从python Gtk3获取gtk主题css属性

Question

I am having trouble in getting certain properties from the system Gtk3 theme css (gtk.css) to render contextual components in my python Gtk3 application.

What I have from my system theme gtk.css are the following:

entry {
  ...
  color: #5c616c;
  border-color: #cfd6e6;
  background-color: #ffffff; }
  entry:focus {
    background-clip: border-box;
    color: #5c616c;
    border-color: #5294e2;
    background-color: #ffffff; }
  entry:disabled {
    color: rgba(92, 97, 108, 0.55);
    border-color: rgba(207, 214, 230, 0.55);
    background-color: rgba(255, 255, 255, 0.55); }
  entry.warning {
    color: white;
    border-color: #F27835;
    background-color: #f7ae86; }
    entry.warning image {
      color: white; }
...

What I would like to get from it are those contextual colors, eg background-color from entry.warning , etc.

I have done some research and here is where I get stuck:

css_provider = Gtk.CssProvider.get_default()
warning_color = css_provider.get_style(something to put here)

Many thanks for your help!

Answer 1

The correct way would be to modify a Gtk.Widget 's Gtk.StyleContext so that the CSS rule applies to it, then use the Gtk.render_whatever() functions to draw your contextual components.

For example to render a background with the same style as the warning background on a Gtk.Entry subclass:

context = my_entry.get_style_context()
context.save()
context.add_class('warning')
Gtk.render_background(context, blah, blah, blah)
context.restore()

Note that it's not possible to get the background color directly from CSS. A CSS background may be a color, or an image, or a gradient.