This changes allocation of the widget trees to happen as a side effect
to the GdkSurface::layout signal, which first passes the GtkNative
instance where it is then forwarded to the implementations of the
GtkNative interface.
The implementations of GtkNative are the ones doing the actual
gtk_widget_allocate(), and they do so in their GtkNativeClass::layout
function.
Don't have GtkRoot listen directly to the layout signal on the frame
clock, but let it pass through GdkSurface. This will allow GdkSurface to
be more involved in the layout phase.
We need to tell people what signal will be emitted when calling
gtk_widget_activate(), and that the shortcuts API might be more
appropriate to what they are looking for.
Setting a field on a class structure is not always an easy task from
languages other than C. While bindings can provide access to the class
pointer, twiddling the fields in the class structure can be awkward.
Additionally, signal ids are not always readily available.
We can paper over the direct access to the class structure, as well as
the "signal name to id" mapping with a simple couple of setter
functions.
We may have the situation of multiple touchpoints in the same
widget, or combinations with other devices. Stack those ::active
states are preserved on widgets on all but the last pointer/touch
going away.
Now that GtkATContext is explicitly realized and unrealized, we should
always create an instance at widget initialization time, and drop it
during the widget finalization. This should make it easier to set up the
initial accessible state of a widget during the instance initialization,
as well as reduce the chances of accidental creation of GtkATContext
instances during the destruction sequence.
By unrealizing the context we avoid additional work during the dispose
phase, in case widget code updates the accessible state. We use
GtkAccessible's API, to ensure we unrealize the right ATContext, instead
of the one we store inside GtkWidgetPrivate.
We drop the ATContext instance inside GtkWidget during finalization, to
mop up eventual vivifications there.
This is leftover code from when widgets were hidden
by default, and was setting them back to their initial
state.
This is getting in the way now, as hiding the widget
updates the HIDDEN accessible state, which ends up
re-creating the at context that we've already disposed
of, leading to memory leaks.
Using GList is a bit lame, and makes the API more complicated to use
than necessary in the common case.
The only real use case for a GList is gtk_widget_add_mnemonic_label(),
and for that we can use the GValue-based API instead.
Fixes: #3343
The accessible-role property in GtkWidget has three possible targets:
- the :accessible-role of a GtkATContext, if realized
- the accessible_role field of GtkWidgetPrivate
- the accessible_role field of GtkWidgetClassPrivate
When we set the accessible role of a widget using the GObject property
mechanism, we want to either set the GtkWidgetPrivate.accessible_role
field, if there's no ATContext *or* if the ATContext is not realized.
Conversely, when we get the accessible-role property we want to have a
series of fallbacks in place:
- if GtkAccessible.get_at_context() returns an ATContext, and that
ATContext is realized, return the :accessible-role of the context
- if GtkWidgetPrivate.accessible_role is not WIDGET, return the
stored accessible role
- return GtkWidgetClassPrivate.accessible_role
This should help catch the case of getting the accessible role of
widgets that override GtkAccessible.get_at_context(), like
GtkModelButton.
See: #3342
We are doing too much work during the construction phase of the
AT-SPI backend for GtkATContext. Instead of having the AtSpiContext
register itself at construction time, let's add explicit realize
and unrealize operations, and connect the ATContext realization to the
rooting operation of a GtkWidget.
We are setting the value to TRUE initially, but
the property had a declared default of FALSE.
This is messing up the simplification of .ui files
with gtk4-builder-tool, since it thinks it can
omit can-target properties when it really can't.
gtk_widget_reposition_after is called both to add new children,
and to reposition existing children. We only want to emit
accessible changes in the former case (since AT-SPI doesn't
have events for reordering).
A bit hacky: we skip parsing values that have a reference or
reference-list type, but we do not error out. Instead, we return a NULL
value, which we catch in the GtkBuildable interface implementation to
get the actual object, and construct a reference list value.
There's still some ickyness around the value type that can only be
solved by having an attribute and role taxonomy.
Accessible attributes are not GObject properties. This means that we
need a custom parser for setting attributes in our UI description files.
The new section is defined as a sub-tree with the `<accessibility>`
element at its root, and elements for each type of accessible
attributes, i.e. properties, relations, and states:
```xml
<object class="..." id="...">
<accessibility>
<property name="label">The accessible label</property>
<state name="pressed">false</state>
<relation name="labelled-by">label1</relation>
</accessibility>
</object>
```
The name of the attribute is the enumeration value; the value is defined
by the WAI-ARIA specification.
There were several places where we were confusing
GList and GSList and list->data and list->next, causing
a crash in the accessible name computation for buttons
with mnemonic labels.
