For some reason beyond my knowledge, my applet is displaying these little warning signs every time I interact with one of its controls.
This does not happen when I use Applet Viewer, so I assume that this is happening since it's not signed.
What is the reason and purpose for this annoying behavior, if this problem is exclusive to unsigned applets?
Also, is it possible to remove these signs?
It's a Java "feature" for letting users know that it is a Java Applet window.
http://www.oracle.com/technetwork/articles/javase/appletwarning-135102.html#6u12
The link also shows how to change the positioning of the warning sign.
Even my signed applets show this warning sign.
I found that my signed applet warning sign disappears if you set the applet to use all-permissions (instead of sandbox).
But that's not exactly recommended.
To change the applet to use all-permissions, edit the jar's MANIFEST.MF to have the line
Permissions: all-permissions
instead of sandbox.