Name: pa48320 Date: 02/14/2002


A customer has reported that applet focus can be lost when running inside the Internet Explorer browser frame, backgrounding the application then bringing it to the foreground again. This can be done by either alt-tabbing IE, or clicking on the title bar of another application and back on IE again.

When IE returns to the foreground, any focus the applet previously held is lost. Note that this does not happen running the applet in a separate frame, nor does it happen in Netscape running either in the browser frame or in a separate frame.

The test case is trivial. It will reproduce with any simple applet, such as...

import java.applet.Applet;
import java.awt.TextField;

public class Foo extends Applet
{

  public void init()
  {
    TextField field = new TextField(10);
    add(field);
  }

}

Run this applet with the Java plugin inside the browser frame, click the text field to give it focus, alt-tab IE into the background, then back into the foreground again, and focus will be lost.

I have discussed this with an ActiveX engineer at Microsoft, and with Stanley Ho at Sun, and am filing this as a Sun bug at the request of a customer. Microsoft says the problem is due to the plugin (an ActiveX control) not handling itself properly. The suggestion is that due to improper handling or registration, the plugin has failed to notify its container (IE) that the control is to be notified during a state change.

Ultimately, I may need to arrange a conference call between the Microsoft engineer and Stanely, but still needed to file the bug.
(Review ID: 139646)
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