[gtk+/combo-refactor: 17/42] Allow minimal implementation of GtkCellLayout

[Tristan Van Berkom <tvb src gnome org>]

commit b541e2ff60c0522265d01cfb54c316f422cde3db
Author: Tristan Van Berkom <tristan van berkom gmail com>
Date:   Mon Nov 22 16:27:52 2010 +0900

    Allow minimal implementation of GtkCellLayout
    
    Since GtkCellArea delegate does all the work, cell layout widgets
    who use a GtkCellArea internally only have to implement the _get_area()
    method, this just reduces code to forward the calls over the the internal
    cell area.

 gtk/gtkcelllayout.c |  149 +++++++++++++++++++++++++++++++++++++++++++--------
 1 files changed, 126 insertions(+), 23 deletions(-)
---
diff --git a/gtk/gtkcelllayout.c b/gtk/gtkcelllayout.c
index b13f090..f25864b 100644
--- a/gtk/gtkcelllayout.c
+++ b/gtk/gtkcelllayout.c
@@ -54,12 +54,23 @@ gtk_cell_layout_pack_start (GtkCellLayout   *cell_layout,
                             GtkCellRenderer *cell,
                             gboolean         expand)
 {
+  GtkCellLayoutIface *iface;
+  GtkCellArea        *area;
+
   g_return_if_fail (GTK_IS_CELL_LAYOUT (cell_layout));
   g_return_if_fail (GTK_IS_CELL_RENDERER (cell));
 
-  (* GTK_CELL_LAYOUT_GET_IFACE (cell_layout)->pack_start) (cell_layout,
-                                                           cell,
-                                                           expand);
+  iface = GTK_CELL_LAYOUT_GET_IFACE (cell_layout);
+
+  if (iface->pack_start)
+    iface->pack_start (cell_layout, cell, expand);
+  else
+    {
+      area = iface->get_area (cell_layout);
+
+      if (area)
+	gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (area), cell, expand);
+    }
 }
 
 /**
@@ -81,12 +92,23 @@ gtk_cell_layout_pack_end (GtkCellLayout   *cell_layout,
                           GtkCellRenderer *cell,
                           gboolean         expand)
 {
+  GtkCellLayoutIface *iface;
+  GtkCellArea        *area;
+
   g_return_if_fail (GTK_IS_CELL_LAYOUT (cell_layout));
   g_return_if_fail (GTK_IS_CELL_RENDERER (cell));
 
-  (* GTK_CELL_LAYOUT_GET_IFACE (cell_layout)->pack_end) (cell_layout,
-                                                         cell,
-                                                         expand);
+  iface = GTK_CELL_LAYOUT_GET_IFACE (cell_layout);
+
+  if (iface->pack_end)
+    iface->pack_end (cell_layout, cell, expand);
+  else
+    {
+      area = iface->get_area (cell_layout);
+
+      if (area)
+	gtk_cell_layout_pack_end (GTK_CELL_LAYOUT (area), cell, expand);
+    }
 }
 
 /**
@@ -101,9 +123,22 @@ gtk_cell_layout_pack_end (GtkCellLayout   *cell_layout,
 void
 gtk_cell_layout_clear (GtkCellLayout *cell_layout)
 {
+  GtkCellLayoutIface *iface;
+  GtkCellArea        *area;
+
   g_return_if_fail (GTK_IS_CELL_LAYOUT (cell_layout));
 
-  (* GTK_CELL_LAYOUT_GET_IFACE (cell_layout)->clear) (cell_layout);
+  iface = GTK_CELL_LAYOUT_GET_IFACE (cell_layout);
+
+  if (iface->clear)
+    iface->clear (cell_layout);
+  else
+    {
+      area = iface->get_area (cell_layout);
+
+      if (area)
+	gtk_cell_layout_clear (GTK_CELL_LAYOUT (area));
+    }
 }
 
 static void
@@ -114,17 +149,28 @@ gtk_cell_layout_set_attributesv (GtkCellLayout   *cell_layout,
   gchar *attribute;
   gint column;
   GtkCellLayoutIface *iface;
+  GtkCellArea        *area;
 
   attribute = va_arg (args, gchar *);
 
   iface = GTK_CELL_LAYOUT_GET_IFACE (cell_layout);
 
-  (* iface->clear_attributes) (cell_layout, cell);
+  if (iface->get_area)
+    area = iface->get_area (cell_layout);
+
+  if (iface->clear_attributes)
+    iface->clear_attributes (cell_layout, cell);
+  else if (area)
+    gtk_cell_layout_clear_attributes (GTK_CELL_LAYOUT (area), cell);
 
   while (attribute != NULL)
     {
       column = va_arg (args, gint);
-      (* iface->add_attribute) (cell_layout, cell, attribute, column);
+      if (iface->add_attribute)
+	iface->add_attribute (cell_layout, cell, attribute, column);
+      else if (area)
+	gtk_cell_layout_add_attribute (GTK_CELL_LAYOUT (area), cell, attribute, column);
+
       attribute = va_arg (args, gchar *);
     }
 }
@@ -178,15 +224,28 @@ gtk_cell_layout_add_attribute (GtkCellLayout   *cell_layout,
                                const gchar     *attribute,
                                gint             column)
 {
+  GtkCellLayoutIface *iface;
+  GtkCellArea        *area;
+
   g_return_if_fail (GTK_IS_CELL_LAYOUT (cell_layout));
   g_return_if_fail (GTK_IS_CELL_RENDERER (cell));
   g_return_if_fail (attribute != NULL);
   g_return_if_fail (column >= 0);
 
-  (* GTK_CELL_LAYOUT_GET_IFACE (cell_layout)->add_attribute) (cell_layout,
-                                                              cell,
-                                                              attribute,
-                                                              column);
+  iface = GTK_CELL_LAYOUT_GET_IFACE (cell_layout);
+
+  if (iface->add_attribute)
+    iface->add_attribute (cell_layout,
+			  cell,
+			  attribute,
+			  column);
+  else
+    {
+      area = iface->get_area (cell_layout);
+
+      if (area)
+	gtk_cell_layout_add_attribute (GTK_CELL_LAYOUT (area), cell, attribute, column);
+    }
 }
 
 /**
@@ -211,14 +270,27 @@ gtk_cell_layout_set_cell_data_func (GtkCellLayout         *cell_layout,
                                     gpointer               func_data,
                                     GDestroyNotify         destroy)
 {
+  GtkCellLayoutIface *iface;
+  GtkCellArea        *area;
+
   g_return_if_fail (GTK_IS_CELL_LAYOUT (cell_layout));
   g_return_if_fail (GTK_IS_CELL_RENDERER (cell));
 
-  (* GTK_CELL_LAYOUT_GET_IFACE (cell_layout)->set_cell_data_func) (cell_layout,
-                                                                   cell,
-                                                                   func,
-                                                                   func_data,
-                                                                   destroy);
+  iface = GTK_CELL_LAYOUT_GET_IFACE (cell_layout);
+
+  if (iface->set_cell_data_func)
+    iface->set_cell_data_func (cell_layout,
+			       cell,
+			       func,
+			       func_data,
+			       destroy);
+  else
+    {
+      area = iface->get_area (cell_layout);
+
+      if (area)
+	gtk_cell_layout_set_cell_data_func (GTK_CELL_LAYOUT (area), cell, func, func_data, destroy);
+    }
 }
 
 /**
@@ -235,11 +307,23 @@ void
 gtk_cell_layout_clear_attributes (GtkCellLayout   *cell_layout,
                                   GtkCellRenderer *cell)
 {
+  GtkCellLayoutIface *iface;
+  GtkCellArea        *area;
+
   g_return_if_fail (GTK_IS_CELL_LAYOUT (cell_layout));
   g_return_if_fail (GTK_IS_CELL_RENDERER (cell));
 
-  (* GTK_CELL_LAYOUT_GET_IFACE (cell_layout)->clear_attributes) (cell_layout,
-                                                                 cell);
+  iface = GTK_CELL_LAYOUT_GET_IFACE (cell_layout);
+
+  if (iface->clear_attributes)
+    iface->clear_attributes (cell_layout, cell);
+  else
+    {
+      area = iface->get_area (cell_layout);
+      
+      if (area)
+	gtk_cell_layout_clear_attributes (GTK_CELL_LAYOUT (area), cell);
+    }
 }
 
 /**
@@ -258,12 +342,23 @@ gtk_cell_layout_reorder (GtkCellLayout   *cell_layout,
                          GtkCellRenderer *cell,
                          gint             position)
 {
+  GtkCellLayoutIface *iface;
+  GtkCellArea        *area;
+
   g_return_if_fail (GTK_IS_CELL_LAYOUT (cell_layout));
   g_return_if_fail (GTK_IS_CELL_RENDERER (cell));
 
-  (* GTK_CELL_LAYOUT_GET_IFACE (cell_layout)->reorder) (cell_layout,
-                                                        cell,
-                                                        position);
+  iface = GTK_CELL_LAYOUT_GET_IFACE (cell_layout);
+
+  if (iface->reorder)
+    iface->reorder (cell_layout, cell, position);
+  else
+    {
+      area = iface->get_area (cell_layout);
+      
+      if (area)
+	gtk_cell_layout_reorder (GTK_CELL_LAYOUT (area), cell, position);
+    }
 }
 
 /**
@@ -282,12 +377,20 @@ GList *
 gtk_cell_layout_get_cells (GtkCellLayout *cell_layout)
 {
   GtkCellLayoutIface *iface;
+  GtkCellArea        *area;
 
   g_return_val_if_fail (GTK_IS_CELL_LAYOUT (cell_layout), NULL);
 
   iface = GTK_CELL_LAYOUT_GET_IFACE (cell_layout);  
   if (iface->get_cells)
     return iface->get_cells (cell_layout);
+  else
+    {
+      area = iface->get_area (cell_layout);
+      
+      if (area)
+	return gtk_cell_layout_get_cells (GTK_CELL_LAYOUT (area));
+    }
 
   return NULL;
 }