path: root/widgets/misc/e-calendar.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:
 *      Damon Chaplin <damon@ximian.com>
 *      Bolian Yin <bolian.yin@sun.com>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

/*
 * ECalendar - displays a table of monthly calendars, allowing highlighting
 * and selection of one or more days. Like GtkCalendar with more features.
 * Most of the functionality is in the ECalendarItem canvas item, though
 * we also add GnomeCanvasWidget buttons to go to the previous/next month and
 * to got to the current day.
 */

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

#include "e-calendar.h"

#include <gtk/gtk.h>
#include <libgnomecanvas/gnome-canvas-widget.h>
#include <glib/gi18n.h>

#define E_CALENDAR_SMALL_FONT_PTSIZE 6

#define E_CALENDAR_SMALL_FONT   \
    "-adobe-utopia-regular-r-normal-*-*-100-*-*-p-*-iso8859-*"
#define E_CALENDAR_SMALL_FONT_FALLBACK  \
    "-adobe-helvetica-medium-r-normal-*-*-80-*-*-p-*-iso8859-*"

/* The space between the arrow buttons and the edge of the widget. */
#define E_CALENDAR_ARROW_BUTTON_X_PAD   2
#define E_CALENDAR_ARROW_BUTTON_Y_PAD   0

/* Vertical padding. The padding above the button includes the space for the
   horizontal line. */
#define E_CALENDAR_YPAD_ABOVE_LOWER_BUTTONS     4
#define E_CALENDAR_YPAD_BELOW_LOWER_BUTTONS     3

/* Horizontal padding inside & between buttons. */
#define E_CALENDAR_IXPAD_BUTTONS            4
#define E_CALENDAR_XPAD_BUTTONS             8

/* The time between steps when the prev/next buttons is pressed, in 1/1000ths
   of a second, and the number of timeouts we skip before we start
   automatically moving back/forward. */
#define E_CALENDAR_AUTO_MOVE_TIMEOUT        150
#define E_CALENDAR_AUTO_MOVE_TIMEOUT_DELAY  2

static void e_calendar_dispose      (GObject    *object);
static void e_calendar_realize      (GtkWidget  *widget);
static void e_calendar_style_set    (GtkWidget  *widget,
                     GtkStyle   *previous_style);
static void e_calendar_get_preferred_width (GtkWidget *widget,
                        gint      *minimal_width,
                        gint      *natural_width);
static void e_calendar_get_preferred_height (GtkWidget *widget,
                         gint      *minimal_height,
                         gint      *natural_height);
static void e_calendar_size_allocate    (GtkWidget  *widget,
                     GtkAllocation  *allocation);
static gint e_calendar_drag_motion  (GtkWidget      *widget,
                     GdkDragContext *context,
                     gint            x,
                     gint            y,
                     guint           time);
static void e_calendar_drag_leave   (GtkWidget      *widget,
                     GdkDragContext *context,
                     guint           time);
static gboolean e_calendar_button_has_focus (ECalendar  *cal);
static gboolean e_calendar_focus (GtkWidget *widget,
                  GtkDirectionType direction);

static void e_calendar_on_prev_pressed  (ECalendar  *cal);
static void e_calendar_on_prev_released (ECalendar  *cal);
static void e_calendar_on_prev_clicked  (ECalendar      *cal);
static void e_calendar_on_next_pressed  (ECalendar  *cal);
static void e_calendar_on_next_released (ECalendar  *cal);
static void e_calendar_on_next_clicked  (ECalendar      *cal);

static void e_calendar_start_auto_move  (ECalendar  *cal,
                     gboolean    moving_forward);
static gboolean e_calendar_auto_move_handler    (gpointer    data);
static void e_calendar_stop_auto_move   (ECalendar  *cal);

G_DEFINE_TYPE (
    ECalendar,
    e_calendar,
    E_TYPE_CANVAS)

static void
e_calendar_class_init (ECalendarClass *class)
{
    GObjectClass   *object_class;
    GtkWidgetClass *widget_class;

    object_class = (GObjectClass *) class;
    widget_class = (GtkWidgetClass *) class;

    object_class->dispose = e_calendar_dispose;

    widget_class->realize          = e_calendar_realize;
    widget_class->style_set        = e_calendar_style_set;
    widget_class->get_preferred_width  = e_calendar_get_preferred_width;
    widget_class->get_preferred_height = e_calendar_get_preferred_height;
    widget_class->size_allocate    = e_calendar_size_allocate;
    widget_class->drag_motion      = e_calendar_drag_motion;
    widget_class->drag_leave       = e_calendar_drag_leave;
    widget_class->focus                = e_calendar_focus;
}

static void
e_calendar_init (ECalendar *cal)
{
    GnomeCanvasGroup *canvas_group;
    PangoFontDescription *small_font_desc;
    GtkWidget *button, *pixmap;
    AtkObject *a11y;

    /* Create the small font. */

    small_font_desc = pango_font_description_copy (
        gtk_widget_get_style (GTK_WIDGET (cal))->font_desc);
    pango_font_description_set_size (
        small_font_desc,
        E_CALENDAR_SMALL_FONT_PTSIZE * PANGO_SCALE);

    canvas_group = GNOME_CANVAS_GROUP (GNOME_CANVAS (cal)->root);

    cal->calitem = E_CALENDAR_ITEM (gnome_canvas_item_new (canvas_group,
                                   e_calendar_item_get_type (),
                                   "week_number_font_desc", small_font_desc,
                                   NULL));

    pango_font_description_free (small_font_desc);

    /* Create the arrow buttons to move to the previous/next month. */
    button = gtk_button_new ();
    gtk_button_set_relief (GTK_BUTTON (button), GTK_RELIEF_NONE);
    gtk_widget_show (button);
    g_signal_connect_swapped (
        button, "pressed",
        G_CALLBACK (e_calendar_on_prev_pressed), cal);
    g_signal_connect_swapped (
        button, "released",
        G_CALLBACK (e_calendar_on_prev_released), cal);
    g_signal_connect_swapped (
        button, "clicked",
        G_CALLBACK (e_calendar_on_prev_clicked), cal);

    pixmap = gtk_arrow_new (GTK_ARROW_LEFT, GTK_SHADOW_NONE);
    gtk_widget_show (pixmap);
    gtk_container_add (GTK_CONTAINER (button), pixmap);

    cal->prev_item = gnome_canvas_item_new (canvas_group,
                        gnome_canvas_widget_get_type (),
                        "widget", button,
                        NULL);
    a11y = gtk_widget_get_accessible (button);
    atk_object_set_name (a11y, _("Previous"));

    button = gtk_button_new ();
    gtk_button_set_relief (GTK_BUTTON (button), GTK_RELIEF_NONE);
    gtk_widget_show (button);
    g_signal_connect_swapped (
        button, "pressed",
        G_CALLBACK (e_calendar_on_next_pressed), cal);
    g_signal_connect_swapped (
        button, "released",
        G_CALLBACK (e_calendar_on_next_released), cal);
    g_signal_connect_swapped (
        button, "clicked",
        G_CALLBACK (e_calendar_on_next_clicked), cal);

    pixmap = gtk_arrow_new (GTK_ARROW_RIGHT, GTK_SHADOW_NONE);
    gtk_widget_show (pixmap);
    gtk_container_add (GTK_CONTAINER (button), pixmap);

    cal->next_item = gnome_canvas_item_new (canvas_group,
                        gnome_canvas_widget_get_type (),
                        "widget", button,
                        NULL);
    a11y = gtk_widget_get_accessible (button);
    atk_object_set_name (a11y, _("Next"));

    cal->min_rows = 1;
    cal->min_cols = 1;
    cal->max_rows = -1;
    cal->max_cols = -1;

    cal->timeout_id = 0;
}

/**
 * e_calendar_new:
 * @Returns: a new #ECalendar.
 *
 * Creates a new #ECalendar.
 **/
GtkWidget *
e_calendar_new          (void)
{
    GtkWidget *cal;
    AtkObject *a11y;

    cal = g_object_new (e_calendar_get_type (), NULL);
    a11y = gtk_widget_get_accessible (cal);
    atk_object_set_name (a11y, _("Month Calendar"));

    return cal;
}

static void
e_calendar_dispose      (GObject *object)
{
    ECalendar *cal;

    g_return_if_fail (object != NULL);
    g_return_if_fail (E_IS_CALENDAR (object));

    cal = E_CALENDAR (object);

    if (cal->timeout_id != 0) {
        g_source_remove (cal->timeout_id);
        cal->timeout_id = 0;
    }

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

static void
e_calendar_realize (GtkWidget *widget)
{
    GtkStyle *style;
    GdkWindow *window;

    (*GTK_WIDGET_CLASS (e_calendar_parent_class)->realize) (widget);

    /* Set the background of the canvas window to the normal color,
       or the arrow buttons are not displayed properly. */
    style = gtk_widget_get_style (widget);
    window = gtk_layout_get_bin_window (GTK_LAYOUT (widget));
    gdk_window_set_background (window, &style->bg[GTK_STATE_NORMAL]);
}

static void
e_calendar_style_set        (GtkWidget  *widget,
                 GtkStyle   *previous_style)
{
    ECalendar *e_calendar;

    e_calendar = E_CALENDAR (widget);
    if (GTK_WIDGET_CLASS (e_calendar_parent_class)->style_set)
        (*GTK_WIDGET_CLASS (e_calendar_parent_class)->style_set) (widget,
                                   previous_style);

    /* Set the background of the canvas window to the normal color,
       or the arrow buttons are not displayed properly. */
    if (gtk_widget_get_realized (widget)) {
        GtkStyle *style;
        GdkWindow *window;

        style = gtk_widget_get_style (widget);
        window = gtk_layout_get_bin_window (GTK_LAYOUT (widget));
        gdk_window_set_background (window, &style->bg[GTK_STATE_NORMAL]);
    }
    e_calendar_item_style_set (widget, e_calendar->calitem);
}

static void
e_calendar_get_preferred_width (GtkWidget *widget,
                                gint      *minimum,
                                gint      *natural)
{
    ECalendar *cal;
    GtkStyle *style;
    gint col_width;

    cal = E_CALENDAR (widget);
    style = gtk_widget_get_style (GTK_WIDGET (cal));

    g_object_get ((cal->calitem), "column_width", &col_width, NULL);

    *minimum = *natural = col_width * cal->min_cols + style->xthickness * 2;
}

static void
e_calendar_get_preferred_height (GtkWidget *widget,
                                 gint      *minimum,
                                 gint      *natural)
{
    ECalendar *cal;
    GtkStyle *style;
    gint row_height;

    cal = E_CALENDAR (widget);
    style = gtk_widget_get_style (GTK_WIDGET (cal));

    g_object_get ((cal->calitem), "row_height", &row_height, NULL);

    *minimum = *natural = row_height * cal->min_rows + style->ythickness * 2;
}

static void
e_calendar_size_allocate    (GtkWidget  *widget,
                 GtkAllocation  *allocation)
{
    ECalendar *cal;
    GtkStyle *style;
    GtkAllocation old_allocation;
    PangoFontDescription *font_desc;
    PangoContext *pango_context;
    PangoFontMetrics *font_metrics;
    gdouble old_x2, old_y2, new_x2, new_y2;
    gdouble xthickness, ythickness, arrow_button_size;

    cal = E_CALENDAR (widget);
    style = gtk_widget_get_style (widget);
    xthickness = style->xthickness;
    ythickness = style->ythickness;

    (*GTK_WIDGET_CLASS (e_calendar_parent_class)->size_allocate) (widget, allocation);

    /* Set up Pango prerequisites */
    font_desc = gtk_widget_get_style (widget)->font_desc;
    pango_context = gtk_widget_get_pango_context (widget);
    font_metrics = pango_context_get_metrics (pango_context, font_desc,
                          pango_context_get_language (pango_context));

    /* Set the scroll region to its allocated size, if changed. */
    gnome_canvas_get_scroll_region (GNOME_CANVAS (cal),
                    NULL, NULL, &old_x2, &old_y2);
    gtk_widget_get_allocation (widget, &old_allocation);
    new_x2 = old_allocation.width - 1;
    new_y2 = old_allocation.height - 1;
    if (old_x2 != new_x2 || old_y2 != new_y2)
        gnome_canvas_set_scroll_region (GNOME_CANVAS (cal),
                        0, 0, new_x2, new_y2);

    /* Take off space for line & buttons if shown. */
    gnome_canvas_item_set (GNOME_CANVAS_ITEM (cal->calitem),
                   "x1", 0.0,
                   "y1", 0.0,
                   "x2", new_x2,
                   "y2", new_y2,
                   NULL);

    /* Position the arrow buttons. */
    arrow_button_size =
        PANGO_PIXELS (pango_font_metrics_get_ascent (font_metrics))
        + PANGO_PIXELS (pango_font_metrics_get_descent (font_metrics))
        + E_CALENDAR_ITEM_YPAD_ABOVE_MONTH_NAME
        + E_CALENDAR_ITEM_YPAD_BELOW_MONTH_NAME
        - E_CALENDAR_ARROW_BUTTON_Y_PAD * 2;

    gnome_canvas_item_set (cal->prev_item,
                   "x", (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL)
                   ? new_x2 + 1 - xthickness * 2 - E_CALENDAR_ARROW_BUTTON_X_PAD
                 - arrow_button_size
                   : xthickness * 2 + E_CALENDAR_ARROW_BUTTON_X_PAD,
                   "y", ythickness * 2
                   + E_CALENDAR_ARROW_BUTTON_Y_PAD,
                   "width", arrow_button_size,
                   "height", arrow_button_size,
                   NULL);

    gnome_canvas_item_set (cal->next_item,
                   "x", (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL)
                   ? xthickness * 2 + E_CALENDAR_ARROW_BUTTON_X_PAD
                   : new_x2 + 1 - xthickness * 2 - E_CALENDAR_ARROW_BUTTON_X_PAD
                 - arrow_button_size,
                   "y", ythickness * 2
                   + E_CALENDAR_ARROW_BUTTON_Y_PAD,
                   "width", arrow_button_size,
                   "height", arrow_button_size,
                   NULL);

    pango_font_metrics_unref (font_metrics);
}

void
e_calendar_set_minimum_size (ECalendar  *cal,
                 gint        rows,
                 gint        cols)
{
    g_return_if_fail (E_IS_CALENDAR (cal));

    cal->min_rows = rows;
    cal->min_cols = cols;

    gnome_canvas_item_set (GNOME_CANVAS_ITEM (cal->calitem),
                   "minimum_rows", rows,
                   "minimum_columns", cols,
                   NULL);

    gtk_widget_queue_resize (GTK_WIDGET (cal));
}

void
e_calendar_set_maximum_size (ECalendar  *cal,
                 gint        rows,
                 gint        cols)
{
    g_return_if_fail (E_IS_CALENDAR (cal));

    cal->max_rows = rows;
    cal->max_cols = cols;

    gnome_canvas_item_set (GNOME_CANVAS_ITEM (cal->calitem),
                   "maximum_rows", rows,
                   "maximum_columns", cols,
                   NULL);

    gtk_widget_queue_resize (GTK_WIDGET (cal));
}

/* Returns the border size on each side of the month displays. */
void
e_calendar_get_border_size  (ECalendar  *cal,
                 gint       *top,
                 gint       *bottom,
                 gint       *left,
                 gint       *right)
{
    GtkStyle *style;

    g_return_if_fail (E_IS_CALENDAR (cal));

    style = gtk_widget_get_style (GTK_WIDGET (cal));

    if (style) {
        *top    = style->ythickness;
        *bottom = style->ythickness;
        *left   = style->xthickness;
        *right  = style->xthickness;
    } else {
        *top = *bottom = *left = *right = 0;
    }
}

static void
e_calendar_on_prev_pressed  (ECalendar  *cal)
{
    e_calendar_start_auto_move (cal, FALSE);
}

static void
e_calendar_on_next_pressed  (ECalendar  *cal)
{
    e_calendar_start_auto_move (cal, TRUE);
}

static void
e_calendar_start_auto_move  (ECalendar  *cal,
                 gboolean    moving_forward)
{
    if (cal->timeout_id == 0) {
        cal->timeout_id = g_timeout_add (E_CALENDAR_AUTO_MOVE_TIMEOUT,
                         e_calendar_auto_move_handler,
                         cal);
    }
    cal->timeout_delay = E_CALENDAR_AUTO_MOVE_TIMEOUT_DELAY;
    cal->moving_forward = moving_forward;

}

static gboolean
e_calendar_auto_move_handler    (gpointer    data)
{
    ECalendar *cal;
    ECalendarItem *calitem;
    gint offset;

    g_return_val_if_fail (E_IS_CALENDAR (data), FALSE);

    cal = E_CALENDAR (data);
    calitem = cal->calitem;

    GDK_THREADS_ENTER ();

    if (cal->timeout_delay > 0) {
        cal->timeout_delay--;
    } else {
        offset = cal->moving_forward ? 1 : -1;
        e_calendar_item_set_first_month (calitem, calitem->year,
                         calitem->month + offset);
    }

    GDK_THREADS_LEAVE ();
    return TRUE;
}

static void
e_calendar_on_prev_released (ECalendar  *cal)
{
    e_calendar_stop_auto_move (cal);
}

static void
e_calendar_on_next_released (ECalendar  *cal)
{
    e_calendar_stop_auto_move (cal);
}

static void
e_calendar_stop_auto_move   (ECalendar  *cal)
{
    if (cal->timeout_id != 0) {
        g_source_remove (cal->timeout_id);
        cal->timeout_id = 0;
    }
}

static void
e_calendar_on_prev_clicked      (ECalendar      *cal)
{
    e_calendar_item_set_first_month (cal->calitem, cal->calitem->year,
        cal->calitem->month - 1);
}

static void
e_calendar_on_next_clicked      (ECalendar      *cal)
{
    e_calendar_item_set_first_month (cal->calitem, cal->calitem->year,
        cal->calitem->month + 1);
}

static gint
e_calendar_drag_motion (GtkWidget      *widget,
            GdkDragContext *context,
            gint            x,
            gint            y,
            guint           time)
{
#if 0
    g_print ("In e_calendar_drag_motion\n");
#endif

    return FALSE;
}

static void
e_calendar_drag_leave (GtkWidget      *widget,
               GdkDragContext *context,
               guint           time)
{
#if 0
    g_print ("In e_calendar_drag_leave\n");
#endif
}

static gboolean
e_calendar_button_has_focus (ECalendar  *cal)
{
    GtkWidget *prev_widget, *next_widget;
    gboolean ret_val;

    g_return_val_if_fail (E_IS_CALENDAR (cal), FALSE);

    prev_widget = GNOME_CANVAS_WIDGET (cal->prev_item)->widget;
    next_widget = GNOME_CANVAS_WIDGET (cal->next_item)->widget;
    ret_val = gtk_widget_has_focus (prev_widget) ||
        gtk_widget_has_focus (next_widget);
    return ret_val;
}

static gboolean
e_calendar_focus (GtkWidget *widget, GtkDirectionType direction)
{
#define E_CALENDAR_FOCUS_CHILDREN_NUM 3
    ECalendar *cal;
    GnomeCanvas *canvas;
    GnomeCanvasItem *children[E_CALENDAR_FOCUS_CHILDREN_NUM];
    gint focused_index = -1;
    gint index;

    g_return_val_if_fail (widget != NULL, FALSE);
    g_return_val_if_fail (E_IS_CALENDAR (widget), FALSE);
    cal = E_CALENDAR (widget);
    canvas = GNOME_CANVAS (widget);

    if (!gtk_widget_get_can_focus (widget))
        return FALSE;

    children[0] = GNOME_CANVAS_ITEM (cal->calitem);
    children[1] = cal->prev_item;
    children[2] = cal->next_item;

    /* get current focused item, if e-calendar has had focus */
    if (gtk_widget_has_focus (widget) || e_calendar_button_has_focus (cal))
        for (index = 0; index < E_CALENDAR_FOCUS_CHILDREN_NUM; ++index) {
            if (canvas->focused_item == NULL)
                break;

            if (children[index] == canvas->focused_item) {
                focused_index = index;
                break;
            }
        }

    if (focused_index == -1)
        if (direction == GTK_DIR_TAB_FORWARD)
            focused_index = 0;
        else
            focused_index = E_CALENDAR_FOCUS_CHILDREN_NUM - 1;
    else
        if (direction == GTK_DIR_TAB_FORWARD)
            ++focused_index;
        else
            --focused_index;

    if (focused_index < 0 ||
        focused_index >= E_CALENDAR_FOCUS_CHILDREN_NUM)
        /* move out of e-calendar */
        return FALSE;
    gnome_canvas_item_grab_focus (children[focused_index]);
    if (GNOME_IS_CANVAS_WIDGET (children[focused_index])) {
        widget = GNOME_CANVAS_WIDGET (children[focused_index])->widget;
        gtk_widget_grab_focus (widget);
    }
    return TRUE;
}

void
e_calendar_set_focusable (ECalendar *cal, gboolean focusable)
{
    GtkWidget *widget;
    GtkWidget *prev_widget, *next_widget;
    GtkWidget *toplevel;

    g_return_if_fail (E_IS_CALENDAR (cal));

    widget = GTK_WIDGET (cal);
    prev_widget = GNOME_CANVAS_WIDGET (cal->prev_item)->widget;
    next_widget = GNOME_CANVAS_WIDGET (cal->next_item)->widget;

    if (focusable) {
        gtk_widget_set_can_focus (widget, TRUE);
        gtk_widget_set_can_focus (prev_widget, TRUE);
        gtk_widget_set_can_focus (next_widget, TRUE);
    }
    else {
        if (gtk_widget_has_focus (GTK_WIDGET (cal)) ||
            e_calendar_button_has_focus (cal)) {
            toplevel = gtk_widget_get_toplevel (widget);
            if (toplevel)
                gtk_widget_grab_focus (toplevel);
        }
        gtk_widget_set_can_focus (widget, FALSE);
        gtk_widget_set_can_focus (prev_widget, FALSE);
        gtk_widget_set_can_focus (next_widget, FALSE);
    }
}