/*
   ============================================================================
	newline.c -- standard pagination functions
	Version 6 -- 1988-11-02 -- D.N. Lynx Crowe
   ============================================================================
*/

#include "stdio.h"
#include "stddefs.h"
#include "pageparm.h"

#ifndef	VERSION
#define	VERSION	"0.00 (Experimental)"
#endif

int	pgmhdr();		/* forward declaration */

/* variables for pagination functions */

int 	npage    = 1; 		/* current page number */
int	nline    = NLPAGE; 	/* current line number */
int	nlpage   = NLPAGE; 	/* number of lines per page */
int	martop   = MTOP;	/* top margin size -- lines */
int	marbot   = MBOT;	/* bottom margin size -- lines */
int	marsize  = MARGIN;	/* left margin size -- characters */
int	newsub   = 1;		/* flag for new sub-heading */
int	minleft  = MINLEFT;	/* minimum remaining lines on the page */

int (*prhead)()  = pgmhdr;	/* pointer to page heading routine */

char	*hdr     = "?????";	/* pointer to program header (for pgmhdr) */
char	*subhdg  = "";		/* pointer to subheading */
char	*verstr  = VERSION;	/* pointer to version string */

FILE	*printer;		/* printer file pointer */

/*  */

/*
   ============================================================================
	newline(fp) -- advance line counter before printing a new line

		Invoke this function BEFORE printing a new line.

		Uses:	nlpage = number of lines per page,
			nline  = current line number,
			npage  = current page number

		Invokes (*prhead)(fp) if nline overflows.  

		Initialize:

			npage  = 1, 
			nline  = nlpage,
			prhead = address of page heading routine

		before first line on page is printed.
   ============================================================================
*/

newline(fp)
FILE *fp;
{
	if (nline++ GE (nlpage - (martop + marbot))) {

		nline = 1;		/* set current line number = 1 */
		fprintf(fp, "\f");	/* force new page */
		(*prhead)(fp);		/* call page heading routine */
		npage++;		/* update page number */
	}
}


/*  */

/*
   ============================================================================
	margin(fp) -- print spaces for a left margin

		marsize = number of blanks for left margin
   ============================================================================
*/

margin(fp)
FILE *fp;
{
	int n;

	for (n = 0; n < marsize; n++)
		putc(' ', fp);
}

/*  */

/*
   ============================================================================
	pgmhdr(fp) -- print program header

		Prints a standard 2+martop line program heading
		including version and page number on the second line.

		hdr = pointer to program heading line (must include a newline)
   ============================================================================
*/

pgmhdr(fp)
FILE *fp;
{
	int	n;

	for (n = 0; n < martop; n++) {
		fprintf(fp, "\n");
		nline++;
	}

	margin(fp);
	fprintf(fp, "%s\n", hdr);
	nline++;

	margin(fp);
	fprintf(fp, "Version %s                                Page %4.4d\n\n", 
		verstr, npage);
	nline++;
	nline++;
}


/*  */

/*
   ============================================================================
	skipnl(fp, n) -- output n newlines to fp
   ============================================================================
*/

skipnl(fp, n)
FILE *fp;
int n;
{
	int	j;

	if (n LE 0)
		return;

	for (j = 0; j < n; j++) {

		newline(fp);
		fprintf(fp, "\n");
	}
}

/*  */

/*
   ============================================================================
	subhdr(fp) -- standard subheading function
   ============================================================================
*/

subhdr(fp)
FILE *fp;
{
	if (newsub) {		/* new sub-heading */

		newsub = FALSE;
		newline(fp);
		newline(fp);
		margin(fp);
		fprintf(fp, "%s\n\n", subhdg);

	} else {		/* continuation of old sub heading */

		newline(fp);
		newline(fp);
		margin(fp);
		fprintf(fp, "%s -- Continued\n\n", subhdg);
	}
}

/*  */

/*
   ============================================================================
	heading(fp) -- standard heading function
   ============================================================================
*/

heading(fp)
FILE *fp;
{
	newline(fp);
	pgmhdr(fp);
	subhdr(fp);
}

/*  */

/*
   ============================================================================
	newsect(fp) -- standard new section function

	Invoke to begin a new section BEFORE printing the first line of the
	section, and BEFORE calling newline().  For example,

		subhdg = "Sub-heading for this section.";
		newsect(fp);
		newline(fp);
		printf(fp, "your line goes here");

	This will force a page break if there are not at least 'minleft'
	left on the page.
   ============================================================================
*/

newsect(fp)
FILE *fp;
{
	newsub = TRUE;

	if (nline NE nlpage) {

		if (nline > (nlpage - minleft))
			nline = nlpage;
		else
			subhdr(fp);
	}
}