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 should not rely on GtkWindow to have global
"activate-default" key bindings that happen to
fall back to activating the focus widget. This is
unreliable, since the bubbling up from the button
to the toplevel may run across other widgets that
may want to use Enter for their own purpose, and
then the button loses out. By adding our own
key bindings, the button gets to handle it before
its ancestors.
This fixes check buttons in the inspector property
list not reacting to Enter despite having focus.
If we leave the valign to be the default fill, then
the images pick up baseline alignment from the environment,
which can occasionally lead to misplaced -/+ icons in
spinbuttons, for example in the "Page Setup" tab of
the print dialog.
Add back a property that determines whether an individual
widget will accept focus or not. :can-focus prevents the
focus from ever entering the entire widget hierarchy
below a widget, and :focusable just determines if grabbing
the focus to the widget itself will succeed.
See #2686
We want to remove GtkBin and GtkContainer as they don't
provide much useful functionality anymore. This requires
us to move get_request_mode and compute_expand down.
We have to implement GtkBuildable, in order to keep
the <child> element in ui files working for buttons.
See #2681
This was only living in gtkcontainer.c for historic
reasons. Move it closer to where it belongs, and
rename it from 'idle' to 'layout', since it is
really about the layout phase of the frame clock,
nowadays.
After the :can-focus change in the previous commit, widgets
need to set suitable focus and grab_focus implementations
to implement the desired focus behavior.
This commit does that for all widgets.
Make widgets can-focus by default, and change the semantics
of can-focus to be recursive . If it is set to FALSE, focus
can not enter the widget or its descendents at all anymore.
This commit temporarily breaks focus behavior of widgets
that did not expect to receive focus.
We no longer translate event coordinates in-place,
so gdk_event_get_position() returns surface-relative
coordinates, not widget-relative ones. Just use the
coordinates we are given.
Restructure the getters for event fields to
be more targeted at particular event types.
Update all callers, and replace all direct
event struct access with getters.
As a side-effect, this drops some unused getters.
The only glancing mention of this we had was that GtkButton mentioned it
in passing when discussing how `button` could get contextual classes,
and even that's not relevant in master anymore... so drop it from there.
This is not an api we want to propagate anymore.
If you need to, you can still emit the "clicked"
action signal on a button using g_signal_emit_by_name.
This isn't really necessary, if keyboard focus forcibly goes somewhere
else we will get ::grab-notify, which is sufficient to deactivate the
button again.
