangers.
The code compiled but had runtime errors:
run JFrameInAContainerTest
java.lang.IllegalArgumentException: adding a window to a container
at java.awt.Container.addImpl(Container.java:1061)
at java.awt.Container.add(Container.java:377)
at JFrameInAContainerTest.main(JFrameInAContainerTest.java:11)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at edu.rice.cs.drjava.model.compiler.JavacCompiler.runCommand(JavacCompiler.java:271)

Thank you again!

[budsy remo]

what is the explanation to this?

[Campbell Ritchie]

Have you read my earlier post?