2 files changed, 50 insertions, 5 deletions

diff --git a/widgets/table/e-tree-memory.c b/widgets/table/e-tree-memory.c
index 330dac93fb..74c160ab9f 100644
--- a/widgets/table/e-tree-memory.c
+++ b/widgets/table/e-tree-memory.c
@@ -42,14 +42,23 @@
 
 #define TREEPATH_CHUNK_AREA_SIZE (30 * sizeof (ETreeMemoryPath))
 
-static ETreeModel *parent_class;
+static ETreeModelClass *parent_class;
 static GMemChunk  *node_chunk;
 
+enum {
+	FILL_IN_CHILDREN,
+	LAST_SIGNAL
+};
+
+static guint signals [LAST_SIGNAL] = { 0, };
+
 typedef struct ETreeMemoryPath ETreeMemoryPath;
 
 struct ETreeMemoryPath {
 	gpointer         node_data;
 
+	guint            children_computed : 1;
+
 	/* parent/child/sibling pointers */
 	ETreeMemoryPath *parent;
 	ETreeMemoryPath *next_sibling;
@@ -71,6 +80,17 @@ struct ETreeMemoryPriv {
 
 /* ETreeMemoryPath functions */
 
+static inline void
+check_children (ETreeMemory *memory, ETreePath node)
+{
+	ETreeMemoryPath *path = node;
+	if (!path->children_computed) {
+		gtk_signal_emit (GTK_OBJECT (memory),
+				 signals[FILL_IN_CHILDREN], node);
+		path->children_computed = TRUE;
+	}
+}
+
 static int
 e_tree_memory_path_depth (ETreeMemoryPath *path)
 {
@@ -227,6 +247,8 @@ static ETreePath
 etmm_get_first_child (ETreeModel *etm, ETreePath node)
 {
 	ETreeMemoryPath *path = node;
+
+	check_children (E_TREE_MEMORY (etm), node);
 	return path->first_child;
 }
 
@@ -234,6 +256,8 @@ static ETreePath
 etmm_get_last_child (ETreeModel *etm, ETreePath node)
 {
 	ETreeMemoryPath *path = node;
+
+	check_children (E_TREE_MEMORY (etm), node);
 	return path->last_child;
 }
 
@@ -262,6 +286,8 @@ static gboolean
 etmm_is_expandable (ETreeModel *etm, ETreePath node)
 {
 	ETreeMemoryPath *path = node;
+
+	check_children (E_TREE_MEMORY (etm), node);
 	return path->first_child != NULL;
 }
 
@@ -271,13 +297,15 @@ etmm_get_children (ETreeModel *etm, ETreePath node, ETreePath **nodes)
 	ETreeMemoryPath *path = node;
 	guint n_children;
 
+	check_children (E_TREE_MEMORY (etm), node);
+
 	n_children = path->num_children;
 
 	if (nodes) {
 		ETreeMemoryPath *p;
 		int i = 0;
 
-		(*nodes) = g_malloc (sizeof (ETreePath) * n_children);
+		(*nodes) = g_new (ETreePath, n_children);
 		for (p = path->first_child; p; p = p->next_sibling) {
 			(*nodes)[i++] = p;
 		}
@@ -303,15 +331,26 @@ etmm_get_expanded_default (ETreeModel *etm)
 
 
 static void
-e_tree_memory_class_init (GtkObjectClass *klass)
+e_tree_memory_class_init (ETreeMemoryClass *klass)
 {
-	ETreeModelClass *tree_class = (ETreeModelClass *) klass;
+	ETreeModelClass *tree_class   = (ETreeModelClass *) klass;
+	GtkObjectClass  *object_class = (GtkObjectClass *) klass;
 
 	parent_class                     = gtk_type_class (PARENT_TYPE);
 	
 	node_chunk                       = g_mem_chunk_create (ETreeMemoryPath, TREEPATH_CHUNK_AREA_SIZE, G_ALLOC_AND_FREE);
 
-	klass->destroy                   = etmm_destroy;
+	signals [FILL_IN_CHILDREN] =
+		gtk_signal_new ("fill_in_children",
+				GTK_RUN_LAST,
+				E_OBJECT_CLASS_TYPE (object_class),
+				GTK_SIGNAL_OFFSET (ETreeMemoryClass, fill_in_children),
+				gtk_marshal_NONE__POINTER,
+				GTK_TYPE_NONE, 1, GTK_TYPE_POINTER);
+
+	E_OBJECT_CLASS_ADD_SIGNALS (object_class, signals, LAST_SIGNAL);
+
+	object_class->destroy            = etmm_destroy;
 
 	tree_class->get_root             = etmm_get_root;
 	tree_class->get_prev             = etmm_get_prev;
@@ -325,6 +364,8 @@ e_tree_memory_class_init (GtkObjectClass *klass)
 	tree_class->get_children         = etmm_get_children;
 	tree_class->depth                = etmm_depth;
 	tree_class->get_expanded_default = etmm_get_expanded_default;
+
+	klass->fill_in_children          = NULL;
 }
 
 static void
@@ -456,6 +497,7 @@ e_tree_memory_node_insert (ETreeMemory *tree_model,
 	new_path = g_chunk_new0 (ETreeMemoryPath, node_chunk);
 
 	new_path->node_data = node_data;
+	new_path->children_computed = FALSE;
 
 	if (parent_path != NULL) {
 		e_tree_memory_path_insert (parent_path, position, new_path);
diff --git a/widgets/table/e-tree-memory.h b/widgets/table/e-tree-memory.h
index e07271221c..bd43c97fde 100644
--- a/widgets/table/e-tree-memory.h
+++ b/widgets/table/e-tree-memory.h
@@ -52,6 +52,9 @@ struct ETreeMemory {
 
 struct ETreeMemoryClass {
 	ETreeModelClass parent_class;
+
+	/* signals */
+	void (*fill_in_children) (ETreeMemory *model, ETreePath node);
 };