The ARIA spec determines the name and description of accessible elements
in a more complex way that simply mapping to a single property; instead,
it will chain up multiple definitions (if it finds them). For instance,
let's assume we have a button that saves a file selected from a file
selection widget; the widgets have the following attributes:
- the file selection widget has a "label" attribute set to the
selected file, e.g. "Final paper.pdf"
- the "download" button has a "label" attribute set to the
"Download" string
- the "download" button has a "labelled-by" attribute set to
reference the file selection widget
The ARIA spec says that the accessible name of the "Download" button
should be computed as "Download Final paper.pdf".
The algorithm defined in section 4.3 of the WAI-ARIA specification
applies to both accessible names (using the "label" and "labelled-by"
attributes), and to accessible descriptions (using the "description" and
"described-by" attributes).
Our Text implementation requires that we have
a GtkEditable with a delegate that is a GtkText
widget.
This change make the Text implementation work for
the custom widget in the tagged entry demo.
Implement the non-questionable parts of the Component interface
for accessibles which are widgets.
This does not include:
- global coordinates
- setters
- scrolling
- alpha, layers, zorder, and the like
We only want to show relevant, local actions for
widgets, but _gtk_widget_get_action_muxer() will
return the muxer of a parent widget (all the way
up to the toplevel), if the widget does not have
any actions of its own. To detect this situation,
compare what _gtk_widget_get_action_muxer() returns
for the parent widget, and act accordingly.
The Selection interface is defined in terms of child
positions, so we need to always translate from that
to model positions if we want to use the selection
model apis.
This implementation works for both GtkListView and
GtkGridView, and by extension, also for GtkColumnView
and GtkDropDown, since those just use a list view
internally.
This is a bit different from the way things were done
in GTK 3 - we follow what was done for GtkStackSwitcher,
and make the tab bar carry the GTK_ACCESSIBLE_TAB_LIST
role, and implement Selection there.
This requires some cleanup to remove assumptions
about accessibles being widgets in the backend,
and some code to navigate the tree with these
extra objects in between widgets.
The accessibles for stack pages have the role
GTK_ACCESSIBLE_ROLE_TAB_PANEL. This is the first
step towards implementing the tabs patterns
as described in the aria authoring guidelines
for GtkStack.
Non need to announce the same things for every context
we create, and the path is not really that interesting.
without knowing what it belongs to. I would suggest to
make it visible in the inspector instead, so you can
look it up for the widgets you are interested in.
We use to set the the 'password text' role for entries with
visibility = FALSE. Nowadays, we have a separate class for
password entries, so fix up the role mapping based on that.
Make text change notification work for editables, by connecting
to the ::insert-text and ::delete-text signals on the wrapped
GtkText widget, and for GtkTextView by connecting to the
corresponding GtkTextBuffer signals.
This code is more or less directly copied from GtkTextViewAccessible
and GtkEntryAccessible in GTK 3.
We are determining editable state based on the
accessible role (although we could make it platform
state now), so cover all the roles that we use for
entry wrappers.
