Option to disable text completion for text files

A user asked for text completion based on strings in the current file; similar to the vim plugin YouCompleteMe.  To your credit, in a timely manner, you implemented the suggestion here: Generic text completion based on strings found in current file. Notice that the original poster also wrote " Of course it should be possible to disable the generic completion engine in the settings." This is indeed not the case.

I find that this generic text completion is very annoying. Were I implementing the suggestion, hitting <Enter> would never accept the suggestion, and having a suggestion up would never prevent <Backspace> from deleting characters.  Every time I end a line, and a suggestion is a longer string than the word I ended the line on, <Enter> accepts the unwanted suggestion; and I have to delete extra characters frequently at the end of a line.  Having a suggestion interfere with <Backspace> just further gets in my way.  Also, having it flashing suggestions while I'm typing text is just plain annoying.

I very much enjoy having a text file in my project that I can just use to take notes as I code.  This has completely ruined it for me, to the extent that I defined an external tool to edit the current file in an external text editor, and a keyboard shortcut <Ctrl-E> to open the current file in an external editor.  Thus, my workflow is to open up a text file I have created in the project in Qt Creator in order to sort out any really thorny issues,   Then, I click on the text document, and hit <Ctrl-E> to open it in the external editor.  Then, as I work, I have to keep clicking on the entries on the Taskbar to keep switching between the two.

Thus, I suggest you complete implementing the above-cited, original suggestion, by making a way to disable generic text completion, entirely.  I am quite happy with code completion while coding C++ in Qt; and I want to leave it on.  I just don't find that I am repeating words often enough in text documents to make it worthwhile to keep having suggestions flash up.  It isn't so bad, when a word processor such as OpenOffice Write does it, because it doesn't get in the way, there.  It never accepts a suggestion with just an <Enter>, never interferes with <Backspace>, and has a whole US-English dictionary from which to make suggestions from.  I put up with all the suggestions flashing by there, because they are occasionally helpful.

To sum things up, I would hope to be able to disable generic text completion.  I also think it would be a good idea for a user to select the accept completion key, such as, e.g. <Alt-Tab>.  Finally, an active completion should never prevent a <Backspace> from deleting a character.