[gtk/ebassi/new-a11y: 54/71] Remove GTK_ACCESSIBLE_STATE_NONE

[Emmanuele Bassi <ebassi src gnome org>]

commit 74705440f59c0f93248fddd231f45151f81de294
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Wed Jul 15 13:20:38 2020 +0100

    Remove GTK_ACCESSIBLE_STATE_NONE
    
    It's pointless, we can use an explicit value of `-1` everywhere.
    Additionally, it complicates all code that uses the state enumeration as
    an array index, since now we need to guard against a negative offset.

 gtk/gtkaccessible.c      |  4 ++--
 gtk/gtkaccessiblevalue.c |  6 ------
 gtk/gtkenums.h           | 19 ++++++++++---------
 3 files changed, 12 insertions(+), 17 deletions(-)
---
diff --git a/gtk/gtkaccessible.c b/gtk/gtkaccessible.c
index c06612ba83..8cace46611 100644
--- a/gtk/gtkaccessible.c
+++ b/gtk/gtkaccessible.c
@@ -108,7 +108,7 @@ gtk_accessible_get_accessible_role (GtkAccessible *self)
  * gtk_accessible_update_state:
  * @self: a #GtkAccessible
  * @first_state: the first #GtkAccessibleState
- * @...: a list of state and value pairs, terminated by %GTK_ACCESSIBLE_STATE_NONE
+ * @...: a list of state and value pairs, terminated by -1
  *
  * Updates a list of accessible states.
  *
@@ -134,7 +134,7 @@ gtk_accessible_update_state (GtkAccessible      *self,
 
   state = first_state;
 
-  while (state != GTK_ACCESSIBLE_STATE_NONE)
+  while (state != -1)
     {
       GtkAccessibleValue *value = gtk_accessible_value_collect_for_state (state, &args);
 
diff --git a/gtk/gtkaccessiblevalue.c b/gtk/gtkaccessiblevalue.c
index 6509272205..db2509ebd6 100644
--- a/gtk/gtkaccessiblevalue.c
+++ b/gtk/gtkaccessiblevalue.c
@@ -538,8 +538,6 @@ typedef GtkAccessibleValue * (* GtkAccessibleValueRefCtor)      (gpointer value)
 GtkAccessibleValue *
 gtk_accessible_value_get_default_for_state (GtkAccessibleState state)
 {
-  g_assert (state != GTK_ACCESSIBLE_STATE_NONE);
-
   const GtkAccessibleCollect *cstate = &collect_states[state];
 
   switch (cstate->value)
@@ -589,8 +587,6 @@ GtkAccessibleValue *
 gtk_accessible_value_collect_for_state (GtkAccessibleState  state,
                                         va_list            *args)
 {
-  g_assert (state != GTK_ACCESSIBLE_STATE_NONE);
-
   const GtkAccessibleCollect *cstate = &collect_states[state];
 
   GtkAccessibleValue *res = NULL;
@@ -697,8 +693,6 @@ GtkAccessibleValue *
 gtk_accessible_value_collect_for_state_value (GtkAccessibleState  state,
                                               const GValue       *value)
 {
-  g_assert (state != GTK_ACCESSIBLE_STATE_NONE);
-
   const GtkAccessibleCollect *cstate = &collect_states[state];
 
   GtkAccessibleValue *res = NULL;
diff --git a/gtk/gtkenums.h b/gtk/gtkenums.h
index d7080d47c7..30bfc568c5 100644
--- a/gtk/gtkenums.h
+++ b/gtk/gtkenums.h
@@ -1302,30 +1302,31 @@ typedef enum {
 
 /**
  * GtkAccessibleState:
- * @GTK_ACCESSIBLE_STATE_NONE: An invalid state, used as a sentinel value
  * @GTK_ACCESSIBLE_STATE_BUSY: A “busy” state
- * @GTK_ACCESSIBLE_STATE_CHECKED: A “checked” state; corresponds to the
- *   #GtkToggleButton:active property on #GtkToggleButton
+ * @GTK_ACCESSIBLE_STATE_CHECKED: A “checked” state; indicates the current
+ *   state of a #GtkCheckButton
  * @GTK_ACCESSIBLE_STATE_DISABLED: A “disabled” state; corresponds to the
- *   #GtkWidget:sensitive property on #GtkWidget
+ *   #GtkWidget:sensitive property on #GtkWidget. It indicates a UI element
+ *   that is perceivable, but not editable or operable
  * @GTK_ACCESSIBLE_STATE_EXPANDED: An “expanded” state; corresponds to the
  *   #GtkExpander:expanded property on #GtkExpander
  * @GTK_ACCESSIBLE_STATE_GRABBED: A “grabbed” state; set when a widget is
  *   being grabbed in a drag and drop operation
  * @GTK_ACCESSIBLE_STATE_HIDDEN: A “hidden” state; corresponds to the
- *   #GtkWidget:visible property on #GtkWidget
+ *   #GtkWidget:visible property on #GtkWidget. You can use this state
+ *   explicitly on UI elements that should not be exposed to an assistive
+ *   technology. See also: %GTK_ACCESSIBLE_STATE_DISABLED
  * @GTK_ACCESSIBLE_STATE_INVALID: An “invalid” state; set when a widget
  *   is showing an error
- * @GTK_ACCESSIBLE_STATE_PRESSED: A “pressed” state; set when a widget
- *   is being activated by a pointer
+ * @GTK_ACCESSIBLE_STATE_PRESSED: A “pressed” state; indicates the current
+ *   state of a #GtkToggleButton
  * @GTK_ACCESSIBLE_STATE_SELECTED: A “selected” state; set when a widget
  *   is selected
  *
  * The possible accessible state of a #GtkAccessible.
  */
 typedef enum {
-  GTK_ACCESSIBLE_STATE_NONE = -1,
-  GTK_ACCESSIBLE_STATE_BUSY = 0,
+  GTK_ACCESSIBLE_STATE_BUSY,
   GTK_ACCESSIBLE_STATE_CHECKED,
   GTK_ACCESSIBLE_STATE_DISABLED,
   GTK_ACCESSIBLE_STATE_EXPANDED,