/********************************************************************
* Description:  message.comp
*               Message HAL component.
*
* Author: Les Newell <les at sheetcam dot com>
* License: GPL Version 2 or later
*
* Copyright (c) 2011 All rights reserved.
*
********************************************************************
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 or later of the GNU General
 * Public License as published by the Free Software Foundation.
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111 USA
 *
 * THE AUTHORS OF THIS LIBRARY ACCEPT ABSOLUTELY NO LIABILITY FOR
 * ANY HARM OR LOSS RESULTING FROM ITS USE.  IT IS _EXTREMELY_ UNWISE
 * TO RELY ON SOFTWARE ALONE FOR SAFETY.  Any machinery capable of
 * harming persons must have provisions for completely removing power
 * from all motors, etc, before persons enter any danger area.  All
 * machinery must be designed to comply with local and national safety
 * codes, and the authors of this software can not, and do not, take
 * any responsibility for such compliance.
 *
 * This code was written as part of the EMC HAL project.  For more
 * information, go to www.linuxcnc.org.
 *
*************************************************************************/

component message "Display a message with a HAL pin";

description """Allows HAL pins to trigger a message.

Example hal commands:

 loadrt message names=oillow,oilpressure messages="Slideway oil low,No oil pressure"
 addf oillow servo-thread
 addf oilpressure servo-thread

 #change this pin to be active low
 setp oillow.edge 0

 net no-oil classicladder.0.out-21 oillow.trigger
 net no-pressure classicladder.0.out-22 oilpressure.trigger

When any pin goes active, it's message will be displayed.""";

pin in bit trigger =FALSE "signal that triggers the message";
pin in bit force =FALSE "A FALSE->TRUE transition forces the message to be displayed again if the trigger is active";

param rw bit edge =TRUE "Selects the desired edge: TRUE means falling, FALSE means rising";

variable int myidx;
variable bool prev_trigger = FALSE;
variable bool prev_force = TRUE;
variable bool prev_edge = TRUE;


option extra_setup yes;

function _ nofp "Display a message";
license "LGPL";
;;


char *messages[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
RTAPI_MP_ARRAY_STRING(messages, 16, "Displayed strings");

FUNCTION(_){
    bool show = false;
    if(prev_edge != edge) /* edge type has changed */
    {
        prev_edge = edge;
        prev_trigger = !edge;
    }
    if(force != prev_force) /* force type has changed */
    {
        prev_force = force;
        if(force && (trigger == edge))
        {
            show = true;
        }
    }
    if(trigger != prev_trigger) /* trigger has changed */
    {
        prev_trigger = trigger;
        if(trigger == edge)
        {
            show = true;
        }
    }
    if(show)
    {
        rtapi_print_msg(RTAPI_MSG_ERR, messages[myidx]);
    }
}

EXTRA_SETUP(){
    myidx = extra_arg;
    if(myidx<0 || myidx >15)
    {
        rtapi_print_msg(RTAPI_MSG_ERR,"Count out of range\n");
        return(EINVAL);
    }
    if(messages[myidx] == 0)
    {
        rtapi_print_msg(RTAPI_MSG_ERR,"Message string missing\n");
        return(EINVAL);
    }
    return(0);
}