Systemcolors in SVGs

[Manuel Mommertz]

Hello,

since 4.6 plasma allows prepered svgs to use system colors. For this to work 
the svg needs to have a css-style with the id 'current-color-scheme' which 
gets replaced by a style containing classes with the actual system colors on 
load.
For someone with knowlage of xml/svg code it should be trivial to apply this 
after the graphic itself was finished. But I think most people creating 
graphics don't want to dive in the source code. For this purpose I am working 
on a little tool to help them.

Take a look at http://kame2.de/KDE/svgmod/
To get a colorscheme aware svg there are four steps needed:
* Define which system colors you want to use.
* Create the svg like you are used to but use one defined color at places 
where on system color should take effect.
* Add the corresponding classes to your svg with svgmod -a
* Transform elements using a defined color to the corresponding system color 
with svgmod -c

A little example:
Say that we want to use window background and window text colors.
Now we create our svg and use color #123456 for text and #abcdef for the 
background. We don't use this colors in any other place. (For now, you need to 
apply this colors to the elements directly, so don't put them in gradients. 
Also don't try to use different system colors for fill and stroke of the same 
element. This limitations should go away in future versions of svgmod.)
After that we need to add the classes ColorScheme-Background and ColorScheme-
Text to the svg in a style with id current-color-scheme:

svgmod -a current-color-scheme ColorScheme-Background '#e0e0e0' \
       -a current-color-scheme ColorScheme-Text '#000000' \
       graphic.svg

The colors #e0e0e0 and #000000 are the colors you see if the svg is not 
processed by plasma. This happens for versions before 4.6 and if you look at 
the graphics with a svg viewer or editor. You are free to choose which ever 
colors you like for that.
In the last step we need to finaly replace the colors #123456 and #abcdef with 
our classes. This is as simple as:

svgmod -c '#123456' ColorScheme-Text \
       -c '#abcdef' ColorScheme-Background \
       graphic.svg

Some things to keep in mind:
Put the colors in quotation marks to prevent the shell from interpreting 
charakters like # and ().
The commands modify the graphic itself. So if you need the original file, make 
a copy before using svgmod or use the -b switch to create a backup. But be 
aware of the fact that -b overwrites a existing backup.

Hope you like this little tool. Please provide feedback to help me making it 
better.

Thanks for reading
Manuel Mommertz