[Lazarus] Getting notified when active editor changes

[Michael Van Canneyt]

Hi,

I'm trying to improve the "file browser" plugin.

I would like to keep it in sync with the currently active editor:
In the file/directory tree, always select the directory/file of the currently
active editor. (if it is in the tree, of course)

For this to work I need to be notified when the uses starts editing another
file - i.e. changes to another source editor.

I have found in LazaIDEintf lots of event handlers, but it seems there is
no event for when the user switches source editors.

I could work with a timer and examine the currently active editor, 
but that seems a bit hackish.

Did I miss such an event handler ? 
If no such event exists, could it be added ?

Michael.