parse file when selected in resource view?

[Rod Price <rprice@xxxxxxxxxxx>]

The Java editor appears to parse Java files on the fly and
display their component parts (classes, methods, etc) when
the file is selected in the resource view.  That is, you can
expand the file by clicking on the "+" next to it and see the
classes, methods, etc.  I'm building an editor for another
type of file which also has an internal structure.  I can
show this structure in the content outliner, but I'm mystified
as to how to show it in the resource view, as the Java editor
does.  How is it done?

Also, parsing my files is somewhat slow.  Is there a way to
parse them only once, when the file is selected in the resource
view, and have the parsed results available to the editor
rather than parsing it again when I open it?

Thanks,

-Rod Price