path: root/e-util/e-cell-date-edit.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/>.
 *
 *
 * Authors:
 *      Damon Chaplin <damon@ximian.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

/*
 * ECellDateEdit - a subclass of ECellPopup used to show a date with a popup
 * window to edit it.
 */

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

#include "e-cell-date-edit.h"

#include <string.h>
#include <time.h>

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

#include <libedataserver/libedataserver.h>

#include "e-calendar.h"
#include "e-cell-text.h"
#include "e-table-item.h"

static void e_cell_date_edit_get_property   (GObject    *object,
                         guint       property_id,
                         GValue     *value,
                         GParamSpec *pspec);
static void e_cell_date_edit_set_property   (GObject    *object,
                         guint       property_id,
                         const GValue   *value,
                         GParamSpec *pspec);
static void e_cell_date_edit_dispose        (GObject    *object);

static gint e_cell_date_edit_do_popup       (ECellPopup *ecp,
                         GdkEvent   *event,
                         gint             row,
                         gint             view_col);
static void e_cell_date_edit_set_popup_values   (ECellDateEdit  *ecde);
static void e_cell_date_edit_select_matching_time (ECellDateEdit    *ecde,
                          gchar     *time);
static void e_cell_date_edit_show_popup     (ECellDateEdit  *ecde,
                         gint             row,
                         gint             view_col);
static void e_cell_date_edit_get_popup_pos  (ECellDateEdit  *ecde,
                         gint             row,
                         gint             view_col,
                         gint       *x,
                         gint       *y,
                         gint       *height,
                         gint       *width);

static void e_cell_date_edit_rebuild_time_list  (ECellDateEdit  *ecde);

static gint e_cell_date_edit_key_press      (GtkWidget  *popup_window,
                         GdkEventKey    *event,
                         ECellDateEdit  *ecde);
static gint  e_cell_date_edit_button_press  (GtkWidget  *popup_window,
                         GdkEvent   *button_event,
                         ECellDateEdit  *ecde);
static void e_cell_date_edit_on_ok_clicked  (GtkWidget  *button,
                         ECellDateEdit  *ecde);
static void e_cell_date_edit_show_time_invalid_warning  (ECellDateEdit  *ecde);
static void e_cell_date_edit_on_now_clicked (GtkWidget  *button,
                         ECellDateEdit  *ecde);
static void e_cell_date_edit_on_none_clicked    (GtkWidget  *button,
                         ECellDateEdit  *ecde);
static void e_cell_date_edit_on_today_clicked   (GtkWidget  *button,
                         ECellDateEdit  *ecde);
static void e_cell_date_edit_update_cell    (ECellDateEdit  *ecde,
                         const gchar    *text);
static void e_cell_date_edit_on_time_selected   (GtkTreeSelection *selection,
                         ECellDateEdit *ecde);
static void e_cell_date_edit_hide_popup     (ECellDateEdit  *ecde);

/* Our arguments. */
enum {
    PROP_0,
    PROP_SHOW_TIME,
    PROP_SHOW_NOW_BUTTON,
    PROP_SHOW_TODAY_BUTTON,
    PROP_ALLOW_NO_DATE_SET,
    PROP_USE_24_HOUR_FORMAT,
    PROP_LOWER_HOUR,
    PROP_UPPER_HOUR
};

G_DEFINE_TYPE (ECellDateEdit, e_cell_date_edit, E_TYPE_CELL_POPUP)

static void
e_cell_date_edit_class_init (ECellDateEditClass *class)
{
    GObjectClass *object_class;
    ECellPopupClass *ecpc;

    object_class = G_OBJECT_CLASS (class);
    object_class->get_property = e_cell_date_edit_get_property;
    object_class->set_property = e_cell_date_edit_set_property;
    object_class->dispose = e_cell_date_edit_dispose;

    ecpc = E_CELL_POPUP_CLASS (class);
    ecpc->popup = e_cell_date_edit_do_popup;

    g_object_class_install_property (
        object_class,
        PROP_SHOW_TIME,
        g_param_spec_boolean (
            "show_time",
            NULL,
            NULL,
            TRUE,
            G_PARAM_READWRITE));

    g_object_class_install_property (
        object_class,
        PROP_SHOW_NOW_BUTTON,
        g_param_spec_boolean (
            "show_now_button",
            NULL,
            NULL,
            TRUE,
            G_PARAM_READWRITE));

    g_object_class_install_property (
        object_class,
        PROP_SHOW_TODAY_BUTTON,
        g_param_spec_boolean (
            "show_today_button",
            NULL,
            NULL,
            TRUE,
            G_PARAM_READWRITE));

    g_object_class_install_property (
        object_class,
        PROP_ALLOW_NO_DATE_SET,
        g_param_spec_boolean (
            "allow_no_date_set",
            NULL,
            NULL,
            TRUE,
            G_PARAM_READWRITE));

    g_object_class_install_property (
        object_class,
        PROP_USE_24_HOUR_FORMAT,
        g_param_spec_boolean (
            "use_24_hour_format",
            NULL,
            NULL,
            TRUE,
            G_PARAM_READWRITE));

    g_object_class_install_property (
        object_class,
        PROP_LOWER_HOUR,
        g_param_spec_int (
            "lower_hour",
            NULL,
            NULL,
            G_MININT,
            G_MAXINT,
            0,
            G_PARAM_READWRITE));

    g_object_class_install_property (
        object_class,
        PROP_UPPER_HOUR,
        g_param_spec_int (
            "upper_hour",
            NULL,
            NULL,
            G_MININT,
            G_MAXINT,
            24,
            G_PARAM_READWRITE));
}

static void
e_cell_date_edit_init (ECellDateEdit *ecde)
{
    GtkWidget *frame, *vbox, *hbox, *vbox2;
    GtkWidget *scrolled_window, *bbox, *tree_view;
    GtkWidget *now_button, *today_button, *none_button, *ok_button;
    GtkListStore *store;

    ecde->lower_hour = 0;
    ecde->upper_hour = 24;
    ecde->use_24_hour_format = TRUE;
    ecde->need_time_list_rebuild = TRUE;
    ecde->freeze_count = 0;
    ecde->time_callback = NULL;
    ecde->time_callback_data = NULL;
    ecde->time_callback_destroy = NULL;

    /* We create one popup window for the ECell, since there will only
     * ever be one popup in use at a time. */
    ecde->popup_window = gtk_window_new (GTK_WINDOW_POPUP);

    gtk_window_set_type_hint (
        GTK_WINDOW (ecde->popup_window),
        GDK_WINDOW_TYPE_HINT_COMBO);
    gtk_window_set_resizable (GTK_WINDOW (ecde->popup_window), TRUE);

    frame = gtk_frame_new (NULL);
    gtk_container_add (GTK_CONTAINER (ecde->popup_window), frame);
    gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_OUT);
    gtk_widget_show (frame);

    vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
    gtk_container_add (GTK_CONTAINER (frame), vbox);
    gtk_widget_show (vbox);

    hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 4);
    gtk_box_pack_start (GTK_BOX (vbox), hbox, FALSE, FALSE, 0);
    gtk_widget_show (hbox);

    ecde->calendar = e_calendar_new ();
    gnome_canvas_item_set (
        GNOME_CANVAS_ITEM (E_CALENDAR (ecde->calendar)->calitem),
        "move_selection_when_moving", FALSE,
        NULL);
    gtk_box_pack_start (GTK_BOX (hbox), ecde->calendar, TRUE, TRUE, 0);
    gtk_widget_show (ecde->calendar);

    vbox2 = gtk_box_new (GTK_ORIENTATION_VERTICAL, 2);
    gtk_box_pack_start (GTK_BOX (hbox), vbox2, TRUE, TRUE, 0);
    gtk_widget_show (vbox2);

    ecde->time_entry = gtk_entry_new ();
    gtk_widget_set_size_request (ecde->time_entry, 50, -1);
    gtk_box_pack_start (
        GTK_BOX (vbox2), ecde->time_entry,
        FALSE, FALSE, 0);
    gtk_widget_show (ecde->time_entry);

    scrolled_window = gtk_scrolled_window_new (NULL, NULL);
    gtk_box_pack_start (GTK_BOX (vbox2), scrolled_window, TRUE, TRUE, 0);
    gtk_scrolled_window_set_policy (
        GTK_SCROLLED_WINDOW (scrolled_window),
        GTK_POLICY_NEVER, GTK_POLICY_ALWAYS);
    gtk_widget_show (scrolled_window);

    store = gtk_list_store_new (1, G_TYPE_STRING);
    tree_view = gtk_tree_view_new_with_model (GTK_TREE_MODEL (store));
    g_object_unref (store);

    gtk_tree_view_append_column (
        GTK_TREE_VIEW (tree_view),
        gtk_tree_view_column_new_with_attributes (
        "Text", gtk_cell_renderer_text_new (), "text", 0, NULL));

    gtk_tree_view_set_headers_visible (GTK_TREE_VIEW (tree_view), FALSE);

    gtk_scrolled_window_add_with_viewport (
        GTK_SCROLLED_WINDOW (scrolled_window), tree_view);
    gtk_container_set_focus_vadjustment (
        GTK_CONTAINER (tree_view),
        gtk_scrolled_window_get_vadjustment (
        GTK_SCROLLED_WINDOW (scrolled_window)));
    gtk_container_set_focus_hadjustment (
        GTK_CONTAINER (tree_view),
        gtk_scrolled_window_get_hadjustment (
        GTK_SCROLLED_WINDOW (scrolled_window)));
    gtk_widget_show (tree_view);
    ecde->time_tree_view = tree_view;
    g_signal_connect (
        gtk_tree_view_get_selection (GTK_TREE_VIEW (tree_view)), "changed",
        G_CALLBACK (e_cell_date_edit_on_time_selected), ecde);

    bbox = gtk_button_box_new (GTK_ORIENTATION_HORIZONTAL);
    gtk_container_set_border_width (GTK_CONTAINER (bbox), 4);
    gtk_box_set_spacing (GTK_BOX (bbox), 2);
    gtk_box_pack_start (GTK_BOX (vbox), bbox, FALSE, FALSE, 0);
    gtk_widget_show (bbox);

    now_button = gtk_button_new_with_label (_("Now"));
    gtk_container_add (GTK_CONTAINER (bbox), now_button);
    gtk_widget_show (now_button);
    g_signal_connect (
        now_button, "clicked",
        G_CALLBACK (e_cell_date_edit_on_now_clicked), ecde);
    ecde->now_button = now_button;

    today_button = gtk_button_new_with_label (_("Today"));
    gtk_container_add (GTK_CONTAINER (bbox), today_button);
    gtk_widget_show (today_button);
    g_signal_connect (
        today_button, "clicked",
        G_CALLBACK (e_cell_date_edit_on_today_clicked), ecde);
    ecde->today_button = today_button;

    /* Translators: "None" as a label of a button to unset date in a
     * date table cell. */
    none_button = gtk_button_new_with_label (C_("table-date", "None"));
    gtk_container_add (GTK_CONTAINER (bbox), none_button);
    gtk_widget_show (none_button);
    g_signal_connect (
        none_button, "clicked",
        G_CALLBACK (e_cell_date_edit_on_none_clicked), ecde);
    ecde->none_button = none_button;

    ok_button = gtk_button_new_with_label (_("OK"));
    gtk_container_add (GTK_CONTAINER (bbox), ok_button);
    gtk_widget_show (ok_button);
    g_signal_connect (
        ok_button, "clicked",
        G_CALLBACK (e_cell_date_edit_on_ok_clicked), ecde);

    g_signal_connect (
        ecde->popup_window, "key_press_event",
        G_CALLBACK (e_cell_date_edit_key_press), ecde);
    g_signal_connect (
        ecde->popup_window, "button_press_event",
        G_CALLBACK (e_cell_date_edit_button_press), ecde);
}

/**
 * e_cell_date_edit_new:
 *
 * Creates a new ECellDateEdit renderer.
 *
 * Returns: an ECellDateEdit object.
 */
ECell *
e_cell_date_edit_new (void)
{
    return g_object_new (e_cell_date_edit_get_type (), NULL);
}

static void
e_cell_date_edit_get_property (GObject *object,
                               guint property_id,
                               GValue *value,
                               GParamSpec *pspec)
{
    ECellDateEdit *ecde;

    ecde = E_CELL_DATE_EDIT (object);

    switch (property_id) {
    case PROP_SHOW_TIME:
        g_value_set_boolean (value, gtk_widget_get_visible (ecde->time_entry));
        return;
    case PROP_SHOW_NOW_BUTTON:
        g_value_set_boolean (value, gtk_widget_get_visible (ecde->now_button));
        return;
    case PROP_SHOW_TODAY_BUTTON:
        g_value_set_boolean (value, gtk_widget_get_visible (ecde->today_button));
        return;
    case PROP_ALLOW_NO_DATE_SET:
        g_value_set_boolean (value, gtk_widget_get_visible (ecde->none_button));
        return;
    case PROP_USE_24_HOUR_FORMAT:
        g_value_set_boolean (value, ecde->use_24_hour_format);
        return;
    case PROP_LOWER_HOUR:
        g_value_set_int (value, ecde->lower_hour);
        return;
    case PROP_UPPER_HOUR:
        g_value_set_int (value, ecde->upper_hour);
        return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
e_cell_date_edit_set_property (GObject *object,
                               guint property_id,
                               const GValue *value,
                               GParamSpec *pspec)
{
    ECellDateEdit *ecde;
    gint ivalue;
    gboolean bvalue;

    ecde = E_CELL_DATE_EDIT (object);

    switch (property_id) {
    case PROP_SHOW_TIME:
        if (g_value_get_boolean (value)) {
            gtk_widget_show (ecde->time_entry);
            gtk_widget_show (ecde->time_tree_view);
        } else {
            gtk_widget_hide (ecde->time_entry);
            gtk_widget_hide (ecde->time_tree_view);
        }
        return;
    case PROP_SHOW_NOW_BUTTON:
        if (g_value_get_boolean (value)) {
            gtk_widget_show (ecde->now_button);
        } else {
            gtk_widget_hide (ecde->now_button);
        }
        return;
    case PROP_SHOW_TODAY_BUTTON:
        if (g_value_get_boolean (value)) {
            gtk_widget_show (ecde->today_button);
        } else {
            gtk_widget_hide (ecde->today_button);
        }
        return;
    case PROP_ALLOW_NO_DATE_SET:
        if (g_value_get_boolean (value)) {
            gtk_widget_show (ecde->none_button);
        } else {
            /* FIXME: What if we have no date set now. */
            gtk_widget_hide (ecde->none_button);
        }
        return;
    case PROP_USE_24_HOUR_FORMAT:
        bvalue = g_value_get_boolean (value);
        if (ecde->use_24_hour_format != bvalue) {
            ecde->use_24_hour_format = bvalue;
            ecde->need_time_list_rebuild = TRUE;
        }
        return;
    case PROP_LOWER_HOUR:
        ivalue = g_value_get_int (value);
        ivalue = CLAMP (ivalue, 0, 24);
        if (ecde->lower_hour != ivalue) {
            ecde->lower_hour = ivalue;
            ecde->need_time_list_rebuild = TRUE;
        }
        return;
    case PROP_UPPER_HOUR:
        ivalue = g_value_get_int (value);
        ivalue = CLAMP (ivalue, 0, 24);
        if (ecde->upper_hour != ivalue) {
            ecde->upper_hour = ivalue;
            ecde->need_time_list_rebuild = TRUE;
        }
        return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
e_cell_date_edit_dispose (GObject *object)
{
    ECellDateEdit *ecde = E_CELL_DATE_EDIT (object);

    e_cell_date_edit_set_get_time_callback (ecde, NULL, NULL, NULL);

    if (ecde->popup_window != NULL) {
        gtk_widget_destroy (ecde->popup_window);
        ecde->popup_window = NULL;
    }

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

static gint
e_cell_date_edit_do_popup (ECellPopup *ecp,
                           GdkEvent *event,
                           gint row,
                           gint view_col)
{
    ECellDateEdit *ecde = E_CELL_DATE_EDIT (ecp);
    GdkWindow *window;

    e_cell_date_edit_show_popup (ecde, row, view_col);
    e_cell_date_edit_set_popup_values (ecde);

    gtk_grab_add (ecde->popup_window);

    /* Set the focus to the first widget. */
    gtk_widget_grab_focus (ecde->time_entry);
    window = gtk_widget_get_window (ecde->popup_window);
    gdk_window_focus (window, GDK_CURRENT_TIME);

    return TRUE;
}

static void
e_cell_date_edit_set_popup_values (ECellDateEdit *ecde)
{
    ECellPopup *ecp = E_CELL_POPUP (ecde);
    ECellText *ecell_text = E_CELL_TEXT (ecp->child);
    ECellView *ecv = (ECellView *) ecp->popup_cell_view;
    ETableItem *eti;
    ETableCol *ecol;
    gchar *cell_text;
    ETimeParseStatus status;
    struct tm date_tm;
    GDate date;
    ECalendarItem *calitem;
    gchar buffer[64];
    gboolean is_date = TRUE;

    eti = E_TABLE_ITEM (ecp->popup_cell_view->cell_view.e_table_item_view);
    ecol = e_table_header_get_column (eti->header, ecp->popup_view_col);

    cell_text = e_cell_text_get_text (
        ecell_text, ecv->e_table_model,
        ecol->spec->model_col, ecp->popup_row);

    /* Try to parse just a date first. If the value is only a date, we
     * use a DATE value. */
    status = e_time_parse_date (cell_text, &date_tm);
    if (status == E_TIME_PARSE_INVALID) {
        is_date = FALSE;
        status = e_time_parse_date_and_time (cell_text, &date_tm);
    }

    /* If there is no date and time set, or the date is invalid, we clear
     * the selections, else we select the appropriate date & time. */
    calitem = E_CALENDAR_ITEM (E_CALENDAR (ecde->calendar)->calitem);
    if (status == E_TIME_PARSE_NONE || status == E_TIME_PARSE_INVALID) {
        gtk_entry_set_text (GTK_ENTRY (ecde->time_entry), "");
        e_calendar_item_set_selection (calitem, NULL, NULL);
        gtk_tree_selection_unselect_all (
            gtk_tree_view_get_selection (
            GTK_TREE_VIEW (ecde->time_tree_view)));
    } else {
        if (is_date) {
            buffer[0] = '\0';
        } else {
            e_time_format_time (
                &date_tm, ecde->use_24_hour_format,
                FALSE, buffer, sizeof (buffer));
        }
        gtk_entry_set_text (GTK_ENTRY (ecde->time_entry), buffer);

        g_date_clear (&date, 1);
        g_date_set_dmy (
            &date,
            date_tm.tm_mday,
            date_tm.tm_mon + 1,
            date_tm.tm_year + 1900);
        e_calendar_item_set_selection (calitem, &date, &date);

        if (is_date) {
            gtk_tree_selection_unselect_all (
                gtk_tree_view_get_selection (
                GTK_TREE_VIEW (ecde->time_tree_view)));
        } else {
            e_cell_date_edit_select_matching_time (ecde, buffer);
        }
    }

    e_cell_text_free_text (ecell_text, cell_text);
}

static void
e_cell_date_edit_select_matching_time (ECellDateEdit *ecde,
                                       gchar *time)
{
    gboolean found = FALSE;
    gboolean valid;
    GtkTreeSelection *selection;
    GtkTreeIter iter;
    GtkTreeModel *model;

    model = gtk_tree_view_get_model (GTK_TREE_VIEW (ecde->time_tree_view));
    selection = gtk_tree_view_get_selection (GTK_TREE_VIEW (ecde->time_tree_view));

    for (valid = gtk_tree_model_get_iter_first (model, &iter);
         valid && !found;
         valid = gtk_tree_model_iter_next (model, &iter)) {
        gchar *str = NULL;

        gtk_tree_model_get (model, &iter, 0, &str, -1);

        if (g_str_equal (str, time)) {
            GtkTreePath *path = gtk_tree_model_get_path (model, &iter);

            gtk_tree_view_set_cursor (
                GTK_TREE_VIEW (ecde->time_tree_view),
                path, NULL, FALSE);
            gtk_tree_view_scroll_to_cell (
                GTK_TREE_VIEW (ecde->time_tree_view),
                path, NULL, FALSE, 0.0, 0.0);
            gtk_tree_path_free (path);

            found = TRUE;
        }

        g_free (str);
    }

    if (!found) {
        gtk_tree_selection_unselect_all (selection);
        gtk_tree_view_scroll_to_point (GTK_TREE_VIEW (ecde->time_tree_view), 0, 0);
    }
}

static void
e_cell_date_edit_show_popup (ECellDateEdit *ecde,
                             gint row,
                             gint view_col)
{
    GdkWindow *window;
    gint x, y, width, height;

    if (ecde->need_time_list_rebuild)
        e_cell_date_edit_rebuild_time_list (ecde);

    /* This code is practically copied from GtkCombo. */

    e_cell_date_edit_get_popup_pos (ecde, row, view_col, &x, &y, &height, &width);

    window = gtk_widget_get_window (ecde->popup_window);
    gtk_window_move (GTK_WINDOW (ecde->popup_window), x, y);
    gtk_widget_set_size_request (ecde->popup_window, width, height);
    gtk_widget_realize (ecde->popup_window);
    gdk_window_resize (window, width, height);
    gtk_widget_show (ecde->popup_window);

    e_cell_popup_set_shown (E_CELL_POPUP (ecde), TRUE);
}

/* Calculates the size and position of the popup window (like GtkCombo). */
static void
e_cell_date_edit_get_popup_pos (ECellDateEdit *ecde,
                                gint row,
                                gint view_col,
                                gint *x,
                                gint *y,
                                gint *height,
                                gint *width)
{
    ECellPopup *ecp = E_CELL_POPUP (ecde);
    ETableItem *eti;
    GtkWidget *canvas;
    GtkRequisition popup_requisition;
    GtkAdjustment *adjustment;
    GtkScrollable *scrollable;
    GdkWindow *window;
    gint avail_height, screen_width, column_width, row_height;
    gdouble x1, y1, wx, wy;
    gint value;

    eti = E_TABLE_ITEM (ecp->popup_cell_view->cell_view.e_table_item_view);
    canvas = GTK_WIDGET (GNOME_CANVAS_ITEM (eti)->canvas);

    window = gtk_widget_get_window (canvas);
    gdk_window_get_origin (window, x, y);

    x1 = e_table_header_col_diff (eti->header, 0, view_col + 1);
    y1 = e_table_item_row_diff (eti, 0, row + 1);
    column_width = e_table_header_col_diff (
        eti->header, view_col, view_col + 1);
    row_height = e_table_item_row_diff (eti, row, row + 1);
    gnome_canvas_item_i2w (GNOME_CANVAS_ITEM (eti), &x1, &y1);

    gnome_canvas_world_to_window (
        GNOME_CANVAS (canvas), x1, y1, &wx, &wy);

    x1 = wx;
    y1 = wy;

    *x += x1;
    /* The ETable positions don't include the grid lines, I think, so we
     * add 1. */
    scrollable = GTK_SCROLLABLE (&GNOME_CANVAS (canvas)->layout);
    adjustment = gtk_scrollable_get_vadjustment (scrollable);
    value = (gint) gtk_adjustment_get_value (adjustment);
    *y += y1 + 1 - value + ((GnomeCanvas *)canvas)->zoom_yofs;

    avail_height = gdk_screen_height () - *y;

    /* We'll use the entire screen width if needed, but we save space for
     * the vertical scrollbar in case we need to show that. */
    screen_width = gdk_screen_width ();

    gtk_widget_get_preferred_size (ecde->popup_window, &popup_requisition, NULL);

    /* Calculate the desired width. */
    *width = popup_requisition.width;

    /* Use at least the same width as the column. */
    if (*width < column_width)
        *width = column_width;

    /* Check if it fits in the available height. */
    if (popup_requisition.height > avail_height) {
        /* It doesn't fit, so we see if we have the minimum space
         * needed. */
        if (*y - row_height > avail_height) {
            /* We don't, so we show the popup above the cell
             * instead of below it. */
            *y -= (popup_requisition.height + row_height);
            if (*y < 0)
                *y = 0;
        }
    }

    /* We try to line it up with the right edge of the column, but we don't
     * want it to go off the edges of the screen. */
    if (*x > screen_width)
        *x = screen_width;
    *x -= *width;
    if (*x < 0)
        *x = 0;

    *height = popup_requisition.height;
}

/* This handles key press events in the popup window. If the Escape key is
 * pressed we hide the popup, and do not change the cell contents. */
static gint
e_cell_date_edit_key_press (GtkWidget *popup_window,
                            GdkEventKey *event,
                            ECellDateEdit *ecde)
{
    /* If the Escape key is pressed we hide the popup. */
    if (event->keyval != GDK_KEY_Escape)
        return FALSE;

    e_cell_date_edit_hide_popup (ecde);

    return TRUE;
}

/* This handles button press events in the popup window. If the button is
 * pressed outside the popup, we hide it and do not change the cell contents.
*/
static gint
e_cell_date_edit_button_press (GtkWidget *popup_window,
                               GdkEvent *button_event,
                               ECellDateEdit *ecde)
{
    GtkWidget *event_widget;

    event_widget = gtk_get_event_widget (button_event);

    if (gtk_widget_get_toplevel (event_widget) != popup_window)
        e_cell_date_edit_hide_popup (ecde);

    return TRUE;
}

/* Clears the time list and rebuilds it using the lower_hour, upper_hour
 * and use_24_hour_format settings. */
static void
e_cell_date_edit_rebuild_time_list (ECellDateEdit *ecde)
{
    GtkListStore *store;
    gchar buffer[40];
    struct tm tmp_tm;
    gint hour, min;

    store = GTK_LIST_STORE (gtk_tree_view_get_model (
        GTK_TREE_VIEW (ecde->time_tree_view)));
    gtk_list_store_clear (store);

    /* Fill the struct tm with some sane values. */
    tmp_tm.tm_year = 2000;
    tmp_tm.tm_mon = 0;
    tmp_tm.tm_mday = 1;
    tmp_tm.tm_sec = 0;
    tmp_tm.tm_isdst = 0;

    for (hour = ecde->lower_hour; hour <= ecde->upper_hour; hour++) {
        /* We don't want to display midnight at the end, since that is
         * really in the next day. */
        if (hour == 24)
            break;

        /* We want to finish on upper_hour, with min == 0. */
        for (min = 0;
             min == 0 || (min < 60 && hour != ecde->upper_hour);
             min += 30) {
            GtkTreeIter iter;

            tmp_tm.tm_hour = hour;
            tmp_tm.tm_min = min;
            e_time_format_time (&tmp_tm, ecde->use_24_hour_format,
                        FALSE, buffer, sizeof (buffer));

            gtk_list_store_append (store, &iter);
            gtk_list_store_set (store, &iter, 0, buffer, -1);
        }
    }

    ecde->need_time_list_rebuild = FALSE;
}

static void
e_cell_date_edit_on_ok_clicked (GtkWidget *button,
                                ECellDateEdit *ecde)
{
    ECalendarItem *calitem;
    GDate start_date, end_date;
    gboolean day_selected;
    struct tm date_tm;
    gchar buffer[64];
    const gchar *text;
    ETimeParseStatus status;
    gboolean is_date = FALSE;

    calitem = E_CALENDAR_ITEM (E_CALENDAR (ecde->calendar)->calitem);
    day_selected = e_calendar_item_get_selection (
        calitem, &start_date, &end_date);

    text = gtk_entry_get_text (GTK_ENTRY (ecde->time_entry));
    status = e_time_parse_time (text, &date_tm);
    if (status == E_TIME_PARSE_INVALID) {
        e_cell_date_edit_show_time_invalid_warning (ecde);
        return;
    } else if (status == E_TIME_PARSE_NONE) {
        is_date = TRUE;
    }

    if (day_selected) {
        date_tm.tm_year = g_date_get_year (&start_date) - 1900;
        date_tm.tm_mon = g_date_get_month (&start_date) - 1;
        date_tm.tm_mday = g_date_get_day (&start_date);
        /* We need to call this to set the weekday. */
        mktime (&date_tm);
        e_time_format_date_and_time (&date_tm,
                         ecde->use_24_hour_format,
                         !is_date, FALSE,
                         buffer, sizeof (buffer));
    } else {
        buffer[0] = '\0';
    }

    e_cell_date_edit_update_cell (ecde, buffer);
    e_cell_date_edit_hide_popup (ecde);
}

static void
e_cell_date_edit_show_time_invalid_warning (ECellDateEdit *ecde)
{
    GtkWidget *dialog;
    struct tm date_tm;
    gchar buffer[64];

    /* Create a useful error message showing the correct format. */
    date_tm.tm_year = 100;
    date_tm.tm_mon = 0;
    date_tm.tm_mday = 1;
    date_tm.tm_hour = 1;
    date_tm.tm_min = 30;
    date_tm.tm_sec = 0;
    date_tm.tm_isdst = -1;
    e_time_format_time (&date_tm, ecde->use_24_hour_format, FALSE,
                buffer, sizeof (buffer));

    /* FIXME: Fix transient settings - I'm not sure it works with popup
     * windows. Maybe we need to use a normal window without decorations.*/
    dialog = gtk_message_dialog_new (
        GTK_WINDOW (ecde->popup_window),
        GTK_DIALOG_DESTROY_WITH_PARENT,
        GTK_MESSAGE_ERROR, GTK_BUTTONS_OK,
        _("The time must be in the format: %s"),
        buffer);
    gtk_dialog_run (GTK_DIALOG (dialog));
    gtk_widget_destroy (dialog);
}

static void
e_cell_date_edit_on_now_clicked (GtkWidget *button,
                                 ECellDateEdit *ecde)
{
    struct tm tmp_tm;
    time_t t;
    gchar buffer[64];

    if (ecde->time_callback) {
        tmp_tm = ecde->time_callback (
            ecde, ecde->time_callback_data);
    } else {
        t = time (NULL);
        tmp_tm = *localtime (&t);
    }

    e_time_format_date_and_time (
        &tmp_tm, ecde->use_24_hour_format,
        TRUE, FALSE, buffer, sizeof (buffer));

    e_cell_date_edit_update_cell (ecde, buffer);
    e_cell_date_edit_hide_popup (ecde);
}

static void
e_cell_date_edit_on_none_clicked (GtkWidget *button,
                                  ECellDateEdit *ecde)
{
    e_cell_date_edit_update_cell (ecde, "");
    e_cell_date_edit_hide_popup (ecde);
}

static void
e_cell_date_edit_on_today_clicked (GtkWidget *button,
                                   ECellDateEdit *ecde)
{
    struct tm tmp_tm;
    time_t t;
    gchar buffer[64];

    if (ecde->time_callback) {
        tmp_tm = ecde->time_callback (
            ecde, ecde->time_callback_data);
    } else {
        t = time (NULL);
        tmp_tm = *localtime (&t);
    }

    tmp_tm.tm_hour = 0;
    tmp_tm.tm_min = 0;
    tmp_tm.tm_sec = 0;

    e_time_format_date_and_time (
        &tmp_tm, ecde->use_24_hour_format,
        FALSE, FALSE, buffer, sizeof (buffer));

    e_cell_date_edit_update_cell (ecde, buffer);
    e_cell_date_edit_hide_popup (ecde);
}

static void
e_cell_date_edit_update_cell (ECellDateEdit *ecde,
                              const gchar *text)
{
    ECellPopup *ecp = E_CELL_POPUP (ecde);
    ECellText *ecell_text = E_CELL_TEXT (ecp->child);
    ECellView *ecv = (ECellView *) ecp->popup_cell_view;
    ETableItem *eti = E_TABLE_ITEM (ecv->e_table_item_view);
    ETableCol *ecol;
    gchar *old_text;

    /* Compare the new text with the existing cell contents. */
    ecol = e_table_header_get_column (eti->header, ecp->popup_view_col);

    old_text = e_cell_text_get_text (
        ecell_text, ecv->e_table_model,
        ecol->spec->model_col, ecp->popup_row);

    /* If they are different, update the cell contents. */
    if (strcmp (old_text, text)) {
        e_cell_text_set_value (
            ecell_text, ecv->e_table_model,
            ecol->spec->model_col, ecp->popup_row, text);
        e_cell_leave_edit (
            ecv, ecp->popup_view_col,
            ecol->spec->model_col, ecp->popup_row, NULL);
    }

    e_cell_text_free_text (ecell_text, old_text);
}

static void
e_cell_date_edit_on_time_selected (GtkTreeSelection *selection,
                                   ECellDateEdit *ecde)
{
    gchar *list_item_text = NULL;
    GtkTreeIter iter;
    GtkTreeModel *model;

    if (!gtk_tree_selection_get_selected (selection, &model, &iter))
        return;

    gtk_tree_model_get (model, &iter, 0, &list_item_text, -1);

    g_return_if_fail (list_item_text != NULL);

    gtk_entry_set_text (GTK_ENTRY (ecde->time_entry), list_item_text);

    g_free (list_item_text);
}

static void
e_cell_date_edit_hide_popup (ECellDateEdit *ecde)
{
    gtk_grab_remove (ecde->popup_window);
    gtk_widget_hide (ecde->popup_window);
    e_cell_popup_set_shown (E_CELL_POPUP (ecde), FALSE);
}

/* These freeze and thaw the rebuilding of the time list. They are useful when
 * setting several properties which result in rebuilds of the list, e.g. the
 * lower_hour, upper_hour and use_24_hour_format properties. */
void
e_cell_date_edit_freeze (ECellDateEdit *ecde)
{
    g_return_if_fail (E_IS_CELL_DATE_EDIT (ecde));

    ecde->freeze_count++;
}

void
e_cell_date_edit_thaw (ECellDateEdit *ecde)
{
    g_return_if_fail (E_IS_CELL_DATE_EDIT (ecde));

    if (ecde->freeze_count > 0) {
        ecde->freeze_count--;

        if (ecde->freeze_count == 0)
            e_cell_date_edit_rebuild_time_list (ecde);
    }
}

/* Sets a callback to use to get the current time. This is useful if the
 * application needs to use its own timezone data rather than rely on the
 * Unix timezone. */
void
e_cell_date_edit_set_get_time_callback (ECellDateEdit *ecde,
                                        ECellDateEditGetTimeCallback cb,
                                        gpointer data,
                                        GDestroyNotify destroy)
{
    g_return_if_fail (E_IS_CELL_DATE_EDIT (ecde));

    if (ecde->time_callback_data && ecde->time_callback_destroy)
        (*ecde->time_callback_destroy) (ecde->time_callback_data);

    ecde->time_callback = cb;
    ecde->time_callback_data = data;
    ecde->time_callback_destroy = destroy;
}