path: root/widgets/misc/e-cell-date-edit.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */

/*
 * Author :
 *  Damon Chaplin <damon@ximian.com>
 *
 * Copyright 2001, Ximian, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU 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 General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 * USA
 */

/*
 * 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 <glib.h>

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

#include <table/e-table-item.h>
#include <table/e-cell-text.h>

#include <libgnomeui/gnome-messagebox.h>
#include <glib/gi18n.h>

#include <libedataserver/e-time-utils.h>

/* This depends on ECalendar which is why I didn't put it in gal. */
#include "e-calendar.h"

static void e_cell_date_edit_destroy        (GtkObject  *object);
static void e_cell_date_edit_get_arg        (GtkObject  *o,
                         GtkArg     *arg,
                         guint       arg_id);
static void e_cell_date_edit_set_arg        (GtkObject  *o,
                         GtkArg     *arg,
                         guint       arg_id);

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

static void e_cell_date_edit_rebuild_time_list  (ECellDateEdit  *ecde);

static int e_cell_date_edit_key_press       (GtkWidget  *popup_window,
                         GdkEventKey    *event,
                         ECellDateEdit  *ecde);
static int  e_cell_date_edit_button_press   (GtkWidget  *popup_window,
                         GdkEventButton *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,
                         char       *text);
static void e_cell_date_edit_on_time_selected   (GtkList    *list,
                         ECellDateEdit  *ecde);
static void e_cell_date_edit_hide_popup     (ECellDateEdit  *ecde);


/* Our arguments. */
enum {
    ARG_0,
    ARG_SHOW_TIME,
    ARG_SHOW_NOW_BUTTON,
    ARG_SHOW_TODAY_BUTTON,
    ARG_ALLOW_NO_DATE_SET,
    ARG_USE_24_HOUR_FORMAT,
    ARG_LOWER_HOUR,
    ARG_UPPER_HOUR
};

G_DEFINE_TYPE (ECellDateEdit, e_cell_date_edit, E_CELL_POPUP_TYPE)


static void
e_cell_date_edit_class_init (ECellDateEditClass *ecdec)
{
    GtkObjectClass  *object_class = (GtkObjectClass *) ecdec;
    ECellPopupClass *ecpc = (ECellPopupClass *) ecdec;

    gtk_object_add_arg_type ("ECellDateEdit::show_time",
                 GTK_TYPE_BOOL, GTK_ARG_READWRITE,
                 ARG_SHOW_TIME);
    gtk_object_add_arg_type ("ECellDateEdit::show_now_button",
                 GTK_TYPE_BOOL, GTK_ARG_READWRITE,
                 ARG_SHOW_NOW_BUTTON);
    gtk_object_add_arg_type ("ECellDateEdit::show_today_button",
                 GTK_TYPE_BOOL, GTK_ARG_READWRITE,
                 ARG_SHOW_TODAY_BUTTON);
    gtk_object_add_arg_type ("ECellDateEdit::allow_no_date_set",
                 GTK_TYPE_BOOL, GTK_ARG_READWRITE,
                 ARG_ALLOW_NO_DATE_SET);
    gtk_object_add_arg_type ("ECellDateEdit::use_24_hour_format",
                 GTK_TYPE_BOOL, GTK_ARG_READWRITE,
                 ARG_USE_24_HOUR_FORMAT);
    gtk_object_add_arg_type ("ECellDateEdit::lower_hour",
                 GTK_TYPE_INT, GTK_ARG_READWRITE,
                 ARG_LOWER_HOUR);
    gtk_object_add_arg_type ("ECellDateEdit::upper_hour",
                 GTK_TYPE_INT, GTK_ARG_READWRITE,
                 ARG_UPPER_HOUR);

    object_class->destroy = e_cell_date_edit_destroy;
    object_class->get_arg = e_cell_date_edit_get_arg;
    object_class->set_arg = e_cell_date_edit_set_arg;

    ecpc->popup = e_cell_date_edit_do_popup;
}


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

    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_policy (GTK_WINDOW (ecde->popup_window),
                   TRUE, TRUE, FALSE);
  
    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_vbox_new (FALSE, 0);
    gtk_container_add (GTK_CONTAINER (frame), vbox);
        gtk_widget_show (vbox);

    hbox = gtk_hbox_new (FALSE, 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_vbox_new (FALSE, 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);

    list = gtk_list_new ();
    gtk_scrolled_window_add_with_viewport (GTK_SCROLLED_WINDOW (scrolled_window), list);
    gtk_container_set_focus_vadjustment (GTK_CONTAINER (list),
                         gtk_scrolled_window_get_vadjustment (GTK_SCROLLED_WINDOW (scrolled_window)));
    gtk_widget_show (list);
    ecde->time_list = list;
    g_signal_connect((list), "selection-changed",
                G_CALLBACK (e_cell_date_edit_on_time_selected),
                ecde);

    bbox = gtk_hbutton_box_new ();
    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;

    none_button = gtk_button_new_with_label (_("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);
}


/*
 * GtkObject::destroy method
 */
static void
e_cell_date_edit_destroy        (GtkObject *object)
{
    ECellDateEdit *ecde = E_CELL_DATE_EDIT (object);

    e_cell_date_edit_set_get_time_callback (ecde, NULL, NULL, NULL);

    gtk_widget_destroy (ecde->popup_window);
    ecde->popup_window = NULL;

    GTK_OBJECT_CLASS (e_cell_date_edit_parent_class)->destroy (object);
}


static void
e_cell_date_edit_get_arg        (GtkObject  *o,
                     GtkArg     *arg,
                     guint       arg_id)
{
    ECellDateEdit *ecde;

    ecde = E_CELL_DATE_EDIT (o);

    switch (arg_id) {
    case ARG_SHOW_TIME:
        GTK_VALUE_BOOL (*arg) = GTK_WIDGET_VISIBLE (ecde->time_entry) ? TRUE : FALSE;
        break;
    case ARG_SHOW_NOW_BUTTON:
        GTK_VALUE_BOOL (*arg) = GTK_WIDGET_VISIBLE (ecde->now_button) ? TRUE : FALSE;
        break;
    case ARG_SHOW_TODAY_BUTTON:
        GTK_VALUE_BOOL (*arg) = GTK_WIDGET_VISIBLE (ecde->today_button) ? TRUE : FALSE;
        break;
    case ARG_ALLOW_NO_DATE_SET:
        GTK_VALUE_BOOL (*arg) = GTK_WIDGET_VISIBLE (ecde->none_button) ? TRUE : FALSE;
        break;
    case ARG_USE_24_HOUR_FORMAT:
        GTK_VALUE_BOOL (*arg) = ecde->use_24_hour_format;
        break;
    case ARG_LOWER_HOUR:
        GTK_VALUE_INT (*arg) = ecde->lower_hour;
        break;
    case ARG_UPPER_HOUR:
        GTK_VALUE_INT (*arg) = ecde->upper_hour;
        break;
    default:
        g_warning ("Invalid arg");
    }
}


static void
e_cell_date_edit_set_arg        (GtkObject  *o,
                     GtkArg     *arg,
                     guint       arg_id)
{
    ECellDateEdit *ecde;
    gint ivalue;
    gboolean bvalue;

    ecde = E_CELL_DATE_EDIT (o);
    
    switch (arg_id){
    case ARG_SHOW_TIME:
        bvalue = GTK_VALUE_BOOL (*arg);
        if (bvalue) {
            gtk_widget_show (ecde->time_entry);
            gtk_widget_show (ecde->time_list);
        } else {
            gtk_widget_hide (ecde->time_entry);
            gtk_widget_hide (ecde->time_list);
        }
        break;
    case ARG_SHOW_NOW_BUTTON:
        bvalue = GTK_VALUE_BOOL (*arg);
        if (bvalue) {
            gtk_widget_show (ecde->now_button);
        } else {
            gtk_widget_hide (ecde->now_button);
        }
        break;
    case ARG_SHOW_TODAY_BUTTON:
        bvalue = GTK_VALUE_BOOL (*arg);
        if (bvalue) {
            gtk_widget_show (ecde->today_button);
        } else {
            gtk_widget_hide (ecde->today_button);
        }
        break;
    case ARG_ALLOW_NO_DATE_SET:
        bvalue = GTK_VALUE_BOOL (*arg);
        if (bvalue) {
            gtk_widget_show (ecde->none_button);
        } else {
            /* FIXME: What if we have no date set now. */
            gtk_widget_hide (ecde->none_button);
        }
        break;
    case ARG_USE_24_HOUR_FORMAT:
        bvalue = GTK_VALUE_BOOL (*arg);
        if (ecde->use_24_hour_format != bvalue) {
            ecde->use_24_hour_format = bvalue;
            ecde->need_time_list_rebuild = TRUE;
        }
        break;
    case ARG_LOWER_HOUR:
        ivalue = GTK_VALUE_INT (*arg);
        ivalue = CLAMP (ivalue, 0, 24);
        if (ecde->lower_hour != ivalue) {
            ecde->lower_hour = ivalue;
            ecde->need_time_list_rebuild = TRUE;
        }
        break;
    case ARG_UPPER_HOUR:
        ivalue = GTK_VALUE_INT (*arg);
        ivalue = CLAMP (ivalue, 0, 24);
        if (ecde->upper_hour != ivalue) {
            ecde->upper_hour = ivalue;
            ecde->need_time_list_rebuild = TRUE;
        }
        break;
    default:
        g_warning ("Invalid arg");
    }

#if 0
    if (ecde->need_time_list_rebuild && ecde->freeze_count == 0)
        e_cell_date_edit_rebuild_time_list (ecde);
#endif
}


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

    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);
    gdk_window_focus (ecde->popup_window->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 = E_TABLE_ITEM (ecp->popup_cell_view->cell_view.e_table_item_view);
    ETableCol *ecol;
    char *cell_text;
    ETimeParseStatus status;
    struct tm date_tm;
    GDate date;
    ECalendarItem *calitem;
    char buffer[64];
    gboolean is_date = TRUE;

    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->col_idx, 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_list_unselect_all (GTK_LIST (ecde->time_list));
    } 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_list_unselect_all (GTK_LIST (ecde->time_list));
        } 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,
                     char       *time)
{
    GtkList *list;
    GtkWidget *listitem, *label;
    GList *elem;
    gboolean found = FALSE;
    const gchar *list_item_text;

    list = GTK_LIST (ecde->time_list);
    elem = list->children;
    while (elem) {
        listitem = GTK_WIDGET (elem->data);
        label = GTK_BIN (listitem)->child;
        list_item_text = gtk_label_get_text (GTK_LABEL (label));

        if (!strcmp (list_item_text, time)) {
            found = TRUE;
            gtk_list_select_child (list, listitem);
            break;
        }

        elem = elem->next;
    }

    if (!found)
        gtk_list_unselect_all (list);
}


static void
e_cell_date_edit_show_popup     (ECellDateEdit  *ecde,
                     int             row,
                     int             view_col)
{
    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);

    gtk_widget_set_uposition (ecde->popup_window, x, y);
    gtk_widget_set_size_request (ecde->popup_window, width, height);
    gtk_widget_realize (ecde->popup_window);
    gdk_window_resize (ecde->popup_window->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,
                     int             row,
                     int             view_col,
                     gint       *x,
                     gint       *y,
                     gint       *height,
                     gint       *width)
{
    ECellPopup *ecp = E_CELL_POPUP (ecde);
    ETableItem *eti = E_TABLE_ITEM (ecp->popup_cell_view->cell_view.e_table_item_view);
    GtkWidget *canvas = GTK_WIDGET (GNOME_CANVAS_ITEM (eti)->canvas);
    GtkRequisition popup_requisition;
    gint avail_height, screen_width, column_width, row_height;
    double x1, y1, wx, wy;
  
    gdk_window_get_origin (canvas->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. */
    *y += y1 + 1
        - (int)((GnomeCanvas *)canvas)->layout.vadjustment->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_size_request (ecde->popup_window, &popup_requisition);
  
    /* 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. */
            avail_height = *y - row_height;
            *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 int
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_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 int
e_cell_date_edit_button_press       (GtkWidget  *popup_window,
                     GdkEventButton *event,
                     ECellDateEdit  *ecde)
{
    GtkWidget *event_widget;

    event_widget = gtk_get_event_widget ((GdkEvent*) 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)
{
    GtkList *list;
    GtkWidget *listitem;
    char buffer[40];
    struct tm tmp_tm;
    gint hour, min;

    list = GTK_LIST (ecde->time_list);

    gtk_list_clear_items (list, 0, -1);

    /* 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) {
            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));
            listitem = gtk_list_item_new_with_label (buffer);
            gtk_widget_show (listitem);
            gtk_container_add (GTK_CONTAINER (list), listitem);
        }
    }

    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;
    char buffer[64];
    const char *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;
    char 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;
    char 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;
    char 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,
                     char       *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->col_idx, 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->col_idx, ecp->popup_row, text);
        e_cell_leave_edit (ecv, ecp->popup_view_col, ecol->col_idx, ecp->popup_row, NULL);
    }

    e_cell_text_free_text (ecell_text, old_text);
}


static void
e_cell_date_edit_on_time_selected   (GtkList    *list,
                     ECellDateEdit  *ecde)
{
    GtkWidget *listitem, *label;
    const gchar *list_item_text;

    if (!list->selection)
        return;

    listitem = list->selection->data;
    label = GTK_BIN (listitem)->child;
    list_item_text = gtk_label_get_text (GTK_LABEL (label));
    gtk_entry_set_text (GTK_ENTRY (ecde->time_entry), 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,
                    GtkDestroyNotify 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;
}