Name: pa48320 Date: 11/29/2001

(this bug is to track the JInitiator Replacement Project. please direct any
questions to ###@###.###. thank you)

There are certain actions which can potentially remove pending
focus transfers from the KeyboardFocusManager?s list. The main
example of that is removing a component from its container. This
is a strange example, since why would one care whether a focus
request was honored on a component we?re about to remove?

Oracle has a requirement to adjust the Z-ordering of components
within a container dynamically (it?s something our tool supports
and of which Oracle Applications has made extensive use).
Unfortunately, the JDK does not provide an API to modify the
order of components within a container, and our Z-ordering
support must be robust enough that we cannot accomplish it
by merely hiding certain components. The only workaround
we?ve found is to remove and re-add a set of components to
the container in question.

In some cases, we will request focus on a component whose
canvas is about to be lowered within the Z-order. The component
itself remains visible and is still a valid focus recipient,
but in order to lower it, its canvas (i.e. its container) must
be removed and re-added to the overall container. As noted above,
this causes the focus request to be ignored, and in this
situation the JDK will be justified in transferring focus to some
arbitrary component since the application has not successfully
managed focus on its own.
(Review ID: 135396)
======================================================================

customer supplies the following test case:

// Testcase 3 (provided for Oracle bug 2112287)
//
// Removing and re-adding lightweight components to the same container
// with a different index is a technique we use to achieve Z-ordering
// support in the JDK.
//
// This SwingFocusTest testcase demonstrates a difference in behavior
// between 1.1.8 and 1.4 in this regard. Namely, requesting focus on
// a component before adjusting its Z-order in this way works properly
// in JDK 1.1.8, but causes focus to be lost in JDK 1.4.
//
// Note that we use an Oracle lightweight component implementation
// called EWT in our code rather than Swing, but for the purposes
// of this testcase Swing demonstrates the same problem. This was
// verified using Swing 1.1.1.
//
public class SwingFocusTestTwo extends JFrame implements ActionListener
{
    JPanel panel = new JPanel();
    MyJButton button1 = new MyJButton("Push!");
    MyJTextField field1 = new MyJTextField(" Field 1");
    MyJTextField field2 = new MyJTextField(" Field 2");

    SwingFocusTestTwo()
    {
        Container contentPane = getContentPane();
        contentPane.add(panel);
        addWindowListener( new WindowAdapter()
        { public void windowClosing(WindowEvent e)
            {
                System.exit(0);
            }
        }
        );
        button1.addActionListener(this);
        panel.add(button1);
        panel.add(field1);
        panel.add(field2);
        pack();
    }

    public void actionPerformed(ActionEvent event)
    {
        if ( event.getSource() == button1 )
        {
            // We've requested focus on field2, possibly
            // much earlier in our code.

             field2.requestFocus();
            //
            // Then we need to raise field2 (or the canvas
            // containing it) to the top of the Z-order,
            // which entails removing and re-adding it to
            // its container.

            panel.remove(field2);
            panel.add(field2, 1);
            pack();
        }
    }

    static public void main(String[] args) {
        (new SwingFocusTestTwo()).setVisible(true);
    }
}

class MyJTextField extends JTextField implements FocusListener
{

    MyJTextField(String s)
    {
        super(s);
        addFocusListener(this);
    }

    public void requestFocus()
    {
        System.out.println("[MyJTextField] requestFocus() from "+
this.getText());
        super.requestFocus();
    }

    public void focusGained(FocusEvent e)
    {
        System.out.println("[MyJTextField] focusGained on " +

((MyJTextField)(e.getComponent())).getText());
    }

    public void focusLost(FocusEvent e)
    {
        System.out.println("[MyJTextField] focusLost on " +

((MyJTextField)(e.getComponent())).getText());
    }
}

class MyJButton extends JButton implements FocusListener
{

    MyJButton(String s)
    {
        super(s);
        addFocusListener(this);
    }

    public void requestFocus()
    {
        System.out.println("[MyJButton] requestFocus() from "+
this.getText());
        super.requestFocus();
    }

    public void focusGained(FocusEvent e)
    {
        System.out.println("[MyJButton] focusGained on " +
                            ((MyJButton)(e.getComponent())).getText());
    }

    public void focusLost(FocusEvent e)
    {
        System.out.println("[MyJButton] focusLost on " +
                            ((MyJButton)(e.getComponent())).getText());
    }
}