Microsoft SDK for Java

Q214780 BUG: Scrolling Over Applet in IE Causes Improper Painting

The information in this article applies to:

SYMPTOMS

When you scroll up and down over a Java applet in a Web page, the components in the applet or the applet itself are repainted incorrectly and appear jumbled or corrupted.

CAUSE

The cause of this problem is not yet known. However, the behavior seems to be much more pronounced when the Use smooth scrolling check box is selected in Microsoft® Internet Explorer. To see the Use smooth scrolling check box in Internet Explorer, go to the View menu, click Internet Options, and click the Advanced tab.

RESOLUTION

Clear the Use smooth scrolling check box in Internet Explorer to eliminate, or significantly reduce, the occurrence of this problem.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

MORE INFORMATION

Steps to Reproduce Behavior

Compile and run the following code:

JAVA SOURCE:

   import java.awt.*;
   import java.applet.*;
   public class PaintApplet extends Applet
   {
     TestPanel tp;
     public void init()
     {
        setForeground(Color.cyan);
        setBackground(Color.blue.darker());
        setLayout(new BorderLayout());
        tp = new TestPanel();
        add(tp, "Center");
     }
   }
   class TestPanel extends Panel
   {
     public void paint(Graphics g)
     {
        Dimension d = getSize();
        int x = d.width/5;
        int y = d.height;
        for (int i = 0; i < x; i++)
        {
          g.drawLine(i*8, 0, 0, y);
        }
     }
   }

HTML SOURCE:

<HTML>
   <HEAD>
   <TITLE>Painting Problem Page</TITLE>
   </HEAD>
   <BODY>
     <applet
        code=PaintApplet.class
        name=PaintApplet
        width=220
        height=600 VIEWASTEXT>
     </applet>
   </BODY>
   </HTML>

RESULT: Scroll up and down over the applet using the Page Up and Page Down keys with the Use smooth scrolling check box selected in Internet Explorer. Notice how the lines drawn on the embedded panel become corrupted. This may take several tries because this problem occurs randomly.

REFERENCES

For the latest Knowledge Base articles and other support information on Microsoft® Visual J++® and the SDK for Java, please see the following pages on the Microsoft Technical Support site:

http://support.microsoft.com/support/visualj/ This link takes you to a site on microsoft.com

http://support.microsoft.com/support/java/ This link takes you to a site on microsoft.com

Additional query words:

AWTPkg

© 1999 Microsoft Corporation. All rights reserved. Terms of use.