auto completion in a self written gui edit for HTML/CSS/PHP

I'd like to write my own GUI text edit for HTML, CSS and PHP. The whole user interface should be as mouse centered as I can get it. If you type "bo" there should be a list with stuff like "body" and "bold", just like you have in every other IDE. Could you point me to some resources on making a fancy editor window?

My choice of programming language is Python, and I'd like to use GTK for t开发者_运维技巧he GUI I think.

I'd suggest you to check out Scintilla, a GTK+ component for editing source code. You might find interesting ideas in its code, or use it as a core building block for your project.