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

/* 
 * Author : 
 *  Damon Chaplin <damon@ximian.com>
 *
 * Copyright 1999, Ximian, Inc.
 * Copyright 1999, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */

/*
 * EDayViewTimeItem - canvas item which displays the times down the left of
 * the EDayView.
 */

#include <config.h>
#include <string.h>
#include <glib.h>
#include <gtk/gtksignal.h>
#include <gtk/gtkradiomenuitem.h>
#include <gtk/gtkcheckmenuitem.h>
#include <libgnome/gnome-i18n.h>
#include <gal/widgets/e-gui-utils.h>
#include "e-day-view-time-item.h"
#include "calendar-config.h"


/* The spacing between items in the time column. GRID_X_PAD is the space down
   either side of the column, i.e. outside the main horizontal grid lines.
   HOUR_L_PAD & HOUR_R_PAD are the spaces on the left & right side of the
   big hour number (this is inside the horizontal grid lines).
   MIN_X_PAD is the spacing either side of the minute number. The smaller
   horizontal grid lines match with this.
   60_MIN_X_PAD is the space either side of the HH:MM display used when
   we are displaying 60 mins per row (inside the main grid lines).
   LARGE_HOUR_Y_PAD is the offset of the large hour string from the top of the
   row.
   SMALL_FONT_Y_PAD is the offset of the small time/minute string from the top
   of the row. */
#define E_DVTMI_TIME_GRID_X_PAD     4
#define E_DVTMI_HOUR_L_PAD      4
#define E_DVTMI_HOUR_R_PAD      2
#define E_DVTMI_MIN_X_PAD       2
#define E_DVTMI_60_MIN_X_PAD        4
#define E_DVTMI_LARGE_HOUR_Y_PAD    1
#define E_DVTMI_SMALL_FONT_Y_PAD    1

static void e_day_view_time_item_class_init (EDayViewTimeItemClass *class);
static void e_day_view_time_item_init (EDayViewTimeItem *dvtmitem);
static void e_day_view_time_item_set_arg (GtkObject *o,
                      GtkArg *arg,
                      guint arg_id);

static void e_day_view_time_item_update (GnomeCanvasItem *item,
                     double *affine,
                     ArtSVP *clip_path, int flags);
static void e_day_view_time_item_draw (GnomeCanvasItem *item,
                       GdkDrawable *drawable,
                       int x, int y,
                       int width, int height);
static double e_day_view_time_item_point (GnomeCanvasItem *item,
                      double x, double y,
                      int cx, int cy,
                      GnomeCanvasItem **actual_item);
static gint e_day_view_time_item_event (GnomeCanvasItem *item,
                    GdkEvent *event);
static void e_day_view_time_item_increment_time (gint   *hour,
                         gint   *minute,
                         gint    mins_per_row);
static void e_day_view_time_item_show_popup_menu (EDayViewTimeItem *dvtmitem,
                          GdkEvent *event);
static void e_day_view_time_item_on_set_divisions (GtkWidget *item,
                           EDayViewTimeItem *dvtmitem);
static void e_day_view_time_item_on_button_press (EDayViewTimeItem *dvtmitem,
                          GdkEvent *event);
static void e_day_view_time_item_on_button_release (EDayViewTimeItem *dvtmitem,
                            GdkEvent *event);
static void e_day_view_time_item_on_motion_notify (EDayViewTimeItem *dvtmitem,
                           GdkEvent *event);
static gint e_day_view_time_item_convert_position_to_row (EDayViewTimeItem *dvtmitem,
                              gint y);


static GnomeCanvasItemClass *parent_class;


/* The arguments we take */
enum {
    ARG_0,
    ARG_DAY_VIEW
};

E_MAKE_TYPE (e_day_view_time_item, "EDayViewTimeItem", EDayViewTimeItem,
         e_day_view_time_item_class_init, e_day_view_time_item_init, GNOME_TYPE_CANVAS_ITEM);

static void
e_day_view_time_item_class_init (EDayViewTimeItemClass *class)
{
    GtkObjectClass  *object_class;
    GnomeCanvasItemClass *item_class;

    parent_class = g_type_class_peek_parent (class);

    object_class = (GtkObjectClass *) class;
    item_class = (GnomeCanvasItemClass *) class;

    gtk_object_add_arg_type ("EDayViewTimeItem::day_view",
                 GTK_TYPE_POINTER, GTK_ARG_WRITABLE,
                 ARG_DAY_VIEW);

    object_class->set_arg = e_day_view_time_item_set_arg;

    /* GnomeCanvasItem method overrides */
    item_class->update      = e_day_view_time_item_update;
    item_class->draw        = e_day_view_time_item_draw;
    item_class->point       = e_day_view_time_item_point;
    item_class->event       = e_day_view_time_item_event;
}


static void
e_day_view_time_item_init (EDayViewTimeItem *dvtmitem)
{
    dvtmitem->dragging_selection = FALSE;
}


static void
e_day_view_time_item_set_arg (GtkObject *o, GtkArg *arg, guint arg_id)
{
    GnomeCanvasItem *item;
    EDayViewTimeItem *dvtmitem;

    item = GNOME_CANVAS_ITEM (o);
    dvtmitem = E_DAY_VIEW_TIME_ITEM (o);
    
    switch (arg_id){
    case ARG_DAY_VIEW:
        dvtmitem->day_view = GTK_VALUE_POINTER (*arg);
        break;
    }
}


static void
e_day_view_time_item_update (GnomeCanvasItem *item,
                double *affine,
                ArtSVP *clip_path,
                int flags)
{
    if (GNOME_CANVAS_ITEM_CLASS (parent_class)->update)
        (* GNOME_CANVAS_ITEM_CLASS (parent_class)->update) (item, affine, clip_path, flags);

    /* The item covers the entire canvas area. */
    item->x1 = 0;
    item->y1 = 0;
    item->x2 = INT_MAX;
    item->y2 = INT_MAX;
}


/* Returns the minimum width needed for the column, by adding up all the
   maximum widths of the strings. The string widths are all calculated in
   the style_set handlers of EDayView and EDayViewTimeCanvas. */
gint
e_day_view_time_item_get_column_width (EDayViewTimeItem *dvtmitem)
{
    EDayView *day_view;
    GtkStyle *style;
    gint digit, large_digit_width, max_large_digit_width = 0;
    gint max_suffix_width, max_minute_or_suffix_width;
    gint column_width_default, column_width_60_min_rows;
    PangoContext *context;

    day_view = dvtmitem->day_view;
    g_return_val_if_fail (day_view != NULL, 0);

    style = gtk_widget_get_style (GTK_WIDGET (day_view));
    g_return_val_if_fail (style != NULL, 0);

    context = gtk_widget_get_pango_context (GTK_WIDGET (day_view));

    /* Find the maximum width a digit can have. FIXME: We could use pango's
     * approximation function, but I worry it won't be precise enough. Also
     * it needs a language tag that I don't know where to get. */
    for (digit = '0'; digit <= '9'; digit++) {
        PangoLayout *layout;
        gchar digit_str [2];

        digit_str [0] = digit;
        digit_str [1] = '\0';

        layout = gtk_widget_create_pango_layout (GTK_WIDGET (day_view), digit_str);
        pango_layout_set_font_description (layout, day_view->large_font_desc);
        pango_layout_get_pixel_size (layout, &large_digit_width, NULL);
        g_object_unref (layout);

        max_large_digit_width = MAX (max_large_digit_width,
                         large_digit_width);
    }

    /* Calculate the width of each time column, using the maximum of the
       default format with large hour numbers, and the 60-min divisions
       format which uses small text. */
    max_suffix_width = MAX (day_view->am_string_width,
                day_view->pm_string_width);

    max_minute_or_suffix_width = MAX (max_suffix_width,
                      day_view->max_minute_width);

    column_width_default = max_large_digit_width * 2
        + max_minute_or_suffix_width
        + E_DVTMI_MIN_X_PAD * 2
        + E_DVTMI_HOUR_L_PAD
        + E_DVTMI_HOUR_R_PAD
        + E_DVTMI_TIME_GRID_X_PAD * 2;

    column_width_60_min_rows = day_view->max_small_hour_width
        + day_view->colon_width
        + max_minute_or_suffix_width
        + E_DVTMI_60_MIN_X_PAD * 2
        + E_DVTMI_TIME_GRID_X_PAD * 2;

    dvtmitem->column_width = MAX (column_width_default,
                      column_width_60_min_rows);

    return dvtmitem->column_width;
}


/*
 * DRAWING ROUTINES - functions to paint the canvas item.
 */

static void
e_day_view_time_item_draw (GnomeCanvasItem *canvas_item,
               GdkDrawable     *drawable,
               int          x,
               int          y,
               int          width,
               int          height)
{
    EDayView *day_view;
    EDayViewTimeItem *dvtmitem;
    GtkStyle *style;
    GdkGC *fg_gc, *dark_gc;
    gchar buffer[64], *suffix;
    gint hour, display_hour, minute, row;
    gint row_y, start_y, large_hour_y_offset, small_font_y_offset;
    gint long_line_x1, long_line_x2, short_line_x1;
    gint large_hour_x2, minute_x2;
    gint hour_width, minute_width, suffix_width;
    gint max_suffix_width, max_minute_or_suffix_width;
    PangoLayout *layout;
    PangoContext *context;
    PangoFontDescription *small_font_desc;
    PangoFontMetrics *large_font_metrics, *small_font_metrics;

    dvtmitem = E_DAY_VIEW_TIME_ITEM (canvas_item);
    day_view = dvtmitem->day_view;
    g_return_if_fail (day_view != NULL);

    style = gtk_widget_get_style (GTK_WIDGET (day_view));
    small_font_desc = style->font_desc;

    context = gtk_widget_get_pango_context (GTK_WIDGET (day_view));
    large_font_metrics = pango_context_get_metrics (context, day_view->large_font_desc,
                            pango_context_get_language (context));
    small_font_metrics = pango_context_get_metrics (context, small_font_desc,
                            pango_context_get_language (context));

    fg_gc = style->fg_gc[GTK_STATE_NORMAL];
    dark_gc = style->dark_gc[GTK_STATE_NORMAL];

    /* The start and end of the long horizontal line between hours. */
    long_line_x1 = E_DVTMI_TIME_GRID_X_PAD - x;
    long_line_x2 = dvtmitem->column_width - E_DVTMI_TIME_GRID_X_PAD - x;

    if (day_view->mins_per_row == 60) {
        /* The right edge of the complete time string in 60-min
           divisions, e.g. "14:00" or "2 pm". */
        minute_x2 = long_line_x2 - E_DVTMI_60_MIN_X_PAD;

        /* These aren't used for 60-minute divisions, but we initialize
           them to keep gcc happy. */
        short_line_x1 = 0;
        large_hour_x2 = 0;
    } else {
        max_suffix_width = MAX (day_view->am_string_width,
                    day_view->pm_string_width);

        max_minute_or_suffix_width = MAX (max_suffix_width,
                          day_view->max_minute_width);

        /* The start of the short horizontal line between the periods
           within each hour. */
        short_line_x1 = long_line_x2 - E_DVTMI_MIN_X_PAD * 2
            - max_minute_or_suffix_width;

        /* The right edge of the large hour string. */
        large_hour_x2 = short_line_x1 - E_DVTMI_HOUR_R_PAD;

        /* The right edge of the minute part of the time. */
        minute_x2 = long_line_x2 - E_DVTMI_MIN_X_PAD;
    }

    /* Start with the first hour & minute shown in the EDayView. */
    hour = day_view->first_hour_shown;
    minute = day_view->first_minute_shown;

    /* The offset of the large hour string from the top of the row. */
    large_hour_y_offset = E_DVTMI_LARGE_HOUR_Y_PAD;

    /* The offset of the small time/minute string from top of row. */
    small_font_y_offset = E_DVTMI_SMALL_FONT_Y_PAD;

    /* Calculate the minimum y position of the first row we need to draw.
       This is normally one row height above the 0 position, but if we
       are using the large font we may have to go back a bit further. */
    start_y = 0 - MAX (day_view->row_height,
               (pango_font_metrics_get_ascent (large_font_metrics) +
                pango_font_metrics_get_descent (large_font_metrics)) / PANGO_SCALE +
               E_DVTMI_LARGE_HOUR_Y_PAD);

    /* Step through each row, drawing the times and the horizontal lines
       between them. */
    for (row = 0, row_y = 0 - y;
         row < day_view->rows && row_y < height;
         row++, row_y += day_view->row_height) {

        /* If the row is above the first row we want to draw just
           increment the time and skip to the next row. */
        if (row_y < start_y) {
            e_day_view_time_item_increment_time (&hour, &minute,
                                 day_view->mins_per_row);
            continue;
        }

        /* Calculate the actual hour number to display. For 12-hour
           format we convert 0-23 to 12-11am/12-11pm. */
        e_day_view_convert_time_to_display (day_view, hour,
                            &display_hour,
                            &suffix, &suffix_width);

        if (day_view->mins_per_row == 60) {
            /* 60 minute intervals - draw a long horizontal line
               between hours and display as one long string,
               e.g. "14:00" or "2 pm". */
            gdk_draw_line (drawable, dark_gc,
                       long_line_x1, row_y,
                       long_line_x2, row_y);

            if (e_calendar_view_get_use_24_hour_format (E_CALENDAR_VIEW (day_view))) {
                g_snprintf (buffer, sizeof (buffer), "%i:%02i",
                        display_hour, minute);
            } else {
                g_snprintf (buffer, sizeof (buffer), "%i %s",
                        display_hour, suffix);
            }

            layout = gtk_widget_create_pango_layout (GTK_WIDGET (day_view), buffer);
            pango_layout_get_pixel_size (layout, &minute_width, NULL);
            gdk_draw_layout (drawable, fg_gc,
                     minute_x2 - minute_width,
                     row_y + small_font_y_offset,
                     layout);
            g_object_unref (layout);
        } else {
            /* 5/10/15/30 minute intervals. */

            if (minute == 0) {
                /* On the hour - draw a long horizontal line
                   before the hour and display the hour in the
                   large font. */
                gdk_draw_line (drawable, dark_gc,
                           long_line_x1, row_y,
                           long_line_x2, row_y);

                g_snprintf (buffer, sizeof (buffer), "%i",
                        display_hour);

                layout = gtk_widget_create_pango_layout (GTK_WIDGET (day_view), buffer);
                pango_layout_set_font_description (layout, day_view->large_font_desc);
                pango_layout_get_pixel_size (layout, &hour_width, NULL);
                gdk_draw_layout (drawable, fg_gc,
                         large_hour_x2 - hour_width,
                         row_y + large_hour_y_offset,
                         layout);
                g_object_unref (layout);
            } else {
                /* Within the hour - draw a short line before
                   the time. */
                gdk_draw_line (drawable, dark_gc,
                           short_line_x1, row_y,
                           long_line_x2, row_y);
            }

            /* Normally we display the minute in each
               interval, but when using 30-minute intervals
               we don't display the '30'. */
            if (day_view->mins_per_row != 30 || minute != 30) {
                /* In 12-hour format we display 'am' or 'pm'
                   instead of '00'. */
                if (minute == 0
                    && !e_calendar_view_get_use_24_hour_format (E_CALENDAR_VIEW (day_view))) {
                    strcpy (buffer, suffix);
                } else {
                    g_snprintf (buffer, sizeof (buffer),
                            "%02i", minute);
                }

                layout = gtk_widget_create_pango_layout (GTK_WIDGET (day_view), buffer);
                pango_layout_get_pixel_size (layout, &minute_width, NULL);
                gdk_draw_layout (drawable, fg_gc,
                         minute_x2 - minute_width,
                         row_y + small_font_y_offset,
                         layout);
                g_object_unref (layout);
            }
        }

        e_day_view_time_item_increment_time (&hour, &minute,
                             day_view->mins_per_row);
    }

    pango_font_metrics_unref (large_font_metrics);
    pango_font_metrics_unref (small_font_metrics);
}


/* Increment the time by the 5/10/15/30/60 minute interval.
   Note that mins_per_row is never > 60, so we never have to
   worry about adding more than 60 minutes. */
static void
e_day_view_time_item_increment_time (gint   *hour,
                     gint   *minute,
                     gint    mins_per_row)
{
    *minute += mins_per_row;
    if (*minute >= 60) {
        *minute -= 60;
        /* Currently we never wrap around to the next day, but
           we may do if we display extra timezones. */
        *hour = (*hour + 1) % 24;
    }
}


static double
e_day_view_time_item_point (GnomeCanvasItem *item, double x, double y,
                int cx, int cy,
                GnomeCanvasItem **actual_item)
{
    *actual_item = item;
    return 0.0;
}


static gint
e_day_view_time_item_event (GnomeCanvasItem *item,
                GdkEvent *event)
{
    EDayViewTimeItem *dvtmitem;

    dvtmitem = E_DAY_VIEW_TIME_ITEM (item);

    switch (event->type) {
    case GDK_BUTTON_PRESS:
        if (event->button.button == 1) {
            e_day_view_time_item_on_button_press (dvtmitem, event);
        } else if (event->button.button == 3) {
            e_day_view_time_item_show_popup_menu (dvtmitem, event);
            return TRUE;
        }
        break;
    case GDK_BUTTON_RELEASE:
        if (event->button.button == 1)
            e_day_view_time_item_on_button_release (dvtmitem,
                                event);
        break;

    case GDK_MOTION_NOTIFY:
        e_day_view_time_item_on_motion_notify (dvtmitem, event);
        break;

    default:
        break;
    }

    return FALSE;
}


static void
e_day_view_time_item_show_popup_menu (EDayViewTimeItem *dvtmitem,
                      GdkEvent *event)
{
    static gint divisions[] = { 60, 30, 15, 10, 5 };
    EDayView *day_view;
    gint num_divisions = sizeof (divisions) / sizeof (divisions[0]);
    GtkWidget *menu, *item;
    gchar buffer[256];
    GSList *group = NULL;
    gint current_divisions, i;

    day_view = dvtmitem->day_view;
    g_return_if_fail (day_view != NULL);

    current_divisions = e_day_view_get_mins_per_row (day_view);

    menu = gtk_menu_new ();

    /* Make sure the menu is destroyed when it disappears. */
    e_auto_kill_popup_menu_on_selection_done (GTK_MENU (menu));

    for (i = 0; i < num_divisions; i++) {
        g_snprintf (buffer, sizeof (buffer),
                _("%02i minute divisions"), divisions[i]);
        item = gtk_radio_menu_item_new_with_label (group, buffer);
        group = gtk_radio_menu_item_group (GTK_RADIO_MENU_ITEM (item));
        gtk_widget_show (item);
        gtk_menu_append (GTK_MENU (menu), item);

        if (current_divisions == divisions[i])
            gtk_check_menu_item_set_active (GTK_CHECK_MENU_ITEM (item), TRUE);

        g_object_set_data (G_OBJECT (item), "divisions",
                   GINT_TO_POINTER (divisions[i]));

        g_signal_connect (item, "toggled",
                  G_CALLBACK (e_day_view_time_item_on_set_divisions), dvtmitem);
    }

    gtk_menu_popup (GTK_MENU (menu), NULL, NULL, NULL, NULL,
            event->button.button, event->button.time);
}


static void
e_day_view_time_item_on_set_divisions (GtkWidget *item,
                       EDayViewTimeItem *dvtmitem)
{
    EDayView *day_view;
    gint divisions;

    day_view = dvtmitem->day_view;
    g_return_if_fail (day_view != NULL);

    if (!gtk_check_menu_item_get_active (GTK_CHECK_MENU_ITEM (item)))
        return;

    divisions = GPOINTER_TO_INT (g_object_get_data (G_OBJECT (item), "divisions"));
    e_day_view_set_mins_per_row (day_view, divisions);
    calendar_config_set_time_divisions (divisions);
}


static void
e_day_view_time_item_on_button_press (EDayViewTimeItem *dvtmitem,
                      GdkEvent *event)
{
    EDayView *day_view;
    GnomeCanvas *canvas;
    gint row;

    day_view = dvtmitem->day_view;
    g_return_if_fail (day_view != NULL);

    canvas = GNOME_CANVAS_ITEM (dvtmitem)->canvas;

    row = e_day_view_time_item_convert_position_to_row (dvtmitem,
                                event->button.y);

    if (row == -1)
        return;

    if (!GTK_WIDGET_HAS_FOCUS (day_view))
        gtk_widget_grab_focus (GTK_WIDGET (day_view));

    if (gdk_pointer_grab (GTK_LAYOUT (canvas)->bin_window, FALSE,
                  GDK_POINTER_MOTION_MASK
                  | GDK_BUTTON_RELEASE_MASK,
                  FALSE, NULL, event->button.time) == 0) {
        e_day_view_start_selection (day_view, -1, row);
        dvtmitem->dragging_selection = TRUE;
    }
}


static void
e_day_view_time_item_on_button_release (EDayViewTimeItem *dvtmitem,
                    GdkEvent *event)
{
    EDayView *day_view;

    day_view = dvtmitem->day_view;
    g_return_if_fail (day_view != NULL);

    if (dvtmitem->dragging_selection) {
        gdk_pointer_ungrab (event->button.time);
        e_day_view_finish_selection (day_view);
        e_day_view_stop_auto_scroll (day_view);
    }

    dvtmitem->dragging_selection = FALSE;
}


static void
e_day_view_time_item_on_motion_notify (EDayViewTimeItem *dvtmitem,
                       GdkEvent *event)
{
    EDayView *day_view;
    GnomeCanvas *canvas;
    gdouble window_y;
    gint y, row;

    if (!dvtmitem->dragging_selection)
        return;

    day_view = dvtmitem->day_view;
    g_return_if_fail (day_view != NULL);

    canvas = GNOME_CANVAS_ITEM (dvtmitem)->canvas;

    y = event->motion.y;
    row = e_day_view_time_item_convert_position_to_row (dvtmitem, y);

    if (row != -1) {
        gnome_canvas_world_to_window (canvas, 0, event->motion.y,
                          NULL, &window_y);
        e_day_view_update_selection (day_view, -1, row);
        e_day_view_check_auto_scroll (day_view, -1, (gint) window_y);
    }
}


/* Returns the row corresponding to the y position, or -1. */
static gint
e_day_view_time_item_convert_position_to_row (EDayViewTimeItem *dvtmitem,
                          gint y)
{
    EDayView *day_view;
    gint row;

    day_view = dvtmitem->day_view;
    g_return_val_if_fail (day_view != NULL, -1);

    if (y < 0)
        return -1;

    row = y / day_view->row_height;
    if (row >= day_view->rows)
        return -1;

    return row;
}