At the moment we have changed,user which lets you filter the text, and is also what's used for undo/redo and other things.
There's a problem with having it in just one call. The problem is that if you want to be able to filter input, you want to be able to filter it *before* it gets inserted to the textblock, but if you want the signal about what's actually changed, you want it *after* it's been inserted to the textblock so functions like efl_text_get() will work.
The solution is therefore to split to two events:
changed,user,pre - called before textblock has actually been touched.
changed,user - will be called after the textblock has been modified.