Swing
-
Deprecated support for Applet/JApplet
The Applet API has been deprecated for removal with Java 9 and formally been removed with Java 26. Support for those containers will be removed after the 2027-12 release.
When opening a JApplet with the editor, the root element will be annotated with <Deprecated>

When trying to create a new JApplet with the editor, the entry in the "New" wizard and the dialog tile will be annotated with (Deprecated)

-
New error code 1003 if multiple layouts are added to a container
This aligns the behavior of the Swing designer with the behavior of the SWT designer. Adding multiple layouts to a composite is generally not supported and causes issues when working with e.g. the GridLayout.
The parser now detects such cases and throws an appropriate error message.

What’s new - v1.21.0