[gtk/wip/ebassi/a11y-2: 432/442] a11y: Simplify GtkNotebookAccessible

[Emmanuele Bassi <ebassi src gnome org>]

commit 7480fb703e3b8569d20a20236347c6d4e0873c26
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Thu May 28 14:54:57 2020 +0100

    a11y: Simplify GtkNotebookAccessible
    
    Let the GtkNotebook explicitly update the accessible object that the
    current page has changed, instead of overriding
    GtkWidgetAccessible.notify_gtk.

 gtk/a11y/gtknotebookaccessible.c        | 73 +++++++++++++--------------------
 gtk/a11y/gtknotebookaccessibleprivate.h | 30 ++++++++++++++
 gtk/gtknotebook.c                       | 10 +++--
 3 files changed, 66 insertions(+), 47 deletions(-)
---
diff --git a/gtk/a11y/gtknotebookaccessible.c b/gtk/a11y/gtknotebookaccessible.c
index 75d8188213..468e2a4206 100644
--- a/gtk/a11y/gtknotebookaccessible.c
+++ b/gtk/a11y/gtknotebookaccessible.c
@@ -17,10 +17,12 @@
 
 #include "config.h"
 
-#include <string.h>
-#include <gtk/gtk.h>
-#include "gtknotebookaccessible.h"
+#include "gtknotebookaccessibleprivate.h"
+
 #include "gtknotebookpageaccessible.h"
+#include "gtknotebook.h"
+
+#include <string.h>
 
 struct _GtkNotebookAccessiblePrivate
 {
@@ -153,55 +155,41 @@ gtk_notebook_accessible_ref_child (AtkObject *obj,
   return child;
 }
 
-static void
-gtk_notebook_accessible_notify_gtk (GObject    *obj,
-                                    GParamSpec *pspec)
+void
+gtk_notebook_accessible_update_page (GtkNotebookAccessible *self,
+                                     int                    page_num)
 {
-  GtkWidget *widget;
-  AtkObject* atk_obj;
+  GtkNotebookAccessiblePrivate *priv = gtk_notebook_accessible_get_instance_private (self);
+  AtkObject *atk_obj = ATK_OBJECT (self);
+  int old_page_num = priv->selected_page;
 
-  widget = GTK_WIDGET (obj);
-  atk_obj = gtk_widget_get_accessible (widget);
+  priv->selected_page = page_num;
 
-  if (strcmp (pspec->name, "page") == 0)
+  /* Notify SELECTED state change for old and new page */
+  if (page_num != old_page_num)
     {
-      gint page_num, old_page_num;
-      GtkNotebookAccessible *accessible;
-      GtkNotebook *notebook;
-
-      accessible = GTK_NOTEBOOK_ACCESSIBLE (atk_obj);
-      notebook = GTK_NOTEBOOK (widget);
-
-      /* Notify SELECTED state change for old and new page */
-      old_page_num = accessible->priv->selected_page;
-      page_num = gtk_notebook_get_current_page (notebook);
-      accessible->priv->selected_page = page_num;
+      AtkObject *child;
 
-      if (page_num != old_page_num)
+      if (old_page_num != -1)
         {
-          AtkObject *child;
-
-          if (old_page_num != -1)
-            {
-              child = gtk_notebook_accessible_ref_child (atk_obj, old_page_num);
-              if (child)
-                {
-                  atk_object_notify_state_change (child, ATK_STATE_SELECTED, FALSE);
-                  g_object_unref (child);
-                }
-            }
-          child = gtk_notebook_accessible_ref_child (atk_obj, page_num);
-          if (child)
+          child = gtk_notebook_accessible_ref_child (atk_obj, old_page_num);
+          if (child != NULL)
             {
-              atk_object_notify_state_change (child, ATK_STATE_SELECTED, TRUE);
+              atk_object_notify_state_change (child, ATK_STATE_SELECTED, FALSE);
               g_object_unref (child);
             }
-          g_signal_emit_by_name (atk_obj, "selection-changed");
-          g_signal_emit_by_name (atk_obj, "visible-data-changed");
         }
+
+      child = gtk_notebook_accessible_ref_child (atk_obj, page_num);
+      if (child != NULL)
+        {
+          atk_object_notify_state_change (child, ATK_STATE_SELECTED, TRUE);
+          g_object_unref (child);
+        }
+
+      g_signal_emit_by_name (atk_obj, "selection-changed");
+      g_signal_emit_by_name (atk_obj, "visible-data-changed");
     }
-  else
-    GTK_WIDGET_ACCESSIBLE_CLASS (gtk_notebook_accessible_parent_class)->notify_gtk (obj, pspec);
 }
 
 /*
@@ -230,14 +218,11 @@ gtk_notebook_accessible_class_init (GtkNotebookAccessibleClass *klass)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
   AtkObjectClass  *class = ATK_OBJECT_CLASS (klass);
-  GtkWidgetAccessibleClass *widget_class = (GtkWidgetAccessibleClass*)klass;
 
   gobject_class->finalize = gtk_notebook_accessible_finalize;
 
   class->ref_child = gtk_notebook_accessible_ref_child;
   class->initialize = gtk_notebook_accessible_initialize;
-
-  widget_class->notify_gtk = gtk_notebook_accessible_notify_gtk;
 }
 
 static void
diff --git a/gtk/a11y/gtknotebookaccessibleprivate.h b/gtk/a11y/gtknotebookaccessibleprivate.h
new file mode 100644
index 0000000000..5e4ab3b9f5
--- /dev/null
+++ b/gtk/a11y/gtknotebookaccessibleprivate.h
@@ -0,0 +1,30 @@
+/* gtknotebookaccessibleprivate.h: GtkNotebookAccessible private API
+ *
+ * Copyright 2020  GNOME Foundation
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "gtknotebookaccessible.h"
+
+G_BEGIN_DECLS
+
+void    gtk_notebook_accessible_update_page     (GtkNotebookAccessible *self,
+                                                 int                    page_num);
+
+G_END_DECLS
diff --git a/gtk/gtknotebook.c b/gtk/gtknotebook.c
index 08beb715a8..7ccaf47a67 100644
--- a/gtk/gtknotebook.c
+++ b/gtk/gtknotebook.c
@@ -55,7 +55,7 @@
 #include "gtkwidgetpaintable.h"
 #include "gtknative.h"
 
-#include "a11y/gtknotebookaccessible.h"
+#include "a11y/gtknotebookaccessibleprivate.h"
 
 #include <stdio.h>
 #include <string.h>
@@ -5298,6 +5298,7 @@ gtk_notebook_real_switch_page (GtkNotebook     *notebook,
 {
   GList *list = gtk_notebook_find_child (notebook, GTK_WIDGET (child));
   GtkNotebookPage *page = GTK_NOTEBOOK_PAGE_FROM_LIST (list);
+  AtkObject *accessible;
   gboolean child_has_focus;
 
   if (notebook->cur_page == page || !gtk_widget_get_visible (GTK_WIDGET (child)))
@@ -5343,6 +5344,11 @@ gtk_notebook_real_switch_page (GtkNotebook     *notebook,
 
   update_arrow_state (notebook);
 
+  accessible = _gtk_widget_peek_accessible (GTK_WIDGET (notebook));
+  if (accessible != NULL)
+    gtk_notebook_accessible_update_page (GTK_NOTEBOOK_ACCESSIBLE (accessible),
+                                         gtk_notebook_get_current_page (notebook));
+
   gtk_widget_queue_resize (GTK_WIDGET (notebook));
   gtk_widget_queue_resize (notebook->tabs_widget);
   g_object_notify_by_pspec (G_OBJECT (notebook), properties[PROP_PAGE]);
@@ -5904,8 +5910,6 @@ gtk_notebook_set_current_page (GtkNotebook *notebook,
   list = g_list_nth (notebook->children, page_num);
   if (list)
     gtk_notebook_switch_page (notebook, GTK_NOTEBOOK_PAGE_FROM_LIST (list));
-
-  g_object_notify_by_pspec (G_OBJECT (notebook), properties[PROP_PAGE]);
 }
 
 /**