Rudimentary implementation of the e, x, and z table layout modifiers

to equalize, maximize, and ignore the width of columns.
Does not yet take vertical rulers into account,
and does not do line breaks within table cells.
Considerably improves the lftp(1) manual; issue noticed by sthen@.

1 files changed, 70 insertions, 6 deletions

diff --git a/usr.bin/mandoc/out.c b/usr.bin/mandoc/out.c
index 09c910c9927..cf33aa6edb0 100644
--- a/usr.bin/mandoc/out.c
+++ b/usr.bin/mandoc/out.c
@@ -1,7 +1,7 @@
-/*	$Id: out.c,v 1.23 2014/08/12 19:27:57 schwarze Exp $ */
+/*	$OpenBSD: out.c,v 1.24 2014/10/14 02:16:02 schwarze Exp $ */
 /*
  * Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2011 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2011, 2014 Ingo Schwarze <schwarze@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -137,11 +137,14 @@ a2roffsu(const char *src, struct roffsu *dst, enum roffscale def)
  * used for the actual width calculations.
  */
 void
-tblcalc(struct rofftbl *tbl, const struct tbl_span *sp)
+tblcalc(struct rofftbl *tbl, const struct tbl_span *sp,
+	size_t totalwidth)
 {
 	const struct tbl_dat	*dp;
 	struct roffcol		*col;
+	size_t			 ewidth, xwidth;
 	int			 spans;
+	int			 icol, maxcol, necol, nxcol;
 
 	/*
 	 * Allocate the master column specifiers.  These will hold the
@@ -153,7 +156,7 @@ tblcalc(struct rofftbl *tbl, const struct tbl_span *sp)
 	tbl->cols = mandoc_calloc((size_t)sp->opts->cols,
 	    sizeof(struct roffcol));
 
-	for ( ; sp; sp = sp->next) {
+	for (maxcol = 0; sp; sp = sp->next) {
 		if (TBL_SPAN_DATA != sp->pos)
 			continue;
 		spans = 1;
@@ -168,11 +171,72 @@ tblcalc(struct rofftbl *tbl, const struct tbl_span *sp)
 			spans = dp->spans;
 			if (1 < spans)
 				continue;
-			assert(dp->layout);
-			col = &tbl->cols[dp->layout->head->ident];
+			icol = dp->layout->head->ident;
+			if (maxcol < icol)
+				maxcol = icol;
+			col = tbl->cols + icol;
+			col->flags |= dp->layout->flags;
+			if (dp->layout->flags & TBL_CELL_WIGN)
+				continue;
 			tblcalc_data(tbl, col, sp->opts, dp);
 		}
 	}
+
+	/*
+	 * Count columns to equalize and columns to maximize.
+	 * Find maximum width of the columns to equalize.
+	 * Find total width of the columns *not* to maximize.
+	 */
+
+	necol = nxcol = 0;
+	ewidth = xwidth = 0;
+	for (icol = 0; icol <= maxcol; icol++) {
+		col = tbl->cols + icol;
+		if (col->flags & TBL_CELL_EQUAL) {
+			necol++;
+			if (ewidth < col->width)
+				ewidth = col->width;
+		}
+		if (col->flags & TBL_CELL_WMAX)
+			nxcol++;
+		else
+			xwidth += col->width;
+	}
+
+	/*
+	 * Equalize columns, if requested for any of them.
+	 * Update total width of the columns not to maximize.
+	 */
+
+	if (necol) {
+		for (icol = 0; icol <= maxcol; icol++) {
+			col = tbl->cols + icol;
+			if ( ! (col->flags & TBL_CELL_EQUAL))
+				continue;
+			if (col->width == ewidth)
+				continue;
+			if (nxcol && totalwidth)
+				xwidth += ewidth - col->width;
+			col->width = ewidth;
+		}
+	}
+
+	/*
+	 * If there are any columns to maximize, find the total
+	 * available width, deducting 3n margins between columns.
+	 * Distribute the available width evenly.
+	 */
+
+	if (nxcol && totalwidth) {
+		xwidth = totalwidth - 3*maxcol - xwidth;
+		for (icol = 0; icol <= maxcol; icol++) {
+			col = tbl->cols + icol;
+			if ( ! (col->flags & TBL_CELL_WMAX))
+				continue;
+			col->width = xwidth / nxcol--;
+			xwidth -= col->width;
+		}
+	}
 }
 
 static void