gtk2/gtk/theme/Default
Georges Basile Stavracas Neto 8cf9810240 pathbar: Reimplement using GtkBox
The path bar does a lot of manual management of buttons, mostly to
be able to show navigation arrows when there's not enough space to
show the full path.

Since the GTK4 migration, this is slightly broken in some cases, due
to the 'need_sliders' variable being always set to TRUE. Furthermore,
after the introduction of the Recent button as a special cased fake
root, the allocation of the buttons is generating warnings.

Reimplement the path bar as a GtkBox, inside a GtkScrolledWindow.
This mimics what Nautilus does, and allows us to make navigation more
predictable, and remove most of the complexity from GtkPathBar. It
also prevents it from generating allocation warnings.

The path bar itself now doesn't override GtkWidget.measure nor
GtkWidget.allocate; instead, it delegates layout to the GtkBinLayout
layout manager.

CSS is adjusted to account for the changed hierarchy of buttons.
2022-12-13 14:45:15 -03:00
..
assets
assets-hc
_colors-public.scss
_colors.scss
_common.scss pathbar: Reimplement using GtkBox 2022-12-13 14:45:15 -03:00
_drawing.scss
assets-hc.svg
assets.svg
assets.txt
Default-dark.scss
Default-hc-dark.scss
Default-hc.scss
Default-light.scss
gtk-dark.css
gtk-hc-dark.css
gtk-hc.css
gtk-light.css
gtk.css
meson.build
README
render-assets.sh

Summary
-------

* To be able to use the latest/adequate version of sass, install sassc
* meson will regenerate the CSS every time you modify the SCSS files.
* Note that meson always builds out-of-tree, so the modified css files will
  appear in your builddir.

Theme variants
--------------

The Default theme comes in 4 variants: light, dark, hc (highcontrast) and
hc-dark (highcontrast inverse). The generated CSS files for the variants
are called Default-$variant.css. For technical reasons, GTK adds one level
of include wrappers around these, which are called gtk-$variant.css.

How to tweak the theme
----------------------

Default is a complex theme, so to keep it maintainable it's written and
processed in SASS. The generated CSS is then transformed into a gresource file
during gtk build and used at runtime in a non-legible or editable form.

It is very likely your change will happen in the _common.scss file. That's where
all the widget selectors are defined. Here's a rundown of the "supporting"
stylesheets, that are unlikely to be the right place for a drive by stylesheet
fix:

_colors.scss        - global color definitions. We keep the number of defined
                      colors to a necessary minimum, most colors are derived
                      from a handful of basics. It covers both the light variant
                      and the dark variant.

_colors-public.scss - SCSS colors exported through gtk to allow for 3rd party
                      apps color mixing.

_drawing.scss       - drawing helper mixings/functions to allow easier
                      definition of widget drawing under specific context. This
                      is why Default isn't 15000 LOC.

_common.scss        - actual definitions of style for each widget. This is
                      where you are likely to add/remove your changes.

You can read about SASS at http://sass-lang.com/documentation/. Once you make
your changes to the _common.scss file, GTK will rebuild the CSS files.