Use QIcon.fromTheme() for icons

like discussed in #950, #2210 advances the icons.

so let’s do it right and use QIcon.fromTheme. we’ll have to simply

1. put the icons into a freedesktop icon theme spec compatible directory (e.g. like here), and bundle this directory as QResources in ':/icons'.

2. anywhere we want to use an icon, we just need to do

   QIcon.fromTheme('document-new')
   

3. if we carefully choose the icon names to be compatible with linux standard names (e.g. aforementioned document-new), it’ll automatically use system icons on linux

this is the best of all worlds:

1. simple to implement
2. cross platform
3. native appearance
4. allows us to let users choose their own icon themes on all platforms (see comment below)!

[blooalien]

Right on. I’ll leave it installed for easy updates until I can see the icons on the toolbar. Greatly looking forward to using Spyder again. Other than this one appearance issue (which honestly made no sense to me that it was even a problem), it’s by far one of the better Python IDEs in existence.

[flying-sheep]

good points, but i disagree about performance:

Qt renders the SVG icons once for every used size, and caches them. that hardly makes any impact.

also the restrictiveness with one color isn’t a good thing. when you look at the (sparingly used) color in the breeze icon set, you’ll see that it draws attention to the right things and is an improvement in terms of usability (especially for users over the age of 25) and distinction.

i’d rather have all people use it efficiently after 25ms more loading time than older users having to frustratingly search icons all the time.

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could you please point me to the bug report about Qt4 having problems with SVG? and how that relates to different platforms?