thermferm/lcd-buffer.c

/*****************************************************************************
 * Copyright (C) 2014
 *   
 * Michiel Broek <mbroek at mbse dot eu>
 *
 * This file is part of the mbsePi-apps
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * mbsePi-apps 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 mbsePi-apps; see the file COPYING.  If not, write to the Free
 * Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *****************************************************************************/

#include "thermferm.h"
#include "lcd-buffer.h"
#include "lcd-pcf8574.h"
#include "panel.h"


int			current_lines = 0;
int			current_offset = 0;
lcd_rows		*my_lcd_rows = NULL;

extern int		lcdHandle;
extern sys_config	Config;


/*
 * Reset the LCD screens chain, it will automatic rebuild.
 */
void lcd_buf_reset(void)
{
    lcd_rows	*tmp, *old;

    for (tmp = my_lcd_rows; tmp; tmp = old) {
	old = tmp->next;
	tmp->next = NULL;
	free(tmp);
    }
    current_lines = current_offset = 0;
    my_lcd_rows = NULL;
}


/*
 * Write to buffer array. Allocate more lines if needed.
 */
void lcd_buf_write(int row, const char *format, ...)
{
    char	buf[81 * sizeof(char)];
    va_list	va_ptr;
    lcd_rows	*tmp, *newrow;
    int		i = 0;

    va_start(va_ptr, format);
    vsnprintf(buf, (Config.lcd_cols + 1) * sizeof(char), format, va_ptr);
    va_end(va_ptr);

    /*
     * Check if the line in row is allocated. If not, do it
     * and make sure the chain is valid.
     */
    while (row > current_lines) {

	syslog(LOG_NOTICE, "lcd_buf_write(%d, ...) allocate new row", row);
	newrow = (lcd_rows *)malloc(sizeof(lcd_rows));
	newrow->next = NULL;
	snprintf(newrow->row, (Config.lcd_cols + 1) * sizeof(char), "                    ");

	if (my_lcd_rows == NULL) {
	    my_lcd_rows = newrow;
	} else {
	    for (tmp = my_lcd_rows; tmp; tmp = tmp->next) {
		if (tmp->next == NULL) {
		    tmp->next = newrow;
		    current_lines++;
		    break;
		}
	    }
	}
    }

    /*
     * Now update the text
     */
    for (tmp = my_lcd_rows; tmp; tmp = tmp->next) {
	i++;
	if (i == row) {
	    snprintf(tmp->row, Config.lcd_cols + 1, "%s", buf);
	    return;
	}
    }
    syslog(LOG_NOTICE, "lcd_buf_write(%d, ...) could not find row, i=%d", row, i);
}


void lcd_buf_step(int key)
{
    if (key == KEY_DOWN) {
	if (current_offset < (current_lines - Config.lcd_rows))
	    current_offset += Config.lcd_rows;
	else
	    current_offset = 0;
	syslog(LOG_NOTICE, "lcd_buf_step(KEY_DOWN) current_lines=%d current_offset=%d", current_lines, current_offset);
	lcd_buf_show();
    }
    if (key == KEY_UP) {
	if (current_offset >= Config.lcd_rows)
	    current_offset -= Config.lcd_rows;
	else
	    current_offset = (current_lines - Config.lcd_rows);
	syslog(LOG_NOTICE, "lcd_buf_step(KEY_UP) current_lines=%d current_offset=%d", current_lines, current_offset);
	lcd_buf_show();
    }
}


/*
 * This will be called from the main thread every second.
 */
void lcd_buf_show(void)
{
    int		i = 0, r = 0;
    lcd_rows	*tmp;

    for (tmp = my_lcd_rows; tmp; tmp = tmp->next) {
	if (i == current_offset)
	    break;
	i++;
    }

    if (tmp == NULL) {
	syslog(LOG_NOTICE, "lcd_buf_show: search after last record, current_offset=%d current_lines=%d i=%d", current_offset, current_lines, i);
	return;
    }

#ifdef HAVE_WIRINGPI_H
    lcdPosition(lcdHandle, 0, r);
    lcdPuts(lcdHandle, tmp->row);
#endif

    r++;
    if (r < Config.lcd_rows) {
	if (tmp->next != NULL)
	    tmp = tmp->next;
	else
	    tmp = my_lcd_rows;
#ifdef HAVE_WIRINGPI_H
	lcdPosition(lcdHandle, 0, r);
	lcdPuts(lcdHandle, tmp->row);
#endif
    }
}