In some cases we explicitly want to unset an accessible attribute; for
instance, an accessible property is gated on a widget property, and if
the widget property gets unset, the accessible property should be reset.
We're currently overloading NULL to mean both "this value is undefined,
and should be reset to its default" and "the value collection failed".
Let's do error reporting right, by using GError to mean "the collection
failed, for this specific reason"; then, we can use a NULL return value
to signal that the accessible attribute should be reset to its default
value.
This is only relevant for pointer-sized attribute values: strings,
references, and reference lists; numeric, boolean, tristate, and token
values either cannot be undefined, or have a specific "undefined" value.
Show a tab for accessibility information.
This shows the role and the accessible attributes
(states, properties, relations).
For now, changing the values is not possible, and
we only show the explicitly set values. In the future,
we want to show the attributes that are relevant for
the role, regardless of whether they are set or not,
and allow changing some of the attributes (the ones
that are not fully managed by GTK itself).
We're stopping activity mode when finalizing, which will change
accessible state; this will create a GtkATContext, and since GtkWidget
drops its GtkATContext on dispose(), we're going to end up leaking it on
the floor:
```
2,007 (64 direct, 1,943 indirect) bytes in 1 blocks are definitely lost in loss record 36,242 of 36,944
at 0x483977F: malloc (vg_replace_malloc.c:307)
by 0x5222105: g_malloc (gmem.c:106)
by 0x523E222: g_slice_alloc (gslice.c:1025)
by 0x523E261: g_slice_alloc0 (gslice.c:1051)
by 0x534B398: g_type_create_instance (gtype.c:1849)
by 0x53302EE: g_object_new_internal (gobject.c:1937)
by 0x53312AF: g_object_new_valist (gobject.c:2262)
by 0x532FEE8: g_object_new (gobject.c:1780)
by 0x4B3F942: gtk_test_at_context_new (gtktestatcontext.c:107)
by 0x491CC50: gtk_at_context_create (gtkatcontext.c:380)
by 0x4BFEDA0: gtk_widget_accessible_get_at_context (gtkwidget.c:8127)
by 0x4906079: gtk_accessible_get_at_context (gtkaccessible.c:83)
by 0x490618F: gtk_accessible_update_state (gtkaccessible.c:137)
by 0x4ACBA6D: gtk_progress_bar_act_mode_leave (gtkprogressbar.c:690)
by 0x4ACB4F8: gtk_progress_bar_finalize (gtkprogressbar.c:564)
```
We're also unparenting widgets and changing styles, which is another
potential source of leaks and side effects.
We must initialize the properties in init, since they
are expected to be there ab initio, and we can't call
gtk_accessible_update_property from finalize - it causes
us to recreate an at context and badness follows.
Accessible values storing references and reference lists can be unset by
using NULL to mean "undefined"; since we cannot return the NULL value,
we need to intercept it when collecting a value, and replace it with an
undefined GtkAccessibleValue, which is also the value used as the
default for GtkAccessibleRelation values that store a reference or a
reference list.
Fixes: #2955
Make both gtk_grid_view_new and gtk_grid_view_new_with_factory
take a model as first argument, and make all arguments
allow-none and transfer full.
Update all callers.
Make both gtk_list_view_new and gtk_list_view_new_with_factory
take a model as first argument, and make all arguments
allow-none and transfer full.
Update all callers.
A dropdown without a model is useless, so accept a model
and expression in the constructor. Allow them to be NULL,
but consume them if given. This makes chained constructors
convenient without breaking language bindings.
Drop gtk_drop_down_set_from_strings() and instead add
gtk_drop_down_new_from_strings().
Update all users.
We don't pay attention to item-type anymore, so
drop the item-type property and the _for_item_type()
constructor, and allow passing NULL to the regular
constructor.
We don't make this constructor transfer-full, since
the selection filter model is not a wrapping model
like the others. It is more like fork than a wrap.
This is for consistency with other wrapping list constructors.
We want them all to be transfer full, allow-none.
Also make the constructor return GtkMultiSelection *.
Update all callers.
Make gtk_tree_list_model_new() take the root model
as first argument, and make it transfer full, for
consistency with other wrapping list constructors.
Update all callers.
Still missing here: Make the model property writable,
and allow passing NULL in the constructor.
