/*
    ####             #    #     # #
    #   #            #    #       #          The FreeWare C library for 
    #   #  ##   ###  #  # #     # ###             RISC OS machines
    #   # #  # #     # #  #     # #  #   ___________________________________
    #   # ####  ###  ##   #     # #  #                                      
    #   # #        # # #  #     # #  #    Please refer to the accompanying
    ####   ### ####  #  # ##### # ###    documentation for conditions of use
    ________________________________________________________________________

    File:    Filter.h
    Author:  Copyright  1993 Shaun Blackmore
    Version: 1.01 (22 Oct 1994)
    Purpose: Assembler veneers for the RISC OS 3 Filter Manager SWIs
*/

#ifndef __Desk_Filter_h
#define __Desk_Filter_h

#ifdef __cplusplus
	extern "C" {
#endif


#ifndef __Desk_Wimp_h
	#include "Desk.Wimp.h"
#endif


typedef int (*Desk_filter_handler)(int event, const Desk_event_pollblock *eventdata,
                             const int task);

extern void Desk_Filter_RegisterPreFilter(char *filtername,
                                     Desk_filter_handler handler, int R12,
                                     Desk_task_handle task);
                              
extern void Desk_Filter_RegisterPostFilter(char *filtername,
                                      Desk_filter_handler handler, int R12,
                                      Desk_task_handle task, int eventmask);

extern void Desk_Filter_DeRegisterPreFilter(char *filtername,
                                       Desk_filter_handler handler, int R12,
                                       Desk_task_handle task);

extern void Desk_Filter_DeRegisterPostFilter(char *filtername,
                                        Desk_filter_handler handler, int R12,
                                        Desk_task_handle task, int eventmask);

#ifdef __cplusplus
}
#endif


#endif
