Bug 470679

Currently the syntax highlighting framework depends on QtGui for its color representation. For Applications linking to QtGui anyway this is of course convenient. But it would be great to have an option to build a variant of the library without QtGui dependencies.

I'm working on a text editor[1] for use in terminals using a toolkit based on QtCore and would like to add syntax highlighting. But pulling in all of QtGui and its dependencies is a problem for usage e.g. on slim server installations or containers.

I've been testing a few things and it seems the amount of features in QColor that are used in the core classes of the syntax highlighting framework is not very big and would be fairly easy to reimplement in a source compatible manner. Of course features like QSyntaxHighlighter and QML support would be disabled in such a build mode.

Of course i assume we would want to keep source and abi compatibility for all the software already using the framework. So i expect that a mode of building the framework without QtGui usage would produce a library with a name suffix (like NoQtGui or Core, or [bikeshed]).
Allowing both to compile from a single source can be done using type aliases and switching most of the framework to use these and have some #ifdef logic to default those aliases to QColor and QRGB. (Or maybe there is an even better way?)

What do the maintainers think? Can this be done upstream? What would be your favored implementation strategy?
If there is a way forward i'm happy to contribute to make this work.

(I'm aware that there currently is a mode to build without QtGui, but that current mode excludes building the library completely and only builds code needed as native executable while cross compiling)


[1] https://github.com/istoph/editor