change things so we focus the cell and select the row, and also dispatch

2000-06-10  Chris Toshok  <toshok@helixcode.com>

	* e-table-item.c (eti_event): change things so we focus the cell
	and select the row, and also dispatch the event to that row/cell.
	This fixes the problem with the tree where you had to click twice
	to activate the tree controls.

	* Makefile.am (libetable_a_SOURCES): remove e-tree-gnode.* and add
	e-tree-simple.*
	(icons): add tree-expanded.xpm and tree-unexpanded.xpm

	* e-cell-tree.c (ect_enter_edit): defer to subcell's view.
	(ect_leave_edit): defer to subcell's view.
	(visible_depth_of_node): visual depth, taking into account that
	the root node of the model might not be displayed.
	(offset_of_node): return the offset used to shift the subcell
	over.
	(ect_draw): don't draw vertical lines if we're the leftmode node
	(a visual root node).  also, don't shift x2 by the subcell offset,
	so we get ellipses like we're supposed to.
	(ect_event): remove GDK_BUTTON_RELEASE from the list of events
	that we care about.

	* e-tree-example-1.c: lots of changes, a more dynamic UI so we can
	test tree model api stuff.

	* e-tree-gnode.c, e-tree-gnode.c: removed files, since their guts
	have been rolled into e-tree-model.c

	* e-tree-model.c, e-tree-model.h: substantially changed.  too much
	to really describe here.  this should really be considered the
	first revision of these files :)

	* e-tree-simple.c, e-tree-simple.h: analogous to e-table-simple, a
	subclass that allows the use of function pointers.

svn path=/trunk/; revision=3519

9 files changed, 832 insertions, 416 deletions

diff --git a/widgets/table/e-cell-tree.c b/widgets/table/e-cell-tree.c
index 9f40bd0eae..c3459ce4f8 100644
--- a/widgets/table/e-cell-tree.c
+++ b/widgets/table/e-cell-tree.c
@@ -49,6 +49,21 @@ static ECellClass *parent_class;
 
 static GdkPixbuf   *tree_expanded_pixbuf, *tree_unexpanded_pixbuf;
 
+#define INDENT_AMOUNT 16
+
+static int
+visible_depth_of_node (ETreeModel *tree_model, ETreePath *path)
+{
+	return (e_tree_model_node_depth (tree_model, path) 
+		- (e_tree_model_root_node_is_visible (tree_model) ? 0 : 1));
+}
+
+static gint
+offset_of_node (ETreeModel *tree_model, ETreePath *path)
+{
+	return (visible_depth_of_node(tree_model, path) + 1) * INDENT_AMOUNT;
+}
+
 static ETreePath*
 e_cell_tree_get_node (ETreeModel *tree_model, int row)
 {
@@ -136,7 +151,6 @@ ect_unrealize (ECellView *ecv)
 		(* parent_class->unrealize) (ecv);
 }
 
-#define INDENT_AMOUNT 16
 /*
  * ECell::draw method
  */
@@ -167,7 +181,7 @@ ect_draw (ECellView *ecell_view, GdkDrawable *drawable,
 		 */
 		node = e_cell_tree_get_node (tree_model, row);
 
-		offset = (e_tree_model_node_depth (tree_model, node) + 1) * INDENT_AMOUNT;
+		offset = offset_of_node (tree_model, node);
 		expandable = e_tree_model_node_is_expandable (tree_model, node);
 		expanded = e_tree_model_node_is_expanded (tree_model, node);
 		subcell_offset = offset;
@@ -196,15 +210,8 @@ ect_draw (ECellView *ecell_view, GdkDrawable *drawable,
 				    rect.x, rect.y, rect.width, rect.height);
 		gdk_gc_set_foreground (tree_view->gc, foreground);
 
+		/* draw our lines */
 		if (E_CELL_TREE(tree_view->cell_view.ecell)->draw_lines) {
-			/* draw our lines */
-			gdk_draw_line (drawable, tree_view->gc,
-				       rect.x + offset - INDENT_AMOUNT / 2,
-				       rect.y,
-				       rect.x + offset - INDENT_AMOUNT / 2,
-				       (e_tree_model_node_get_next (tree_model, node)
-					? rect.y + rect.height
-					: rect.y + rect.height / 2));
 
 			gdk_draw_line (drawable, tree_view->gc,
 				       rect.x + offset - INDENT_AMOUNT / 2 + 1,
@@ -212,12 +219,22 @@ ect_draw (ECellView *ecell_view, GdkDrawable *drawable,
 				       rect.x + offset,
 				       rect.y + rect.height / 2);
 
+			if (visible_depth_of_node (tree_model, node) != 0) {
+				gdk_draw_line (drawable, tree_view->gc,
+					       rect.x + offset - INDENT_AMOUNT / 2,
+					       rect.y,
+					       rect.x + offset - INDENT_AMOUNT / 2,
+					       (e_tree_model_node_get_next (tree_model, node)
+						? rect.y + rect.height
+						: rect.y + rect.height / 2));
+			}
+
 			/* now traverse back up to the root of the tree, checking at
 			   each level if the node has siblings, and drawing the
 			   correct vertical pipe for it's configuration. */
 			node = e_tree_model_node_get_parent (tree_model, node);
 			offset -= INDENT_AMOUNT;
-			while (node && ! e_tree_model_node_is_root (tree_model, node)) {
+			while (node && visible_depth_of_node (tree_model, node) != 0) {
 				if (e_tree_model_node_get_next(tree_model, node)) {
 					gdk_draw_line (drawable, tree_view->gc,
 						       rect.x + offset - INDENT_AMOUNT / 2,
@@ -255,7 +272,7 @@ ect_draw (ECellView *ecell_view, GdkDrawable *drawable,
 	   subcell_offset pixels */
 	e_cell_draw (tree_view->subcell_view, drawable,
 		     model_col, view_col, row, selected,
-		     x1 + subcell_offset, y1, x2 + subcell_offset, y2);
+		     x1 + subcell_offset, y1, x2, y2);
 }
 
 /*
@@ -267,13 +284,12 @@ ect_event (ECellView *ecell_view, GdkEvent *event, int model_col, int view_col,
 	ECellTreeView *tree_view = (ECellTreeView *) ecell_view;
 
 	switch (event->type) {
-	case GDK_BUTTON_PRESS:
-	case GDK_BUTTON_RELEASE: {
+	case GDK_BUTTON_PRESS: {
 		/* if the event happened in our area of control (and
                    we care about it), handle it. */
 		ETreeModel *tree_model = e_cell_tree_get_tree_model (ecell_view->e_table_model, row);
 		ETreePath *node = e_cell_tree_get_node (tree_model, row);
-		int offset = (e_tree_model_node_depth (tree_model, node) + 1) * INDENT_AMOUNT;
+		int offset = offset_of_node (tree_model, node);
 
 		/* only activate the tree control if the click/release happens in the icon's area. */
 		if (event->button.x > (offset - INDENT_AMOUNT) && event->button.x < offset) {
@@ -284,6 +300,8 @@ ect_event (ECellView *ecell_view, GdkEvent *event, int model_col, int view_col,
 			}
 			return TRUE;
 		}
+		else if (event->button.x < (offset - INDENT_AMOUNT))
+			return TRUE;
 	}
 	default:
 		/* otherwise, pass it off to our subcell_view */
@@ -309,7 +327,10 @@ ect_height (ECellView *ecell_view, int model_col, int view_col, int row)
 static void *
 ect_enter_edit (ECellView *ecell_view, int model_col, int view_col, int row)
 {
-	return NULL;
+	/* just defer to our subcell's view */
+	ECellTreeView *tree_view = (ECellTreeView *) ecell_view;
+
+	return e_cell_enter_edit (tree_view->subcell_view, model_col, view_col, row);
 }
 
 /*
@@ -318,6 +339,10 @@ ect_enter_edit (ECellView *ecell_view, int model_col, int view_col, int row)
 static void
 ect_leave_edit (ECellView *ecell_view, int model_col, int view_col, int row, void *edit_context)
 {
+	/* just defer to our subcell's view */
+	ECellTreeView *tree_view = (ECellTreeView *) ecell_view;
+
+	e_cell_leave_edit (tree_view->subcell_view, model_col, view_col, row, edit_context);
 }
 
 /*
diff --git a/widgets/table/e-table-item.c b/widgets/table/e-table-item.c
index 3a4d98bf91..0de4181cdf 100644
--- a/widgets/table/e-table-item.c
+++ b/widgets/table/e-table-item.c
@@ -1197,6 +1197,14 @@ eti_event (GnomeCanvasItem *item, GdkEvent *e)
 			if (!find_cell (eti, e->button.x, e->button.y, &col, &row, &x1, &y1))
 				return TRUE;
 			
+			if (eti->cursor_row != row || eti->cursor_col != col){
+				/*
+				 * Focus the cell, and select the row
+				 */
+				e_table_item_leave_edit (eti);
+				e_table_item_focus (eti, col, row);
+			}
+
 			if (eti->cursor_row == row && eti->cursor_col == col){
 				
 				ecol = e_table_header_get_column (eti->header, col);
@@ -1209,12 +1217,6 @@ eti_event (GnomeCanvasItem *item, GdkEvent *e)
 				e->button.y = y1;
 				
 				e_cell_event (ecell_view, e, ecol->col_idx, col, row);
-			} else {
-				/*
-				 * Focus the cell, and select the row
-				 */
-				e_table_item_leave_edit (eti);
-				e_table_item_focus (eti, col, row);
 			}
 			break;
 		case 3:
diff --git a/widgets/table/e-tree-example-1.c b/widgets/table/e-tree-example-1.c
index e5563a8071..c598e33ea4 100644
--- a/widgets/table/e-tree-example-1.c
+++ b/widgets/table/e-tree-example-1.c
@@ -4,7 +4,6 @@
 #include <string.h>
 #include <gnome.h>
 #include "e-util/e-cursors.h"
-#include "e-tree-gnode.h"
 #include "e-table-header.h"
 #include "e-table-header-item.h"
 #include "e-table-item.h"
@@ -12,6 +11,7 @@
 #include "e-cell-tree.h"
 #include "e-cell-checkbox.h"
 #include "e-table.h"
+#include "e-tree-simple.h"
 
 #include <gdk-pixbuf/gdk-pixbuf.h>
 
@@ -56,6 +56,8 @@ char *headers [COLS] = {
   "Date"
 };
 
+GtkWidget *e_table;
+
 /*
  * ETableSimple callbacks
  * These are the callbacks that define the behavior of our custom model.
@@ -73,12 +75,12 @@ my_col_count (ETableModel *etc, void *data)
 	return COLS;
 }
 
-/* This function returns the value at a particular point in our ETableModel. */
+/* This function returns the value at a particular point in our ETreeModel. */
 static void *
-my_value_at (ETreeModel *etc, GNode *node, int col, void *data)
+my_value_at (ETreeModel *etm, ETreePath *path, int col, void *model_data)
 {
 	switch (col) {
-	case 0: return "Re: Two things";
+	case 0: return e_tree_model_node_get_data (etm, path);
 	case 1: return "Chris Toshok";
 	case 2: return "toshok@helixcode.com";
 	case 3: return "Jun 07 2000";
@@ -86,67 +88,163 @@ my_value_at (ETreeModel *etc, GNode *node, int col, void *data)
 	}
 }
 
-/* This function sets the value at a particular point in our ETableModel. */
+/* This function sets the value at a particular point in our ETreeModel. */
 static void
-my_set_value_at (ETableModel *etc, GNode *node, int col, const void *val, void *data)
+my_set_value_at (ETreeModel *etm, ETreePath *path, int col, const void *val, void *model_data)
 {
+	if (col == 0) {
+		char *str = e_tree_model_node_get_data (etm, path);
+		g_free (str);
+		e_tree_model_node_set_data (etm, path, g_strdup(val));
+	}
 }
 
 /* This function returns whether a particular cell is editable. */
 static gboolean
-my_is_editable (ETableModel *etc, GNode *node, int col, void *data)
+my_is_editable (ETreeModel *etm, ETreePath *path, int col, void *model_data)
 {
-	return FALSE;
+	if (col == 0)
+		return TRUE;
+	else
+		return FALSE;
 }
 
-/* This function duplicates the value passed to it. */
-static void *
-my_duplicate_value (ETableModel *etc, int col, const void *value, void *data)
+static void
+toggle_root (GtkButton *button, gpointer data)
+{
+	ETreeModel *e_tree_model = (ETreeModel*)data;
+	e_tree_model_root_node_set_visible (e_tree_model, !e_tree_model_root_node_is_visible (e_tree_model));
+}
+
+static void
+add_sibling (GtkButton *button, gpointer data)
+{
+	ETreeModel *e_tree_model = E_TREE_MODEL (data);
+	int selected_row;
+	ETreePath *selected_node;
+	ETreePath *parent_node;
+
+	selected_row = e_table_get_selected_view_row (E_TABLE (e_table));
+	if (selected_row == -1)
+		return;
+
+	selected_node = e_tree_model_node_at_row (e_tree_model, selected_row);
+	g_assert (selected_node);
+
+	parent_node = e_tree_model_node_get_parent (e_tree_model, selected_node);
+
+	e_tree_model_node_insert_before (e_tree_model, parent_node,
+					 selected_node, "User added sibling");
+
+}
+
+static void
+add_child (GtkButton *button, gpointer data)
+{
+	ETreeModel *e_tree_model = E_TREE_MODEL (data);
+	int selected_row;
+	ETreePath *selected_node;
+
+	selected_row = e_table_get_selected_view_row (E_TABLE (e_table));
+	if (selected_row == -1)
+		return;
+
+	selected_node = e_tree_model_node_at_row (e_tree_model, selected_row);
+	g_assert (selected_node);
+
+	e_tree_model_node_insert (e_tree_model, selected_node,
+				  0, "User added child");
+}
+
+static void
+remove_node (GtkButton *button, gpointer data)
 {
-	return g_strdup (value);
+	ETreeModel *e_tree_model = E_TREE_MODEL (data);
+	int selected_row;
+	char *str;
+	ETreePath *selected_node;
+
+	selected_row = e_table_get_selected_view_row (E_TABLE (e_table));
+	if (selected_row == -1)
+		return;
+
+	selected_node = e_tree_model_node_at_row (e_tree_model, selected_row);
+	g_assert (selected_node);
+
+	if (e_tree_model_node_get_children (e_tree_model, selected_node, NULL) > 0)
+		return;
+
+	str = (char*)e_tree_model_node_remove (e_tree_model, selected_node);
+	printf ("removed node %s\n", str);
+	g_free (str);
 }
 
-/* This function frees the value passed to it. */
 static void
-my_free_value (ETableModel *etc, int col, void *value, void *data)
+expand_all (GtkButton *button, gpointer data)
 {
-	g_free (value);
+	ETreeModel *e_tree_model = E_TREE_MODEL (data);
+	int selected_row;
+	ETreePath *selected_node;
+
+	selected_row = e_table_get_selected_view_row (E_TABLE (e_table));
+	if (selected_row == -1)
+		return;
+
+	selected_node = e_tree_model_node_at_row (e_tree_model, selected_row);
+	g_assert (selected_node);
+
+	e_tree_model_node_set_expanded_recurse (e_tree_model, selected_node, TRUE);
 }
 
-/* This function is for when the model is unfrozen.  This can mostly
-   be ignored for simple models.  */
 static void
-my_thaw (ETableModel *etc, void *data)
+collapse_all (GtkButton *button, gpointer data)
 {
+	ETreeModel *e_tree_model = E_TREE_MODEL (data);
+	int selected_row;
+	ETreePath *selected_node;
+
+	selected_row = e_table_get_selected_view_row (E_TABLE (e_table));
+	if (selected_row == -1)
+		return;
+
+	selected_node = e_tree_model_node_at_row (e_tree_model, selected_row);
+	g_assert (selected_node);
+
+	e_tree_model_node_set_expanded_recurse (e_tree_model, selected_node, FALSE);
 }
 
 /* We create a window containing our new tree. */
 static void
 create_tree (void)
 {
-	GtkWidget *e_table, *window, *frame;
+	GtkWidget *window, *frame, *button, *vbox;
 	ECell *cell_left_just;
 	ECell *cell_tree;
 	ETableHeader *e_table_header;
 	int i, j;
 	ETreeModel *e_tree_model = NULL;
-	GNode *root_node;
+	ETreePath *root_node;
+
+	/* here we create our model.  This uses the functions we defined
+	   earlier. */
+	e_tree_model = e_tree_simple_new (my_value_at,
+					  my_set_value_at,
+					  my_is_editable,
+					  NULL);
 
 	/* create a root node with 5 children */
-	root_node = g_node_new (NULL);
+	root_node = e_tree_model_node_insert (e_tree_model, NULL,
+					      0, g_strdup("Root Node"));
+
 	for (i = 0; i < 5; i++){
-		GNode *n = g_node_insert (root_node, 0, g_node_new(NULL));
+		ETreePath *n = e_tree_model_node_insert (e_tree_model,
+							 root_node, 0, g_strdup("First level of children"));
 		for (j = 0; j < 5; j ++) {
-			g_node_insert (n, 0, g_node_new(NULL));
+			e_tree_model_node_insert (e_tree_model,
+						  n, 0, g_strdup("Second level of children"));
 		}
 	}
 
-	/* Next we create our model.  This uses the functions we defined
-	   earlier. */
-	e_tree_model = e_tree_gnode_new (root_node,
-					 my_value_at,
-					 NULL);
-
 	/*
 	 * Next we create a header.  The ETableHeader is used in two
 	 * different way.  The first is the full_header.  This is the
@@ -200,6 +298,7 @@ create_tree (void)
 	window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
 
 	/* This frame is simply to get a bevel around our table. */
+	vbox = gtk_vbox_new (FALSE, 0);
 	frame = gtk_frame_new (NULL);
 
 	/*
@@ -213,8 +312,34 @@ create_tree (void)
 
 	/* Build the gtk widget hierarchy. */
 	gtk_container_add (GTK_CONTAINER (frame), e_table);
-	gtk_container_add (GTK_CONTAINER (window), frame);
+	gtk_box_pack_start (GTK_BOX (vbox), frame, TRUE, TRUE, 0);
+
+	button = gtk_button_new_with_label ("Toggle Root Node");
+	gtk_signal_connect (GTK_OBJECT (button), "clicked", toggle_root, e_tree_model);
+	gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);
+
+	button = gtk_button_new_with_label ("Add Sibling");
+	gtk_signal_connect (GTK_OBJECT (button), "clicked", add_sibling, e_tree_model);
+	gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);
 
+	button = gtk_button_new_with_label ("Add Child");
+	gtk_signal_connect (GTK_OBJECT (button), "clicked", add_child, e_tree_model);
+	gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);
+
+	button = gtk_button_new_with_label ("Remove Node");
+	gtk_signal_connect (GTK_OBJECT (button), "clicked", remove_node, e_tree_model);
+	gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);
+
+	button = gtk_button_new_with_label ("Expand All Below");
+	gtk_signal_connect (GTK_OBJECT (button), "clicked", expand_all, e_tree_model);
+	gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);
+
+	button = gtk_button_new_with_label ("Collapse All Below");
+	gtk_signal_connect (GTK_OBJECT (button), "clicked", collapse_all, e_tree_model);
+	gtk_box_pack_end (GTK_BOX (vbox), button, FALSE, FALSE, 0);
+
+	gtk_container_add (GTK_CONTAINER (window), vbox);
+	
 	/* Size the initial window. */
 	gtk_widget_set_usize (window, 200, 200);
 
diff --git a/widgets/table/e-tree-gnode.c b/widgets/table/e-tree-gnode.c
deleted file mode 100644
index ce53751b56..0000000000
--- a/widgets/table/e-tree-gnode.c
+++ /dev/null
@@ -1,210 +0,0 @@
-/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
-/*
- * e-tree-gnode.c: a Tree Model that reflects a GNode structure visually.
- *
- * Author:
- *   Chris Toshok (toshok@helixcode.com)
- *
- * (C) 2000 Helix Code, Inc.
- */
-#include <config.h>
-#include <gtk/gtksignal.h>
-#include "e-util/e-util.h"
-#include "e-tree-gnode.h"
-
-#define PARENT_TYPE E_TREE_MODEL_TYPE
-
-static ETreePath *
-gnode_get_root (ETreeModel *etm)
-{
-  ETreeGNode *etg = E_TREE_GNODE (etm);
-  ETreePath *path = NULL;
-
-  path = g_list_append(path, etg->root);
-
-  return path;
-}
-
-static ETreePath *
-gnode_get_prev (ETreeModel *etm, ETreePath *node)
-{
-  ETreePath *prev_path;
-
-  GNode *gnode;
-  GNode *prev_sibling;
-
-  g_return_val_if_fail (node && node->data, NULL);
-
-  gnode = (GNode*)node->data;
-  prev_sibling = g_node_prev_sibling(gnode);
-
-  if (!prev_sibling)
-	  return NULL;
-
-  prev_path = g_list_copy (node->next);
-  prev_path = g_list_prepend (prev_path, prev_sibling);
-  return prev_path;
-}
-
-static ETreePath *
-gnode_get_next (ETreeModel *etm, ETreePath *node)
-{
-  ETreePath *next_path;
-  GNode *gnode;
-  GNode *next_sibling;
-
-  g_return_val_if_fail (node && node->data, NULL);
-
-  gnode = (GNode*)node->data;
-  next_sibling = g_node_next_sibling(gnode);
-
-  if (!next_sibling)
-	  return NULL;
-
-  next_path = g_list_copy (node->next);
-  next_path = g_list_prepend (next_path, next_sibling);
-  return next_path;
-}
-
-static void *
-gnode_value_at (ETreeModel *etm, ETreePath *node, int col)
-{
-  ETreeGNode *etg = E_TREE_GNODE (etm);
-  GNode *gnode;
-
-  g_return_val_if_fail (node && node->data, NULL);
-
-  gnode = (GNode*)node->data;
-
-  return etg->value_at (etm, gnode, col, etg->data);
-}
-
-static void
-gnode_set_value_at (ETreeModel *etm, ETreePath *node, int col, const void *val)
-{
-  ETreeGNode *etg = E_TREE_GNODE (etm);
-  GNode *gnode;
-
-  g_return_if_fail (node && node->data);
-
-  gnode = (GNode*)node->data;
-
-  /* XXX */
-}
-
-static gboolean
-gnode_is_editable (ETreeModel *etm, ETreePath *node, int col)
-{
-  ETreeGNode *etg = E_TREE_GNODE (etm);
-  GNode *gnode;
-
-  g_return_val_if_fail (node && node->data, FALSE);
-
-  gnode = (GNode*)node->data;
-
-  /* XXX */
-  return FALSE;
-}
-
-static guint
-gnode_get_children (ETreeModel *etm, ETreePath *node, ETreePath ***paths)
-{
-  ETreeGNode *etg = E_TREE_GNODE (etm);
-  GNode *gnode;
-  guint n_children;
-
-  g_return_val_if_fail (node && node->data, 0);
-
-  gnode = (GNode*)node->data;
-
-  n_children = g_node_n_children (gnode);
-
-  if (paths)
-    {
-      int i;
-      (*paths) = g_malloc (sizeof (ETreePath*) * n_children);
-      for (i = 0; i < n_children; i ++) {
-	(*paths)[i] = g_list_copy (node);
-	(*paths)[i] = g_list_prepend ((*paths)[i], g_node_nth_child (gnode, i));
-      }
-    }
-
-  return n_children;
-}
-
-static void
-gnode_release_paths (ETreeModel *etm, ETreePath **paths, guint num_paths)
-{
-	guint i;
-	g_return_if_fail (paths);
-
-	for (i = 0; i < num_paths; i ++)
-		g_list_free (paths[i]);
-	g_free (paths);
-}
-
-static gboolean
-gnode_is_expanded (ETreeModel *etm, ETreePath *node)
-{
-  ETreeGNode *etg = E_TREE_GNODE (etm);
-  GNode *gnode;
-
-  g_return_val_if_fail (node && node->data, FALSE);
-
-  gnode = (GNode*)node->data;
-
-  return (gboolean)gnode->data;
-}
-
-static void
-gnode_set_expanded (ETreeModel *etm, ETreePath *node, gboolean expanded)
-{
-  ETreeGNode *etg = E_TREE_GNODE (etm);
-  GNode *gnode;
-  int num_descendents;
-
-  g_return_if_fail (node && node->data);
-
-  gnode = (GNode*)node->data;
-
-  /* XXX */
-  gnode->data = (gpointer)expanded;
-
-  e_table_model_changed (E_TABLE_MODEL(etm));
-}
-
-static void
-e_tree_gnode_class_init (GtkObjectClass *object_class)
-{
-	ETreeModelClass *model_class = (ETreeModelClass *) object_class;
-
-	model_class->get_root = gnode_get_root;
-	model_class->get_next = gnode_get_next;
-	model_class->get_prev = gnode_get_prev;
-	model_class->value_at = gnode_value_at;
-	model_class->set_value_at = gnode_set_value_at;
-	model_class->is_editable = gnode_is_editable;
-	model_class->get_children = gnode_get_children;
-	model_class->release_paths = gnode_release_paths;
-	model_class->is_expanded = gnode_is_expanded;
-	model_class->set_expanded = gnode_set_expanded;
-}
-
-E_MAKE_TYPE(e_tree_gnode, "ETreeGNode", ETreeGNode, e_tree_gnode_class_init, NULL, PARENT_TYPE)
-
-ETreeModel *
-e_tree_gnode_new (GNode *root_node,
-		  ETreeGNodeValueAtFn value_at,
-		  void *data)
-{
-	ETreeGNode *etg;
-
-	etg = gtk_type_new (e_tree_gnode_get_type ());
-
-	etg->root = root_node;
-
-	etg->value_at = value_at;
-	etg->data = data;
-
-	return (ETreeModel*)etg;
-}
diff --git a/widgets/table/e-tree-gnode.h b/widgets/table/e-tree-gnode.h
deleted file mode 100644
index 56e6b19b80..0000000000
--- a/widgets/table/e-tree-gnode.h
+++ /dev/null
@@ -1,37 +0,0 @@
-/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
-
-#ifndef _E_TREE_GNODE_H_
-#define _E_TREE_GNODE_H_
-
-#include "e-tree-model.h"
-
-#define E_TREE_GNODE_TYPE        (e_tree_gnode_get_type ())
-#define E_TREE_GNODE(o)          (GTK_CHECK_CAST ((o), E_TREE_GNODE_TYPE, ETreeGNode))
-#define E_TREE_GNODE_CLASS(k)    (GTK_CHECK_CLASS_CAST((k), E_TREE_GNODE_TYPE, ETreeGNodeClass))
-#define E_IS_TREE_GNODE(o)       (GTK_CHECK_TYPE ((o), E_TREE_GNODE_TYPE))
-#define E_IS_TREE_GNODE_CLASS(k) (GTK_CHECK_CLASS_TYPE ((k), E_TREE_GNODE_TYPE))
-
-typedef void *(*ETreeGNodeValueAtFn)(ETreeModel *model, GNode *node, int col, void *data);
-
-
-typedef struct {
-	ETreeModel parent;
-
-	GNode *root;
-
-	ETreeGNodeValueAtFn value_at;
-
-	void *data;
-} ETreeGNode;
-
-typedef struct {
-	ETreeModelClass parent_class;
-} ETreeGNodeClass;
-
-GtkType e_tree_gnode_get_type (void);
-
-ETreeModel *e_tree_gnode_new (GNode *tree,
-			      ETreeGNodeValueAtFn value_at,
-			      void *data);
-
-#endif /* _E_TREE_GNODE_H_ */
diff --git a/widgets/table/e-tree-model.c b/widgets/table/e-tree-model.c
index d67e59f3f5..c11cb58831 100644
--- a/widgets/table/e-tree-model.c
+++ b/widgets/table/e-tree-model.c
@@ -20,98 +20,222 @@
 
 static ETableModel *e_tree_model_parent_class;
 
+typedef struct {
+	gboolean expanded;
+	guint visible_descendents;
+	gpointer node_data;
+} ENode;
+
+enum {
+	NODE_CHANGED,
+	NODE_INSERTED,
+	NODE_REMOVED,
+	LAST_SIGNAL
+};
+
+static guint e_tree_model_signals [LAST_SIGNAL] = {0, };
+
+static void add_visible_descendents_to_array (ETreeModel *etm, GNode *gnode, int *row, int *count);
+
+
 /* virtual methods */
 
-static ETreePath*
-etree_get_root (ETreeModel *etm)
+static void
+etree_destroy (GtkObject *object)
 {
-	/* shouldn't be called */
-	g_assert(0);
-	return NULL;
+	/* XXX lots of stuff to free here */
 }
 
-static void*
-etree_value_at (ETreeModel *etm, ETreePath* node, int col)
+static ETreePath*
+etree_get_root (ETreeModel *etm)
 {
-	/* shouldn't be called */
-	g_assert(0);
-	return NULL;
+	return etm->root;
 }
 
-static void
-etree_set_value_at (ETreeModel *etm, ETreePath* node, int col, const void *val)
+static ETreePath*
+etree_get_parent (ETreeModel *etm, ETreePath *path)
 {
-	/* shouldn't be called */
-	g_assert(0);
+	g_return_val_if_fail (path, NULL);
+	
+	return path->parent;
 }
 
-static gboolean
-etree_is_editable (ETreeModel *etm, ETreePath* node, int col)
+static ETreePath*
+etree_get_next (ETreeModel *etm, ETreePath *node)
 {
-	/* shouldn't be called */
-	g_assert(0);
-	return FALSE;
+	g_return_val_if_fail (node, NULL);
+
+	return g_node_next_sibling(node);
 }
 
-static gboolean
-etree_is_expanded (ETreeModel *etm, ETreePath* node)
+static ETreePath*
+etree_get_prev (ETreeModel *etm, ETreePath *node)
 {
-	/* shouldn't be called */
-	g_assert(0);
-	return FALSE;
+	g_return_val_if_fail (node, NULL);
+
+	return g_node_prev_sibling (node);
 }
 
 static guint
 etree_get_children (ETreeModel *etm, ETreePath* node, ETreePath ***paths)
 {
-	/* shouldn't be called */
-	g_assert(0);
-	return 0;
+	guint n_children;
+
+	g_return_val_if_fail (node, 0);
+
+	n_children = g_node_n_children (node);
+
+	if (paths) {
+		int i;
+		(*paths) = g_malloc (sizeof (ETreePath*) * n_children);
+		for (i = 0; i < n_children; i ++) {
+			(*paths)[i] = g_node_nth_child (node, i);
+		}
+	}
+
+	return n_children;
 }
 
-static void
-etree_release_paths (ETreeModel *etm, ETreePath **paths, guint num_paths)
+static gboolean
+etree_is_expanded (ETreeModel *etm, ETreePath* node)
 {
-	/* shouldn't be called */
-	g_assert(0);
+	g_return_val_if_fail (node && node->data, FALSE);
+	
+	return ((ENode*)node->data)->expanded;
+}
+
+static gboolean
+etree_is_visible (ETreeModel *etm, ETreePath* node)
+{
+	g_return_val_if_fail (node, FALSE);
+
+	for (node = node->parent; node; node = node->parent) {
+		if (!((ENode*)node->data)->expanded)
+			return FALSE;
+	}
+
+	return TRUE;
 }
 
 static void
 etree_set_expanded (ETreeModel *etm, ETreePath* node, gboolean expanded)
 {
-	/* shouldn't be called */
-	g_assert(0);
+	GNode *child;
+	ENode *enode;
+	int row;
+	
+	g_return_if_fail (node && node->data);
+
+	enode = ((ENode*)node->data);
+
+	if (enode->expanded == expanded)
+		return;
+
+	enode->expanded = expanded;
+
+	row = e_tree_model_row_of_node (etm, node) + 1;
+
+	if (expanded) {
+		GNode *parent;
+
+		if (e_tree_model_node_is_visible (etm, node)) {
+			enode->visible_descendents = 0;
+			for (child = g_node_first_child (node); child;
+			     child = g_node_next_sibling (child)) {
+				add_visible_descendents_to_array (etm, child, &row, &enode->visible_descendents);
+			}
+		}
+		/* now iterate back up the tree, adding to our
+		   ancestors' visible descendents */
+
+		for (parent = node->parent; parent; parent = parent->parent) {
+			ENode *parent_enode = (ENode*)parent->data;
+			parent_enode->visible_descendents += enode->visible_descendents;
+		}
+	}
+	else {
+		int i;
+		GNode *parent;
+
+		if (e_tree_model_node_is_visible (etm, node)) {
+			for (i = 0; i < enode->visible_descendents; i ++) {
+				etm->row_array = g_array_remove_index (etm->row_array, row);
+				e_table_model_row_deleted (E_TABLE_MODEL (etm), row);
+			}
+		}
+		/* now iterate back up the tree, subtracting from our
+		   ancestors' visible descendents */
+
+		for (parent = node->parent; parent; parent = parent->parent) {
+			ENode *parent_enode = (ENode*)parent->data;
+
+			parent_enode->visible_descendents -= enode->visible_descendents;
+		}
+
+		enode->visible_descendents = 0;
+	}
 }
 
+/* fairly naive implementation */
 static void
-etree_destroy (GtkObject *object)
+etree_set_expanded_recurse (ETreeModel *etm, ETreePath* node, gboolean expanded)
 {
+	ETreePath **paths;
+	guint num_children;
+	int i;
+
+	e_tree_model_node_set_expanded (etm, node, expanded);
+
+	num_children = e_tree_model_node_get_children (etm, node, &paths);
+	if (num_children) {
+		for (i = 0; i < num_children; i ++) {
+			e_tree_model_node_set_expanded_recurse (etm, paths[i], expanded);
+		}
+
+		g_free (paths);
+	}
 }
 
-guint
-e_tree_model_node_num_visible_descendents (ETreeModel *etm, ETreePath *node)
+static ETreePath *
+etree_node_at_row (ETreeModel *etree, int row)
 {
-	int count = 1;
-	if (e_tree_model_node_is_expanded (etm, node)) {
-		ETreePath **paths;
-		int i;
-		int num_paths;
+	GNode *node = g_array_index (etree->row_array, GNode*, row);
 
-		num_paths = e_tree_model_node_get_children (etm, node, &paths);
+	return node;
+}
 
-		for (i = 0; i < num_paths; i ++)
-			count += e_tree_model_node_num_visible_descendents(etm, paths[i]);
+
+/* ETable analogs */
+static void*
+etree_value_at (ETreeModel *etm, ETreePath* node, int col)
+{
+	/* shouldn't be called */
+	g_assert (0);
+	return NULL;
+}
 
-		e_tree_model_release_paths (etm, paths, num_paths);
-	}
+static void
+etree_set_value_at (ETreeModel *etm, ETreePath* node, int col, const void *val)
+{
+	/* shouldn't be called */
+	g_assert (0);
+}
 
-	return count;
+static gboolean
+etree_is_editable (ETreeModel *etm, ETreePath* node, int col)
+{
+	/* shouldn't be called */
+	g_assert(0);
+	return FALSE;
 }
 
+
+/* ETable virtual functions we map */
 static int
 etable_row_count (ETableModel *etm)
 {
-	return e_tree_model_node_num_visible_descendents (E_TREE_MODEL (etm), e_tree_model_get_root (E_TREE_MODEL (etm)));
+	ETreeModel *tree = E_TREE_MODEL (etm);
+	return tree->row_array->len;
 }
 
 static void *
@@ -155,6 +279,7 @@ etable_is_cell_editable (ETableModel *etm, int col, int row)
 	return et_class->is_editable (etree, node, col);
 }
 
+
 static void
 e_tree_model_class_init (GtkObjectClass *klass)
 {
@@ -165,11 +290,38 @@ e_tree_model_class_init (GtkObjectClass *klass)
 	
 	klass->destroy = etree_destroy;
 
+	e_tree_model_signals [NODE_CHANGED] =
+		gtk_signal_new ("node_changed",
+				GTK_RUN_LAST,
+				klass->type,
+				GTK_SIGNAL_OFFSET (ETreeModelClass, node_changed),
+				gtk_marshal_NONE__POINTER,
+				GTK_TYPE_NONE, 1, GTK_TYPE_POINTER);
+
+	e_tree_model_signals [NODE_INSERTED] =
+		gtk_signal_new ("node_inserted",
+				GTK_RUN_LAST,
+				klass->type,
+				GTK_SIGNAL_OFFSET (ETreeModelClass, node_inserted),
+				gtk_marshal_NONE__POINTER_POINTER,
+				GTK_TYPE_NONE, 2, GTK_TYPE_POINTER, GTK_TYPE_POINTER);
+
+	e_tree_model_signals [NODE_REMOVED] =
+		gtk_signal_new ("node_removed",
+				GTK_RUN_LAST,
+				klass->type,
+				GTK_SIGNAL_OFFSET (ETreeModelClass, node_removed),
+				gtk_marshal_NONE__POINTER_POINTER,
+				GTK_TYPE_NONE, 2, GTK_TYPE_POINTER, GTK_TYPE_POINTER);
+
+	gtk_object_class_add_signals (klass, e_tree_model_signals, LAST_SIGNAL);
+
 	table_class->row_count        = etable_row_count;
 	table_class->value_at         = etable_value_at;
 	table_class->set_value_at     = etable_set_value_at;
 	table_class->is_cell_editable = etable_is_cell_editable;
 #if 0
+	/* XX need to pass these through */
 	table_class->duplicate_value  = etable_duplicate_value;
 	table_class->free_value       = etable_free_value;
 	table_class->initialize_value = etable_initialize_value;
@@ -178,19 +330,68 @@ e_tree_model_class_init (GtkObjectClass *klass)
 #endif
 
 	tree_class->get_root          = etree_get_root;
+	tree_class->get_prev          = etree_get_prev;
+	tree_class->get_next          = etree_get_next;
+	tree_class->get_parent        = etree_get_parent;
+
 	tree_class->value_at          = etree_value_at;
 	tree_class->set_value_at      = etree_set_value_at;
 	tree_class->is_editable       = etree_is_editable;
 
 	tree_class->get_children      = etree_get_children;
-	tree_class->release_paths     = etree_release_paths;
 	tree_class->is_expanded       = etree_is_expanded;
+	tree_class->is_visible        = etree_is_visible;
 	tree_class->set_expanded      = etree_set_expanded;
+	tree_class->set_expanded_recurse = etree_set_expanded_recurse;
+	tree_class->node_at_row       = etree_node_at_row;
 }
 
 E_MAKE_TYPE(e_tree_model, "ETreeModel", ETreeModel, e_tree_model_class_init, NULL, PARENT_TYPE)
 
+
 /* signals */
+void
+e_tree_model_node_changed  (ETreeModel *tree_model, ETreePath *node)
+{
+	g_return_if_fail (tree_model != NULL);
+	g_return_if_fail (E_IS_TREE_MODEL (tree_model));
+	
+	gtk_signal_emit (GTK_OBJECT (tree_model),
+			 e_tree_model_signals [NODE_CHANGED]);
+}
+
+void
+e_tree_model_node_inserted (ETreeModel *tree_model,
+			    ETreePath *parent_node,
+			    ETreePath *inserted_node)
+{
+	g_return_if_fail (tree_model != NULL);
+	g_return_if_fail (E_IS_TREE_MODEL (tree_model));
+	
+	gtk_signal_emit (GTK_OBJECT (tree_model),
+			 e_tree_model_signals [NODE_INSERTED],
+			 parent_node, inserted_node);
+}
+
+void
+e_tree_model_node_removed  (ETreeModel *tree_model, ETreePath *parent_node, ETreePath *removed_node)
+{
+	g_return_if_fail (tree_model != NULL);
+	g_return_if_fail (E_IS_TREE_MODEL (tree_model));
+	
+	gtk_signal_emit (GTK_OBJECT (tree_model),
+			 e_tree_model_signals [NODE_REMOVED],
+			 parent_node, removed_node);
+}
+
+
+void
+e_tree_model_construct (ETreeModel *etree)
+{
+	etree->root = NULL;
+	etree->root_visible = TRUE;
+	etree->row_array = g_array_new (FALSE, FALSE, sizeof(GNode*));
+}
 
 ETreeModel *
 e_tree_model_new ()
@@ -202,52 +403,56 @@ e_tree_model_new ()
 	return et;
 }
 
-static ETreePath *
-e_tree_model_node_at_row_1 (ETreeModel *etree, int *row, ETreePath *node)
+ETreePath *
+e_tree_model_get_root (ETreeModel *etree)
 {
-	ETreePath *ret = NULL;
-
-	if (*row == 0)
-		ret = node;
-	else if (e_tree_model_node_is_expanded (etree, node)) {
-		int num_children;
-		int i;
-		ETreePath **paths;
+	return ETM_CLASS(etree)->get_root(etree);
+}
 
-		num_children = e_tree_model_node_get_children (etree, node, &paths);
+ETreePath *
+e_tree_model_node_at_row (ETreeModel *etree, int row)
+{
+	return ETM_CLASS(etree)->node_at_row (etree, row);
+}
 
-		for (i = 0; i < num_children; i ++) {
-			ETreePath *p;
+int
+e_tree_model_row_of_node (ETreeModel *etree, ETreePath *node)
+{
+	int i;
 
-			(*row) --;
+	for (i = 0; i < etree->row_array->len; i ++)
+		if (g_array_index (etree->row_array, GNode*, i) == node)
+			return i;
 
-			p = e_tree_model_node_at_row_1 (etree, row, paths[i]);
+	return -1;
+}
 
-			if (p) {
-				ret = p;
-				break;
+void
+e_tree_model_root_node_set_visible (ETreeModel *etm, gboolean visible)
+{
+	if (visible != etm->root_visible) {
+		etm->root_visible = visible;
+		if (etm->root) {
+			if (visible) {
+				etm->row_array = g_array_insert_val (etm->row_array, 0, etm->root);
 			}
+			else {
+				ETreePath *root_path = e_tree_model_get_root (etm);
+				etm->row_array = g_array_remove_index (etm->row_array, 0);
+				e_tree_model_node_set_expanded (etm, root_path, TRUE);
+			}
+			
+			e_table_model_changed (E_TABLE_MODEL (etm));
 		}
-
-		/* XXX need to find why this release is causing problems */
-		/* e_tree_model_release_paths (etree, paths, num_children); */
 	}
-
-	return ret;
 }
 
-ETreePath *
-e_tree_model_get_root (ETreeModel *etree)
+gboolean
+e_tree_model_root_node_is_visible (ETreeModel *etm)
 {
-	return ETM_CLASS(etree)->get_root(etree);
+	return etm->root_visible;
 }
 
-ETreePath *
-e_tree_model_node_at_row (ETreeModel *etree, int row)
-{
-	/* XXX icky, perform a depth first search of the tree.  we need this optimized sorely */
-	return e_tree_model_node_at_row_1 (etree, &row, ETM_CLASS(etree)->get_root(etree));
-}
 
 ETreePath *
 e_tree_model_node_get_next (ETreeModel *etree, ETreePath *node)
@@ -264,18 +469,13 @@ e_tree_model_node_get_prev (ETreeModel *etree, ETreePath *node)
 guint
 e_tree_model_node_depth (ETreeModel *etree, ETreePath *path)
 {
-	return g_list_length (path) - 1;
+	return g_node_depth (path) - 1;
 }
 
 ETreePath *
 e_tree_model_node_get_parent (ETreeModel *etree, ETreePath *path)
 {
-	g_return_val_if_fail (path, NULL);
-
-	if (path->next == NULL)
-		return NULL;
-	else
-		return g_list_copy (path->next);
+	return ETM_CLASS(etree)->get_parent(etree, path);
 }
 
 gboolean
@@ -296,21 +496,190 @@ e_tree_model_node_is_expanded (ETreeModel *etree, ETreePath *path)
 	return ETM_CLASS(etree)->is_expanded (etree, path);
 }
 
+gboolean
+e_tree_model_node_is_visible (ETreeModel *etree, ETreePath *path)
+{
+	return ETM_CLASS(etree)->is_visible (etree, path);
+}
+
 void
 e_tree_model_node_set_expanded (ETreeModel *etree, ETreePath *path, gboolean expanded)
 {
 	ETM_CLASS(etree)->set_expanded (etree, path, expanded);
 }
 
+void
+e_tree_model_node_set_expanded_recurse (ETreeModel *etree, ETreePath *path, gboolean expanded)
+{
+	ETM_CLASS(etree)->set_expanded_recurse (etree, path, expanded);
+}
+
 guint
 e_tree_model_node_get_children (ETreeModel *etree, ETreePath *path, ETreePath ***paths)
 {
 	return ETM_CLASS(etree)->get_children (etree, path, paths);
 }
 
+guint
+e_tree_model_node_num_visible_descendents (ETreeModel *etm, ETreePath *node)
+{
+	ENode *enode = (ENode*)node->data;
+
+	return enode->visible_descendents;
+}
+
+gpointer
+e_tree_model_node_get_data (ETreeModel *etm, ETreePath *node)
+{
+	ENode *enode;
+
+	g_return_val_if_fail (node && node->data, NULL);
+
+	enode = (ENode*)node->data;
+
+	return enode->node_data;
+}
+
 void
-e_tree_model_release_paths (ETreeModel *etree, ETreePath **paths, guint num_paths)
+e_tree_model_node_set_data (ETreeModel *etm, ETreePath *node, gpointer node_data)
 {
-	ETM_CLASS(etree)->release_paths (etree, paths, num_paths);
+	ENode *enode;
+
+	g_return_if_fail (node && node->data);
+
+	enode = (ENode*)node->data;
+
+	enode->node_data = node_data;
 }
 
+ETreePath*
+e_tree_model_node_insert (ETreeModel *tree_model,
+			  ETreePath *parent_path,
+			  int position,
+			  gpointer node_data)
+{
+	ENode *node;
+	ETreePath *new_path;
+
+	g_return_val_if_fail (parent_path != NULL || tree_model->root == NULL, NULL);
+
+	node = g_new0 (ENode, 1);
+
+	node->expanded = FALSE;
+	node->node_data = node_data;
+
+	if (parent_path != NULL) {
+
+		new_path = g_node_new (node);
+
+		g_node_insert (parent_path, position, new_path);
+
+		if (e_tree_model_node_is_visible (tree_model, new_path)) {
+			int parent_row;
+			GNode *node;
+
+			/* we need to iterate back up to the root, incrementing the number of visible
+			   descendents */
+			for (node = parent_path; node; node = node->parent) {
+				ENode *parent_enode = (ENode*)node->data;
+
+				parent_enode->visible_descendents ++;
+			}
+				
+			/* finally, insert a row into the table */
+			parent_row = e_tree_model_row_of_node (tree_model, parent_path);
+
+			tree_model->row_array = g_array_insert_val (tree_model->row_array,
+								    parent_row + position + 1, new_path);
+		}
+	}
+	else {
+		tree_model->root = g_node_new (node);
+		if (tree_model->root_visible)
+			tree_model->row_array = g_array_insert_val (tree_model->row_array, 0, tree_model->root);
+		new_path = tree_model->root;
+	}
+
+	/* FIXME: find out the number of descendents that will be visible,
+	   and call insert_row that many times. */
+	e_table_model_changed (E_TABLE_MODEL(tree_model));
+
+	return new_path;
+}
+			  
+ETreePath *
+e_tree_model_node_insert_before (ETreeModel *etree, ETreePath *parent,
+				 ETreePath *sibling, gpointer node_data)
+{
+	return e_tree_model_node_insert (etree, parent,
+					 g_node_child_position (parent, sibling),
+					 node_data);
+}
+
+gpointer
+e_tree_model_node_remove (ETreeModel *etree, ETreePath *path)
+{
+	GNode *parent = path->parent;
+	ENode *enode = (ENode*)path->data;
+	gpointer ret = enode->node_data;
+
+	g_return_val_if_fail (!g_node_first_child(path), NULL);
+
+	/* clean up the display */
+	if (parent) {
+		if (e_tree_model_node_is_visible (etree, path)) {
+			int row = e_tree_model_row_of_node (etree, path);
+			etree->row_array = g_array_remove_index (etree->row_array, row);
+			e_table_model_row_deleted (E_TABLE_MODEL (etree), row);
+
+			/* we need to iterate back up to the root, incrementing the number of visible
+			   descendents */
+			for (; parent; parent = parent->parent) {
+				ENode *parent_enode = (ENode*)parent->data;
+
+				parent_enode->visible_descendents --;
+			}
+		}
+	}
+	else if (path == etree->root) {
+		etree->root = NULL;
+		if (etree->root_visible) {
+			etree->row_array = g_array_remove_index (etree->row_array, 0);
+			e_table_model_row_deleted (E_TABLE_MODEL (etree), 0);
+		}
+	}
+	else {
+		/* XXX invalid path */
+		return NULL;
+	}
+
+
+	/* now free up the storage from that path */
+	g_node_destroy (path);
+	g_free (enode);
+
+	return ret;
+}
+
+
+static void
+add_visible_descendents_to_array (ETreeModel *etm, GNode *gnode, int *row, int *count)
+{
+	GNode *child;
+	ENode *enode;
+
+	/* add a row for this node */
+	etm->row_array = g_array_insert_val (etm->row_array, (*row), gnode);
+	e_table_model_row_inserted (E_TABLE_MODEL (etm), (*row)++);
+	(*count) ++;
+
+	/* then loop over its children, calling this routine for each
+           of them */
+	enode = (ENode*)gnode->data;
+	if (enode->expanded) {
+		for (child = g_node_first_child (gnode); child;
+		     child = g_node_next_sibling (child)) {
+			add_visible_descendents_to_array (etm, child, row, count);
+		}
+	}
+}
diff --git a/widgets/table/e-tree-model.h b/widgets/table/e-tree-model.h
index 6924f3ea0e..45351b8f6c 100644
--- a/widgets/table/e-tree-model.h
+++ b/widgets/table/e-tree-model.h
@@ -10,18 +10,13 @@
 #define E_IS_TREE_MODEL(o)       (GTK_CHECK_TYPE ((o), E_TREE_MODEL_TYPE))
 #define E_IS_TREE_MODEL_CLASS(k) (GTK_CHECK_CLASS_TYPE ((k), E_TREE_MODEL_TYPE))
 
-typedef gpointer ETreePathItem;
-typedef GList ETreePath;
+typedef GNode ETreePath;
 
 typedef struct {
 	ETableModel base;
-
-	ETableModel *source;
-
-	ETreePath *root_node;
-
-	GArray  *array;
-
+	GNode      *root;
+	gboolean   root_visible;
+	GArray     *row_array; /* used in the mapping between ETable and our tree */
 } ETreeModel;
 
 typedef struct {
@@ -32,41 +27,75 @@ typedef struct {
 	 */
 	ETreePath *(*get_root)      (ETreeModel *etm);
 
+	ETreePath *(*get_parent)    (ETreeModel *etm, ETreePath* node);
 	ETreePath *(*get_next)      (ETreeModel *etm, ETreePath* node);
 	ETreePath *(*get_prev)      (ETreeModel *etm, ETreePath* node);
+	guint      (*get_children)         (ETreeModel *etm, ETreePath* node, ETreePath ***paths);
+
+	gboolean   (*is_expanded)          (ETreeModel *etm, ETreePath* node);
+	gboolean   (*is_visible)           (ETreeModel *etm, ETreePath* node);
+	void       (*set_expanded)         (ETreeModel *etm, ETreePath* node, gboolean expanded);
+	void       (*set_expanded_recurse) (ETreeModel *etm, ETreePath *node, gboolean expanded);
+	void       (*set_expanded_level)   (ETreeModel *etm, ETreePath *node, gboolean expanded, int level);
 
+	ETreePath* (*node_at_row)          (ETreeModel *etm, int row);
+
+	/*
+	 * ETable analogs
+	 */
 	void      *(*value_at)      (ETreeModel *etm, ETreePath* node, int col);
 	void       (*set_value_at)  (ETreeModel *etm, ETreePath* node, int col, const void *val);
 	gboolean   (*is_editable)   (ETreeModel *etm, ETreePath* node, int col);
 
-	guint      (*get_children)  (ETreeModel *etm, ETreePath* node, ETreePath ***paths);
-	void       (*release_paths) (ETreeModel *etm, ETreePath **paths, guint num_paths);
-	gboolean   (*is_expanded)   (ETreeModel *etm, ETreePath* node);
-	void       (*set_expanded)  (ETreeModel *etm, ETreePath* node, gboolean expanded);
 
 	/*
 	 * Signals
 	 */
+	void       (*node_changed)  (ETreeModel *etm, ETreePath *node);
+	void       (*node_inserted) (ETreeModel *etm, ETreePath *parent, ETreePath *inserted_node);
+	void       (*node_removed)  (ETreeModel *etm, ETreePath *parent, ETreePath *removed_node);
 
 } ETreeModelClass;
 
 GtkType     e_tree_model_get_type (void);
-
+void        e_tree_model_construct (ETreeModel *etree);
 ETreeModel *e_tree_model_new (void);
 
-/* operations on "nodes" in the tree */
-ETreePath * e_tree_model_get_root (ETreeModel *etree);
-ETreePath * e_tree_model_node_at_row (ETreeModel *etree, int row);
-guint e_tree_model_node_depth (ETreeModel *etree, ETreePath *path);
+/* tree traversal operations */
+ETreePath *e_tree_model_get_root        (ETreeModel *etree);
 ETreePath *e_tree_model_node_get_parent (ETreeModel *etree, ETreePath *path);
-ETreePath *e_tree_model_node_get_next (ETreeModel *etree, ETreePath *path);
-ETreePath *e_tree_model_node_get_prev (ETreeModel *etree, ETreePath *path);
-gboolean e_tree_model_node_is_root (ETreeModel *etree, ETreePath *path);
-
-gboolean e_tree_model_node_is_expandable (ETreeModel *etree, ETreePath *path);
-gboolean e_tree_model_node_is_expanded (ETreeModel *etree, ETreePath *path);
-guint e_tree_model_node_get_children (ETreeModel *etree, ETreePath *path, ETreePath ***paths);
-void e_tree_model_release_paths (ETreeModel *etree, ETreePath **paths, guint num_paths);
-guint e_tree_model_node_num_visible_descendents (ETreeModel *etm, ETreePath *node);
+ETreePath *e_tree_model_node_get_next   (ETreeModel *etree, ETreePath *path);
+ETreePath *e_tree_model_node_get_prev   (ETreeModel *etree, ETreePath *path);
+
+/* node operations */
+ETreePath *e_tree_model_node_insert        (ETreeModel *etree, ETreePath *parent, int position, gpointer node_data);
+ETreePath *e_tree_model_node_insert_before (ETreeModel *etree, ETreePath *parent, ETreePath *sibling, gpointer node_data);
+gpointer   e_tree_model_node_remove        (ETreeModel *etree, ETreePath *path);
+
+/* node accessors */
+gboolean e_tree_model_node_is_root                 (ETreeModel *etree, ETreePath *path);
+gboolean e_tree_model_node_is_expandable           (ETreeModel *etree, ETreePath *path);
+gboolean e_tree_model_node_is_expanded             (ETreeModel *etree, ETreePath *path);
+gboolean e_tree_model_node_is_visible              (ETreeModel *etree, ETreePath *path);
+void     e_tree_model_node_set_expanded            (ETreeModel *etree, ETreePath *path, gboolean expanded);
+void     e_tree_model_node_set_expanded_recurse    (ETreeModel *etree, ETreePath *path, gboolean expanded);
+guint    e_tree_model_node_get_children            (ETreeModel *etree, ETreePath *path, ETreePath ***paths);
+guint    e_tree_model_node_depth                   (ETreeModel *etree, ETreePath *path);
+guint    e_tree_model_node_num_visible_descendents (ETreeModel *etm, ETreePath *node);
+gpointer e_tree_model_node_get_data                (ETreeModel *etm, ETreePath *node);
+void     e_tree_model_node_set_data                (ETreeModel *etm, ETreePath *node, gpointer node_data);
+
+/* display oriented routines */
+ETreePath *e_tree_model_node_at_row           (ETreeModel *etree, int row);
+int        e_tree_model_row_of_node           (ETreeModel *etree, ETreePath *path);
+void       e_tree_model_root_node_set_visible (ETreeModel *etree, gboolean visible);
+gboolean   e_tree_model_root_node_is_visible  (ETreeModel *etree);
+
+/*
+** Routines for emitting signals on the ETreeModel
+*/
+void  e_tree_model_node_changed  (ETreeModel *tree_model, ETreePath *node);
+void  e_tree_model_node_inserted (ETreeModel *tree_model, ETreePath *parent_node, ETreePath *inserted_node);
+void  e_tree_model_node_removed  (ETreeModel *tree_model, ETreePath *parent_node, ETreePath *removed_node);
 
 #endif /* _E_TREE_MODEL_H */
diff --git a/widgets/table/e-tree-simple.c b/widgets/table/e-tree-simple.c
new file mode 100644
index 0000000000..9bf747a43f
--- /dev/null
+++ b/widgets/table/e-tree-simple.c
@@ -0,0 +1,73 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+/*
+ * e-tree-simple.c: a Tree Model that offers a function pointer
+ * interface to using ETreeModel, similar to ETableSimple.
+ *
+ * Author:
+ *   Chris Toshok (toshok@helixcode.com)
+ *
+ * (C) 2000 Helix Code, Inc.  */
+
+#include <config.h>
+#include <gtk/gtksignal.h>
+#include "e-util/e-util.h"
+#include "e-tree-simple.h"
+
+#define PARENT_TYPE E_TREE_MODEL_TYPE
+
+static void *
+simple_value_at (ETreeModel *etm, ETreePath *node, int col)
+{
+	ETreeSimple *simple = E_TREE_SIMPLE(etm);
+
+	return simple->value_at (etm, node, col, simple->model_data);
+}
+
+static void
+simple_set_value_at (ETreeModel *etm, ETreePath *node, int col, const void *val)
+{
+	ETreeSimple *simple = E_TREE_SIMPLE(etm);
+
+	simple->set_value_at (etm, node, col, val, simple->model_data);
+}
+
+static gboolean
+simple_is_editable (ETreeModel *etm, ETreePath *node, int col)
+{
+	ETreeSimple *simple = E_TREE_SIMPLE(etm);
+
+	return simple->is_editable (etm, node, col, simple->model_data);
+}
+
+static void
+e_tree_simple_class_init (GtkObjectClass *object_class)
+{
+	ETreeModelClass *model_class = (ETreeModelClass *) object_class;
+
+	model_class->value_at = simple_value_at;
+	model_class->set_value_at = simple_set_value_at;
+	model_class->is_editable = simple_is_editable;
+}
+
+E_MAKE_TYPE(e_tree_simple, "ETreeSimple", ETreeSimple, e_tree_simple_class_init, NULL, PARENT_TYPE)
+
+ETreeModel *
+e_tree_simple_new (ETreeSimpleValueAtFn value_at,
+		   ETreeSimpleSetValueAtFn set_value_at,
+		   ETreeSimpleIsEditableFn is_editable,
+		   gpointer model_data)
+{
+	ETreeSimple *etg;
+
+	etg = gtk_type_new (e_tree_simple_get_type ());
+
+	e_tree_model_construct (E_TREE_MODEL (etg));
+
+	etg->value_at = value_at;
+	etg->set_value_at = set_value_at;
+	etg->is_editable = is_editable;
+	etg->model_data = model_data;
+
+	return (ETreeModel*)etg;
+}
+
diff --git a/widgets/table/e-tree-simple.h b/widgets/table/e-tree-simple.h
new file mode 100644
index 0000000000..6820b14673
--- /dev/null
+++ b/widgets/table/e-tree-simple.h
@@ -0,0 +1,40 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+
+#ifndef _E_TREE_SIMPLE_H_
+#define _E_TREE_SIMPLE_H_
+
+#include "e-tree-model.h"
+
+#define E_TREE_SIMPLE_TYPE        (e_tree_simple_get_type ())
+#define E_TREE_SIMPLE(o)          (GTK_CHECK_CAST ((o), E_TREE_SIMPLE_TYPE, ETreeSimple))
+#define E_TREE_SIMPLE_CLASS(k)    (GTK_CHECK_CLASS_CAST((k), E_TREE_SIMPLE_TYPE, ETreeSimpleClass))
+#define E_IS_TREE_SIMPLE(o)       (GTK_CHECK_TYPE ((o), E_TREE_SIMPLE_TYPE))
+#define E_IS_TREE_SIMPLE_CLASS(k) (GTK_CHECK_CLASS_TYPE ((k), E_TREE_SIMPLE_TYPE))
+
+
+typedef void*    (*ETreeSimpleValueAtFn)    (ETreeModel *etree, ETreePath *path, int col, void *model_data);
+typedef void     (*ETreeSimpleSetValueAtFn) (ETreeModel *etree, ETreePath *path, int col, const void *val, void *model_data);
+typedef gboolean (*ETreeSimpleIsEditableFn) (ETreeModel *etree, ETreePath *path, int col, void *model_data);
+
+typedef struct {
+	ETreeModel parent;
+
+	ETreeSimpleValueAtFn value_at;
+	ETreeSimpleSetValueAtFn set_value_at;
+	ETreeSimpleIsEditableFn is_editable;
+
+	gpointer model_data;
+} ETreeSimple;
+
+typedef struct {
+	ETreeModelClass parent_class;
+} ETreeSimpleClass;
+
+GtkType e_tree_simple_get_type (void);
+
+ETreeModel *e_tree_simple_new (ETreeSimpleValueAtFn value_at,
+			       ETreeSimpleSetValueAtFn set_value_at,
+			       ETreeSimpleIsEditableFn is_editable,
+			       gpointer model_data);
+
+#endif /* _E_TREE_SIMPLE_H_ */