I want to make my own source code editor, what are the good choices to make?

I've had it of those dozens of editors which never provides simple things like:

distinguish type keywords and instruction keywords so I can put different colors on them.
being cross platform using a standard GUI lib like qt gtk etc (notepad++, yes, I almost hate you).
enough keyboard shortcut like duplicate line, comment selection, and a decent find-replace.
Decent task-easing features like single-click-on-the-number-line-margin to select the entire line.
Scintilla or another good-enough lexer that highlights enough different things, because brain-compiling code is one thing, quickly identify with the eyes what is what is something I find important.

I just want to support very basic languages like C, C++, maybe Python, not HTML or CSS.

Is Scintilla a good choice to just highlight those languages, and is a lexer really necessary ?

Isn't QT enough to program a text editor such as the one I want to do ? I know there is QScintilla, but is there a reason I shouldn't use a lib that integrates a lexer ? Why is Scintilla such a good lib ?

Is QT a good choice for such an editor ? (I also want to hard embed ProFont in the editor to kill any reluctant font problem between OSes).

EDIT: In short, I want to make an editor, only with the same syntax highlight features of notepad++. That's my main goal, and the use of QScintilla might be a little harder than I thought...

EDIT2: Well I found textadept, it's not so known but is quite awesome. I didn't manage to make my lexer, since I have other to do which I do under windows, unfortunately it's slow on the mac. Apparently there isn't any Scite official build for the mac.

Solution

Like everyone else is saying, it's probably more trouble than it's worth, but if you really want to do it, Qt's a good choice since it's cross platform. Use QSyntaxHighlighter to do your keyword/type highlighting, and take full advantage Qt's support for keyboard shortcuts.