path: root/calendar/month-view.c

/* Month view display for gncal
 *
 * Copyright (C) 1998 Red Hat Software, Inc.
 *
 * Author: Federico Mena <federico@nuclecu.unam.mx>
 */

#include <config.h>
#include <libgnomeui/gnome-canvas-text.h>
#include "layout.h"
#include "month-view.h"
#include "main.h"
#include "mark.h"
#include "timeutil.h"


#define SPACING 4       /* Spacing between title and calendar */


/* This is a child in the month view.  Each child has a number of canvas items associated to it --
 * it can be more than one box because an event may span several weeks.
 */
struct child {
    iCalObject *ico;    /* The calendar object this child refers to */
    time_t start, end;  /* Start and end times for the instance of the event */
    int slot_start;     /* The first slot this child uses */
    int slots_used;     /* The number of slots occupied by this child */
    GList *segments;    /* The list of segments needed to display this child */
};

/* Each child is composed of one or more segments.  Each segment can be considered to be
 * the entire child clipped to a particular week, as events may span several weeks in the
 * month view.
 */
struct segment {
    time_t start, end;  /* Start/end times for this segment */
    GnomeCanvasItem *item;  /* Canvas item used to display this segment */
};


static void month_view_class_init    (MonthViewClass *class);
static void month_view_init          (MonthView      *mv);
static void month_view_size_request  (GtkWidget      *widget,
                      GtkRequisition *requisition);
static void month_view_size_allocate (GtkWidget      *widget,
                      GtkAllocation  *allocation);


static GnomeCanvasClass *parent_class;


GtkType
month_view_get_type (void)
{
    static GtkType month_view_type = 0;

    if (!month_view_type) {
        GtkTypeInfo month_view_info = {
            "MonthView",
            sizeof (MonthView),
            sizeof (MonthViewClass),
            (GtkClassInitFunc) month_view_class_init,
            (GtkObjectInitFunc) month_view_init,
            NULL, /* reserved_1 */
            NULL, /* reserved_2 */
            (GtkClassInitFunc) NULL
        };

        month_view_type = gtk_type_unique (gnome_canvas_get_type (), &month_view_info);
    }

    return month_view_type;
}

static void
month_view_class_init (MonthViewClass *class)
{
    GtkWidgetClass *widget_class;

    widget_class = (GtkWidgetClass *) class;

    parent_class = gtk_type_class (gnome_canvas_get_type ());

    widget_class->size_request = month_view_size_request;
    widget_class->size_allocate = month_view_size_allocate;
}

static void
month_view_init (MonthView *mv)
{
    /* Title */

    mv->title = gnome_canvas_item_new (gnome_canvas_root (GNOME_CANVAS (mv)),
                       gnome_canvas_text_get_type (),
                       "anchor", GTK_ANCHOR_N,
                       "font", HEADING_FONT,
                       "fill_color", "black",
                       NULL);

    /* Month item */

    mv->mitem = gnome_month_item_new (gnome_canvas_root (GNOME_CANVAS (mv)));
    gnome_canvas_item_set (mv->mitem,
                   "x", 0.0,
                   "anchor", GTK_ANCHOR_NW,
                   "day_anchor", GTK_ANCHOR_NE,
                   "start_on_monday", week_starts_on_monday,
                   "heading_padding", 2.0,
                   "heading_font", BIG_DAY_HEADING_FONT,
                   "day_font", BIG_NORMAL_DAY_FONT,
                   NULL);

    mv->old_current_index = -1;
}

GtkWidget *
month_view_new (GnomeCalendar *calendar, time_t month)
{
    MonthView *mv;

    g_return_val_if_fail (calendar != NULL, NULL);
    g_return_val_if_fail (GNOME_IS_CALENDAR (calendar), NULL);

    mv = gtk_type_new (month_view_get_type ());
    mv->calendar = calendar;

    month_view_colors_changed (mv);
    month_view_set (mv, month);
    return GTK_WIDGET (mv);
}

static void
month_view_size_request (GtkWidget *widget, GtkRequisition *requisition)
{
    g_return_if_fail (widget != NULL);
    g_return_if_fail (IS_MONTH_VIEW (widget));
    g_return_if_fail (requisition != NULL);

    if (GTK_WIDGET_CLASS (parent_class)->size_request)
        (* GTK_WIDGET_CLASS (parent_class)->size_request) (widget, requisition);

    requisition->width = 200;
    requisition->height = 150;
}

/* Adjusts a single segment from a child.  Takes the dimensions of the day the segment is on and
 * resizes the segment's canvas item to the apporpriate size and position.
 */
static void
adjust_segment (MonthView *mv, struct child *child, struct segment *seg)
{
    GnomeMonthItem *mitem;
    struct tm tm;
    int day_index;
    GnomeCanvasItem *item;
    double day_width, day_height;
    double x1, y1, x2, y2;
    double y;
    double slot_width;
    time_t day_begin_time, day_end_time;
    double start_factor, end_factor;

    mitem = GNOME_MONTH_ITEM (mv->mitem);

    /* Find out the dimensions of the day item for the segment */

    tm = *localtime (&seg->start);
    day_index = gnome_month_item_day2index (mitem, tm.tm_mday);
    g_assert (day_index != -1);

    item = gnome_month_item_num2child (mitem, day_index + GNOME_MONTH_ITEM_DAY_GROUP);
    gnome_canvas_item_get_bounds (item, &x1, &y1, &x2, &y2);

    /* Get the bottom coordinate of the day label */

    item = gnome_month_item_num2child (mitem, day_index + GNOME_MONTH_ITEM_DAY_LABEL);
    gnome_canvas_item_get_bounds (item, NULL, NULL, NULL, &y);

    /* Calculate usable area */

    y1 += y;
    day_width = x2 - x1;
    day_height = y2 - y1;

    slot_width = day_width / mv->num_slots;

    /* Set the coordinates of the segment's item */

    day_begin_time = time_day_begin (seg->start);
    day_end_time = time_day_end (seg->end);

    start_factor = (double) (seg->start - day_begin_time) / (day_end_time - day_begin_time);
    end_factor = (double) (seg->end - day_begin_time) / (day_end_time - day_begin_time);

    gnome_canvas_item_set (seg->item,
                   "x1", x1 + slot_width * child->slot_start,
                   "y1", y1 + day_height * start_factor,
                   "x2", x1 + slot_width * (child->slot_start + child->slots_used),
                   "y2", y1 + day_height * end_factor,
                   NULL);
}

/* Adjusts the child events of the month view to the appropriate size and position */
static void
adjust_children (MonthView *mv)
{
    GList *children;
    struct child *child;
    GList *segments;
    struct segment *seg;

    for (children = mv->children; children; children = children->next) {
        child = children->data;

        for (segments = child->segments; segments; segments = segments->next) {
            seg = segments->data;

            adjust_segment (mv, child, seg);
        }
    }
}

static void
month_view_size_allocate (GtkWidget *widget, GtkAllocation *allocation)
{
    MonthView *mv;
    GdkFont *font;
    GtkArg arg;
    int y;

    g_return_if_fail (widget != NULL);
    g_return_if_fail (IS_MONTH_VIEW (widget));
    g_return_if_fail (allocation != NULL);

    mv = MONTH_VIEW (widget);

    if (GTK_WIDGET_CLASS (parent_class)->size_allocate)
        (* GTK_WIDGET_CLASS (parent_class)->size_allocate) (widget, allocation);

    gnome_canvas_set_scroll_region (GNOME_CANVAS (mv), 0, 0, allocation->width, allocation->height);

    /* Adjust items to new size */

    arg.name = "font_gdk";
    gtk_object_getv (GTK_OBJECT (mv->title), 1, &arg);
    font = GTK_VALUE_BOXED (arg);

    gnome_canvas_item_set (mv->title,
                   "x", (double) allocation->width / 2.0,
                   "y", (double) SPACING,
                   NULL);

    y = font->ascent + font->descent + 2 * SPACING;
    gnome_canvas_item_set (mv->mitem,
                   "y", (double) y,
                   "width", (double) (allocation->width - 1),
                   "height", (double) (allocation->height - y - 1),
                   NULL);

    /* Adjust children */

    adjust_children (mv);
}

/* Destroys a child structure and its associated canvas items */
static void
child_destroy (MonthView *mv, struct child *child)
{
    GList *list;
    struct segment *seg;

    /* Destroy the segments */

    for (list = child->segments; list; list = list->next) {
        seg = list->data;

        gtk_object_destroy (GTK_OBJECT (seg->item));
        g_free (seg);
    }

    g_list_free (child->segments);

    /* Destroy the child */

    g_free (child);
}

/* Creates the list of segments that are used to display a child.  Each child may have several
 * segments, because it may span several days in the month view.  This function only creates the
 * segment structures and the associated canvas items, but it does not set their final position in
 * the month view canvas -- that is done by the adjust_children() function.
 */
static void
child_create_segments (MonthView *mv, struct child *child)
{
    time_t t;
    time_t month_begin, month_end;
    time_t day_begin_time, day_end_time;
    struct segment *seg;

    /* Get the month's extents */

    t = time_from_day (mv->year, mv->month, 1);
    month_begin = time_month_begin (t);
    month_end = time_month_end (t);

    /* Get the first day of the event */

    t = MAX (child->start, month_begin);
    day_begin_time = time_day_begin (t);
    day_end_time = time_day_end (day_begin_time);

    /* Loop until the event ends or the month ends -- the segments list is created in reverse
     * order.
     */

    do {
        seg = g_new (struct segment, 1);

        /* Clip the child to this day */

        seg->start = MAX (child->start, day_begin_time);
        seg->end = MIN (child->end, day_end_time);

        seg->item = gnome_canvas_item_new (GNOME_CANVAS_GROUP (mv->mitem),
                           gnome_canvas_rect_get_type (),
                           "fill_color", color_spec_from_prop (COLOR_PROP_MARK_DAY_BG),
                           "outline_color", "black",
                           "width_pixels", 0,
                           NULL);

        child->segments = g_list_prepend (child->segments, seg);

        /* Next day */

        day_begin_time = time_add_day (day_begin_time, 1);
        day_end_time = time_day_end (day_begin_time);
    } while ((child->end > day_begin_time) && (day_begin_time < month_end));

    /* Reverse the list to put it in increasing order */

    child->segments = g_list_reverse (child->segments);
}

/* Comparison function used to create the sorted list of children.  Sorts first by increasing start
 * time and then by decreasing end time, so that "longer" events are first in the list.
 */
static gint
child_compare (gconstpointer a, gconstpointer b)
{
    const struct child *ca, *cb;
    time_t diff;

    ca = a;
    cb = b;

    diff = ca->start - cb->start;

    if (diff == 0)
        diff = cb->end - ca->end;

    return (diff < 0) ? -1 : ((diff > 0) ? 1 : 0);
}

/* This is the callback function used from the calendar iterator.  It adds events to the list of
 * children in the month view.
 */
static int
add_event (iCalObject *ico, time_t start, time_t end, void *data)
{
    MonthView *mv;
    struct child *child;

    mv = MONTH_VIEW (data);

    child = g_new (struct child, 1);
    child->ico = ico;
    child->start = start;
    child->end = end;
    child->segments = NULL;

    child_create_segments (mv, child);

    /* Add it to the list of children */

    mv->children = g_list_insert_sorted (mv->children, child, child_compare);

    return TRUE; /* means "we are not yet finished" */
}

/* Time query function for the layout engine */
static void
child_query_func (GList *list, time_t *start, time_t *end)
{
    struct child *child;

    child = list->data;

    *start = child->start;
    *end = child->end;
}

/* Uses the generic event layout engine to set the children's layout information */
static void
layout_children (MonthView *mv)
{
    GList *list;
    struct child *child;
    int *allocations;
    int *slots;
    int i;

    layout_events (mv->children, child_query_func, &mv->num_slots, &allocations, &slots);

    if (mv->num_slots == 0)
        return;

    for (list = mv->children, i = 0; list; list = list->next, i++) {
        child = list->data;
        child->slot_start = allocations[i];
        child->slots_used = slots[i];
    }

    g_free (allocations);
    g_free (slots);
}

void
month_view_update (MonthView *mv, iCalObject *object, int flags)
{
    GList *list;
    time_t t;
    time_t month_begin, month_end;

    g_return_if_fail (mv != NULL);
    g_return_if_fail (IS_MONTH_VIEW (mv));

    /* Destroy the old list of children */

    for (list = mv->children; list; list = list->next)
        child_destroy (mv, list->data);

    g_list_free (mv->children);
    mv->children = NULL;

    /* Create a new list of children and lay them out */

    t = time_from_day (mv->year, mv->month, 1);
    month_begin = time_month_begin (t);
    month_end = time_month_end (t);

    calendar_iterate (mv->calendar->cal, month_begin, month_end, add_event, mv);
    layout_children (mv);
    adjust_children (mv);
}

/* Unmarks the old day that was marked as current and marks the current day if appropriate */
static void
mark_current_day (MonthView *mv)
{
    time_t t;
    struct tm *tm;
    GnomeCanvasItem *item;

    /* Unmark the old day */

    if (mv->old_current_index != -1) {
        item = gnome_month_item_num2child (GNOME_MONTH_ITEM (mv->mitem),
                           GNOME_MONTH_ITEM_DAY_LABEL + mv->old_current_index);
        gnome_canvas_item_set (item,
                       "fill_color", color_spec_from_prop (COLOR_PROP_DAY_FG),
                       "font", BIG_NORMAL_DAY_FONT,
                       NULL);

        mv->old_current_index = -1;
    }

    /* Mark the new day */

    t = time (NULL);
    tm = localtime (&t);

    if (((tm->tm_year + 1900) == mv->year) && (tm->tm_mon == mv->month)) {
        mv->old_current_index = gnome_month_item_day2index (GNOME_MONTH_ITEM (mv->mitem), tm->tm_mday);
        g_assert (mv->old_current_index != -1);

        item = gnome_month_item_num2child (GNOME_MONTH_ITEM (mv->mitem),
                           GNOME_MONTH_ITEM_DAY_LABEL + mv->old_current_index);
        gnome_canvas_item_set (item,
                       "fill_color", color_spec_from_prop (COLOR_PROP_CURRENT_DAY_FG),
                       "font", BIG_CURRENT_DAY_FONT,
                       NULL);
    }
}

void
month_view_set (MonthView *mv, time_t month)
{
    struct tm *tm;
    char buf[100];

    g_return_if_fail (mv != NULL);
    g_return_if_fail (IS_MONTH_VIEW (mv));

    /* Title */

    tm = localtime (&month);

    mv->year = tm->tm_year + 1900;
    mv->month = tm->tm_mon;
    
    strftime (buf, 100, "%B %Y", tm);

    gnome_canvas_item_set (mv->title,
                   "text", buf,
                   NULL);

    /* Month item */

    gnome_canvas_item_set (mv->mitem,
                   "year", mv->year,
                   "month", mv->month,
                   NULL);

    /* Update events */

    month_view_update (mv, NULL, 0);
    mark_current_day (mv);
}

void
month_view_time_format_changed (MonthView *mv)
{
    g_return_if_fail (mv != NULL);
    g_return_if_fail (IS_MONTH_VIEW (mv));

    gnome_canvas_item_set (mv->mitem,
                   "start_on_monday", week_starts_on_monday,
                   NULL);

    month_view_set (mv, time_month_begin (time_from_day (mv->year, mv->month, 1)));
}

void
month_view_colors_changed (MonthView *mv)
{
    g_return_if_fail (mv != NULL);
    g_return_if_fail (IS_MONTH_VIEW (mv));

    colorify_month_item (GNOME_MONTH_ITEM (mv->mitem), default_color_func, NULL);
    mark_current_day (mv);

    /* FIXME: set children to the marked color */
}