[gtk/a11y/atspi] Document accessible roles for stacks and notebooks

[Matthias Clasen <matthiasc src gnome org>]

commit 1bf21d3dba1f6c95d3562ab9a2fb98235122c4ba
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Oct 14 22:27:09 2020 -0400

    Document accessible roles for stacks and notebooks
    
    This was forgotten when I implemented the Tabs pattern.

 docs/reference/gtk/section-accessibility.md | 3 +++
 gtk/gtkenums.h                              | 6 +++---
 gtk/gtknotebook.c                           | 6 ++++++
 gtk/gtkstack.c                              | 5 +++++
 gtk/gtkstackswitcher.c                      | 5 +++++
 5 files changed, 22 insertions(+), 3 deletions(-)
---
diff --git a/docs/reference/gtk/section-accessibility.md b/docs/reference/gtk/section-accessibility.md
index 37309df83b..d60713c394 100644
--- a/docs/reference/gtk/section-accessibility.md
+++ b/docs/reference/gtk/section-accessibility.md
@@ -63,6 +63,9 @@ Each role name is part of the #GtkAccessibleRole enumeration.
 | `SEPARATOR` | A divider that separates sections of content or groups of items | #GtkSeparator |
 | `SPIN_BUTTON` | A range control that allows seelcting among discrete choices | #GtkSpinButton |
 | `SWITCH` | A control that represents on/off values | #GtkSwitch |
+| `TAB` | A tab in a list of tabs for switching pages | #GtkStackSwitcher, #GtkNotebook |
+| `TAB_LIST` | A list of tabs for switching pages | #GtkStackSwitcher, #GtkNotebook |
+| `TAB_PANEL` | A page in a notebook or stack | #GtkStack |
 | `TEXT_BOX` | A type of input that allows free-form text as its value. | #GtkEntry, #GtkPasswordEntry, 
#GtkTextView |
 | `WINDOW` | An application window | #GtkWindow |
 | `...` | … |
diff --git a/gtk/gtkenums.h b/gtk/gtkenums.h
index 4aa4b8b4e6..d4495da91d 100644
--- a/gtk/gtkenums.h
+++ b/gtk/gtkenums.h
@@ -1232,10 +1232,10 @@ typedef enum {
  * @GTK_ACCESSIBLE_ROLE_STRUCTURE: Unused
  * @GTK_ACCESSIBLE_ROLE_SWITCH: A type of checkbox that represents on/off values,
  *    as opposed to checked/unchecked values.
- * @GTK_ACCESSIBLE_ROLE_TAB: Unused
+ * @GTK_ACCESSIBLE_ROLE_TAB: An item in a list of tab used for switching pages.
  * @GTK_ACCESSIBLE_ROLE_TABLE: Unused
- * @GTK_ACCESSIBLE_ROLE_TAB_LIST: Unused
- * @GTK_ACCESSIBLE_ROLE_TAB_PANEL: Unused
+ * @GTK_ACCESSIBLE_ROLE_TAB_LIST: A list of tabs for switching pages.
+ * @GTK_ACCESSIBLE_ROLE_TAB_PANEL: A page in a notebook or stack.
  * @GTK_ACCESSIBLE_ROLE_TEXT_BOX: A type of input that allows free-form text
  *    as its value.
  * @GTK_ACCESSIBLE_ROLE_TIME: Unused
diff --git a/gtk/gtknotebook.c b/gtk/gtknotebook.c
index 116e7d54d9..81346060c1 100644
--- a/gtk/gtknotebook.c
+++ b/gtk/gtknotebook.c
@@ -144,6 +144,12 @@
  * A tab node gets the .dnd style class while it is moved with drag-and-drop.
  *
  * The nodes are always arranged from left-to-right, regardless of text direction.
+ *
+ * # Accessibility
+ *
+ * GtkNotebook uses the #GTK_ACCESSIBLE_ROLE_TAB_LIST and
+ * #GTK_ACCESSIBLE_ROLE_TAB roles for its list of tabs and the
+ * #GTK_ACCESSIBLE_ROLE_TAB_PANEL for the pages.
  */
 
 
diff --git a/gtk/gtkstack.c b/gtk/gtkstack.c
index 2c9b53bd07..a9a0902c23 100644
--- a/gtk/gtkstack.c
+++ b/gtk/gtkstack.c
@@ -80,6 +80,11 @@
  * # CSS nodes
  *
  * GtkStack has a single CSS node named stack.
+ *
+ * # Accessibility
+ *
+ * GtkStack uses the #GTK_ACCESSIBLE_ROLE_TAB_PANEL for the stack
+ * pages.
  */
 
 /**
diff --git a/gtk/gtkstackswitcher.c b/gtk/gtkstackswitcher.c
index 4392cc9cdb..fe6976b762 100644
--- a/gtk/gtkstackswitcher.c
+++ b/gtk/gtkstackswitcher.c
@@ -59,6 +59,11 @@
  * When circumstances require it, GtkStackSwitcher adds the
  * .needs-attention style class to the widgets representing the
  * stack pages.
+ *
+ * # Accessibility
+ *
+ * GtkStackSwitcher uses the #GTK_ACCESSIBLE_ROLE_TAB_LIST role
+ * and uses the #GTK_ACCESSIBLE_ROLE_TAB for its buttons.
  */
 
 #define TIMEOUT_EXPAND 500