Drops the in-tree icon theme parser and lookup logic in favor of
libsfdo-icon, which implements the icon theme spec.
Absolute icon paths are handled in swaybar itself with an access()
probe, since libsfdo intentionally doesn't deal with them. Pixmap
fallback still kicks in if load_image() fails on the absolute path.
KDE's IconThemePath is honored via sfdo_icon_theme_load_from() with
a per-SNI override theme that gets dropped when the property changes.
The min/max size cache per SNI is replaced by re-lookup when the
rendered size changes; libsfdo caches the parsed theme internally
and reads gtk's icon-theme.cache files, so this is cheap.
Theme switching at runtime is preserved via a new
tray_reload_icon_theme() called from parse_bar_config(). The old
code worked here implicitly because all themes were preloaded.
Closes: https://github.com/swaywm/sway/issues/8607
This removes any pending messages once the item is destroyed.
Furthermore, this installs SNI event calbacks asynchronously
in order to prevent sd-bus from bypassing pending messages.
In case a tray icon cannot be found or does not have a desirable size,
swaybar retries the search again and again, which increases load on disk
and CPU. This commit solves it by storing target_size for each icon, so
that swaybar does not search for an icon of some size if it already tried to.
Fixes#3789.
