To build a better world sometimes means having to tear the old one down.
-- Alexander Pierce, "Captain America: The Winter Soldier"
ATK served us well for nearly 20 years, but the world has changed, and
GTK has changed with it. Now ATK is mostly a hindrance towards improving
the accessibility stack:
- it maps to a very specific implementation, AT-SPI, which is Linux and
Unix specific
- it requires implementing the same functionality in three different
layers of the stack: AT-SPI, ATK, and GTK
- only GTK uses it; every other Linux and Unix toolkit and application
talks to AT-SPI directly, including assistive technologies
Sadly, we cannot incrementally port GTK to a new accessibility stack;
since ATK insulates us entirely from the underlying implementation, we
cannot replace it piecemeal. Instead, we're going to remove everything
and then incrementally build on a clean slate:
- add an "accessible" interface, implemented by GTK objects directly,
which describe the accessible role and state changes for every UI
element
- add an "assistive technology context" to proxy a native accessibility
API, and assign it to every widget
- implement the AT context depending on the platform
For more information, see: https://gitlab.gnome.org/GNOME/gtk/-/issues/2833
We had a pretty complex setup where we tried to avoid scaling up themes from dirs
that specified a size. However, not only was it very complex, but it didn't quite
work with window scales, because when using e.g. a size 32 directory for 16@2x
the dir size is wrong anyway. Additionally it turns out most code either picks
an existing icon size, or uses the FORCE_SIZE flags, so it doesn't seem
like a useful behaviour.
This change drops the FORCE_SIZE flags, and always scales
icons. Additionally it moves the scaling of the icon to rendering,
which seems more modern, and allows us to (later) share icons loaded
for different sizes that happened to use the same source file (at
different scales).
Note that this changes the behaviour of
gtk_icon_paintable_download_texture() is it now returns the unscaled
source icon. However, ignore thats, as I plan to remove this function
and replace it with a way to render a paintable to a cairo-surface
instead.
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.
... instead of going via surfaces.
A side effect is that the pixbuf property is no longer readable because
we have no good way to get the pixbuf back out of the texture, but I
don't think this matters a lot.
If people want to read the pixbuf property, we need to add some code to
make that work.
Instead of loading them into surfaces (which we want to get rid of), we
load into textures.
In fact, we introduce a new paintable subclass called a GtkScaler that
takes care of tracking scaling.
This also ideally gets rid of an extra conversion once renderers learn
to render textures directly.
Remove all the old 2.x and 3.x version annotations.
GTK+ 4 is a new start, and from the perspective of a
GTK+ 4 developer all these APIs have been around since
the beginning.
Change the name of the property from stock-size to icon-size,
and make it an enum property instead of uint. This makes it
impossible to specify invalid numeric values in ui files, and
at the same time makes it possible to refer to the existing
values by their nick.
Fix up the callers.
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.
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.
Rather than store the pixbufs as themselves we immediately convert
them to surfaces. In the uncommon case that a pixbuf is read back
from the renderer we generate a new one from the surface data.
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+.
Do not call _gtk_icon_helper_clear explicitely when the properties
are set, since the corresponding _gtk_icon_helper_set_* method
already calls clear internally.
While at it rename the reset function to make it clear that it
is calling notify for the previous image type and avoid the
notification if the image type is not changing.
Applications forget to set the follow-state property and then some
themes used a style where normal symbolic icons have the same color as
prelit or selected backgrounds and that suddenly made icons invisible
and who wants that?
https://bugzilla.gnome.org/show_bug.cgi?id=746201
