/*

 * Copyright (c) 2007 Pete Mack and others

 * This code released under the Gnu Public License. See www.fsf.org

 * for current GPL license details. Addition permission granted to

 * incorporate modifications in all Angband variants as defined in the

 * Angband variants FAQ. See rec.games.roguelike.angband for FAQ.

 */



#ifndef INCLUDED_UI_MENU_H

#define INCLUDED_UI_MENU_H



/* ============= Constants ============ */



/* Colors for interactive menus */

enum

{

	CURS_UNKNOWN = 0,		/* Use gray; dark blue for cursor */

	CURS_KNOWN = 1			/* Use white; light blue for cursor */

};



/* Cursor colours for different states */

extern const byte curs_attrs[2][2];



/* Standard menu orderings */

extern const char lower_case[];			/* abc..z */

extern const char upper_case[];			/* ABC..Z */







/* Forward declare */

/* RISC OS already has a menu_item in system library */

#ifdef RISCOS

#define menu_item ang_menu_item

#endif



typedef struct menu_item menu_item;

typedef struct menu_type menu_type;

typedef struct menu_skin menu_skin;

typedef struct menu_iter menu_iter;





/* ================== MENUS ================= */



/*

 * Performs an action on object with an optional environment label 

 * Member function of "menu_iter" VTAB

 */

typedef void (*action_f)(void *object, const char *name);



/* 

 * Displays a single row in a menu

 * Driver function for populating a single menu row.

 * Member function for "menu_iter" VTAB

 */

typedef void (*display_row_f) (menu_type *menu, int pos,

			       bool cursor, int row, int col, int width);



/* 

 * Driver function for displaying a page of rows.

 * Member function of "menu_skin" VTAB

 */

typedef void (*display_list_f)(menu_type *menu, int cursor, int *top, region *);





/* Primitive menu item with bound action */

typedef struct menu_action

{

	int id;			/* Object id used to define macros &c */

	const char *name;	/* Name of the action */

	action_f action;	/* Action to perform, if any */

	void *data;		/* Local environment for the action, if required */

} menu_action;





/* Decorated menu item with bound action */

struct menu_item

{

	menu_action act; /* Base type */

	char sel;        /* Character used for selection, if special-purpose */

	                 /* bindings are desired. */

	int flags;	 /* State of the menu item.  See menu flags below */

};





/* TODO: menu registry */

/*

  Together, these classes define the constant properties of

  the various menu classes.



  A menu consists of:

   - menu_iter, which describes how to handle the type of "list" that's 

     being displayed as a menu

   - a menu_skin, which describes the layout of the menu on the screen.

   - various bits and bobs of other data (e.g. the actual list of entries)

 */





/* Flags for menu appearance & behavior */

/* ==================================== */



/* Tags are associated with the view, not the element */

#define MN_REL_TAGS 0x0100 

/* No tags -- movement key and mouse browsing only */

#define MN_NO_TAGS  0x0200 

/* Tags to be generated by the display function */

#define MN_PVT_TAGS  0x0400 

/* Tag selections can be made regardless of the case of the key pressed. 

 * i.e. 'a' activates the line tagged 'A'. */

#define MN_CASELESS_TAGS 0x0800 



/* double tap (or keypress) for selection; single tap is cursor movement */

#define MN_DBL_TAP 0x1000 

/* Do not invoke the specified action; menu selection only */

#define MN_NO_ACT 0x2000 

/* No cursor movement */

#define MN_NO_CURSOR 0x8000 





/* Row flags in action_menu structure. */

#define MN_DISABLED   0x0100000 /* Neither action nor selection is permitted */

#define MN_GRAYED     0x0200000 /* Row is displayed with CURS_UNKNOWN colors */

#define MN_GREYED     0x0200000 /* Row is displayed with CURS_UNKNOWN colors */

#define MN_SELECTED   0x0400000 /* Row is currently selected */

#define MN_SELECTABLE 0x0800000 /* Row is permitted to be selected */

#define MN_HIDDEN     0x1000000 /* Row is hidden, but may be selected via */

                                /* key-binding.  */





/** Identifier for the type of menu layout to use */

typedef enum

{

	MN_SKIN_SCROLL = 1,   /**< Ordinary scrollable single-column list */

	MN_SKIN_COLUMNS = 2   /**< Multicolumn view */

} skin_id;





/* Class functions for menu layout */

struct menu_skin

{

	/* Determines the cursor index given a (mouse) location */

	int (*get_cursor)(int row, int col, int n, int top, region *loc);

	/* Displays the current list of visible menu items */

	display_list_f display_list;

	/* Specifies the relative menu item given the state of the menu */

	char (*get_tag)(menu_type *menu, int pos);

};





/* Identifiers for canned row iterator implementations */

typedef enum

{

	/* A simple list of actions with an associated name and id.

	   An array of menu_action */

	MN_ITER_ACTIONS = 1,



	/* Slightly more sophisticated, a list of menu items that also

	   allows per-item flags and a "selection" character to be specified.

	   An array of menu_item */

	MN_ITER_ITEMS   = 2,



	/* A list of strings to be selected from - no associated actions.

	   An array of const char * */

	MN_ITER_STRINGS = 3

} menu_iter_id;





/* Class functions for menu row-level accessor functions */

struct menu_iter

{

	/* Optional selection tag function */

	char (*get_tag)(menu_type *menu, int oid);

	/* Optional validity checker.  All rows are assumed valid if not present. */

 	/* To support "hidden" items, it uses 3-level logic: 0 = no  1 = yes 2 = hide */

	int (*valid_row)(menu_type *menu, int oid);

	/* Displays a menu row at specified location */

	display_row_f display_row;

	/* Handler function called for selection or command key events */

	bool (*row_handler)(char cmd, void *db, int oid);

};





/* A menu defines either an action

 * or db row event

 */

struct menu_type

{

	/* menu inherits from panel */

	event_listener target;

	void (*refresh)();

	region boundary;



	/* set of commands that may be performed on a menu item */

	const char *cmd_keys;



	/* Public variables */

	const char *title;

	const char *prompt;



	/* Keyboard shortcuts for menu selection */

	/* IMPORTANT: this cannot intersect with cmd_keys */

	const char *selections; 



	int flags;              /* Flags specifying the behavior of this menu. */

	int filter_count;       /* number of rows in current view */

	const int *filter_list;       /* optional filter (view) of menu objects */



	int count;              /* number of rows in underlying data set */

	void *menu_data;  /* the data used to access rows. */



  	/* auxiliary browser help function */

	void (*browse_hook)(int oid, void *db, const region *loc);



	/* These are "protected" - not visible for canned menu classes, */

	/* The per-row functions  */

	const menu_iter *row_funcs;





	/* State variables for the menu */

	int cursor;             /* Currently selected row */

	int top;                /* Position in list for partial display */

	region active;          /* Subregion actually active for selection */



	/* helper functions for layout information. */

	const menu_skin *skin;  /* Defines menu appearance */

};





/* 

 * Select a row from a menu.

 * 

 * Arguments:

 *  object_list - optional ordered subset of menu OID.  If NULL, cursor is used for OID

 *  cursor - current (absolute) position in menu.  Modified on selection.

 *  loc - location to display the menu.

 * Return: A command key; cursor is set to the corresponding row.

 * (This is a stand-in for a menu event)

 * reserved commands are 0xff for selection and ESCAPE for escape.

 */

ui_event_data menu_select(menu_type *menu, int *cursor, int no_handle);



/* TODO: This belongs in the VTAB */

bool menu_layout(menu_type *menu, const region *loc);



/* accessor & utility functions */

void menu_set_filter(menu_type *menu, const int object_list[], int n);

void menu_release_filter(menu_type *menu);





/* Find a menu iterator struct */

const menu_iter *find_menu_iter(menu_iter_id iter_id);



/* Initialize a menu given skin ID and an iterator */

bool menu_init(menu_type *menu, skin_id skin, const menu_iter *iter, const region *loc);



/* Refresh the menu */

void menu_refresh(menu_type *menu);





#endif /* INCLUDED_UI_MENU_H */