At the end of GtkImage css validation (during style-updated) when the
css properties (like the icon size) are valid we call _gtk_icon_helper_preload
which does an async icon theme lookup and load. This will happen on a thread
in parallel with the rest of the css machinery, and hopefully by the
time we need the icon it will be ready. If not we will block when we need
it, but during that blocking all the other icons will be loaded.
Testing widget-factory this changes the time of snapshot() from 31 to
25 msec, but on the other hand we also load a few more icons that we
didn't before causing the css validation phase to be about 8 msec slower.
This is because we're preloading all the images in the window, not only
the ones that are visible.
Unfortunately we still load a bunch of icons in snapshot(), from
GtkCssImageIconTheme, and ideally we should try to preload those also.
That's kinda weird but allows us to delete the texture case from
GtkIconHelper and GTK_IMAGE_TEXTURE from the GtkImageType enum.
And it doesn't cause any other problems because the cell renderer
can't deal with paintables - otherwise it would mirror GtkImage and have
a "paintable" property instead.
This only implements the vfuncs, but does not actually emit signals
yet.
It's also not useed for anything other than snapshot() so far, this
will come in later commits.
This is in preparation for accepting the image type paintable.
It's a bit incovenient because we need more code to track width/height
ourselves (as the paintable no longer does it for us), but it's not too
hard.
GtkIconHelper does not track invalidations on the paintable.
Instead of looking at the icon size, look at the CSS value for
-gtk-icon-size. Set style classes depending on icon size instead.
Trivially change Adwaita and HighContrast to report the same values as
before.
Instead, add a function gtk_image_set_icon_size() for the cases where
overriding the icon size is necessary.
Treat icon sizes the same way as pixel sizes, too. So gtk_image_clear()
no longer unsets the icon size.
These are no longer used, instead we always covert to surface as
early as possible and drop the pixbuf.
This means we never store both the pixbuf and the surface at
for any longer time, which is wasteful. Also, its one step further
to drop GdkPixbufs from generic use in our APIs.
It's not a GtkCssGadget anymore, it doesn't have any properties or
signals either and it's not public. Further, its lifetime is very clear
the way it's being used inside GTK+.
Gadgets don't connect to style-changed for widget nodes, and
GtkImage uses its widget node for the icon helper. The visible
effect of this is that symbolic icons don't change color when
switching to the dark variant of Adwaita.
Fix this by manually invalidating the icon helper.
Make gtk_icon_helper_ensure_surface() a private function that just
ensures the surface was loaded.
Add gtk_icon_helper_load_surface() that is called by the above function
and the dnd code to actually load the surface.
We render the source into a cairo_surface_t so that we can render it
with cairo directly, rather than having to convert it from a pixbuf
every time. We also specify the target window when creating the cairo
surface so that rendering can be faster.
Using cairo surfaces also allows us to seamlessly support window scales.
We also add a GTK_IMAGE_SURFACE source type.
