If you have taken the time to read:
you know that XMLmind XML Editor (XXE for short) can be customized/extended substantially without having to write a single line of code. However there are some cases where programming against the Java™ API of XXE becomes inevitable.
This guide is divided into five parts:
Custom commands are, by far, the most commonly used kind of extension .
What to do when XXE CSS support is not powerful enough to style some XML elements exactly like you want?
Support for remote document storage, image file formats, XSL-FO processors, spell checking engines, etc, are all implemented as plug-ins. Why not implement your own?
AppParts —application parts— are high-level building blocks used to create and extend the XMLmind XML Editor desktop application.
This guide ends with an appendix explaining how to package one or more extensions (of any kind) as an add-on for use by XXE integrated add-on manager.