Notify GtkTreeView if a node stops being a parent.

GtkTreeView requires the row-has-child-toggled signal to be emitted in
this situation, so do it from ItemDeleted handler.

Curiously, it handles adding the first child automatically. That's good,
because detecting this situation when adding the first child wouldn't be
trivial and so not having to do it is a plus. (Emitting it on every node
addition doesn't sound like a terribly bright idea.)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@68915 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/dataview.cpp

@@ -1588,12 +1588,14 @@ bool wxGtkDataViewModelNotifier::ItemDeleted( const wxDataViewItem &parent, cons
         GTK_TREE_MODEL(wxgtk_model), &iter ));
 #else
     // so get the path from the parent
-    GtkTreeIter iter;
-    iter.stamp = wxgtk_model->stamp;
-    iter.user_data = (gpointer) parent.GetID();
-    wxGtkTreePath path(wxgtk_tree_model_get_path(
-        GTK_TREE_MODEL(wxgtk_model), &iter ));
+    GtkTreeIter parentIter;
+    parentIter.stamp = wxgtk_model->stamp;
+    parentIter.user_data = (gpointer) parent.GetID();
+    wxGtkTreePath parentPath(wxgtk_tree_model_get_path(
+        GTK_TREE_MODEL(wxgtk_model), &parentIter ));
+
     // and add the final index ourselves
+    wxGtkTreePath path(gtk_tree_path_copy(parentPath));
     int index = m_internal->GetIndexOf( parent, item );
     gtk_tree_path_append_index( path, index );
 #endif
@@ -1603,6 +1605,17 @@ bool wxGtkDataViewModelNotifier::ItemDeleted( const wxDataViewItem &parent, cons
 
     m_internal->ItemDeleted( parent, item );
 
+    // Did we remove the last child, causing 'parent' to become a leaf?
+    if ( !m_wx_model->IsContainer(parent) )
+    {
+        gtk_tree_model_row_has_child_toggled
+        (
+            GTK_TREE_MODEL(wxgtk_model),
+            parentPath,
+            &parentIter
+        );
+    }
+
     return true;
 }