Completer with existing ui form

I'm studding an demo called "Customer Completer." That example shows how to add a completer to TextEdit Widget added through code not ui form. I have a project where i use an UI widget form that contain QTextEdit item.

How do I implement a text completer similar with "Custom Completer" only where I have existing QTextEdit item on UI widget form?:confused:

The QTextEdit doesn't seem to have a possibility to relate to QCompleter. For QTextEdit you probably have to do completion yourself. Try overloading the QTextEdit class. QCompleter really seems to be for single line texts.