Name: dbT83986 Date: 12/30/98


/*

Window.toFront() unreliable on Win32

I am using JDK1.2 Beta4, but I was able to try this on
JDK 1.2 FCS level M and got essentially the same results.

The problem is that Window.toFront() doesn't work under
most circumstances. The following sample app demonstrates
the problem in several flavors.

When you compile and run the app it will bring up a single
simple window titled "Window 1". Every 5 seconds it will
cause toFront() to be called on the Window. If you click
on some other app (so that the Java program drops behind
the other windows on the desktop) you will note that
Window 1 *does* come to the top as expected.

But now click on the titlebar of Window 1, which activates
it and brings it to the top. Then click on a non-Java app
again, and you will notice that toFront no longer works.
Once you have explicitly activated the Window it seems as
though toFront becomes a no-op from then on.

There is a second flavor of the same problem, almost
certainly related. First uncomment the block of code
indicated in the constructor method and recompile. Now
the app will start up creating *two* windows instead of
one. In this scenario toFront() *never* works at all.

These problems may be related to Win32's notion of
"foreground thread"; I suspect that if there was an API
to activate a Window and make the AWT event queue thread
the "foreground thread" then whatever toFront() is doing
might start to work.

We are trying to build a complex Java IDE that interacts
with some non-Java components; we often need to force one
of the Java Windows to the top so it will not be obscured
by the non-Java windows. As long as toFront() is broken
it makes the IDE very frustrating to use, since the Java
Window you want to work on is never on top when you need it.

*/

import java.awt.*;
import java.awt.event.*;
import com.sun.java.swing.*;

public class ToFrontTest implements Runnable, ActionListener
{
public static void main(String args[])
{
new ToFrontTest();
}

public JFrame jf1;
public JFrame jf2;
public JButton jb1;
public JButton jb2;

public ToFrontTest()
{
jf1 = new JFrame("Window 1");
jb1 = new JButton("Quit");

jf1.setSize(300,100);
jf1.getContentPane().setLayout(new FlowLayout());
jf1.getContentPane().add(jb1);

jf1.show();

jb1.addActionListener(this);

/***************** Uncomment this block to add a second window
jf2 = new JFrame("Window 2");
jb2 = new JButton("Do Nothing");

jf2.setLocation(300,0);
jf2.setSize(300,100);
jf2.getContentPane().setLayout(new FlowLayout());
jf2.getContentPane().add(jb2);

jf2.show();
/******************/

while (true)
{
for (int i=5; i>0; i--)
{
System.out.println(i + "...");

try
{
Thread.currentThread().sleep(1000);
}
catch (Exception ex)
{
}
}

//
// Just in case, cause "toFront" to be run
// on the AWT Event Thread. (It actually
// seems to make no difference where the
// "toFront" is done, it behaves the same.)
//
SwingUtilities.invokeLater(this);
}
}

public void actionPerformed(ActionEvent e)
{
System.exit(0);
}

public void run()
{
System.out.println("Bring 'Window 1' toFront");
jf1.toFront();
}
}
(Review ID: 40483)
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Name: vi73552 Date: 06/14/99


The method toFront() does not work since JDK1.2beta?
It does not work in 1.2, 1.2.1, 1.2.2.
I am currently not able to deploy my messaging application since it's not possible to open windows or frames that show above ALL other windows.
(Review ID: 84311)
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<<< Addtional information >>>

 I tried the above sample code with a little modification and found
 out that it still happned.

 1. reproducing
  1) Modify the above source code and compile by JDK1.3.0fcs

*** ToFrontTest.java Mon Oct 1 11:15:22 2001
--- ToFrontTest.java-rev Mon Oct 1 11:16:33 2001
***************
*** 1,6 ****
  import java.awt.*;
  import java.awt.event.*;
! import com.sun.java.swing.*;
  
  public class ToFrontTest implements Runnable, ActionListener
  {
--- 1,6 ----
  import java.awt.*;
  import java.awt.event.*;
! import javax.swing.*;
  
  public class ToFrontTest implements Runnable, ActionListener
  {

 2) Invoke "java ToFronTest"
   -> Here, you will see the behavior as the above-mentioned.


 2. Configration
   
    MPU: Pentium II 400[MHz]
    Memory: 256[MB]
    OS: windows98(Second Edition, Japanes)

    MPU: Celeron 300[MHz]
    Memory: 128[MB]
    OS: windows2000(SP2, Japanese)

    JDK: JDK1.3.0fcs, JDK1.3.1_01 and Merlin-beta3-b80

 3. Note
 
    This does not happen on Windows NT(sp5, Japanese).
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