path: root/e-util/e-table-sort-info.c

/*
 * e-table-sort-info.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.
 *
 * 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 General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 *
 */

#include "e-table-sort-info.h"

#include <string.h>

#include "e-table-specification.h"
#include "e-xml-utils.h"

#define E_TABLE_SORT_INFO_GET_PRIVATE(obj) \
    (G_TYPE_INSTANCE_GET_PRIVATE \
    ((obj), E_TYPE_TABLE_SORT_INFO, ETableSortInfoPrivate))

typedef struct _ColumnData ColumnData;

struct _ETableSortInfoPrivate {
    GWeakRef specification;
    GArray *groupings;
    GArray *sortings;
    gboolean can_group;
};

struct _ColumnData {
    ETableColumnSpecification *column_spec;
    GtkSortType sort_type;
};

enum {
    PROP_0,
    PROP_SPECIFICATION
};

enum {
    SORT_INFO_CHANGED,
    GROUP_INFO_CHANGED,
    LAST_SIGNAL
};

static guint signals[LAST_SIGNAL];

G_DEFINE_TYPE (ETableSortInfo , e_table_sort_info, G_TYPE_OBJECT)

static void
column_data_clear (ColumnData *data)
{
    g_clear_object (&data->column_spec);
}

static void
table_sort_info_parser_start_group (GMarkupParseContext *context,
                                    const gchar *element_name,
                                    const gchar **attribute_names,
                                    const gchar **attribute_values,
                                    ETableSortInfo *sort_info,
                                    GPtrArray *columns,
                                    GError **error)
{
    const gchar *index_str;
    gboolean ascending;
    gboolean success;

    success = g_markup_collect_attributes (
        element_name,
        attribute_names,
        attribute_values,
        error,

        G_MARKUP_COLLECT_STRING,
        "column",
        &index_str,

        G_MARKUP_COLLECT_BOOLEAN |
        G_MARKUP_COLLECT_OPTIONAL,
        "ascending",
        &ascending,

        G_MARKUP_COLLECT_INVALID);

    if (success) {
        ETableColumnSpecification *column_spec;
        ColumnData column_data;
        gint64 index;

        g_return_if_fail (index_str != NULL);
        index = g_ascii_strtoll (index_str, NULL, 10);

        g_return_if_fail (index < columns->len);
        column_spec = g_ptr_array_index (columns, index);

        column_data.column_spec = g_object_ref (column_spec);

        if (ascending)
            column_data.sort_type = GTK_SORT_ASCENDING;
        else
            column_data.sort_type = GTK_SORT_DESCENDING;

        g_array_append_val (sort_info->priv->groupings, column_data);
    }
}

static void
table_sort_info_parser_start_leaf (GMarkupParseContext *context,
                                   const gchar *element_name,
                                   const gchar **attribute_names,
                                   const gchar **attribute_values,
                                   ETableSortInfo *sort_info,
                                   GPtrArray *columns,
                                   GError **error)
{
    const gchar *index_str;
    gboolean ascending;
    gboolean success;

    success = g_markup_collect_attributes (
        element_name,
        attribute_names,
        attribute_values,
        error,

        G_MARKUP_COLLECT_STRING,
        "column",
        &index_str,

        G_MARKUP_COLLECT_BOOLEAN |
        G_MARKUP_COLLECT_OPTIONAL,
        "ascending",
        &ascending,

        G_MARKUP_COLLECT_INVALID);

    if (success) {
        ETableColumnSpecification *column_spec;
        ColumnData column_data;
        gint64 index;

        g_return_if_fail (index_str != NULL);
        index = g_ascii_strtoll (index_str, NULL, 10);

        g_return_if_fail (index < columns->len);
        column_spec = g_ptr_array_index (columns, index);

        column_data.column_spec = g_object_ref (column_spec);

        if (ascending)
            column_data.sort_type = GTK_SORT_ASCENDING;
        else
            column_data.sort_type = GTK_SORT_DESCENDING;

        g_array_append_val (sort_info->priv->sortings, column_data);
    }
}

static void
table_sort_info_parser_start_element (GMarkupParseContext *context,
                                      const gchar *element_name,
                                      const gchar **attribute_names,
                                      const gchar **attribute_values,
                                      gpointer user_data,
                                      GError **error)
{
    ETableSpecification *specification;
    ETableSortInfo *sort_info;
    GPtrArray *columns;

    sort_info = E_TABLE_SORT_INFO (user_data);
    specification = e_table_sort_info_ref_specification (sort_info);
    columns = e_table_specification_ref_columns (specification);

    if (g_str_equal (element_name, "group"))
        table_sort_info_parser_start_group (
            context,
            element_name,
            attribute_names,
            attribute_values,
            sort_info,
            columns,
            error);

    if (g_str_equal (element_name, "leaf"))
        table_sort_info_parser_start_leaf (
            context,
            element_name,
            attribute_names,
            attribute_values,
            sort_info,
            columns,
            error);

    g_object_unref (specification);
    g_ptr_array_unref (columns);
}

static void
table_sort_info_parser_error (GMarkupParseContext *context,
                              GError *error,
                              gpointer user_data)
{
    g_object_unref (E_TABLE_SORT_INFO (user_data));
}

static const GMarkupParser table_sort_info_parser = {
    table_sort_info_parser_start_element,
    NULL,
    NULL,
    NULL,
    table_sort_info_parser_error
};

static void
table_sort_info_set_specification (ETableSortInfo *sort_info,
                                   ETableSpecification *specification)
{
    g_return_if_fail (E_IS_TABLE_SPECIFICATION (specification));

    g_weak_ref_set (&sort_info->priv->specification, specification);
}

static void
table_sort_info_set_property (GObject *object,
                              guint property_id,
                              const GValue *value,
                              GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_SPECIFICATION:
            table_sort_info_set_specification (
                E_TABLE_SORT_INFO (object),
                g_value_get_object (value));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
table_sort_info_get_property (GObject *object,
                              guint property_id,
                              GValue *value,
                              GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_SPECIFICATION:
            g_value_take_object (
                value,
                e_table_sort_info_ref_specification (
                E_TABLE_SORT_INFO (object)));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
table_sort_info_dispose (GObject *object)
{
    ETableSortInfoPrivate *priv;

    priv = E_TABLE_SORT_INFO_GET_PRIVATE (object);

    g_weak_ref_set (&priv->specification, NULL);

    g_array_set_size (priv->groupings, 0);
    g_array_set_size (priv->sortings, 0);

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

static void
table_sort_info_finalize (GObject *object)
{
    ETableSortInfoPrivate *priv;

    priv = E_TABLE_SORT_INFO_GET_PRIVATE (object);

    g_array_free (priv->groupings, TRUE);
    g_array_free (priv->sortings, TRUE);

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

static void
e_table_sort_info_class_init (ETableSortInfoClass *class)
{
    GObjectClass * object_class;

    g_type_class_add_private (class, sizeof (ETableSortInfoPrivate));

    object_class = G_OBJECT_CLASS (class);
    object_class->set_property = table_sort_info_set_property;
    object_class->get_property = table_sort_info_get_property;
    object_class->dispose = table_sort_info_dispose;
    object_class->finalize = table_sort_info_finalize;

    g_object_class_install_property (
        object_class,
        PROP_SPECIFICATION,
        g_param_spec_object (
            "specification",
            "Table Specification",
            "Specification for the table state",
            E_TYPE_TABLE_SPECIFICATION,
            G_PARAM_READWRITE |
            G_PARAM_CONSTRUCT_ONLY |
            G_PARAM_STATIC_STRINGS));

    signals[SORT_INFO_CHANGED] = g_signal_new (
        "sort_info_changed",
        G_TYPE_FROM_CLASS (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETableSortInfoClass, sort_info_changed),
        (GSignalAccumulator) NULL, NULL,
        g_cclosure_marshal_VOID__VOID,
        G_TYPE_NONE, 0);

    signals[GROUP_INFO_CHANGED] = g_signal_new (
        "group_info_changed",
        G_TYPE_FROM_CLASS (object_class),
        G_SIGNAL_RUN_LAST,
        G_STRUCT_OFFSET (ETableSortInfoClass, group_info_changed),
        (GSignalAccumulator) NULL, NULL,
        g_cclosure_marshal_VOID__VOID,
        G_TYPE_NONE, 0);
}

static void
e_table_sort_info_init (ETableSortInfo *sort_info)
{
    sort_info->priv = E_TABLE_SORT_INFO_GET_PRIVATE (sort_info);

    sort_info->priv->groupings = g_array_new (
        FALSE, TRUE, sizeof (ColumnData));
    g_array_set_clear_func (
        sort_info->priv->groupings,
        (GDestroyNotify) column_data_clear);

    sort_info->priv->sortings = g_array_new (
        FALSE, TRUE, sizeof (ColumnData));
    g_array_set_clear_func (
        sort_info->priv->sortings,
        (GDestroyNotify) column_data_clear);

    sort_info->priv->can_group = TRUE;
}

/**
 * e_table_sort_info_new:
 * @specification: an #ETableSpecification
 *
 * This creates a new #ETableSortInfo object that contains no
 * grouping and no sorting defined as of yet.  This object is used
 * to keep track of multi-level sorting and multi-level grouping of
 * an #ETable.
 *
 * Returns: A new #ETableSortInfo object
 */
ETableSortInfo *
e_table_sort_info_new (ETableSpecification *specification)
{
    g_return_val_if_fail (E_IS_TABLE_SPECIFICATION (specification), NULL);

    return g_object_new (
        E_TYPE_TABLE_SORT_INFO,
        "specification", specification, NULL);
}

/**
 * e_table_sort_info_parse_context_push:
 * @context: a #GMarkupParseContext
 * @specification: an #ETableSpecification
 *
 * Creates a new #ETableSortInfo from a segment of XML data being fed to
 * @context.  Call this function for the appropriate opening tag from the
 * <structfield>start_element</structfield> callback of a #GMarkupParser,
 * then call e_table_sort_info_parse_context_pop() for the corresponding
 * closing tag from the <structfield>end_element</structfield> callback.
 **/
void
e_table_sort_info_parse_context_push (GMarkupParseContext *context,
                                      ETableSpecification *specification)
{
    g_return_if_fail (context != NULL);
    g_return_if_fail (E_IS_TABLE_SPECIFICATION (specification));

    g_markup_parse_context_push (
        context, &table_sort_info_parser,
        e_table_sort_info_new (specification));
}

/**
 * e_table_sort_info_parse_context_pop:
 * @context: a #GMarkupParseContext
 *
 * Creates a new #ETableSortInfo from a segment of XML data being fed to
 * @context.  Call e_table_sort_info_parse_context_push() for the appropriate
 * opening tag from the <structfield>start_element</structfield> callback of a
 * #GMarkupParser, then call this function for the corresponding closing tag
 * from the <structfield>end_element</structfield> callback.
 *
 * Unreference the newly-created #ETableSortInfo with g_object_unref() when
 * finished with it.
 *
 * Returns: an #ETableSortInfo
 **/
ETableSortInfo *
e_table_sort_info_parse_context_pop (GMarkupParseContext *context)
{
    gpointer user_data;

    g_return_val_if_fail (context != NULL, NULL);

    user_data = g_markup_parse_context_pop (context);

    return E_TABLE_SORT_INFO (user_data);
}

/**
 * e_table_sort_info_ref_specification:
 * @sort_info: an #ETableSortInfo
 *
 * Returns the #ETableSpecification passed to e_table_sort_info_new().
 *
 * The returned #ETableSpecification is referenced for thread-safety and must
 * be unreferenced with g_object_unref() when finished with it.
 *
 * Returns: an #ETableSpecification
 **/
ETableSpecification *
e_table_sort_info_ref_specification (ETableSortInfo *sort_info)
{
    g_return_val_if_fail (E_IS_TABLE_SORT_INFO (sort_info), NULL);

    return g_weak_ref_get (&sort_info->priv->specification);
}

gboolean
e_table_sort_info_get_can_group (ETableSortInfo *sort_info)
{
    g_return_val_if_fail (E_IS_TABLE_SORT_INFO (sort_info), FALSE);

    return sort_info->priv->can_group;
}

void
e_table_sort_info_set_can_group (ETableSortInfo *sort_info,
                                 gboolean can_group)
{
    g_return_if_fail (E_IS_TABLE_SORT_INFO (sort_info));

    sort_info->priv->can_group = can_group;
}

/**
 * e_table_sort_info_grouping_get_count:
 * @sort_info: an #ETableSortInfo
 *
 * Returns: the number of grouping criteria in the object.
 */
guint
e_table_sort_info_grouping_get_count (ETableSortInfo *sort_info)
{
    guint count = 0;

    g_return_val_if_fail (E_IS_TABLE_SORT_INFO (sort_info), 0);

    if (e_table_sort_info_get_can_group (sort_info))
        count = sort_info->priv->groupings->len;

    return count;
}

/**
 * e_table_sort_info_grouping_truncate:
 * @sort_info: an #ETableSortInfo
 * @length: position where the truncation happens.
 *
 * This routine can be used to reduce or grow the number of grouping
 * criteria in the object.
 */
void
e_table_sort_info_grouping_truncate (ETableSortInfo *sort_info,
                                     guint length)
{
    g_return_if_fail (E_IS_TABLE_SORT_INFO (sort_info));

    g_array_set_size (sort_info->priv->groupings, length);

    g_signal_emit (sort_info, signals[GROUP_INFO_CHANGED], 0);
}

/**
 * e_table_sort_info_grouping_get_nth:
 * @sort_info: an #ETableSortInfo
 * @n: Item information to fetch.
 * @out_sort_type: return location for a #GtkSortType value, or %NULL
 *
 * Returns: the description of the @n-th grouping criteria in the @info object.
 */
ETableColumnSpecification *
e_table_sort_info_grouping_get_nth (ETableSortInfo *sort_info,
                                    guint n,
                                    GtkSortType *out_sort_type)
{
    ETableColumnSpecification *column_spec = NULL;
    GArray *array;
    gboolean can_group;

    g_return_val_if_fail (E_IS_TABLE_SORT_INFO (sort_info), NULL);

    array = sort_info->priv->groupings;
    can_group = e_table_sort_info_get_can_group (sort_info);

    if (can_group && n < array->len) {
        ColumnData *column_data;

        column_data = &g_array_index (array, ColumnData, n);

        if (out_sort_type != NULL)
            *out_sort_type = column_data->sort_type;

        column_spec = column_data->column_spec;
    }

    return column_spec;
}

/**
 * e_table_sort_info_grouping_set_nth:
 * @sort_info: an #ETableSortInfo
 * @n: Item information to fetch.
 * @spec: an #ETableColumnSpecification
 * @sort_type: a #GtkSortType
 *
 * Sets the grouping criteria for index @n to @spec and @sort_type.
 */
void
e_table_sort_info_grouping_set_nth (ETableSortInfo *sort_info,
                                    guint n,
                                    ETableColumnSpecification *spec,
                                    GtkSortType sort_type)
{
    GArray *array;
    ColumnData *column_data;

    g_return_if_fail (E_IS_TABLE_SORT_INFO (sort_info));
    g_return_if_fail (E_IS_TABLE_COLUMN_SPECIFICATION (spec));

    array = sort_info->priv->groupings;
    g_array_set_size (array, MAX (n + 1, array->len));
    column_data = &g_array_index (array, ColumnData, n);

    column_data_clear (column_data);

    column_data->column_spec = g_object_ref (spec);
    column_data->sort_type = sort_type;

    g_signal_emit (sort_info, signals[GROUP_INFO_CHANGED], 0);
}

/**
 * e_table_sort_info_get_count:
 * @sort_info: an #ETableSortInfo
 *
 * Returns: the number of sorting criteria in the object.
 */
guint
e_table_sort_info_sorting_get_count (ETableSortInfo *sort_info)
{
    g_return_val_if_fail (E_IS_TABLE_SORT_INFO (sort_info), 0);

    return sort_info->priv->sortings->len;
}

/**
 * e_table_sort_info_sorting_remove:
 * @sort_info: an #ETableSortInfo
 * @n: the index of the element to remove
 *
 * Removes the sorting element at the given index.  The following sorting
 * elements are moved down one place.
 **/
void
e_table_sort_info_sorting_remove (ETableSortInfo *sort_info,
                                  guint n)
{
    g_return_if_fail (E_IS_TABLE_SORT_INFO (sort_info));

    g_array_remove_index (sort_info->priv->sortings, n);

    g_signal_emit (sort_info, signals[SORT_INFO_CHANGED], 0);
}

/**
 * e_table_sort_info_sorting_truncate:
 * @sort_info: an #ETableSortInfo
 * @length: position where the truncation happens.
 *
 * This routine can be used to reduce or grow the number of sort
 * criteria in the object.
 */
void
e_table_sort_info_sorting_truncate (ETableSortInfo *sort_info,
                                    guint length)
{
    g_return_if_fail (E_IS_TABLE_SORT_INFO (sort_info));

    g_array_set_size (sort_info->priv->sortings, length);

    g_signal_emit (sort_info, signals[SORT_INFO_CHANGED], 0);
}

/**
 * e_table_sort_info_sorting_get_nth:
 * @sort_info: an #ETableSortInfo
 * @n: Item information to fetch.
 * @out_sort_type: return location for a #GtkSortType value, or %NULL
 *
 * Returns: the description of the @n-th grouping criteria in the @info object.
 */
ETableColumnSpecification *
e_table_sort_info_sorting_get_nth (ETableSortInfo *sort_info,
                                   guint n,
                                   GtkSortType *out_sort_type)
{
    ETableColumnSpecification *column_spec = NULL;
    GArray *array;

    g_return_val_if_fail (E_IS_TABLE_SORT_INFO (sort_info), NULL);

    array = sort_info->priv->sortings;

    if (n < array->len) {
        ColumnData *column_data;

        column_data = &g_array_index (array, ColumnData, n);

        if (out_sort_type != NULL)
            *out_sort_type = column_data->sort_type;

        column_spec = column_data->column_spec;
    }

    return column_spec;
}

/**
 * e_table_sort_info_sorting_set_nth:
 * @sort_info: an #ETableSortInfo
 * @n: Item information to fetch.
 * @spec: an #ETableColumnSpecification
 * @sort_type: a #GtkSortType
 *
 * Sets the sorting criteria for index @n to @spec and @sort_type.
 */
void
e_table_sort_info_sorting_set_nth (ETableSortInfo *sort_info,
                                   guint n,
                                   ETableColumnSpecification *spec,
                                   GtkSortType sort_type)
{
    GArray *array;
    ColumnData *column_data;

    g_return_if_fail (E_IS_TABLE_SORT_INFO (sort_info));
    g_return_if_fail (E_IS_TABLE_COLUMN_SPECIFICATION (spec));

    array = sort_info->priv->sortings;
    g_array_set_size (array, MAX (n + 1, array->len));
    column_data = &g_array_index (array, ColumnData, n);

    column_data_clear (column_data);

    column_data->column_spec = g_object_ref (spec);
    column_data->sort_type = sort_type;

    g_signal_emit (sort_info, signals[SORT_INFO_CHANGED], 0);
}

/**
 * @sort_info: an #ETableSortInfo
 * @n: Index to insert to.
 * @spec: an #ETableColumnSpecification
 * @sort_type: a #GtkSortType
 *
 * Inserts the sorting criteria for index @n to @spec and @sort_type.
 *
 * Since: 3.12
 **/
void
e_table_sort_info_sorting_insert (ETableSortInfo *sort_info,
                  guint n,
                  ETableColumnSpecification *spec,
                  GtkSortType sort_type)
{
    GArray *array;
    ColumnData *column_data, tmp;

    g_return_if_fail (E_IS_TABLE_SORT_INFO (sort_info));
    g_return_if_fail (E_IS_TABLE_COLUMN_SPECIFICATION (spec));

    array = sort_info->priv->sortings;
    if (array->len == 0) {
        e_table_sort_info_sorting_set_nth (sort_info, 0, spec, sort_type);
        return;
    }

    if ((gint) n == -1)
        n = 0;
    else if (n > array->len)
        n = array->len;

    tmp.column_spec = NULL;
    tmp.sort_type = sort_type;
    column_data = &tmp;

    if (n == array->len)
        g_array_append_val (array, column_data);
    else
        g_array_insert_val (array, n, column_data);

    column_data = &g_array_index (array, ColumnData, n);
    column_data->column_spec = g_object_ref (spec);
    column_data->sort_type = sort_type;

    g_signal_emit (sort_info, signals[SORT_INFO_CHANGED], 0);
}

/**
 * e_table_sort_info_load_from_node:
 * @sort_info: an #ETableSortInfo
 * @node: pointer to the xmlNode that describes the sorting and grouping information
 * @state_version:
 *
 * This loads the state for the #ETableSortInfo object @info from the
 * xml node @node.
 */
void
e_table_sort_info_load_from_node (ETableSortInfo *sort_info,
                                  xmlNode *node,
                                  gdouble state_version)
{
    ETableSpecification *specification;
    GPtrArray *columns;
    xmlNode *grouping;
    guint gcnt = 0;
    guint scnt = 0;

    g_return_if_fail (E_IS_TABLE_SORT_INFO (sort_info));
    g_return_if_fail (node != NULL);

    specification = e_table_sort_info_ref_specification (sort_info);
    columns = e_table_specification_ref_columns (specification);

    for (grouping = node->children; grouping; grouping = grouping->next) {

        if (grouping->type != XML_ELEMENT_NODE)
            continue;

        if (g_str_equal ((gchar *) grouping->name, "group")) {
            GtkSortType sort_type;
            gboolean ascending;
            guint index;

            index = e_xml_get_integer_prop_by_name (
                grouping, (guchar *) "column");
            ascending = e_xml_get_bool_prop_by_name (
                grouping, (guchar *) "ascending");

            if (ascending)
                sort_type = GTK_SORT_ASCENDING;
            else
                sort_type = GTK_SORT_DESCENDING;

            if (index < columns->len)
                e_table_sort_info_grouping_set_nth (
                    sort_info, gcnt++,
                    columns->pdata[index],
                    sort_type);
        }

        if (g_str_equal ((gchar *) grouping->name, "leaf")) {
            GtkSortType sort_type;
            gboolean ascending;
            gint index;;

            index = e_xml_get_integer_prop_by_name (
                grouping, (guchar *) "column");
            ascending = e_xml_get_bool_prop_by_name (
                grouping, (guchar *) "ascending");

            if (ascending)
                sort_type = GTK_SORT_ASCENDING;
            else
                sort_type = GTK_SORT_DESCENDING;

            if (index < columns->len)
                e_table_sort_info_sorting_set_nth (
                    sort_info, scnt++,
                    columns->pdata[index],
                sort_type);
        }
    }

    g_object_unref (specification);
    g_ptr_array_unref (columns);

    g_signal_emit (sort_info, signals[SORT_INFO_CHANGED], 0);
}

/**
 * e_table_sort_info_save_to_node:
 * @sort_info: an #ETableSortInfo
 * @parent: xmlNode that will be hosting the saved state of the @info object.
 *
 * This function is used
 *
 * Returns: the node that has been appended to @parent as a child containing
 * the sorting and grouping information for this ETableSortInfo object.
 */
xmlNode *
e_table_sort_info_save_to_node (ETableSortInfo *sort_info,
                                xmlNode *parent)
{
    ETableSpecification *specification;
    xmlNode *grouping;
    guint sort_count;
    guint group_count;
    guint ii;

    g_return_val_if_fail (E_IS_TABLE_SORT_INFO (sort_info), NULL);

    sort_count = e_table_sort_info_sorting_get_count (sort_info);
    group_count = e_table_sort_info_grouping_get_count (sort_info);

    grouping = xmlNewChild (parent, NULL, (guchar *) "grouping", NULL);

    specification = e_table_sort_info_ref_specification (sort_info);

    for (ii = 0; ii < group_count; ii++) {
        ETableColumnSpecification *column_spec;
        GtkSortType sort_type;
        xmlNode *new_node;
        gint index;

        column_spec = e_table_sort_info_grouping_get_nth (
            sort_info, ii, &sort_type);

        index = e_table_specification_get_column_index (
            specification, column_spec);

        if (index < 0) {
            g_warn_if_reached ();
            continue;
        }

        new_node = xmlNewChild (
            grouping, NULL, (guchar *) "group", NULL);

        e_xml_set_integer_prop_by_name (
            new_node, (guchar *) "column", index);
        e_xml_set_bool_prop_by_name (
            new_node, (guchar *) "ascending",
            (sort_type == GTK_SORT_ASCENDING));
    }

    for (ii = 0; ii < sort_count; ii++) {
        ETableColumnSpecification *column_spec;
        GtkSortType sort_type;
        xmlNode *new_node;
        gint index;

        column_spec = e_table_sort_info_sorting_get_nth (
            sort_info, ii, &sort_type);

        index = e_table_specification_get_column_index (
            specification, column_spec);

        if (index < 0) {
            g_warn_if_reached ();
            continue;
        }

        new_node = xmlNewChild (
            grouping, NULL, (guchar *) "leaf", NULL);

        e_xml_set_integer_prop_by_name (
            new_node, (guchar *) "column", index);
        e_xml_set_bool_prop_by_name (
            new_node, (guchar *) "ascending",
            (sort_type == GTK_SORT_ASCENDING));
    }

    g_object_unref (specification);

    return grouping;
}

ETableSortInfo *
e_table_sort_info_duplicate (ETableSortInfo *sort_info)
{
    ETableSpecification *specification;
    ETableSortInfo *new_info;
    gint ii;

    g_return_val_if_fail (E_IS_TABLE_SORT_INFO (sort_info), NULL);

    specification = e_table_sort_info_ref_specification (sort_info);
    new_info = e_table_sort_info_new (specification);
    g_object_unref (specification);

    g_array_set_size (
        new_info->priv->groupings,
        sort_info->priv->groupings->len);
    memmove (
        new_info->priv->groupings->data,
        sort_info->priv->groupings->data,
        sort_info->priv->groupings->len *
        g_array_get_element_size (sort_info->priv->groupings));

    for (ii = 0; ii < new_info->priv->groupings->len; ii++) {
        ColumnData *column_data;

        column_data = &g_array_index (new_info->priv->groupings, ColumnData, ii);

        g_object_ref (column_data->column_spec);
    }

    g_array_set_size (
        new_info->priv->sortings,
        sort_info->priv->sortings->len);
    memmove (
        new_info->priv->sortings->data,
        sort_info->priv->sortings->data,
        sort_info->priv->sortings->len *
        g_array_get_element_size (sort_info->priv->sortings));

    for (ii = 0; ii < new_info->priv->sortings->len; ii++) {
        ColumnData *column_data;

        column_data = &g_array_index (new_info->priv->sortings, ColumnData, ii);

        g_object_ref (column_data->column_spec);
    }

    new_info->priv->can_group = sort_info->priv->can_group;

    return new_info;
}