- ChatZilla uses XUL overlays to include the tasks menu, and to add itself
as a menu item in the tasks menu.
- XUL Overlays are fragments of XUL stored in a separate file.
- Overlays get superimposed on another XUL file when it is loaded.
- Overlays can be included via two methods...
- Manual inclusion from main XUL file, using
<?xul-overlay href="..."?> processing instruction, commonly used to include
global menus or toolbars.
- "Automatic" inclusion via the Chrome Registry, commonly used
to append optional menu items to known menus.
- If an ID in the overlay file matches an ID in the content model,
the overlay's children are appended to the content.