static void charlcd_write_char()

in charlcd.c [365:462]

• 63 lines of code
• 21 McCabe index (conditional complexity)

static void charlcd_write_char(struct charlcd *lcd, char c)
{
	struct charlcd_priv *priv = charlcd_to_priv(lcd);

	/* first, we'll test if we're in escape mode */
	if ((c != '\n') && priv->esc_seq.len >= 0) {
		/* yes, let's add this char to the buffer */
		priv->esc_seq.buf[priv->esc_seq.len++] = c;
		priv->esc_seq.buf[priv->esc_seq.len] = '\0';
	} else {
		/* aborts any previous escape sequence */
		priv->esc_seq.len = -1;

		switch (c) {
		case LCD_ESCAPE_CHAR:
			/* start of an escape sequence */
			priv->esc_seq.len = 0;
			priv->esc_seq.buf[priv->esc_seq.len] = '\0';
			break;
		case '\b':
			/* go back one char and clear it */
			if (lcd->addr.x > 0) {
				/* back one char */
				if (!lcd->ops->shift_cursor(lcd,
							CHARLCD_SHIFT_LEFT))
					lcd->addr.x--;
			}
			/* replace with a space */
			charlcd_print(lcd, ' ');
			/* back one char again */
			if (!lcd->ops->shift_cursor(lcd, CHARLCD_SHIFT_LEFT))
				lcd->addr.x--;

			break;
		case '\f':
			/* quickly clear the display */
			charlcd_clear_display(lcd);
			break;
		case '\n':
			/*
			 * flush the remainder of the current line and
			 * go to the beginning of the next line
			 */
			for (; lcd->addr.x < lcd->width; lcd->addr.x++)
				lcd->ops->print(lcd, ' ');

			lcd->addr.x = 0;
			lcd->addr.y = (lcd->addr.y + 1) % lcd->height;
			lcd->ops->gotoxy(lcd, lcd->addr.x, lcd->addr.y);
			break;
		case '\r':
			/* go to the beginning of the same line */
			lcd->addr.x = 0;
			lcd->ops->gotoxy(lcd, lcd->addr.x, lcd->addr.y);
			break;
		case '\t':
			/* print a space instead of the tab */
			charlcd_print(lcd, ' ');
			break;
		default:
			/* simply print this char */
			charlcd_print(lcd, c);
			break;
		}
	}

	/*
	 * now we'll see if we're in an escape mode and if the current
	 * escape sequence can be understood.
	 */
	if (priv->esc_seq.len >= 2) {
		int processed = 0;

		if (!strcmp(priv->esc_seq.buf, "[2J")) {
			/* clear the display */
			charlcd_clear_display(lcd);
			processed = 1;
		} else if (!strcmp(priv->esc_seq.buf, "[H")) {
			/* cursor to home */
			charlcd_home(lcd);
			processed = 1;
		}
		/* codes starting with ^[[L */
		else if ((priv->esc_seq.len >= 3) &&
			 (priv->esc_seq.buf[0] == '[') &&
			 (priv->esc_seq.buf[1] == 'L')) {
			processed = handle_lcd_special_code(lcd);
		}

		/* LCD special escape codes */
		/*
		 * flush the escape sequence if it's been processed
		 * or if it is getting too long.
		 */
		if (processed || (priv->esc_seq.len >= LCD_ESCAPE_LEN))
			priv->esc_seq.len = -1;
	} /* escape codes */
}