[Qt-creator] Color schema settings for third party plugins

[Hugo Parente Lima]

Hi list,

My plugin does highlithing with hardcoded colors and now I finally 
decided to spend some time making this configurable, however this 
configuration on QtCreator itself is not so flexible, color schemas for 
QML, diff, C++, etc... are all inside the TextEditor settings,so if a 
new plugin decides to add some highlighting options it need to change 
the TextEditor plugin, a impossible thing for third party plugins.

So my suggestion is about the UI itself and being a nice guy with third 
party plugins:

- Move the color schema configuration to their own language settings 
pane, i.e. instead of having a general color schema settings on 
TextEditor settings, the color schema for C++ would be moved to the C++ 
settings, the same for QML, Diff (may fit better in version control 
settings), etc...
- Make the ColorSchemeEdit widget available to external plugins like 
mine :-)

Font family, size and zoom level would still in Text Editor, since I 
see no sense in have different fonts for different languages, so this 
suggestion is just for the color schema settings.

As this is not available in QtC (yet?) I'm implementing it on my plugin 
using the force brute way... that's doing the color schema widget 
myself, a sad task since this is already done and working in QtC.

Depending on the acceptance for this suggestion I can try to write a 
patch, however my time is a bit limited so it will be done depending on 
my free time, mood to code after spend the entire day coding at work, 
etc...

--
Hugo