path: root/e-util/e-tree.c

/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 *
 * Authors:
 *      Chris Lahey <clahey@ximian.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <gtk/gtk.h>
#include <glib/gi18n.h>
#include <gdk/gdkkeysyms.h>

#include <libgnomecanvas/libgnomecanvas.h>

#include "e-canvas-background.h"
#include "e-canvas-utils.h"
#include "e-canvas.h"
#include "e-table-column-specification.h"
#include "e-table-header-item.h"
#include "e-table-header.h"
#include "e-table-item.h"
#include "e-table-sort-info.h"
#include "e-table-utils.h"
#include "e-text.h"
#include "e-tree-selection-model.h"
#include "e-tree-table-adapter.h"
#include "e-tree.h"
#include "gal-a11y-e-tree.h"

#define COLUMN_HEADER_HEIGHT 16

#define d(x)

#define E_TREE_GET_PRIVATE(obj) \
    (G_TYPE_INSTANCE_GET_PRIVATE \
    ((obj), E_TYPE_TREE, ETreePrivate))

typedef struct _ETreeDragSourceSite ETreeDragSourceSite;

enum {
    CURSOR_CHANGE,
    CURSOR_ACTIVATED,
    SELECTION_CHANGE,
    DOUBLE_CLICK,
    RIGHT_CLICK,
    CLICK,
    KEY_PRESS,
    START_DRAG,
    STATE_CHANGE,
    WHITE_SPACE_EVENT,

    CUT_CLIPBOARD,
    COPY_CLIPBOARD,
    PASTE_CLIPBOARD,
    SELECT_ALL,

    TREE_DRAG_BEGIN,
    TREE_DRAG_END,
    TREE_DRAG_DATA_GET,
    TREE_DRAG_DATA_DELETE,

    TREE_DRAG_LEAVE,
    TREE_DRAG_MOTION,
    TREE_DRAG_DROP,
    TREE_DRAG_DATA_RECEIVED,

    LAST_SIGNAL
};

enum {
    PROP_0,
    PROP_LENGTH_THRESHOLD,
    PROP_HORIZONTAL_DRAW_GRID,
    PROP_VERTICAL_DRAW_GRID,
    PROP_DRAW_FOCUS,
    PROP_ETTA,
    PROP_UNIFORM_ROW_HEIGHT,
    PROP_IS_EDITING,
    PROP_ALWAYS_SEARCH,
    PROP_HADJUSTMENT,
    PROP_VADJUSTMENT,
    PROP_HSCROLL_POLICY,
    PROP_VSCROLL_POLICY
};

enum {
    ET_SCROLL_UP = 1 << 0,
    ET_SCROLL_DOWN = 1 << 1,
    ET_SCROLL_LEFT = 1 << 2,
    ET_SCROLL_RIGHT = 1 << 3
};

struct _ETreePrivate {
    ETreeModel *model;
    ETreeTableAdapter *etta;

    ETableHeader *full_header, *header;

    guint structure_change_id, expansion_change_id;

    ETableSortInfo *sort_info;

    guint sort_info_change_id, group_info_change_id;

    ESelectionModel *selection;
    ETableSpecification *spec;

    ETableSearch     *search;

    ETableCol        *current_search_col;

    guint     search_search_id;
    guint     search_accept_id;

    gint reflow_idle_id;
    gint scroll_idle_id;
    gint hover_idle_id;

    gboolean show_cursor_after_reflow;

    gint table_model_change_id;
    gint table_row_change_id;
    gint table_cell_change_id;
    gint table_rows_delete_id;

    GnomeCanvasItem *info_text;
    guint info_text_resize_id;

    GnomeCanvas *header_canvas, *table_canvas;

    GnomeCanvasItem *header_item, *root;

    GnomeCanvasItem *white_item;
    GnomeCanvasItem *item;

    gint length_threshold;

    /*
     * Configuration settings
     */
    guint alternating_row_colors : 1;
    guint horizontal_draw_grid : 1;
    guint vertical_draw_grid : 1;
    guint draw_focus : 1;
    guint row_selection_active : 1;

    guint horizontal_scrolling : 1;

    guint scroll_direction : 4;

    guint do_drag : 1;

    guint uniform_row_height : 1;

    guint search_col_set : 1;
    guint always_search : 1;

    ECursorMode cursor_mode;

    gint drop_row;
    ETreePath drop_path;
    gint drop_col;

    GnomeCanvasItem *drop_highlight;
    gint last_drop_x;
    gint last_drop_y;
    gint last_drop_time;
    GdkDragContext *last_drop_context;

    gint hover_x;
    gint hover_y;

    gint drag_row;
    ETreePath drag_path;
    gint drag_col;
    ETreeDragSourceSite *site;

    GList *expanded_list;

    gboolean state_changed;
    guint state_change_freeze;

    gboolean is_dragging;
};

static guint signals[LAST_SIGNAL];

static void et_grab_focus (GtkWidget *widget);

static void et_drag_begin (GtkWidget *widget,
               GdkDragContext *context,
               ETree *tree);
static void et_drag_end (GtkWidget *widget,
             GdkDragContext *context,
             ETree *tree);
static void et_drag_data_get (GtkWidget *widget,
                 GdkDragContext *context,
                 GtkSelectionData *selection_data,
                 guint info,
                 guint time,
                 ETree *tree);
static void et_drag_data_delete (GtkWidget *widget,
                GdkDragContext *context,
                ETree *tree);

static void et_drag_leave (GtkWidget *widget,
              GdkDragContext *context,
              guint time,
              ETree *tree);
static gboolean et_drag_motion (GtkWidget *widget,
                   GdkDragContext *context,
                   gint x,
                   gint y,
                   guint time,
                   ETree *tree);
static gboolean et_drag_drop (GtkWidget *widget,
                 GdkDragContext *context,
                 gint x,
                 gint y,
                 guint time,
                 ETree *tree);
static void et_drag_data_received (GtkWidget *widget,
                  GdkDragContext *context,
                  gint x,
                  gint y,
                  GtkSelectionData *selection_data,
                  guint info,
                  guint time,
                  ETree *tree);

static void scroll_off (ETree *tree);
static void scroll_on (ETree *tree, guint scroll_direction);
static void hover_off (ETree *tree);
static void hover_on (ETree *tree, gint x, gint y);
static void context_destroyed (gpointer data, GObject *ctx);

G_DEFINE_TYPE_WITH_CODE (ETree, e_tree, GTK_TYPE_TABLE,
             G_IMPLEMENT_INTERFACE (GTK_TYPE_SCROLLABLE, NULL))

static void
tree_item_is_editing_changed_cb (ETableItem *item,
                 GParamSpec *param,
                 ETree *tree)
{
    g_return_if_fail (E_IS_TREE (tree));

    g_object_notify (G_OBJECT (tree), "is-editing");
}

static void
et_disconnect_from_etta (ETree *tree)
{
    if (tree->priv->table_model_change_id != 0)
        g_signal_handler_disconnect (
            tree->priv->etta,
            tree->priv->table_model_change_id);
    if (tree->priv->table_row_change_id != 0)
        g_signal_handler_disconnect (
            tree->priv->etta,
            tree->priv->table_row_change_id);
    if (tree->priv->table_cell_change_id != 0)
        g_signal_handler_disconnect (
            tree->priv->etta,
            tree->priv->table_cell_change_id);
    if (tree->priv->table_rows_delete_id != 0)
        g_signal_handler_disconnect (
            tree->priv->etta,
            tree->priv->table_rows_delete_id);

    tree->priv->table_model_change_id = 0;
    tree->priv->table_row_change_id = 0;
    tree->priv->table_cell_change_id = 0;
    tree->priv->table_rows_delete_id = 0;
}

static void
clear_current_search_col (ETree *tree)
{
    tree->priv->search_col_set = FALSE;
}

static ETableCol *
current_search_col (ETree *tree)
{
    if (!tree->priv->search_col_set) {
        tree->priv->current_search_col =
            e_table_util_calculate_current_search_col (
                tree->priv->header,
                tree->priv->full_header,
                tree->priv->sort_info,
                tree->priv->always_search);
        tree->priv->search_col_set = TRUE;
    }

    return tree->priv->current_search_col;
}

static void
e_tree_state_change (ETree *tree)
{
    if (tree->priv->state_change_freeze)
        tree->priv->state_changed = TRUE;
    else
        g_signal_emit (tree, signals[STATE_CHANGE], 0);
}

static void
change_trigger (GObject *object,
                ETree *tree)
{
    e_tree_state_change (tree);
}

static void
search_col_change_trigger (GObject *object,
                           ETree *tree)
{
    clear_current_search_col (tree);
    e_tree_state_change (tree);
}

static void
disconnect_header (ETree *tree)
{
    if (tree->priv->header == NULL)
        return;

    if (tree->priv->structure_change_id)
        g_signal_handler_disconnect (
            tree->priv->header,
            tree->priv->structure_change_id);
    if (tree->priv->expansion_change_id)
        g_signal_handler_disconnect (
            tree->priv->header,
            tree->priv->expansion_change_id);
    if (tree->priv->sort_info) {
        if (tree->priv->sort_info_change_id)
            g_signal_handler_disconnect (
                tree->priv->sort_info,
                tree->priv->sort_info_change_id);
        if (tree->priv->group_info_change_id)
            g_signal_handler_disconnect (
                tree->priv->sort_info,
                tree->priv->group_info_change_id);

        g_object_unref (tree->priv->sort_info);
    }
    g_object_unref (tree->priv->header);
    tree->priv->header = NULL;
    tree->priv->sort_info = NULL;
}

static void
connect_header (ETree *tree,
                ETableState *state)
{
    GValue *val = g_new0 (GValue, 1);

    if (tree->priv->header != NULL)
        disconnect_header (tree);

    tree->priv->header = e_table_state_to_header (
        GTK_WIDGET (tree), tree->priv->full_header, state);

    tree->priv->structure_change_id = g_signal_connect (
        tree->priv->header, "structure_change",
        G_CALLBACK (search_col_change_trigger), tree);

    tree->priv->expansion_change_id = g_signal_connect (
        tree->priv->header, "expansion_change",
        G_CALLBACK (change_trigger), tree);

    if (state->sort_info) {
        tree->priv->sort_info = e_table_sort_info_duplicate (state->sort_info);
        e_table_sort_info_set_can_group (tree->priv->sort_info, FALSE);
        tree->priv->sort_info_change_id = g_signal_connect (
            tree->priv->sort_info, "sort_info_changed",
            G_CALLBACK (search_col_change_trigger), tree);

        tree->priv->group_info_change_id = g_signal_connect (
            tree->priv->sort_info, "group_info_changed",
            G_CALLBACK (search_col_change_trigger), tree);
    } else
        tree->priv->sort_info = NULL;

    g_value_init (val, G_TYPE_OBJECT);
    g_value_set_object (val, tree->priv->sort_info);
    g_object_set_property (G_OBJECT (tree->priv->header), "sort_info", val);
    g_free (val);
}

static void
et_dispose (GObject *object)
{
    ETreePrivate *priv;

    priv = E_TREE_GET_PRIVATE (object);

    if (priv->search != NULL) {
        g_signal_handler_disconnect (
            priv->search, priv->search_search_id);
        g_signal_handler_disconnect (
            priv->search, priv->search_accept_id);
        g_object_unref (priv->search);
        priv->search = NULL;
    }

    if (priv->reflow_idle_id > 0) {
        g_source_remove (priv->reflow_idle_id);
        priv->reflow_idle_id = 0;
    }

    scroll_off (E_TREE (object));
    hover_off (E_TREE (object));
    g_list_foreach (
        priv->expanded_list,
        (GFunc) g_free, NULL);
    g_list_free (priv->expanded_list);
    priv->expanded_list = NULL;

    et_disconnect_from_etta (E_TREE (object));

    if (priv->etta != NULL) {
        g_object_unref (priv->etta);
        priv->etta = NULL;
    }

    if (priv->model != NULL) {
        g_object_unref (priv->model);
        priv->model = NULL;
    }

    if (priv->full_header != NULL) {
        g_object_unref (priv->full_header);
        priv->full_header = NULL;
    }

    disconnect_header (E_TREE (object));

    if (priv->selection != NULL) {
        g_object_unref (priv->selection);
        priv->selection = NULL;
    }

    if (priv->spec != NULL) {
        g_object_unref (priv->spec);
        priv->spec = NULL;
    }

    if (priv->header_canvas != NULL) {
        gtk_widget_destroy (GTK_WIDGET (priv->header_canvas));
        priv->header_canvas = NULL;
    }

    if (priv->site)
        e_tree_drag_source_unset (E_TREE (object));

    if (priv->last_drop_context != NULL) {
        g_object_weak_unref (
            G_OBJECT (priv->last_drop_context),
            context_destroyed, object);
        priv->last_drop_context = NULL;
    }

    if (priv->info_text != NULL) {
        g_object_run_dispose (G_OBJECT (priv->info_text));
        priv->info_text = NULL;
    }
    priv->info_text_resize_id = 0;

    if (priv->table_canvas != NULL) {
        gtk_widget_destroy (GTK_WIDGET (priv->table_canvas));
        priv->table_canvas = NULL;
    }

    /* do not unref it, it was owned by priv->table_canvas */
    priv->item = NULL;

    /* Chain up to parent's dispose() method. */
    G_OBJECT_CLASS (e_tree_parent_class)->dispose (object);
}

static void
et_unrealize (GtkWidget *widget)
{
    scroll_off (E_TREE (widget));
    hover_off (E_TREE (widget));

    if (GTK_WIDGET_CLASS (e_tree_parent_class)->unrealize)
        GTK_WIDGET_CLASS (e_tree_parent_class)->unrealize (widget);
}

typedef struct {
    ETree *tree;
    gchar *string;
} SearchSearchStruct;

static gboolean
search_search_callback (ETreeModel *model,
                        ETreePath path,
                        gpointer data)
{
    SearchSearchStruct *cb_data = data;
    gconstpointer value;
    ETableCol *col = current_search_col (cb_data->tree);

    value = e_tree_model_value_at (
        model, path,
        cb_data->tree->priv->current_search_col->spec->model_col);

    return col->search (value, cb_data->string);
}

static gboolean
et_search_search (ETableSearch *search,
                  gchar *string,
                  ETableSearchFlags flags,
                  ETree *tree)
{
    ETreePath cursor;
    ETreePath found;
    SearchSearchStruct cb_data;
    ETableCol *col = current_search_col (tree);

    if (col == NULL)
        return FALSE;

    cb_data.tree = tree;
    cb_data.string = string;

    cursor = e_tree_get_cursor (tree);

    if (cursor && (flags & E_TABLE_SEARCH_FLAGS_CHECK_CURSOR_FIRST)) {
        gconstpointer value;

        value = e_tree_model_value_at (
            tree->priv->model, cursor, col->spec->model_col);

        if (col->search (value, string)) {
            return TRUE;
        }
    }

    found = e_tree_model_node_find (
        tree->priv->model, cursor, NULL,
        search_search_callback, &cb_data);
    if (found == NULL)
        found = e_tree_model_node_find (
            tree->priv->model, NULL, cursor,
            search_search_callback, &cb_data);

    if (found && found != cursor) {
        gint model_row;

        e_tree_table_adapter_show_node (tree->priv->etta, found);
        model_row = e_tree_table_adapter_row_of_node (tree->priv->etta, found);

        e_selection_model_select_as_key_press (
            E_SELECTION_MODEL (tree->priv->selection),
            model_row, col->spec->model_col,
            GDK_CONTROL_MASK);
        return TRUE;
    } else if (cursor && !(flags & E_TABLE_SEARCH_FLAGS_CHECK_CURSOR_FIRST)) {
        gconstpointer value;

        value = e_tree_model_value_at (
            tree->priv->model, cursor, col->spec->model_col);

        return col->search (value, string);
    } else
        return FALSE;
}

static void
et_search_accept (ETableSearch *search,
                  ETree *tree)
{
    ETableCol *col = current_search_col (tree);
    gint cursor;

    if (col == NULL)
        return;

    g_object_get (tree->priv->selection, "cursor_row", &cursor, NULL);

    e_selection_model_select_as_key_press (
        E_SELECTION_MODEL (tree->priv->selection),
        cursor, col->spec->model_col, 0);
}

static void
e_tree_init (ETree *tree)
{
    gtk_widget_set_can_focus (GTK_WIDGET (tree), TRUE);

    gtk_table_set_homogeneous (GTK_TABLE (tree), FALSE);

    tree->priv = E_TREE_GET_PRIVATE (tree);

    tree->priv->alternating_row_colors = 1;
    tree->priv->horizontal_draw_grid = 1;
    tree->priv->vertical_draw_grid = 1;
    tree->priv->draw_focus = 1;
    tree->priv->cursor_mode = E_CURSOR_SIMPLE;
    tree->priv->length_threshold = 200;

    tree->priv->drop_row = -1;
    tree->priv->drop_col = -1;

    tree->priv->drag_row = -1;
    tree->priv->drag_col = -1;

    tree->priv->selection =
        E_SELECTION_MODEL (e_tree_selection_model_new ());

    tree->priv->search = e_table_search_new ();

    tree->priv->search_search_id = g_signal_connect (
        tree->priv->search, "search",
        G_CALLBACK (et_search_search), tree);

    tree->priv->search_accept_id = g_signal_connect (
        tree->priv->search, "accept",
        G_CALLBACK (et_search_accept), tree);

    tree->priv->always_search = g_getenv ("GAL_ALWAYS_SEARCH") ? TRUE : FALSE;

    tree->priv->state_changed = FALSE;
    tree->priv->state_change_freeze = 0;

    tree->priv->is_dragging = FALSE;
}

/* Grab_focus handler for the ETree */
static void
et_grab_focus (GtkWidget *widget)
{
    ETree *tree;

    tree = E_TREE (widget);

    gtk_widget_grab_focus (GTK_WIDGET (tree->priv->table_canvas));
}

/* Focus handler for the ETree */
static gint
et_focus (GtkWidget *container,
          GtkDirectionType direction)
{
    ETree *tree;

    tree = E_TREE (container);

    if (gtk_container_get_focus_child (GTK_CONTAINER (container))) {
        gtk_container_set_focus_child (GTK_CONTAINER (container), NULL);
        return FALSE;
    }

    return gtk_widget_child_focus (
        GTK_WIDGET (tree->priv->table_canvas), direction);
}

static void
set_header_canvas_width (ETree *tree)
{
    gdouble oldwidth, oldheight, width;

    if (!(tree->priv->header_item &&
        tree->priv->header_canvas && tree->priv->table_canvas))
        return;

    gnome_canvas_get_scroll_region (
        GNOME_CANVAS (tree->priv->table_canvas),
        NULL, NULL, &width, NULL);
    gnome_canvas_get_scroll_region (
        GNOME_CANVAS (tree->priv->header_canvas),
        NULL, NULL, &oldwidth, &oldheight);

    if (oldwidth != width ||
        oldheight != E_TABLE_HEADER_ITEM (tree->priv->header_item)->height - 1)
        gnome_canvas_set_scroll_region (
            GNOME_CANVAS (tree->priv->header_canvas),
            0, 0, width, /*  COLUMN_HEADER_HEIGHT - 1 */
            E_TABLE_HEADER_ITEM (tree->priv->header_item)->height - 1);

}

static void
header_canvas_size_allocate (GtkWidget *widget,
                             GtkAllocation *alloc,
                             ETree *tree)
{
    GtkAllocation allocation;

    set_header_canvas_width (tree);

    widget = GTK_WIDGET (tree->priv->header_canvas);
    gtk_widget_get_allocation (widget, &allocation);

    /* When the header item is created ->height == 0,
     * as the font is only created when everything is realized.
     * So we set the usize here as well, so that the size of the
     * header is correct */
    if (allocation.height != E_TABLE_HEADER_ITEM (tree->priv->header_item)->height)
        gtk_widget_set_size_request (
            widget, -1,
            E_TABLE_HEADER_ITEM (tree->priv->header_item)->height);
}

static void
e_tree_setup_header (ETree *tree)
{
    GtkWidget *widget;
    gchar *pointer;

    widget = e_canvas_new ();
    gtk_widget_set_can_focus (widget, FALSE);
    tree->priv->header_canvas = GNOME_CANVAS (widget);
    gtk_widget_show (widget);

    pointer = g_strdup_printf ("%p", (gpointer) tree);

    tree->priv->header_item = gnome_canvas_item_new (
        gnome_canvas_root (tree->priv->header_canvas),
        e_table_header_item_get_type (),
        "ETableHeader", tree->priv->header,
        "full_header", tree->priv->full_header,
        "sort_info", tree->priv->sort_info,
        "dnd_code", pointer,
        "tree", tree,
        NULL);

    g_free (pointer);

    g_signal_connect (
        tree->priv->header_canvas, "size_allocate",
        G_CALLBACK (header_canvas_size_allocate), tree);

    gtk_widget_set_size_request (
        GTK_WIDGET (tree->priv->header_canvas), -1,
        E_TABLE_HEADER_ITEM (tree->priv->header_item)->height);
}

static void
scroll_to_cursor (ETree *tree)
{
    ETreePath path;
    GtkAdjustment *adjustment;
    GtkScrollable *scrollable;
    gint x, y, w, h;
    gdouble page_size;
    gdouble lower;
    gdouble upper;
    gdouble value;

    path = e_tree_get_cursor (tree);
    x = y = w = h = 0;

    if (path != NULL) {
        ETreeTableAdapter *adapter;
        gint row;
        gint col = 0;

        adapter = e_tree_get_table_adapter (tree);
        row = e_tree_table_adapter_row_of_node (adapter, path);

        if (row >= 0)
            e_table_item_get_cell_geometry (
                E_TABLE_ITEM (tree->priv->item),
                &row, &col, &x, &y, &w, &h);
    }

    scrollable = GTK_SCROLLABLE (tree->priv->table_canvas);
    adjustment = gtk_scrollable_get_vadjustment (scrollable);

    page_size = gtk_adjustment_get_page_size (adjustment);
    lower = gtk_adjustment_get_lower (adjustment);
    upper = gtk_adjustment_get_upper (adjustment);
    value = gtk_adjustment_get_value (adjustment);

    if (y < value || y + h > value + page_size) {
        value = CLAMP (y - page_size / 2, lower, upper - page_size);
        gtk_adjustment_set_value (adjustment, value);
    }
}

static gboolean
tree_canvas_reflow_idle (ETree *tree)
{
    gdouble height, width;
    gdouble oldheight, oldwidth;
    GtkAllocation allocation;
    GtkWidget *widget;

    widget = GTK_WIDGET (tree->priv->table_canvas);
    gtk_widget_get_allocation (widget, &allocation);

    g_object_get (
        tree->priv->item,
        "height", &height, "width", &width, NULL);

    height = MAX ((gint) height, allocation.height);
    width = MAX ((gint) width, allocation.width);

    /* I have no idea why this needs to be -1, but it works. */
    gnome_canvas_get_scroll_region (
        GNOME_CANVAS (tree->priv->table_canvas),
        NULL, NULL, &oldwidth, &oldheight);

    if (oldwidth != width - 1 ||
        oldheight != height - 1) {
        gnome_canvas_set_scroll_region (
            GNOME_CANVAS (tree->priv->table_canvas),
            0, 0, width - 1, height - 1);
        set_header_canvas_width (tree);
    }

    tree->priv->reflow_idle_id = 0;

    if (tree->priv->show_cursor_after_reflow) {
        tree->priv->show_cursor_after_reflow = FALSE;
        scroll_to_cursor (tree);
    }

    return FALSE;
}

static void
tree_canvas_size_allocate (GtkWidget *widget,
                           GtkAllocation *alloc,
                           ETree *tree)
{
    gdouble width;
    gdouble height;
    GValue *val = g_new0 (GValue, 1);
    g_value_init (val, G_TYPE_DOUBLE);

    width = alloc->width;
    g_value_set_double (val, width);
    g_object_get (
        tree->priv->item,
        "height", &height,
        NULL);
    height = MAX ((gint) height, alloc->height);

    g_object_set (
        tree->priv->item,
        "width", width,
        NULL);
    g_object_set_property (G_OBJECT (tree->priv->header), "width", val);
    g_free (val);

    if (tree->priv->reflow_idle_id)
        g_source_remove (tree->priv->reflow_idle_id);
    tree_canvas_reflow_idle (tree);
}

static void
tree_canvas_reflow (GnomeCanvas *canvas,
                    ETree *tree)
{
    if (!tree->priv->reflow_idle_id)
        tree->priv->reflow_idle_id = g_idle_add_full (
            400, (GSourceFunc) tree_canvas_reflow_idle,
            tree, NULL);
}

static void
item_cursor_change (ETableItem *eti,
                    gint row,
                    ETree *tree)
{
    ETreePath path = e_tree_table_adapter_node_at_row (tree->priv->etta, row);

    g_signal_emit (tree, signals[CURSOR_CHANGE], 0, row, path);
}

static void
item_cursor_activated (ETableItem *eti,
                       gint row,
                       ETree *tree)
{
    ETreePath path = e_tree_table_adapter_node_at_row (tree->priv->etta, row);

    g_signal_emit (tree, signals[CURSOR_ACTIVATED], 0, row, path);
}

static void
item_double_click (ETableItem *eti,
                   gint row,
                   gint col,
                   GdkEvent *event,
                   ETree *tree)
{
    ETreePath path = e_tree_table_adapter_node_at_row (tree->priv->etta, row);

    g_signal_emit (tree, signals[DOUBLE_CLICK], 0, row, path, col, event);
}

static gboolean
item_right_click (ETableItem *eti,
                  gint row,
                  gint col,
                  GdkEvent *event,
                  ETree *tree)
{
    ETreePath path = e_tree_table_adapter_node_at_row (tree->priv->etta, row);
    gboolean return_val = 0;

    g_signal_emit (
        tree, signals[RIGHT_CLICK], 0,
        row, path, col, event, &return_val);

    return return_val;
}

static gboolean
item_click (ETableItem *eti,
            gint row,
            gint col,
            GdkEvent *event,
            ETree *tree)
{
    gboolean return_val = 0;
    ETreePath path = e_tree_table_adapter_node_at_row (tree->priv->etta, row);

    g_signal_emit (
        tree, signals[CLICK], 0, row, path, col, event, &return_val);

    return return_val;
}

static gint
item_key_press (ETableItem *eti,
                gint row,
                gint col,
                GdkEvent *event,
                ETree *tree)
{
    gint return_val = 0;
    GdkEventKey *key = (GdkEventKey *) event;
    ETreePath path;
    gint y, row_local, col_local;
    GtkAdjustment *adjustment;
    GtkScrollable *scrollable;
    gdouble page_size;
    gdouble upper;
    gdouble value;

    scrollable = GTK_SCROLLABLE (tree->priv->table_canvas);
    adjustment = gtk_scrollable_get_vadjustment (scrollable);

    page_size = gtk_adjustment_get_page_size (adjustment);
    upper = gtk_adjustment_get_upper (adjustment);
    value = gtk_adjustment_get_value (adjustment);

    switch (key->keyval) {
    case GDK_KEY_Page_Down:
    case GDK_KEY_KP_Page_Down:
        y = CLAMP (value + (2 * page_size - 50), 0, upper);
        y -= value;
        e_tree_get_cell_at (tree, 30, y, &row_local, &col_local);

        if (row_local == -1)
            row_local = e_table_model_row_count (
                E_TABLE_MODEL (tree->priv->etta)) - 1;

        col_local = e_selection_model_cursor_col (
            E_SELECTION_MODEL (tree->priv->selection));
        e_selection_model_select_as_key_press (
            E_SELECTION_MODEL (tree->priv->selection),
            row_local, col_local, key->state);

        return_val = 1;
        break;
    case GDK_KEY_Page_Up:
    case GDK_KEY_KP_Page_Up:
        y = CLAMP (value - (page_size - 50), 0, upper);
        y -= value;
        e_tree_get_cell_at (tree, 30, y, &row_local, &col_local);

        if (row_local == -1)
            row_local = e_table_model_row_count (
                E_TABLE_MODEL (tree->priv->etta)) - 1;

        col_local = e_selection_model_cursor_col (
            E_SELECTION_MODEL (tree->priv->selection));
        e_selection_model_select_as_key_press (
            E_SELECTION_MODEL (tree->priv->selection),
            row_local, col_local, key->state);

        return_val = 1;
        break;
    case GDK_KEY_plus:
    case GDK_KEY_KP_Add:
    case GDK_KEY_Right:
    case GDK_KEY_KP_Right:
        /* Only allow if the Shift modifier is used.
         * eg. Ctrl-Equal shouldn't be handled.  */
        if ((key->state & (GDK_SHIFT_MASK | GDK_LOCK_MASK |
            GDK_MOD1_MASK)) != GDK_SHIFT_MASK)
            break;
        if (row != -1) {
            path = e_tree_table_adapter_node_at_row (
                tree->priv->etta, row);
            if (path)
                e_tree_table_adapter_node_set_expanded (
                    tree->priv->etta, path, TRUE);
        }
        return_val = 1;
        break;
    case GDK_KEY_underscore:
    case GDK_KEY_KP_Subtract:
    case GDK_KEY_Left:
    case GDK_KEY_KP_Left:
        /* Only allow if the Shift modifier is used.
         * eg. Ctrl-Minus shouldn't be handled.  */
        if ((key->state & (GDK_SHIFT_MASK | GDK_LOCK_MASK |
            GDK_MOD1_MASK)) != GDK_SHIFT_MASK)
            break;
        if (row != -1) {
            path = e_tree_table_adapter_node_at_row (
                tree->priv->etta, row);
            if (path)
                e_tree_table_adapter_node_set_expanded (
                    tree->priv->etta, path, FALSE);
        }
        return_val = 1;
        break;
    case GDK_KEY_BackSpace:
        if (e_table_search_backspace (tree->priv->search))
            return TRUE;
        /* Fallthrough */
    default:
        if ((key->state & ~(GDK_SHIFT_MASK | GDK_LOCK_MASK |
            GDK_MOD1_MASK | GDK_MOD2_MASK | GDK_MOD3_MASK |
            GDK_MOD4_MASK | GDK_MOD5_MASK)) == 0
            && ((key->keyval >= GDK_KEY_a && key->keyval <= GDK_KEY_z) ||
            (key->keyval >= GDK_KEY_A && key->keyval <= GDK_KEY_Z) ||
            (key->keyval >= GDK_KEY_0 && key->keyval <= GDK_KEY_9))) {
            e_table_search_input_character (tree->priv->search, key->keyval);
        }
        path = e_tree_table_adapter_node_at_row (tree->priv->etta, row);
        g_signal_emit (
            tree,
            signals[KEY_PRESS], 0,
            row, path, col, event, &return_val);
        break;
    }
    return return_val;
}

static gint
item_start_drag (ETableItem *eti,
                 gint row,
                 gint col,
                 GdkEvent *event,
                 ETree *tree)
{
    ETreePath path;
    gint return_val = 0;

    path = e_tree_table_adapter_node_at_row (tree->priv->etta, row);

    g_signal_emit (
        tree, signals[START_DRAG], 0,
        row, path, col, event, &return_val);

    return return_val;
}

static void
et_selection_model_selection_changed (ETableSelectionModel *etsm,
                                      ETree *tree)
{
    g_signal_emit (tree, signals[SELECTION_CHANGE], 0);
}

static void
et_selection_model_selection_row_changed (ETableSelectionModel *etsm,
                                          gint row,
                                          ETree *tree)
{
    g_signal_emit (tree, signals[SELECTION_CHANGE], 0);
}

static void
et_build_item (ETree *tree)
{
    tree->priv->item = gnome_canvas_item_new (
        GNOME_CANVAS_GROUP (
            gnome_canvas_root (tree->priv->table_canvas)),
        e_table_item_get_type (),
        "ETableHeader", tree->priv->header,
        "ETableModel", tree->priv->etta,
        "selection_model", tree->priv->selection,
        "alternating_row_colors", tree->priv->alternating_row_colors,
        "horizontal_draw_grid", tree->priv->horizontal_draw_grid,
        "vertical_draw_grid", tree->priv->vertical_draw_grid,
        "drawfocus", tree->priv->draw_focus,
        "cursor_mode", tree->priv->cursor_mode,
        "length_threshold", tree->priv->length_threshold,
        "uniform_row_height", tree->priv->uniform_row_height,
        NULL);

    g_signal_connect (
        tree->priv->item, "cursor_change",
        G_CALLBACK (item_cursor_change), tree);
    g_signal_connect (
        tree->priv->item, "cursor_activated",
        G_CALLBACK (item_cursor_activated), tree);
    g_signal_connect (
        tree->priv->item, "double_click",
        G_CALLBACK (item_double_click), tree);
    g_signal_connect (
        tree->priv->item, "right_click",
        G_CALLBACK (item_right_click), tree);
    g_signal_connect (
        tree->priv->item, "click",
        G_CALLBACK (item_click), tree);
    g_signal_connect (
        tree->priv->item, "key_press",
        G_CALLBACK (item_key_press), tree);
    g_signal_connect (
        tree->priv->item, "start_drag",
        G_CALLBACK (item_start_drag), tree);
    g_signal_connect (
        tree->priv->item, "notify::is-editing",
        G_CALLBACK (tree_item_is_editing_changed_cb), tree);
}

static void
et_canvas_style_set (GtkWidget *widget,
                     GtkStyle *prev_style)
{
    GtkStyle *style;

    style = gtk_widget_get_style (widget);

    gnome_canvas_item_set (
        E_TREE (widget)->priv->white_item,
        "fill_color_gdk", &style->base[GTK_STATE_NORMAL],
        NULL);
}

static gboolean
white_item_event (GnomeCanvasItem *white_item,
                  GdkEvent *event,
                  ETree *tree)
{
    gboolean return_val = 0;

    g_signal_emit (
        tree,
        signals[WHITE_SPACE_EVENT], 0,
        event, &return_val);

    return return_val;
}

static gint
et_canvas_root_event (GnomeCanvasItem *root,
                      GdkEvent *event,
                      ETree *tree)
{
    switch (event->type) {
    case GDK_BUTTON_PRESS:
    case GDK_2BUTTON_PRESS:
    case GDK_BUTTON_RELEASE:
        if (event->button.button != 4 && event->button.button != 5) {
            if (gtk_widget_has_focus (GTK_WIDGET (root->canvas))) {
                GnomeCanvasItem *item = GNOME_CANVAS (root->canvas)->focused_item;

                if (E_IS_TABLE_ITEM (item)) {
                    e_table_item_leave_edit (E_TABLE_ITEM (item));
                    return TRUE;
                }
            }
        }
        break;
    default:
        break;
    }

    return FALSE;
}

/* Handler for focus events in the table_canvas; we have to repaint ourselves
 * and give the focus to some ETableItem.
 */
static gboolean
table_canvas_focus_event_cb (GtkWidget *widget,
                             GdkEventFocus *event,
                             gpointer data)
{
    GnomeCanvas *canvas;
    ETree *tree;

    gtk_widget_queue_draw (widget);

    if (!event->in)
        return TRUE;

    canvas = GNOME_CANVAS (widget);
    tree = E_TREE (data);

    if (!canvas->focused_item ||
        (e_selection_model_cursor_row (tree->priv->selection) == -1)) {
        e_table_item_set_cursor (E_TABLE_ITEM (tree->priv->item), 0, 0);
        gnome_canvas_item_grab_focus (tree->priv->item);
    }

    return TRUE;
}

static void
e_tree_setup_table (ETree *tree)
{
    GtkWidget *widget;
    GtkStyle *style;

    tree->priv->table_canvas = GNOME_CANVAS (e_canvas_new ());
    g_signal_connect (
        tree->priv->table_canvas, "size_allocate",
        G_CALLBACK (tree_canvas_size_allocate), tree);
    g_signal_connect (
        tree->priv->table_canvas, "focus_in_event",
        G_CALLBACK (table_canvas_focus_event_cb), tree);
    g_signal_connect (
        tree->priv->table_canvas, "focus_out_event",
        G_CALLBACK (table_canvas_focus_event_cb), tree);

    g_signal_connect (
        tree->priv->table_canvas, "drag_begin",
        G_CALLBACK (et_drag_begin), tree);
    g_signal_connect (
        tree->priv->table_canvas, "drag_end",
        G_CALLBACK (et_drag_end), tree);
    g_signal_connect (
        tree->priv->table_canvas, "drag_data_get",
        G_CALLBACK (et_drag_data_get), tree);
    g_signal_connect (
        tree->priv->table_canvas, "drag_data_delete",
        G_CALLBACK (et_drag_data_delete), tree);
    g_signal_connect (
        tree, "drag_motion",
        G_CALLBACK (et_drag_motion), tree);
    g_signal_connect (
        tree, "drag_leave",
        G_CALLBACK (et_drag_leave), tree);
    g_signal_connect (
        tree, "drag_drop",
        G_CALLBACK (et_drag_drop), tree);
    g_signal_connect (
        tree, "drag_data_received",
        G_CALLBACK (et_drag_data_received), tree);

    g_signal_connect (
        tree->priv->table_canvas, "reflow",
        G_CALLBACK (tree_canvas_reflow), tree);

    widget = GTK_WIDGET (tree->priv->table_canvas);
    style = gtk_widget_get_style (widget);

    gtk_widget_show (widget);

    tree->priv->white_item = gnome_canvas_item_new (
        gnome_canvas_root (tree->priv->table_canvas),
        e_canvas_background_get_type (),
        "fill_color_gdk", &style->base[GTK_STATE_NORMAL],
        NULL);

    g_signal_connect (
        tree->priv->white_item, "event",
        G_CALLBACK (white_item_event), tree);
    g_signal_connect (
        gnome_canvas_root (tree->priv->table_canvas), "event",
        G_CALLBACK (et_canvas_root_event), tree);

    et_build_item (tree);
}

void
e_tree_set_state_object (ETree *tree,
                         ETableState *state)
{
    GValue *val;
    GtkAllocation allocation;
    GtkWidget *widget;

    val = g_new0 (GValue, 1);
    g_value_init (val, G_TYPE_DOUBLE);

    connect_header (tree, state);

    widget = GTK_WIDGET (tree->priv->table_canvas);
    gtk_widget_get_allocation (widget, &allocation);

    g_value_set_double (val, (gdouble) allocation.width);
    g_object_set_property (G_OBJECT (tree->priv->header), "width", val);
    g_free (val);

    if (tree->priv->header_item)
        g_object_set (
            tree->priv->header_item,
            "ETableHeader", tree->priv->header,
            "sort_info", tree->priv->sort_info,
            NULL);

    if (tree->priv->item)
        g_object_set (
            tree->priv->item,
            "ETableHeader", tree->priv->header,
            NULL);

    if (tree->priv->etta)
        e_tree_table_adapter_set_sort_info (
            tree->priv->etta, tree->priv->sort_info);

    e_tree_state_change (tree);
}

/**
 * e_tree_set_state:
 * @tree: #ETree object that will be modified
 * @state_str: a string with the XML representation of the #ETableState.
 *
 * This routine sets the state (as described by #ETableState) of the
 * #ETree object.
 */
void
e_tree_set_state (ETree *tree,
                  const gchar *state_str)
{
    ETableState *state;

    g_return_if_fail (E_IS_TREE (tree));
    g_return_if_fail (state_str != NULL);

    state = e_table_state_new (tree->priv->spec);
    e_table_state_load_from_string (state, state_str);

    if (state->col_count > 0)
        e_tree_set_state_object (tree, state);

    g_object_unref (state);
}

/**
 * e_tree_get_state_object:
 * @tree: #ETree object to act on
 *
 * Builds an #ETableState corresponding to the current state of the
 * #ETree.
 *
 * Return value:
 * The %ETableState object generated.
 **/
ETableState *
e_tree_get_state_object (ETree *tree)
{
    ETableState *state;
    GPtrArray *columns;
    gint full_col_count;
    gint i, j;

    columns = e_table_specification_ref_columns (tree->priv->spec);

    state = e_table_state_new (tree->priv->spec);

    g_clear_object (&state->sort_info);
    if (tree->priv->sort_info != NULL)
        state->sort_info = g_object_ref (tree->priv->sort_info);

    state->col_count = e_table_header_count (tree->priv->header);
    full_col_count = e_table_header_count (tree->priv->full_header);

    state->column_specs = g_new (
        ETableColumnSpecification *, state->col_count);
    state->expansions = g_new (gdouble, state->col_count);

    for (i = 0; i < state->col_count; i++) {
        ETableCol *col = e_table_header_get_column (tree->priv->header, i);
        state->column_specs[i] = NULL;
        for (j = 0; j < full_col_count; j++) {
            if (col->spec->model_col == e_table_header_index (tree->priv->full_header, j)) {
                state->column_specs[i] =
                    g_object_ref (columns->pdata[j]);
                break;
            }
        }
        state->expansions[i] = col->expansion;
    }

    g_ptr_array_unref (columns);

    return state;
}

/**
 * e_tree_get_state:
 * @tree: The #ETree to act on
 *
 * Builds a state object based on the current state and returns the
 * string corresponding to that state.
 *
 * Return value:
 * A string describing the current state of the #ETree.
 **/
gchar *
e_tree_get_state (ETree *tree)
{
    ETableState *state;
    gchar *string;

    state = e_tree_get_state_object (tree);
    string = e_table_state_save_to_string (state);
    g_object_unref (state);
    return string;
}

/**
 * e_tree_get_spec:
 * @tree: The #ETree to query
 *
 * Returns the specification object.
 *
 * Return value:
 **/
ETableSpecification *
e_tree_get_spec (ETree *tree)
{
    g_return_val_if_fail (E_IS_TREE (tree), NULL);

    return tree->priv->spec;
}

static void
et_table_model_changed (ETableModel *model,
                        ETree *tree)
{
    if (tree->priv->horizontal_scrolling)
        e_table_header_update_horizontal (tree->priv->header);
}

static void
et_table_row_changed (ETableModel *table_model,
                      gint row,
                      ETree *tree)
{
    et_table_model_changed (table_model, tree);
}

static void
et_table_cell_changed (ETableModel *table_model,
                       gint view_col,
                       gint row,
                       ETree *tree)
{
    et_table_model_changed (table_model, tree);
}

static void
et_table_rows_deleted (ETableModel *table_model,
                       gint row,
                       gint count,
                       ETree *tree)
{
    ETreeTableAdapter *adapter;
    ETreePath * node, * prev_node;

    /* If the cursor is still valid after this deletion, we're done */
    if (e_selection_model_cursor_row (tree->priv->selection) >= 0
            || row == 0)
        return;

    adapter = e_tree_get_table_adapter (tree);
    prev_node = e_tree_table_adapter_node_at_row (adapter, row - 1);
    node = e_tree_get_cursor (tree);

    /* Check if the cursor is a child of the node directly before the
     * deleted region (implying that an expander was collapsed with
     * the cursor inside it) */
    while (node) {
        node = e_tree_model_node_get_parent (tree->priv->model, node);
        if (node == prev_node) {
            /* Set the cursor to the still-visible parent */
            e_tree_set_cursor (tree, prev_node);
            return;
        }
    }
}

static void
et_connect_to_etta (ETree *tree)
{
    tree->priv->table_model_change_id = g_signal_connect (
        tree->priv->etta, "model_changed",
        G_CALLBACK (et_table_model_changed), tree);

    tree->priv->table_row_change_id = g_signal_connect (
        tree->priv->etta, "model_row_changed",
        G_CALLBACK (et_table_row_changed), tree);

    tree->priv->table_cell_change_id = g_signal_connect (
        tree->priv->etta, "model_cell_changed",
        G_CALLBACK (et_table_cell_changed), tree);

    tree->priv->table_rows_delete_id = g_signal_connect (
        tree->priv->etta, "model_rows_deleted",
        G_CALLBACK (et_table_rows_deleted), tree);

}

static gboolean
et_real_construct (ETree *tree,
                   ETreeModel *etm,
                   ETableExtras *ete,
                   ETableSpecification *specification,
                   ETableState *state)
{
    GtkAdjustment *adjustment;
    GtkScrollable *scrollable;
    gint row = 0;

    if (ete)
        g_object_ref (ete);
    else
        ete = e_table_extras_new ();

    tree->priv->alternating_row_colors = specification->alternating_row_colors;
    tree->priv->horizontal_draw_grid = specification->horizontal_draw_grid;
    tree->priv->vertical_draw_grid = specification->vertical_draw_grid;
    tree->priv->draw_focus = specification->draw_focus;
    tree->priv->cursor_mode = specification->cursor_mode;
    tree->priv->full_header = e_table_spec_to_full_header (specification, ete);

    connect_header (tree, state);

    tree->priv->horizontal_scrolling = specification->horizontal_scrolling;

    tree->priv->model = etm;
    g_object_ref (etm);

    tree->priv->etta = E_TREE_TABLE_ADAPTER (
        e_tree_table_adapter_new (
            tree->priv->model,
            tree->priv->sort_info,
            tree->priv->full_header));

    et_connect_to_etta (tree);

    g_object_set (
        tree->priv->selection,
        "model", tree->priv->model,
        "etta", tree->priv->etta,
        "selection_mode", specification->selection_mode,
        "cursor_mode", specification->cursor_mode,
        NULL);

    g_signal_connect (
        tree->priv->selection, "selection_changed",
        G_CALLBACK (et_selection_model_selection_changed), tree);
    g_signal_connect (
        tree->priv->selection, "selection_row_changed",
        G_CALLBACK (et_selection_model_selection_row_changed), tree);

    if (!specification->no_headers) {
        e_tree_setup_header (tree);
    }
    e_tree_setup_table (tree);

    scrollable = GTK_SCROLLABLE (tree->priv->table_canvas);

    adjustment = gtk_scrollable_get_vadjustment (scrollable);
    gtk_adjustment_set_step_increment (adjustment, 20);

    adjustment = gtk_scrollable_get_hadjustment (scrollable);
    gtk_adjustment_set_step_increment (adjustment, 20);

    if (!specification->no_headers) {
        /*
         * The header
         */
        gtk_table_attach (
            GTK_TABLE (tree),
            GTK_WIDGET (tree->priv->header_canvas),
            0, 1, 0 + row, 1 + row,
            GTK_FILL | GTK_EXPAND,
            GTK_FILL, 0, 0);
        row++;
    }

    gtk_table_attach (
        GTK_TABLE (tree),
        GTK_WIDGET (tree->priv->table_canvas),
        0, 1, 0 + row, 1 + row,
        GTK_FILL | GTK_EXPAND,
        GTK_FILL | GTK_EXPAND,
        0, 0);

    g_object_unref (ete);

    return TRUE;
}

/**
 * e_tree_construct:
 * @tree: The newly created #ETree object.
 * @etm: The model for this table.
 * @ete: An optional #ETableExtras.  (%NULL is valid.)
 * @specification: an #ETableSpecification
 *
 * This is the internal implementation of e_tree_new() for use by
 * subclasses or language bindings.  See e_tree_new() for details.
 *
 * Return value: %TRUE on success, %FALSE if an error occurred
 **/
gboolean
e_tree_construct (ETree *tree,
                  ETreeModel *etm,
                  ETableExtras *ete,
                  ETableSpecification *specification)
{
    ETableState *state;

    g_return_val_if_fail (E_IS_TREE (tree), FALSE);
    g_return_val_if_fail (E_IS_TREE_MODEL (etm), FALSE);
    g_return_val_if_fail (ete == NULL || E_IS_TABLE_EXTRAS (ete), FALSE);
    g_return_val_if_fail (E_IS_TABLE_SPECIFICATION (specification), FALSE);

    state = g_object_ref (specification->state);

    et_real_construct (tree, etm, ete, specification, state);

    tree->priv->spec = g_object_ref (specification);
    tree->priv->spec->allow_grouping = FALSE;

    g_object_unref (state);

    return TRUE;
}

/**
 * e_tree_new:
 * @etm: The model for this tree
 * @ete: An optional #ETableExtras  (%NULL is valid.)
 * @specification: an #ETableSpecification
 *
 * This function creates an #ETree from the given parameters.  The
 * #ETreeModel is a tree model to be represented.  The #ETableExtras
 * is an optional set of pixbufs, cells, and sorting functions to be
 * used when interpreting the spec.  If you pass in %NULL it uses the
 * default #ETableExtras.  (See e_table_extras_new()).
 *
 * @specification is the specification of the set of viewable columns and the
 * default sorting state and such.  @state is an optional string specifying
 * the current sorting state and such.
 *
 * Return value:
 * The newly created #ETree or %NULL if there's an error.
 **/
GtkWidget *
e_tree_new (ETreeModel *etm,
            ETableExtras *ete,
            ETableSpecification *specification)
{
    ETree *tree;

    g_return_val_if_fail (E_IS_TREE_MODEL (etm), NULL);
    g_return_val_if_fail (ete == NULL || E_IS_TABLE_EXTRAS (ete), NULL);
    g_return_val_if_fail (E_IS_TABLE_SPECIFICATION (specification), NULL);

    tree = g_object_new (E_TYPE_TREE, NULL);

    if (!e_tree_construct (tree, etm, ete, specification)) {
        g_object_unref (tree);
        return NULL;
    }

    return GTK_WIDGET (tree);
}

void
e_tree_show_cursor_after_reflow (ETree *tree)
{
    g_return_if_fail (E_IS_TREE (tree));

    tree->priv->show_cursor_after_reflow = TRUE;
}

void
e_tree_set_cursor (ETree *tree,
                   ETreePath path)
{
    g_return_if_fail (E_IS_TREE (tree));
    g_return_if_fail (path != NULL);

    e_tree_selection_model_select_single_path (
        E_TREE_SELECTION_MODEL (tree->priv->selection), path);
    e_tree_selection_model_change_cursor (
        E_TREE_SELECTION_MODEL (tree->priv->selection), path);
}

ETreePath
e_tree_get_cursor (ETree *tree)
{
    return e_tree_selection_model_get_cursor (
        E_TREE_SELECTION_MODEL (tree->priv->selection));
}

/* Standard functions */
static void
et_foreach_recurse (ETreeModel *model,
                    ETreePath path,
                    ETreeForeachFunc callback,
                    gpointer closure)
{
    ETreePath child;

    callback (path, closure);

    child = e_tree_model_node_get_first_child (E_TREE_MODEL (model), path);
    for (; child; child = e_tree_model_node_get_next (E_TREE_MODEL (model), child))
        if (child)
            et_foreach_recurse (model, child, callback, closure);
}

void
e_tree_path_foreach (ETree *tree,
                     ETreeForeachFunc callback,
                     gpointer closure)
{
    ETreePath root;

    g_return_if_fail (E_IS_TREE (tree));

    root = e_tree_model_get_root (tree->priv->model);

    if (root)
        et_foreach_recurse (tree->priv->model,
                    root,
                    callback,
                    closure);
}

static void
et_get_property (GObject *object,
                 guint property_id,
                 GValue *value,
                 GParamSpec *pspec)
{
    ETree *tree = E_TREE (object);

    switch (property_id) {
    case PROP_ETTA:
        g_value_set_object (value, tree->priv->etta);
        break;

    case PROP_UNIFORM_ROW_HEIGHT:
        g_value_set_boolean (value, tree->priv->uniform_row_height);
        break;

    case PROP_IS_EDITING:
        g_value_set_boolean (value, e_tree_is_editing (tree));
        break;

    case PROP_ALWAYS_SEARCH:
        g_value_set_boolean (value, tree->priv->always_search);
        break;

    case PROP_HADJUSTMENT:
        if (tree->priv->table_canvas)
            g_object_get_property (
                G_OBJECT (tree->priv->table_canvas),
                "hadjustment", value);
        else
            g_value_set_object (value, NULL);
        break;

    case PROP_VADJUSTMENT:
        if (tree->priv->table_canvas)
            g_object_get_property (
                G_OBJECT (tree->priv->table_canvas),
                "vadjustment", value);
        else
            g_value_set_object (value, NULL);
        break;

    case PROP_HSCROLL_POLICY:
        if (tree->priv->table_canvas)
            g_object_get_property (
                G_OBJECT (tree->priv->table_canvas),
                "hscroll-policy", value);
        else
            g_value_set_enum (value, 0);
        break;

    case PROP_VSCROLL_POLICY:
        if (tree->priv->table_canvas)
            g_object_get_property (
                G_OBJECT (tree->priv->table_canvas),
                "vscroll-policy", value);
        else
            g_value_set_enum (value, 0);
        break;

    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
        break;
    }
}

typedef struct {
    gchar     *arg;
    gboolean  setting;
} bool_closure;

static void
et_set_property (GObject *object,
                 guint property_id,
                 const GValue *value,
                 GParamSpec *pspec)
{
    ETree *tree = E_TREE (object);

    switch (property_id) {
    case PROP_LENGTH_THRESHOLD:
        tree->priv->length_threshold = g_value_get_int (value);
        if (tree->priv->item) {
            gnome_canvas_item_set (
                GNOME_CANVAS_ITEM (tree->priv->item),
                "length_threshold",
                tree->priv->length_threshold,
                NULL);
        }
        break;

    case PROP_HORIZONTAL_DRAW_GRID:
        tree->priv->horizontal_draw_grid = g_value_get_boolean (value);
        if (tree->priv->item) {
            gnome_canvas_item_set (
                GNOME_CANVAS_ITEM (tree->priv->item),
                "horizontal_draw_grid",
                tree->priv->horizontal_draw_grid,
                NULL);
        }
        break;

    case PROP_VERTICAL_DRAW_GRID:
        tree->priv->vertical_draw_grid = g_value_get_boolean (value);
        if (tree->priv->item) {
            gnome_canvas_item_set (
                GNOME_CANVAS_ITEM (tree->priv->item),
                "vertical_draw_grid",
                tree->priv->vertical_draw_grid,
                NULL);
        }
        break;

    case PROP_DRAW_FOCUS:
        tree->priv->draw_focus = g_value_get_boolean (value);
        if (tree->priv->item) {
            gnome_canvas_item_set (
                GNOME_CANVAS_ITEM (tree->priv->item),
                "drawfocus",
                tree->priv->draw_focus,
                NULL);
        }
        break;

    case PROP_UNIFORM_ROW_HEIGHT:
        tree->priv->uniform_row_height = g_value_get_boolean (value);
        if (tree->priv->item) {
            gnome_canvas_item_set (
                GNOME_CANVAS_ITEM (tree->priv->item),
                "uniform_row_height",
                tree->priv->uniform_row_height,
                NULL);
        }
        break;

    case PROP_ALWAYS_SEARCH:
        if (tree->priv->always_search == g_value_get_boolean (value))
            return;
        tree->priv->always_search = g_value_get_boolean (value);
        clear_current_search_col (tree);
        break;

    case PROP_HADJUSTMENT:
        if (tree->priv->table_canvas)
            g_object_set_property (
                G_OBJECT (tree->priv->table_canvas),
                "hadjustment", value);
        break;

    case PROP_VADJUSTMENT:
        if (tree->priv->table_canvas)
            g_object_set_property (
                G_OBJECT (tree->priv->table_canvas),
                "vadjustment", value);
        break;

    case PROP_HSCROLL_POLICY:
        if (tree->priv->table_canvas)
            g_object_set_property (
                G_OBJECT (tree->priv->table_canvas),
                "hscroll-policy", value);
        break;

    case PROP_VSCROLL_POLICY:
        if (tree->priv->table_canvas)
            g_object_set_property (
                G_OBJECT (tree->priv->table_canvas),
                "vscroll-policy", value);
        break;
    }
}

/**
 * e_tree_get_model:
 * @tree: the ETree
 *
 * Returns the model upon which this ETree is based.
 *
 * Returns: the model
 **/
ETreeModel *
e_tree_get_model (ETree *tree)
{
    g_return_val_if_fail (E_IS_TREE (tree), NULL);

    return tree->priv->model;
}

/**
 * e_tree_get_selection_model:
 * @tree: the ETree
 *
 * Returns the selection model of this ETree.
 *
 * Returns: the selection model
 **/
ESelectionModel *
e_tree_get_selection_model (ETree *tree)
{
    g_return_val_if_fail (E_IS_TREE (tree), NULL);

    return tree->priv->selection;
}

/**
 * e_tree_get_table_adapter:
 * @tree: the ETree
 *
 * Returns the table adapter this ETree uses.
 *
 * Returns: the model
 **/
ETreeTableAdapter *
e_tree_get_table_adapter (ETree *tree)
{
    g_return_val_if_fail (E_IS_TREE (tree), NULL);

    return tree->priv->etta;
}

ETableItem *
e_tree_get_item (ETree *tree)
{
    g_return_val_if_fail (E_IS_TREE (tree), NULL);

    return E_TABLE_ITEM (tree->priv->item);
}

GnomeCanvasItem *
e_tree_get_header_item (ETree *tree)
{
    g_return_val_if_fail (E_IS_TREE (tree), NULL);

    return tree->priv->header_item;
}

struct _ETreeDragSourceSite
{
    GdkModifierType    start_button_mask;
    GtkTargetList     *target_list;        /* Targets for drag data */
    GdkDragAction      actions;            /* Possible actions */
    GdkPixbuf         *pixbuf;             /* Icon for drag data */

    /* Stored button press information to detect drag beginning */
    gint               state;
    gint               x, y;
    gint               row, col;
};

typedef enum
{
  GTK_DRAG_STATUS_DRAG,
  GTK_DRAG_STATUS_WAIT,
  GTK_DRAG_STATUS_DROP
} GtkDragStatus;

typedef struct _GtkDragDestInfo GtkDragDestInfo;
typedef struct _GtkDragSourceInfo GtkDragSourceInfo;

struct _GtkDragDestInfo
{
  GtkWidget         *widget;       /* Widget in which drag is in */
  GdkDragContext    *context;      /* Drag context */
  GtkDragSourceInfo *proxy_source; /* Set if this is a proxy drag */
  GtkSelectionData  *proxy_data;   /* Set while retrieving proxied data */
  guint              dropped : 1;     /* Set after we receive a drop */
  guint32            proxy_drop_time; /* Timestamp for proxied drop */
  guint              proxy_drop_wait : 1; /* Set if we are waiting for a
                       * status reply before sending
                       * a proxied drop on.
                       */
  gint               drop_x, drop_y; /* Position of drop */
};

struct _GtkDragSourceInfo
{
  GtkWidget         *widget;
  GtkTargetList     *target_list; /* Targets for drag data */
  GdkDragAction      possible_actions; /* Actions allowed by source */
  GdkDragContext    *context;     /* drag context */
  GtkWidget         *icon_window; /* Window for drag */
  GtkWidget         *ipc_widget;  /* GtkInvisible for grab, message passing */
  GdkCursor         *cursor;      /* Cursor for drag */
  gint hot_x, hot_y;          /* Hot spot for drag */
  gint button;            /* mouse button starting drag */

  GtkDragStatus      status;      /* drag status */
  GdkEvent          *last_event;  /* motion event waiting for response */

  gint               start_x, start_y; /* Initial position */
  gint               cur_x, cur_y;     /* Current Position */

  GList             *selections;  /* selections we've claimed */

  GtkDragDestInfo   *proxy_dest;  /* Set if this is a proxy drag */

  guint              drop_timeout;     /* Timeout for aborting drop */
  guint              destroy_icon : 1; /* If true, destroy icon_window
                    */
};

/* Drag & drop stuff. */

/* Source side */

static gint
et_real_start_drag (ETree *tree,
                    gint row,
                    ETreePath path,
                    gint col,
                    GdkEvent *event)
{
    GtkDragSourceInfo *info;
    GdkDragContext *context;
    ETreeDragSourceSite *site;

    if (tree->priv->do_drag) {
        site = tree->priv->site;

        site->state = 0;
        context = e_tree_drag_begin (
            tree, row, col,
            site->target_list,
            site->actions,
            1, event);

        if (context) {
            info = g_dataset_get_data (context, "gtk-info");

            if (info && !info->icon_window) {
                if (site->pixbuf)
                    gtk_drag_set_icon_pixbuf (
                        context,
                        site->pixbuf,
                        -2, -2);
                else
                    gtk_drag_set_icon_default (context);
            }
        }
        return TRUE;
    }
    return FALSE;
}

void
e_tree_drag_source_set (ETree *tree,
                        GdkModifierType start_button_mask,
                        const GtkTargetEntry *targets,
                        gint n_targets,
                        GdkDragAction actions)
{
    ETreeDragSourceSite *site;
    GtkWidget *canvas;

    g_return_if_fail (E_IS_TREE (tree));

    canvas = GTK_WIDGET (tree->priv->table_canvas);
    site = tree->priv->site;

    tree->priv->do_drag = TRUE;

    gtk_widget_add_events (
        canvas,
        gtk_widget_get_events (canvas) |
        GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
        GDK_BUTTON_MOTION_MASK | GDK_STRUCTURE_MASK);

    if (site) {
        if (site->target_list)
            gtk_target_list_unref (site->target_list);
    } else {
        site = g_new0 (ETreeDragSourceSite, 1);
        tree->priv->site = site;
    }

    site->start_button_mask = start_button_mask;

    if (targets)
        site->target_list = gtk_target_list_new (targets, n_targets);
    else
        site->target_list = NULL;

    site->actions = actions;
}

void
e_tree_drag_source_unset (ETree *tree)
{
    ETreeDragSourceSite *site;

    g_return_if_fail (E_IS_TREE (tree));

    site = tree->priv->site;

    if (site) {
        if (site->target_list)
            gtk_target_list_unref (site->target_list);
        g_free (site);
        tree->priv->site = NULL;
    }
}

/* There probably should be functions for setting the targets
 * as a GtkTargetList
 */

GdkDragContext *
e_tree_drag_begin (ETree *tree,
                   gint row,
                   gint col,
                   GtkTargetList *targets,
                   GdkDragAction actions,
                   gint button,
                   GdkEvent *event)
{
    ETreePath path;

    g_return_val_if_fail (E_IS_TREE (tree), NULL);

    path = e_tree_table_adapter_node_at_row (tree->priv->etta, row);

    tree->priv->drag_row = row;
    tree->priv->drag_path = path;
    tree->priv->drag_col = col;

    return gtk_drag_begin (
        GTK_WIDGET (tree->priv->table_canvas),
        targets,
        actions,
        button,
        event);
}

/**
 * e_tree_is_dragging:
 * @tree: An #ETree widget
 *
 * Returns whether is @tree in a drag&drop operation.
 **/
gboolean
e_tree_is_dragging (ETree *tree)
{
    g_return_val_if_fail (E_IS_TREE (tree), FALSE);

    return tree->priv->is_dragging;
}

/**
 * e_tree_get_cell_at:
 * @tree: An ETree widget
 * @x: X coordinate for the pixel
 * @y: Y coordinate for the pixel
 * @row_return: Pointer to return the row value
 * @col_return: Pointer to return the column value
 *
 * Return the row and column for the cell in which the pixel at (@x, @y) is
 * contained.
 **/
void
e_tree_get_cell_at (ETree *tree,
                    gint x,
                    gint y,
                    gint *row_return,
                    gint *col_return)
{
    GtkAdjustment *adjustment;
    GtkScrollable *scrollable;

    g_return_if_fail (E_IS_TREE (tree));
    g_return_if_fail (row_return != NULL);
    g_return_if_fail (col_return != NULL);

    /* FIXME it would be nice if it could handle a NULL row_return or
     * col_return gracefully.  */

    if (row_return)
        *row_return = -1;
    if (col_return)
        *col_return = -1;

    scrollable = GTK_SCROLLABLE (tree->priv->table_canvas);

    adjustment = gtk_scrollable_get_hadjustment (scrollable);
    x += gtk_adjustment_get_value (adjustment);

    adjustment = gtk_scrollable_get_vadjustment (scrollable);
    y += gtk_adjustment_get_value (adjustment);

    e_table_item_compute_location (
        E_TABLE_ITEM (tree->priv->item),
        &x, &y, row_return, col_return);
}

/**
 * e_tree_get_cell_geometry:
 * @tree: The tree.
 * @row: The row to get the geometry of.
 * @col: The col to get the geometry of.
 * @x_return: Returns the x coordinate of the upper right hand corner
 * of the cell with respect to the widget.
 * @y_return: Returns the y coordinate of the upper right hand corner
 * of the cell with respect to the widget.
 * @width_return: Returns the width of the cell.
 * @height_return: Returns the height of the cell.
 *
 * Computes the data about this cell.
 **/
void
e_tree_get_cell_geometry (ETree *tree,
                          gint row,
                          gint col,
                          gint *x_return,
                          gint *y_return,
                          gint *width_return,
                          gint *height_return)
{
    GtkAdjustment *adjustment;
    GtkScrollable *scrollable;

    g_return_if_fail (E_IS_TREE (tree));
    g_return_if_fail (row >= 0);
    g_return_if_fail (col >= 0);

    /* FIXME it would be nice if it could handle a NULL row_return or
     * col_return gracefully.  */

    e_table_item_get_cell_geometry (
        E_TABLE_ITEM (tree->priv->item),
        &row, &col, x_return, y_return,
        width_return, height_return);

    scrollable = GTK_SCROLLABLE (tree->priv->table_canvas);

    if (x_return) {
        adjustment = gtk_scrollable_get_hadjustment (scrollable);
        (*x_return) -= gtk_adjustment_get_value (adjustment);
    }

    if (y_return) {
        adjustment = gtk_scrollable_get_vadjustment (scrollable);
        (*y_return) -= gtk_adjustment_get_value (adjustment);
    }
}

static void
et_drag_begin (GtkWidget *widget,
               GdkDragContext *context,
               ETree *tree)
{
    tree->priv->is_dragging = TRUE;

    g_signal_emit (
        tree,
        signals[TREE_DRAG_BEGIN], 0,
        tree->priv->drag_row,
        tree->priv->drag_path,
        tree->priv->drag_col,
        context);
}

static void
et_drag_end (GtkWidget *widget,
             GdkDragContext *context,
             ETree *tree)
{
    tree->priv->is_dragging = FALSE;

    g_signal_emit (
        tree,
        signals[TREE_DRAG_END], 0,
        tree->priv->drag_row,
        tree->priv->drag_path,
        tree->priv->drag_col,
        context);
}

static void
et_drag_data_get (GtkWidget *widget,
                  GdkDragContext *context,
                  GtkSelectionData *selection_data,
                  guint info,
                  guint time,
                  ETree *tree)
{
    g_signal_emit (
        tree,
        signals[TREE_DRAG_DATA_GET], 0,
        tree->priv->drag_row,
        tree->priv->drag_path,
        tree->priv->drag_col,
        context,
        selection_data,
        info,
        time);
}

static void
et_drag_data_delete (GtkWidget *widget,
                     GdkDragContext *context,
                     ETree *tree)
{
    g_signal_emit (
        tree,
        signals[TREE_DRAG_DATA_DELETE], 0,
        tree->priv->drag_row,
        tree->priv->drag_path,
        tree->priv->drag_col,
        context);
}

static gboolean
do_drag_motion (ETree *tree,
                GdkDragContext *context,
                gint x,
                gint y,
                guint time)
{
    gboolean ret_val = FALSE;
    gint row, col;
    ETreePath path;

    e_tree_get_cell_at (tree, x, y, &row, &col);

    if (row != tree->priv->drop_row && col != tree->priv->drop_col) {
        g_signal_emit (
            tree, signals[TREE_DRAG_LEAVE], 0,
            tree->priv->drop_row,
            tree->priv->drop_path,
            tree->priv->drop_col,
            context,
            time);
    }

    path = e_tree_table_adapter_node_at_row (tree->priv->etta, row);

    tree->priv->drop_row = row;
    tree->priv->drop_path = path;
    tree->priv->drop_col = col;
    g_signal_emit (
        tree, signals[TREE_DRAG_MOTION], 0,
        tree->priv->drop_row,
        tree->priv->drop_path,
        tree->priv->drop_col,
        context,
        x, y,
        time,
        &ret_val);

    return ret_val;
}

static gboolean
scroll_timeout (gpointer data)
{
    ETree *tree = data;
    gint dx = 0, dy = 0;
    GtkAdjustment *adjustment;
    GtkScrollable *scrollable;
    gdouble old_h_value;
    gdouble new_h_value;
    gdouble old_v_value;
    gdouble new_v_value;
    gdouble page_size;
    gdouble lower;
    gdouble upper;

    if (tree->priv->scroll_direction & ET_SCROLL_DOWN)
        dy += 20;
    if (tree->priv->scroll_direction & ET_SCROLL_UP)
        dy -= 20;

    if (tree->priv->scroll_direction & ET_SCROLL_RIGHT)
        dx += 20;
    if (tree->priv->scroll_direction & ET_SCROLL_LEFT)
        dx -= 20;

    scrollable = GTK_SCROLLABLE (tree->priv->table_canvas);

    adjustment = gtk_scrollable_get_hadjustment (scrollable);

    page_size = gtk_adjustment_get_page_size (adjustment);
    lower = gtk_adjustment_get_lower (adjustment);
    upper = gtk_adjustment_get_upper (adjustment);

    old_h_value = gtk_adjustment_get_value (adjustment);
    new_h_value = CLAMP (old_h_value + dx, lower, upper - page_size);

    gtk_adjustment_set_value (adjustment, new_h_value);

    adjustment = gtk_scrollable_get_vadjustment (scrollable);

    page_size = gtk_adjustment_get_page_size (adjustment);
    lower = gtk_adjustment_get_lower (adjustment);
    upper = gtk_adjustment_get_upper (adjustment);

    old_v_value = gtk_adjustment_get_value (adjustment);
    new_v_value = CLAMP (old_v_value + dy, lower, upper - page_size);

    gtk_adjustment_set_value (adjustment, new_v_value);

    if (new_h_value != old_h_value || new_v_value != old_v_value)
        do_drag_motion (
            tree,
            tree->priv->last_drop_context,
            tree->priv->last_drop_x,
            tree->priv->last_drop_y,
            tree->priv->last_drop_time);

    return TRUE;
}

static void
scroll_on (ETree *tree,
           guint scroll_direction)
{
    if (tree->priv->scroll_idle_id == 0 ||
            scroll_direction != tree->priv->scroll_direction) {
        if (tree->priv->scroll_idle_id != 0)
            g_source_remove (tree->priv->scroll_idle_id);
        tree->priv->scroll_direction = scroll_direction;
        tree->priv->scroll_idle_id = g_timeout_add (100, scroll_timeout, tree);
    }
}

static void
scroll_off (ETree *tree)
{
    if (tree->priv->scroll_idle_id) {
        g_source_remove (tree->priv->scroll_idle_id);
        tree->priv->scroll_idle_id = 0;
    }
}

static gboolean
hover_timeout (gpointer data)
{
    ETree *tree = data;
    gint x = tree->priv->hover_x;
    gint y = tree->priv->hover_y;
    gint row, col;
    ETreePath path;

    e_tree_get_cell_at (tree, x, y, &row, &col);

    path = e_tree_table_adapter_node_at_row (tree->priv->etta, row);
    if (path && e_tree_model_node_is_expandable (tree->priv->model, path)) {
        if (!e_tree_table_adapter_node_is_expanded (tree->priv->etta, path)) {
            tree->priv->expanded_list = g_list_prepend (
                tree->priv->expanded_list,
                e_tree_model_get_save_id (
                tree->priv->model, path));

            e_tree_table_adapter_node_set_expanded (
                tree->priv->etta, path, TRUE);
        }
    }

    return TRUE;
}

static void
hover_on (ETree *tree,
          gint x,
          gint y)
{
    tree->priv->hover_x = x;
    tree->priv->hover_y = y;
    if (tree->priv->hover_idle_id != 0)
        g_source_remove (tree->priv->hover_idle_id);
    tree->priv->hover_idle_id = g_timeout_add (500, hover_timeout, tree);
}

static void
hover_off (ETree *tree)
{
    if (tree->priv->hover_idle_id) {
        g_source_remove (tree->priv->hover_idle_id);
        tree->priv->hover_idle_id = 0;
    }
}

static void
collapse_drag (ETree *tree,
               ETreePath drop)
{
    GList *list;

    /* We only want to leave open parents of the node dropped in.
     * Not the node itself. */
    if (drop) {
        drop = e_tree_model_node_get_parent (tree->priv->model, drop);
    }

    for (list = tree->priv->expanded_list; list; list = list->next) {
        gchar *save_id = list->data;
        ETreePath path;

        path = e_tree_model_get_node_by_id (tree->priv->model, save_id);
        if (path) {
            ETreePath search;
            gboolean found = FALSE;

            for (search = drop; search;
                search = e_tree_model_node_get_parent (
                tree->priv->model, search)) {
                if (path == search) {
                    found = TRUE;
                    break;
                }
            }

            if (!found)
                e_tree_table_adapter_node_set_expanded (
                    tree->priv->etta, path, FALSE);
        }
        g_free (save_id);
    }
    g_list_free (tree->priv->expanded_list);
    tree->priv->expanded_list = NULL;
}

static void
context_destroyed (gpointer data,
                   GObject *ctx)
{
    ETree *tree = data;
    if (tree->priv) {
        tree->priv->last_drop_x       = 0;
        tree->priv->last_drop_y       = 0;
        tree->priv->last_drop_time    = 0;
        tree->priv->last_drop_context = NULL;
        collapse_drag (tree, NULL);
        scroll_off (tree);
        hover_off (tree);
    }
    g_object_unref (tree);
}

static void
context_connect (ETree *tree,
                 GdkDragContext *context)
{
    if (context == tree->priv->last_drop_context)
        return;

    if (tree->priv->last_drop_context)
        g_object_weak_unref (
            G_OBJECT (tree->priv->last_drop_context),
            context_destroyed, tree);
    else
        g_object_ref (tree);

    g_object_weak_ref (G_OBJECT (context), context_destroyed, tree);
}

static void
et_drag_leave (GtkWidget *widget,
               GdkDragContext *context,
               guint time,
               ETree *tree)
{
    g_signal_emit (
        tree,
        signals[TREE_DRAG_LEAVE], 0,
        tree->priv->drop_row,
        tree->priv->drop_path,
        tree->priv->drop_col,
        context,
        time);
    tree->priv->drop_row = -1;
    tree->priv->drop_col = -1;

    scroll_off (tree);
    hover_off (tree);
}

static gboolean
et_drag_motion (GtkWidget *widget,
                GdkDragContext *context,
                gint x,
                gint y,
                guint time,
                ETree *tree)
{
    GtkAllocation allocation;
    gint ret_val;
    guint direction = 0;

    tree->priv->last_drop_x = x;
    tree->priv->last_drop_y = y;
    tree->priv->last_drop_time = time;
    context_connect (tree, context);
    tree->priv->last_drop_context = context;

    if (tree->priv->hover_idle_id != 0) {
        if (abs (tree->priv->hover_x - x) > 3 ||
            abs (tree->priv->hover_y - y) > 3) {
            hover_on (tree, x, y);
        }
    } else {
        hover_on (tree, x, y);
    }

    ret_val = do_drag_motion (tree, context, x, y, time);

    gtk_widget_get_allocation (widget, &allocation);

    if (y < 20)
        direction |= ET_SCROLL_UP;
    if (y > allocation.height - 20)
        direction |= ET_SCROLL_DOWN;
    if (x < 20)
        direction |= ET_SCROLL_LEFT;
    if (x > allocation.width - 20)
        direction |= ET_SCROLL_RIGHT;

    if (direction != 0)
        scroll_on (tree, direction);
    else
        scroll_off (tree);

    return ret_val;
}

static gboolean
et_drag_drop (GtkWidget *widget,
              GdkDragContext *context,
              gint x,
              gint y,
              guint time,
              ETree *tree)
{
    gboolean ret_val = FALSE;
    gint row, col;
    ETreePath path;

    e_tree_get_cell_at (tree, x, y, &row, &col);

    path = e_tree_table_adapter_node_at_row (tree->priv->etta, row);

    if (row != tree->priv->drop_row && col != tree->priv->drop_row) {
        g_signal_emit (
            tree, signals[TREE_DRAG_LEAVE], 0,
            tree->priv->drop_row,
            tree->priv->drop_path,
            tree->priv->drop_col,
            context,
            time);
        g_signal_emit (
            tree, signals[TREE_DRAG_MOTION], 0,
            row,
            path,
            col,
            context,
            x,
            y,
            time,
            &ret_val);
    }
    tree->priv->drop_row = row;
    tree->priv->drop_path = path;
    tree->priv->drop_col = col;

    g_signal_emit (
        tree, signals[TREE_DRAG_DROP], 0,
        tree->priv->drop_row,
        tree->priv->drop_path,
        tree->priv->drop_col,
        context,
        x,
        y,
        time,
        &ret_val);

    tree->priv->drop_row = -1;
    tree->priv->drop_path = NULL;
    tree->priv->drop_col = -1;

    collapse_drag (tree, path);

    scroll_off (tree);
    return ret_val;
}

static void
et_drag_data_received (GtkWidget *widget,
                       GdkDragContext *context,
                       gint x,
                       gint y,
                       GtkSelectionData *selection_data,
                       guint info,
                       guint time,
                       ETree *tree)
{
    gint row, col;
    ETreePath path;

    e_tree_get_cell_at (tree, x, y, &row, &col);

    path = e_tree_table_adapter_node_at_row (tree->priv->etta, row);
    g_signal_emit (
        tree, signals[TREE_DRAG_DATA_RECEIVED], 0,
        row,
        path,
        col,
        context,
        x,
        y,
        selection_data,
        info,
        time);
}

static void
e_tree_class_init (ETreeClass *class)
{
    GObjectClass *object_class;
    GtkWidgetClass *widget_class;

    g_type_class_add_private (class, sizeof (ETreePrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->dispose = et_dispose;
    object_class->set_property = et_set_property;
    object_class->get_property = et_get_property;

    widget_class = GTK_WIDGET_CLASS (class);
    widget_class->grab_focus = et_grab_focus;
    widget_class->unrealize = et_unrealize;
    widget_class->style_set = et_canvas_style_set;
    widget_class->focus = et_focus;

    class->start_drag = et_real_start_drag;

    signals[CURSOR_CHANGE] = g_signal_new (
        "cursor_change",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, cursor_change),
        NULL, NULL,
        e_marshal_NONE__INT_POINTER,
        G_TYPE_NONE, 2,
        G_TYPE_INT,
        G_TYPE_POINTER);

    signals[CURSOR_ACTIVATED] = g_signal_new (
        "cursor_activated",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, cursor_activated),
        NULL, NULL,
        e_marshal_NONE__INT_POINTER,
        G_TYPE_NONE, 2,
        G_TYPE_INT,
        G_TYPE_POINTER);

    signals[SELECTION_CHANGE] = g_signal_new (
        "selection_change",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, selection_change),
        NULL, NULL,
        g_cclosure_marshal_VOID__VOID,
        G_TYPE_NONE, 0);

    signals[DOUBLE_CLICK] = g_signal_new (
        "double_click",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, double_click),
        NULL, NULL,
        e_marshal_NONE__INT_POINTER_INT_BOXED,
        G_TYPE_NONE, 4,
        G_TYPE_INT,
        G_TYPE_POINTER,
        G_TYPE_INT,
        GDK_TYPE_EVENT | G_SIGNAL_TYPE_STATIC_SCOPE);

    signals[RIGHT_CLICK] = g_signal_new (
        "right_click",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, right_click),
        g_signal_accumulator_true_handled, NULL,
        e_marshal_BOOLEAN__INT_POINTER_INT_BOXED,
        G_TYPE_BOOLEAN, 4,
        G_TYPE_INT,
        G_TYPE_POINTER,
        G_TYPE_INT,
        GDK_TYPE_EVENT | G_SIGNAL_TYPE_STATIC_SCOPE);

    signals[CLICK] = g_signal_new (
        "click",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, click),
        g_signal_accumulator_true_handled, NULL,
        e_marshal_BOOLEAN__INT_POINTER_INT_BOXED,
        G_TYPE_BOOLEAN, 4,
        G_TYPE_INT,
        G_TYPE_POINTER,
        G_TYPE_INT,
        GDK_TYPE_EVENT | G_SIGNAL_TYPE_STATIC_SCOPE);

    signals[KEY_PRESS] = g_signal_new (
        "key_press",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, key_press),
        g_signal_accumulator_true_handled, NULL,
        e_marshal_BOOLEAN__INT_POINTER_INT_BOXED,
        G_TYPE_BOOLEAN, 4,
        G_TYPE_INT,
        G_TYPE_POINTER,
        G_TYPE_INT,
        GDK_TYPE_EVENT | G_SIGNAL_TYPE_STATIC_SCOPE);

    signals[START_DRAG] = g_signal_new (
        "start_drag",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, start_drag),
        NULL, NULL,
        e_marshal_NONE__INT_POINTER_INT_BOXED,
        G_TYPE_NONE, 4,
        G_TYPE_INT,
        G_TYPE_POINTER,
        G_TYPE_INT,
        GDK_TYPE_EVENT | G_SIGNAL_TYPE_STATIC_SCOPE);

    signals[STATE_CHANGE] = g_signal_new (
        "state_change",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, state_change),
        NULL, NULL,
        g_cclosure_marshal_VOID__VOID,
        G_TYPE_NONE, 0);

    signals[WHITE_SPACE_EVENT] = g_signal_new (
        "white_space_event",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, white_space_event),
        g_signal_accumulator_true_handled, NULL,
        e_marshal_BOOLEAN__POINTER,
        G_TYPE_BOOLEAN, 1,
        GDK_TYPE_EVENT | G_SIGNAL_TYPE_STATIC_SCOPE);

    signals[TREE_DRAG_BEGIN] = g_signal_new (
        "tree_drag_begin",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, tree_drag_begin),
        NULL, NULL,
        e_marshal_NONE__INT_POINTER_INT_BOXED,
        G_TYPE_NONE, 4,
        G_TYPE_INT,
        G_TYPE_POINTER,
        G_TYPE_INT,
        GDK_TYPE_DRAG_CONTEXT);

    signals[TREE_DRAG_END] = g_signal_new (
        "tree_drag_end",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, tree_drag_end),
        NULL, NULL,
        e_marshal_NONE__INT_POINTER_INT_BOXED,
        G_TYPE_NONE, 4,
        G_TYPE_INT,
        G_TYPE_POINTER,
        G_TYPE_INT,
        GDK_TYPE_DRAG_CONTEXT);

    signals[TREE_DRAG_DATA_GET] = g_signal_new (
        "tree_drag_data_get",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, tree_drag_data_get),
        NULL, NULL,
        e_marshal_NONE__INT_POINTER_INT_OBJECT_BOXED_UINT_UINT,
        G_TYPE_NONE, 7,
        G_TYPE_INT,
        G_TYPE_POINTER,
        G_TYPE_INT,
        GDK_TYPE_DRAG_CONTEXT,
        GTK_TYPE_SELECTION_DATA | G_SIGNAL_TYPE_STATIC_SCOPE,
        G_TYPE_UINT,
        G_TYPE_UINT);

    signals[TREE_DRAG_DATA_DELETE] = g_signal_new (
        "tree_drag_data_delete",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, tree_drag_data_delete),
        NULL, NULL,
        e_marshal_NONE__INT_POINTER_INT_OBJECT,
        G_TYPE_NONE, 4,
        G_TYPE_INT,
        G_TYPE_POINTER,
        G_TYPE_INT,
        GDK_TYPE_DRAG_CONTEXT);

    signals[TREE_DRAG_LEAVE] = g_signal_new (
        "tree_drag_leave",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, tree_drag_leave),
        NULL, NULL,
        e_marshal_NONE__INT_POINTER_INT_OBJECT_UINT,
        G_TYPE_NONE, 5,
        G_TYPE_INT,
        G_TYPE_POINTER,
        G_TYPE_INT,
        GDK_TYPE_DRAG_CONTEXT,
        G_TYPE_UINT);

    signals[TREE_DRAG_MOTION] = g_signal_new (
        "tree_drag_motion",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, tree_drag_motion),
        NULL, NULL,
        e_marshal_BOOLEAN__INT_POINTER_INT_OBJECT_INT_INT_UINT,
        G_TYPE_BOOLEAN, 7,
        G_TYPE_INT,
        G_TYPE_POINTER,
        G_TYPE_INT,
        GDK_TYPE_DRAG_CONTEXT,
        G_TYPE_INT,
        G_TYPE_INT,
        G_TYPE_UINT);

    signals[TREE_DRAG_DROP] = g_signal_new (
        "tree_drag_drop",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, tree_drag_drop),
        NULL, NULL,
        e_marshal_BOOLEAN__INT_POINTER_INT_OBJECT_INT_INT_UINT,
        G_TYPE_BOOLEAN, 7,
        G_TYPE_INT,
        G_TYPE_POINTER,
        G_TYPE_INT,
        GDK_TYPE_DRAG_CONTEXT,
        G_TYPE_INT,
        G_TYPE_INT,
        G_TYPE_UINT);

    signals[TREE_DRAG_DATA_RECEIVED] = g_signal_new (
        "tree_drag_data_received",
        G_OBJECT_CLASS_TYPE (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETreeClass, tree_drag_data_received),
        NULL, NULL,
        e_marshal_NONE__INT_POINTER_INT_OBJECT_INT_INT_BOXED_UINT_UINT,
        G_TYPE_NONE, 9,
        G_TYPE_INT,
        G_TYPE_POINTER,
        G_TYPE_INT,
        GDK_TYPE_DRAG_CONTEXT,
        G_TYPE_INT,
        G_TYPE_INT,
        GTK_TYPE_SELECTION_DATA,
        G_TYPE_UINT,
        G_TYPE_UINT);

    g_object_class_install_property (
        object_class,
        PROP_LENGTH_THRESHOLD,
        g_param_spec_int (
            "length_threshold",
            "Length Threshold",
            "Length Threshold",
            0, G_MAXINT, 0,
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        object_class,
        PROP_HORIZONTAL_DRAW_GRID,
        g_param_spec_boolean (
            "horizontal_draw_grid",
            "Horizontal Draw Grid",
            "Horizontal Draw Grid",
            FALSE,
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        object_class,
        PROP_VERTICAL_DRAW_GRID,
        g_param_spec_boolean (
            "vertical_draw_grid",
            "Vertical Draw Grid",
            "Vertical Draw Grid",
            FALSE,
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        object_class,
        PROP_DRAW_FOCUS,
        g_param_spec_boolean (
            "drawfocus",
            "Draw focus",
            "Draw focus",
            FALSE,
            G_PARAM_WRITABLE));

    g_object_class_install_property (
        object_class,
        PROP_ETTA,
        g_param_spec_object (
            "ETreeTableAdapter",
            "ETree table adapter",
            "ETree table adapter",
            E_TYPE_TREE_TABLE_ADAPTER,
            G_PARAM_READABLE));

    g_object_class_install_property (
        object_class,
        PROP_UNIFORM_ROW_HEIGHT,
        g_param_spec_boolean (
            "uniform_row_height",
            "Uniform row height",
            "Uniform row height",
            FALSE,
            G_PARAM_READWRITE));

    g_object_class_install_property (
        object_class,
        PROP_IS_EDITING,
        g_param_spec_boolean (
            "is-editing",
            "Whether is in an editing mode",
            "Whether is in an editing mode",
            FALSE,
            G_PARAM_READABLE));

    g_object_class_install_property (
        object_class,
        PROP_ALWAYS_SEARCH,
        g_param_spec_boolean (
            "always_search",
            "Always search",
            "Always search",
            FALSE,
            G_PARAM_READWRITE));

    gtk_widget_class_install_style_property (
        widget_class,
        g_param_spec_int (
            "expander_size",
            "Expander Size",
            "Size of the expander arrow",
            0, G_MAXINT, 10,
            G_PARAM_READABLE));

    gtk_widget_class_install_style_property (
        widget_class,
        g_param_spec_int (
            "vertical-spacing",
            "Vertical Row Spacing",
            "Vertical space between rows. "
            "It is added to top and to bottom of a row",
            0, G_MAXINT, 3,
            G_PARAM_READABLE |
            G_PARAM_STATIC_STRINGS));

    /* Scrollable interface */
    g_object_class_override_property (
        object_class, PROP_HADJUSTMENT, "hadjustment");
    g_object_class_override_property (
        object_class, PROP_VADJUSTMENT, "vadjustment");
    g_object_class_override_property (
        object_class, PROP_HSCROLL_POLICY, "hscroll-policy");
    g_object_class_override_property (
        object_class, PROP_VSCROLL_POLICY, "vscroll-policy");

    gal_a11y_e_tree_init ();
}

static void
tree_size_allocate (GtkWidget *widget,
                    GtkAllocation *alloc,
                    ETree *tree)
{
    gdouble width;

    g_return_if_fail (E_IS_TREE (tree));
    g_return_if_fail (tree->priv->info_text != NULL);

    gnome_canvas_get_scroll_region (
        GNOME_CANVAS (tree->priv->table_canvas),
        NULL, NULL, &width, NULL);

    width -= 60.0;

    g_object_set (
        tree->priv->info_text, "width", width,
        "clip_width", width, NULL);
}

/**
 * e_tree_set_info_message:
 * @tree: #ETree instance
 * @info_message: Message to set. Can be NULL.
 *
 * Creates an info message in table area, or removes old.
 **/
void
e_tree_set_info_message (ETree *tree,
                         const gchar *info_message)
{
    GtkAllocation allocation;
    GtkWidget *widget;

    g_return_if_fail (E_IS_TREE (tree));

    if (!tree->priv->info_text && (!info_message || !*info_message))
        return;

    if (!info_message || !*info_message) {
        g_signal_handler_disconnect (tree, tree->priv->info_text_resize_id);
        g_object_run_dispose (G_OBJECT (tree->priv->info_text));
        tree->priv->info_text = NULL;
        return;
    }

    widget = GTK_WIDGET (tree->priv->table_canvas);
    gtk_widget_get_allocation (widget, &allocation);

    if (!tree->priv->info_text) {
        if (allocation.width > 60) {
            tree->priv->info_text = gnome_canvas_item_new (
                GNOME_CANVAS_GROUP (gnome_canvas_root (tree->priv->table_canvas)),
                e_text_get_type (),
                "line_wrap", TRUE,
                "clip", TRUE,
                "justification", GTK_JUSTIFY_LEFT,
                "text", info_message,
                "width", (gdouble) allocation.width - 60.0,
                "clip_width", (gdouble) allocation.width - 60.0,
                NULL);

            e_canvas_item_move_absolute (tree->priv->info_text, 30, 30);

            tree->priv->info_text_resize_id = g_signal_connect (
                tree, "size_allocate",
                G_CALLBACK (tree_size_allocate), tree);
        }
    } else
        gnome_canvas_item_set (tree->priv->info_text, "text", info_message, NULL);
}

void
e_tree_freeze_state_change (ETree *tree)
{
    g_return_if_fail (E_IS_TREE (tree));

    tree->priv->state_change_freeze++;
    if (tree->priv->state_change_freeze == 1)
        tree->priv->state_changed = FALSE;

    g_return_if_fail (tree->priv->state_change_freeze != 0);
}

void
e_tree_thaw_state_change (ETree *tree)
{
    g_return_if_fail (E_IS_TREE (tree));
    g_return_if_fail (tree->priv->state_change_freeze != 0);

    tree->priv->state_change_freeze--;
    if (tree->priv->state_change_freeze == 0 && tree->priv->state_changed) {
        tree->priv->state_changed = FALSE;
        e_tree_state_change (tree);
    }
}

gboolean
e_tree_is_editing (ETree *tree)
{
    g_return_val_if_fail (E_IS_TREE (tree), FALSE);

    return tree->priv->item && e_table_item_is_editing (E_TABLE_ITEM (tree->priv->item));
}