/*
 *
 * 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>
 *
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */
/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */

#ifndef _E_CALENDAR_ITEM_H_
#define _E_CALENDAR_ITEM_H_

#include <libgnomecanvas/gnome-canvas.h>

G_BEGIN_DECLS

/*
 * ECalendarItem - canvas item displaying a calendar.
 */

#define	E_CALENDAR_ITEM_YPAD_ABOVE_MONTH_NAME	1
#define	E_CALENDAR_ITEM_YPAD_BELOW_MONTH_NAME	1

/* The number of rows & columns of days in each month. */
#define E_CALENDAR_ROWS_PER_MONTH	6
#define E_CALENDAR_COLS_PER_MONTH	7

/* Used to mark days as bold in e_calendar_item_mark_day(). */
#define E_CALENDAR_ITEM_MARK_BOLD	(1 << 0)
#define E_CALENDAR_ITEM_MARK_ITALIC     (1 << 1)

/*
 * These are the padding sizes between various pieces of the calendar.
 */

/* The minimum padding around the numbers in each cell/day. */
#define	E_CALENDAR_ITEM_MIN_CELL_XPAD	4
#define	E_CALENDAR_ITEM_MIN_CELL_YPAD	0

/* Vertical padding. */
#define	E_CALENDAR_ITEM_YPAD_ABOVE_DAY_LETTERS		1
#define	E_CALENDAR_ITEM_YPAD_BELOW_DAY_LETTERS		0
#define	E_CALENDAR_ITEM_YPAD_ABOVE_CELLS		1
#define	E_CALENDAR_ITEM_YPAD_BELOW_CELLS		2

/* Horizontal padding in the heading bars. */
#define	E_CALENDAR_ITEM_XPAD_BEFORE_MONTH_NAME_WITH_BUTTON	16
#define	E_CALENDAR_ITEM_XPAD_BEFORE_MONTH_NAME			3
#define	E_CALENDAR_ITEM_XPAD_AFTER_MONTH_NAME			3
#define	E_CALENDAR_ITEM_XPAD_AFTER_MONTH_NAME_WITH_BUTTON	16

/* Horizontal padding in the month displays. */
#define	E_CALENDAR_ITEM_XPAD_BEFORE_WEEK_NUMBERS	4
#define	E_CALENDAR_ITEM_XPAD_AFTER_WEEK_NUMBERS		2
#define	E_CALENDAR_ITEM_XPAD_BEFORE_CELLS		1
#define	E_CALENDAR_ITEM_XPAD_AFTER_CELLS		4

/* These index our colors array. */
typedef enum
{
	E_CALENDAR_ITEM_COLOR_TODAY_BOX,
	E_CALENDAR_ITEM_COLOR_SELECTION_FG,
	E_CALENDAR_ITEM_COLOR_SELECTION_BG_FOCUSED,
	E_CALENDAR_ITEM_COLOR_SELECTION_BG,
	E_CALENDAR_ITEM_COLOR_PREV_OR_NEXT_MONTH_FG,

	E_CALENDAR_ITEM_COLOR_LAST
} ECalendarItemColors;

typedef struct _ECalendarItem       ECalendarItem;
typedef struct _ECalendarItemClass  ECalendarItemClass;

/* The type of the callback function optionally used to get the colors to
   use for each day. */
typedef void (*ECalendarItemStyleCallback)   (ECalendarItem	*calitem,
					      gint		 year,
					      gint		 month,
					      gint		 day,
					      gint		 day_style,
					      gboolean		 today,
					      gboolean		 prev_or_next_month,
					      gboolean		 selected,
					      gboolean		 has_focus,
					      gboolean		 drop_target,
					      GdkColor	       **bg_color,
					      GdkColor	       **fg_color,
					      GdkColor	       **box_color,
					      gboolean		*bold,
					      gboolean		*italic,
					      gpointer		 data);

/* The type of the callback function optionally used to get the current time.
 */
typedef struct tm (*ECalendarItemGetTimeCallback) (ECalendarItem *calitem,
						   gpointer	  data);

/* Standard GObject macros */
#define E_TYPE_CALENDAR_ITEM \
	(e_calendar_item_get_type ())
#define E_CALENDAR_ITEM(obj) \
	(G_TYPE_CHECK_INSTANCE_CAST \
	((obj), E_TYPE_CALENDAR_ITEM, ECalendarItem))
#define E_CALENDAR_ITEM_CLASS(cls) \
	(G_TYPE_CHECK_CLASS_CAST \
	((cls), E_TYPE_CALENDAR_ITEM, ECalendarItemClass))
#define E_IS_CALENDAR_ITEM(obj) \
	(G_TYPE_CHECK_INSTANCE_TYPE \
	((obj), E_TYPE_CALENDAR_ITEM))
#define E_IS_CALENDAR_ITEM_CLASS(cls) \
	(G_TYPE_CHECK_CLASS_TYPE \
	((cls), E_TYPE_CALENDAR_ITEM))
#define E_CALENDAR_ITEM_GET_CLASS(obj) \
	(G_TYPE_INSTANCE_GET_CLASS \
	((obj), E_TYPE_CALENDAR_ITEM, ECalendarItemClass))

struct _ECalendarItem
{
	GnomeCanvasItem canvas_item;

	/* The year & month of the first calendar being displayed. */
	gint year;
	gint month;	/* 0 to 11 */

	/* Points to an array of styles, one gchar for each day. We use 32
	   chars for each month, with n + 2 months, where n is the number of
	   complete months shown (since we show some days before the first
	   month and after the last month grayes out).
	   A value of 0 is the default, and 1 is bold. */
	guint8 *styles;

	/*
	 * Options.
	 */

	/* The minimum & maximum number of rows & columns of months.
	   If the maximum values are -1 then there is no maximum.
	   The minimum valies default to 1. The maximum values to -1. */
	gint min_rows;
	gint min_cols;
	gint max_rows;
	gint max_cols;

	/* The actual number of rows & columns of months. */
	gint rows;
	gint cols;

	/* Whether we show week nubers. */
	gboolean show_week_numbers;

	/* The first day of the week, 0 (Monday) to 6 (Sunday). */
	gint week_start_day;

	/* Whether the cells expand to fill extra space. */
	gboolean expand;

	/* The maximum number of days that can be selected. Defaults to 1. */
	gint max_days_selected;

	/* The number of days selected before we switch to selecting whole
	   weeks, or -1 if we never switch. Defaults to -1. */
	gint days_to_start_week_selection;

	/* Whether the selection is moved when we move back/forward one month.
	   Used for things like the EDateEdit which only want the selection to
	   be changed when the user explicitly selects a day. */
	gboolean move_selection_when_moving;

	/* Whether the selection day is preserved when we  move back/forward
	   one month. Used for the work week and week view. */
	gboolean preserve_day_when_moving;

	/* Whether to display the pop-up, TRUE by default */
	gboolean display_popup;

	/*
	 * Internal stuff.
	 */

	/* Bounds of item. */
	gdouble x1, y1, x2, y2;

	/* The minimum size of each month, based on the fonts used. */
	gint min_month_width;
	gint min_month_height;

	/* The actual size of each month, after dividing extra space. */
	gint month_width;
	gint month_height;

	/* The offset to the left edge of the first calendar. */
	gint x_offset;

	/* The padding around each calendar month. */
	gint month_lpad, month_rpad;
	gint month_tpad, month_bpad;

	/* The size of each cell. */
	gint cell_width;
	gint cell_height;

	/* The current selection. The month offsets are from 0, which is the
	   top-left calendar month view. Note that -1 is used for the last days
	   from the previous month. The days are real month days. */
	gboolean selecting;
	GDate *selecting_axis;
	gboolean selection_dragging_end;
	gboolean selection_from_full_week;
	gboolean selection_set;
	gint selection_start_month_offset;
	gint selection_start_day;
	gint selection_end_month_offset;
	gint selection_end_day;
	gint selection_real_start_month_offset;
	gint selection_real_start_day;

	/* Widths of the day characters. */
	gint day_widths[7];
	gint max_day_width;

	/* Widths of the digits, '0' .. '9'. */
	gint digit_widths[10];
	gint max_digit_width;

	gint week_number_digit_widths[10];
	gint max_week_number_digit_width;

	/* Fonts for drawing text. If font isn't set it uses the font from the
	   canvas widget. If week_number_font isn't set it uses font. */
	PangoFontDescription *font_desc;
	PangoFontDescription *week_number_font_desc;

	ECalendarItemStyleCallback style_callback;
	gpointer style_callback_data;
	GDestroyNotify style_callback_destroy;

	ECalendarItemGetTimeCallback time_callback;
	gpointer time_callback_data;
	GDestroyNotify time_callback_destroy;

	/* Colors for drawing. */
	GdkColor colors[E_CALENDAR_ITEM_COLOR_LAST];

	/* Our idle handler for emitting signals. */
	gint signal_emission_idle_id;

	/* A flag to indicate that the selection or date range has changed.
	   When set the idle function will emit the signal and reset it to
	   FALSE. This is so we don't emit it several times when args are set
	   etc. */
	gboolean selection_changed;
	gboolean date_range_changed;
};

struct _ECalendarItemClass
{
	GnomeCanvasItemClass parent_class;

	void (* date_range_changed)	(ECalendarItem *calitem);
	void (* selection_changed)	(ECalendarItem *calitem);
	void (* selection_preview_changed)	(ECalendarItem *calitem);
};

GType	e_calendar_item_get_type		(void);

/* FIXME: months are 0-11 throughout, but 1-12 may be better. */

void	e_calendar_item_get_first_month		(ECalendarItem *calitem,
						 gint *year,
						 gint *month);
void	e_calendar_item_set_first_month		(ECalendarItem *calitem,
						 gint year,
						 gint month);

/* Get the maximum number of days selectable */
gint	e_calendar_item_get_max_days_sel	(ECalendarItem *calitem);

/* Set the maximum number of days selectable */
void	e_calendar_item_set_max_days_sel	(ECalendarItem *calitem,
						 gint days);

/* Get the maximum number of days selectable */
gint	e_calendar_item_get_days_start_week_sel	(ECalendarItem *calitem);

/* Set the maximum number of days selectable */
void	e_calendar_item_set_days_start_week_sel	(ECalendarItem *calitem,
						 gint days);

/* Set the maximum number of days before whole weeks are selected */
gboolean
	e_calendar_item_get_display_popup	(ECalendarItem *calitem);

/* Get the maximum number of days before whole weeks are selected */
void	e_calendar_item_set_display_popup	(ECalendarItem *calitem,
						 gboolean display);

/* Gets the range of dates actually shown. Months are 0 to 11.
   This also includes the last days of the previous month and the first days
   of the following month, which are normally shown in gray.
   It returns FALSE if no dates are currently shown. */
gboolean
	e_calendar_item_get_date_range		(ECalendarItem *calitem,
						 gint *start_year,
						 gint *start_month,
						 gint *start_day,
						 gint *end_year,
						 gint *end_month,
						 gint *end_day);

/* Returns the selected date range. It returns FALSE if no days are currently
   selected. */
gboolean
	e_calendar_item_get_selection		(ECalendarItem *calitem,
						 GDate *start_date,
						 GDate *end_date);
/* Sets the selected date range, and changes the date range shown so at least
   the start of the selection is shown. If start_date is NULL it clears the
   selection. */
void	e_calendar_item_set_selection		(ECalendarItem *calitem,
						 const GDate *start_date,
						 const GDate *end_date);

/* Marks a particular day. Passing E_CALENDAR_ITEM_MARK_BOLD as the day style
   will result in the day being shown as bold by default. The style callback
   could support more day_styles, or the style callback could determine the
   colors itself, without needing to mark days. */
void	e_calendar_item_clear_marks		(ECalendarItem *calitem);
void	e_calendar_item_mark_day		(ECalendarItem *calitem,
						 gint year,
						 gint month,
						 gint day,
						 guint8 day_style,
						 gboolean add_day_style);

/* Mark a range of days. Any days outside the currently shown range are
   ignored. */
void	e_calendar_item_mark_days		(ECalendarItem *calitem,
						 gint start_year,
						 gint start_month,
						 gint start_day,
						 gint end_year,
						 gint end_month,
						 gint end_day,
						 guint8 day_style,
						 gboolean add_day_style);

/* Sets the function to call to get the colors to use for a particular day. */
void	e_calendar_item_set_style_callback	(ECalendarItem *calitem,
						 ECalendarItemStyleCallback cb,
						 gpointer data,
						 GDestroyNotify  destroy);

/* 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_calendar_item_set_get_time_callback	(ECalendarItem *calitem,
						 ECalendarItemGetTimeCallback cb,
						 gpointer data,
						 GDestroyNotify  destroy);
void	e_calendar_item_normalize_date		(ECalendarItem *calitem,
						 gint *year,
						 gint *month);
gint	e_calendar_item_get_week_number		(ECalendarItem *calitem,
						 gint day,
						 gint month,
						 gint year);
void	e_calendar_item_style_set		(GtkWidget *widget,
						 ECalendarItem *calitem);

G_END_DECLS

#endif /* _E_CALENDAR_ITEM_H_ */
