[gtk+] GtkLabelAccessible: avoid extra selection-changed emissions

[Matthias Clasen <matthiasc src gnome org>]

commit 102faa30372aa7ae5b69404ff8ef5e632810db63
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Jul 16 09:44:02 2011 -0400

    GtkLabelAccessible: avoid extra selection-changed emissions
    
    This copies the same code that the entry accessible uses
    to check for selection changes.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=654428

 gtk/a11y/gtklabelaccessible.c |   39 +++++++++++++++++++++++++++++++++------
 gtk/a11y/gtklabelaccessible.h |    2 ++
 2 files changed, 35 insertions(+), 6 deletions(-)
---
diff --git a/gtk/a11y/gtklabelaccessible.c b/gtk/a11y/gtklabelaccessible.c
index f4bc905..6320eed 100644
--- a/gtk/a11y/gtklabelaccessible.c
+++ b/gtk/a11y/gtklabelaccessible.c
@@ -69,6 +69,31 @@ gtk_label_accessible_initialize (AtkObject *obj,
     obj->role = ATK_ROLE_LABEL;
 }
 
+static gboolean
+check_for_selection_change (GtkLabelAccessible *accessible,
+                            GtkLabel           *label)
+{
+  gboolean ret_val = FALSE;
+  gint start, end;
+
+  if (gtk_label_get_selection_bounds (label, &start, &end))
+    {
+      if (end != accessible->cursor_position ||
+          start != accessible->selection_bound)
+        ret_val = TRUE;
+    }
+  else
+    {
+      ret_val = (accessible->cursor_position != accessible->selection_bound);
+    }
+
+  accessible->cursor_position = end;
+  accessible->selection_bound = start;
+
+  return ret_val;
+}
+
+
 static void
 gtk_label_accessible_notify_gtk (GObject    *obj,
                                  GParamSpec *pspec)
@@ -91,30 +116,32 @@ gtk_label_accessible_notify_gtk (GObject    *obj,
       /* Create a delete text and an insert text signal */
       length = g_utf8_strlen (accessible->text, -1);
       if (length > 0)
-        g_signal_emit_by_name (atk_obj, "text_changed::delete", 0, length);
+        g_signal_emit_by_name (atk_obj, "text-changed::delete", 0, length);
 
       g_free (accessible->text);
       accessible->text = g_strdup (text);
 
       length = g_utf8_strlen (accessible->text, -1);
       if (length > 0)
-        g_signal_emit_by_name (atk_obj, "text_changed::insert", 0, length);
+        g_signal_emit_by_name (atk_obj, "text-changed::insert", 0, length);
 
       if (atk_obj->name == NULL)
         /* The label has changed so notify a change in accessible-name */
         g_object_notify (G_OBJECT (atk_obj), "accessible-name");
 
-      g_signal_emit_by_name (atk_obj, "visible_data_changed");
+      g_signal_emit_by_name (atk_obj, "visible-data-changed");
     }
   else if (g_strcmp0 (pspec->name, "cursor-position") == 0)
     {
-      g_signal_emit_by_name (atk_obj, "text_caret_moved",
+      g_signal_emit_by_name (atk_obj, "text-caret-moved",
                              _gtk_label_get_cursor_position (GTK_LABEL (widget)));
-      g_signal_emit_by_name (atk_obj, "text_selection_changed");
+      if (check_for_selection_change (atk_obj, GTK_LABEL (widget)))
+        g_signal_emit_by_name (atk_obj, "text-selection-changed");
     }
   else if (g_strcmp0 (pspec->name, "selection-bound") == 0)
     {
-      g_signal_emit_by_name (atk_obj, "text_selection_changed");
+      if (check_for_selection_change (atk_obj, GTK_LABEL (widget)))
+        g_signal_emit_by_name (atk_obj, "text-selection-changed");
     }
   else
     GTK_WIDGET_ACCESSIBLE_CLASS (_gtk_label_accessible_parent_class)->notify_gtk (obj, pspec);
diff --git a/gtk/a11y/gtklabelaccessible.h b/gtk/a11y/gtklabelaccessible.h
index 0a9fbd6..1fed206 100644
--- a/gtk/a11y/gtklabelaccessible.h
+++ b/gtk/a11y/gtklabelaccessible.h
@@ -39,6 +39,8 @@ struct _GtkLabelAccessible
   GtkWidgetAccessible parent;
 
   gchar *text;
+  gint cursor_position;
+  gint selection_bound;
 };
 
 struct _GtkLabelAccessibleClass