Name: kaC94536 Date: 01/31/2000



Calling of JInternalFrame.getPreferredSize() method can change preferred size of
JInternalFrame component.

Java 2 Platform SE v1.2.2 specification does not say that simple calling of getPreferredSize()
method can change preferred size of the component.

Frame window of the following test contains tested JInternalFrame component.
If you resize main JFrame window, you'll see that the JInternal frame sometimes grows or shrinks
during main frame resizing.
If you click on the button "Check", the JInternalFrame.getPreferredSize() method is called twice,
and you can see preferred size of the tested JInternalFrame component after each call of this
method in standart output device. In this case, each time you call getPreferredSize(), the
preferred size of the tested frame increases by border insets size + panes size (see
BasicInternalFrameUI.InternalFrameLayout.PreferredLayoutSize() method in
/javax/swing/plaf/basic/BasicInternalFrameUI.java).
 
--------------------test.java---------------------------------------------

import javax.swing.*;
import javax.swing.plaf.basic.*;
import java.awt.*;
import java.awt.event.*;

public class test extends JFrame {
    public test() {
        super("JInternalFrame test");
        getContentPane().add( new TestPanel(), BorderLayout.CENTER );
    }

    public static void main(String[] args) {
        JFrame frame = new test();
        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        frame.pack();
        frame.setSize(new Dimension(500,300));
        frame.setVisible(true);
    }
}

class TestPanel extends JPanel implements ActionListener {
    protected JInternalFrame aFrame;
    public TestPanel() {
        aFrame = new JInternalFrame("Test", true);
        aFrame.getContentPane().add(new JLabel("I'm a JInternalFrame component!"));
        add(aFrame);
        JButton b1 = new JButton("Check");
        b1.setVerticalTextPosition(AbstractButton.CENTER);
        b1.setHorizontalTextPosition(AbstractButton.LEFT);
        b1.setActionCommand("Check");
        b1.addActionListener(this);
        add(b1);
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getActionCommand().equals("Check")) {
            System.out.println();
            System.out.println("Frame preferred size " + aFrame.getPreferredSize());
            System.out.println("Frame preferred size " + aFrame.getPreferredSize());
            System.out.println("Insets " + aFrame.getInsets());
            BasicInternalFrameUI l = (BasicInternalFrameUI) aFrame.getUI();
            if ( l.getNorthPane() != null )
                System.out.println("NorthPane " + l.getNorthPane().getPreferredSize());
            if (l.getSouthPane() != null)
                System.out.println("SouthPane " + l.getSouthPane().getPreferredSize());
            if (l.getEastPane() != null)
                System.out.println("EastPane " + l.getEastPane().getPreferredSize());
            if (l.getWestPane() != null)
                System.out.println("WestPane " + l.getWestPane().getPreferredSize());
        }
    }
}


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