[gtk+] Add more defensive code to avoid accessing GtkIconView's cell area before it exists.

[Tristan Van Berkom <tvb src gnome org>]

commit 4d76644f5c753874224d62c660ba96ec6c19c6f1
Author: Tristan Van Berkom <tristan van berkom gmail com>
Date:   Wed Feb 23 20:50:50 2011 +0900

    Add more defensive code to avoid accessing GtkIconView's cell area before it exists.
    
    Adding these cases here to cater to icon view subclasses that want to
    access icon view APIs from the instance structure initializer instead
    of properly waiting for the super class to initialize and adding renderers
    from the ->constructor() vfunc.

 gtk/gtkiconview.c |   87 +++++++++++++++++++++++++++++++++++++---------------
 1 files changed, 62 insertions(+), 25 deletions(-)
---
diff --git a/gtk/gtkiconview.c b/gtk/gtkiconview.c
index 3d8d606..44d0ed5 100644
--- a/gtk/gtkiconview.c
+++ b/gtk/gtkiconview.c
@@ -392,6 +392,8 @@ static void                 gtk_icon_view_remove_editable                (GtkCel
 static void                 gtk_icon_view_context_changed                (GtkCellAreaContext     *context,
 									  GParamSpec             *pspec,
 									  GtkIconView            *icon_view);
+static void                 update_text_cell                             (GtkIconView            *icon_view);
+static void                 update_pixbuf_cell                           (GtkIconView            *icon_view);
 
 /* Source side drag signals */
 static void gtk_icon_view_drag_begin       (GtkWidget        *widget,
@@ -2884,11 +2886,14 @@ gtk_icon_view_invalidate_sizes (GtkIconView *icon_view)
 		  (GFunc)gtk_icon_view_item_invalidate_size, NULL);
 
   /* Reset the context */
-  g_signal_handler_block (icon_view->priv->cell_area_context, 
-			  icon_view->priv->context_changed_id);
-  gtk_cell_area_context_reset (icon_view->priv->cell_area_context);
-  g_signal_handler_unblock (icon_view->priv->cell_area_context, 
-			    icon_view->priv->context_changed_id);
+  if (icon_view->priv->cell_area_context)
+    {
+      g_signal_handler_block (icon_view->priv->cell_area_context, 
+			      icon_view->priv->context_changed_id);
+      gtk_cell_area_context_reset (icon_view->priv->cell_area_context);
+      g_signal_handler_unblock (icon_view->priv->cell_area_context, 
+				icon_view->priv->context_changed_id);
+    }
 
   /* Re-layout the items */
   gtk_icon_view_queue_layout (icon_view);
@@ -3258,7 +3263,12 @@ gtk_icon_view_row_changed (GtkTreeModel *model,
   if (gtk_tree_path_get_depth (path) > 1)
     return;
 
-  gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+  /* An icon view subclass might add it's own model and populate
+   * things at init() time instead of waiting for the constructor() 
+   * to be called 
+   */
+  if (icon_view->priv->cell_area)
+    gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
 
   /* Here we can use a "grow-only" strategy for optimization
    * and only invalidate a single item and queue a relayout
@@ -4121,6 +4131,9 @@ gtk_icon_view_ensure_cell_area (GtkIconView *icon_view,
   priv->context_changed_id =
     g_signal_connect (priv->cell_area_context, "notify",
                       G_CALLBACK (gtk_icon_view_context_changed), icon_view);
+
+  update_text_cell (icon_view);
+  update_pixbuf_cell (icon_view);
 }
 
 static GtkCellArea *
@@ -4881,6 +4894,9 @@ gtk_icon_view_get_model (GtkIconView *icon_view)
 static void
 update_text_cell (GtkIconView *icon_view)
 {
+  if (!icon_view->priv->cell_area)
+    return;
+
   if (icon_view->priv->text_column == -1 &&
       icon_view->priv->markup_column == -1)
     {
@@ -4931,6 +4947,9 @@ update_text_cell (GtkIconView *icon_view)
 static void
 update_pixbuf_cell (GtkIconView *icon_view)
 {
+  if (!icon_view->priv->cell_area)
+    return;
+
   if (icon_view->priv->pixbuf_column == -1)
     {
       if (icon_view->priv->pixbuf_cell != NULL)
@@ -5001,8 +5020,8 @@ gtk_icon_view_set_text_column (GtkIconView *icon_view,
       icon_view->priv->text_column = column;
     }
 
-
-  gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+  if (icon_view->priv->cell_area)
+    gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
 
   update_text_cell (icon_view);
 
@@ -5064,7 +5083,8 @@ gtk_icon_view_set_markup_column (GtkIconView *icon_view,
       icon_view->priv->markup_column = column;
     }
 
-  gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+  if (icon_view->priv->cell_area)
+    gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
 
   update_text_cell (icon_view);
 
@@ -5124,7 +5144,8 @@ gtk_icon_view_set_pixbuf_column (GtkIconView *icon_view,
       icon_view->priv->pixbuf_column = column;
     }
 
-  gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+  if (icon_view->priv->cell_area)
+    gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
 
   update_pixbuf_cell (icon_view);
 
@@ -5441,11 +5462,15 @@ gtk_icon_view_set_item_orientation (GtkIconView    *icon_view,
     {
       icon_view->priv->item_orientation = orientation;
 
-      if (GTK_IS_ORIENTABLE (icon_view->priv->cell_area))
-	gtk_orientable_set_orientation (GTK_ORIENTABLE (icon_view->priv->cell_area), 
-					icon_view->priv->item_orientation);
+      if (icon_view->priv->cell_area)
+	{
+	  if (GTK_IS_ORIENTABLE (icon_view->priv->cell_area))
+	    gtk_orientable_set_orientation (GTK_ORIENTABLE (icon_view->priv->cell_area), 
+					    icon_view->priv->item_orientation);
+
+	  gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+	}
 
-      gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
       gtk_icon_view_invalidate_sizes (icon_view);
 
       update_text_cell (icon_view);
@@ -5543,7 +5568,9 @@ gtk_icon_view_set_item_width (GtkIconView *icon_view,
     {
       icon_view->priv->item_width = item_width;
       
-      gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+      if (icon_view->priv->cell_area)
+	gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+
       gtk_icon_view_invalidate_sizes (icon_view);
       
       update_text_cell (icon_view);
@@ -5592,9 +5619,11 @@ gtk_icon_view_set_spacing (GtkIconView *icon_view,
     {
       icon_view->priv->spacing = spacing;
 
-      gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+      if (icon_view->priv->cell_area)
+	gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+
       gtk_icon_view_invalidate_sizes (icon_view);
-      
+
       g_object_notify (G_OBJECT (icon_view), "spacing");
     }  
 }
@@ -5637,9 +5666,11 @@ gtk_icon_view_set_row_spacing (GtkIconView *icon_view,
     {
       icon_view->priv->row_spacing = row_spacing;
 
-      gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+      if (icon_view->priv->cell_area)
+	gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+
       gtk_icon_view_invalidate_sizes (icon_view);
-      
+
       g_object_notify (G_OBJECT (icon_view), "row-spacing");
     }  
 }
@@ -5682,9 +5713,11 @@ gtk_icon_view_set_column_spacing (GtkIconView *icon_view,
     {
       icon_view->priv->column_spacing = column_spacing;
 
-      gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+      if (icon_view->priv->cell_area)
+	gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+
       gtk_icon_view_invalidate_sizes (icon_view);
-      
+
       g_object_notify (G_OBJECT (icon_view), "column-spacing");
     }  
 }
@@ -5728,9 +5761,11 @@ gtk_icon_view_set_margin (GtkIconView *icon_view,
     {
       icon_view->priv->margin = margin;
 
-      gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+      if (icon_view->priv->cell_area)
+	gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+
       gtk_icon_view_invalidate_sizes (icon_view);
-      
+
       g_object_notify (G_OBJECT (icon_view), "margin");
     }  
 }
@@ -5773,9 +5808,11 @@ gtk_icon_view_set_item_padding (GtkIconView *icon_view,
     {
       icon_view->priv->item_padding = item_padding;
 
-      gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+      if (icon_view->priv->cell_area)
+	gtk_cell_area_stop_editing (icon_view->priv->cell_area, TRUE);
+
       gtk_icon_view_invalidate_sizes (icon_view);
-      
+
       g_object_notify (G_OBJECT (icon_view), "item-padding");
     }  
 }