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
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
Split the focus tracking into a separate
GtkEventControllerFocus, and change the API one more time.
We are back to having ::focus-in and ::focus-out signals.
Update all users.
Instead of relying on gdk's antiquated crossing events,
create a new GtkCrossingData struct that contains the
actual widgets, and a new event controller vfunc that
expects this struct. This also saves us from making sense
of X's crossing modes and details, and makes for a
generally simpler api.
The ::focus-in and ::focus-out signals of GtkEventControllerKey
have been replaced by a single ::focus-change signal that
takes GtkCrossingData as an argument. All callers have
been updated.
Change the reorder api to insert after a sibling,
so that moving to first place becomes reorder (... NULL).
And add a insert_after api that can replace the common
container_add / reorder_after (... NULL) combination.
Update all callers.
The previous type was a pointer to a pointer, which seems to be a copy-paste
error from GtkBuildable.custom_tag_start which is an out parameter. It was
always cast in use so this is an API break, but not an ABI one.
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.
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.
Nulling priv->button in _unset_tree_view() is asymmetrical: we create
it via init(), not _set_tree_view(), so we shouldn’t null in the latter.
Worse, doing so manifests in criticals + a SEGV easily with basic use of
testtreecolumns, removing the TVC from a TV then trying to add it to one
Finally, the wrong null-out meant dispose() failed to unref the button,
so it leaked.
https://bugzilla.gnome.org/show_bug.cgi?id=728452https://bugzilla.gnome.org/show_bug.cgi?id=788614
This patch makes that work using 1 of 2 options:
1. Add all missing enums to the switch statement
or
2. Cast the switch argument to a uint to avoid having to do that (mostly
for GdkEventType).
I even found a bug while doing that: clearing a GtkImage with a surface
did not notify thae surface property.
The reason for enabling this flag even though it is tedious at times is
that it is very useful when adding values to an enum, because it makes
GTK immediately warn about all the switch statements where this enum is
relevant.
And I expect changes to enums to be frequent during the GTK4 development
cycle.
If the column is not clickable, it may make some sense to stop
event propagation here for button events. However motion events
should be left alone.
Fixes treeview column resize pointer cursors, since that's
implemented up the bubbling phase in the treeview.
Those should be interpreted by widget-local gestures, not guessed at a
high level with no notions of the specific context. Users will want
GtkGestureMultiPress to replace these events.
Since setting a clip is mandatory for almost all widgets, we can as well
change the size-allocate signature to include a out_clip parameter, just
like GtkCssGadget did. And since we now always propagate baselines, we
might as well pass that one on to size-allocate.
This way we can also make sure to transform the clip returned from
size-allocate to parent-coordinates, i.e. the same coordinate space
priv->allocation is in.
