Implement centering and adjustment to the right margin directly in

the terminal filling routine, controlled by new flags TERMP_CENTER
and TERMP_RIGHT.
This became possible by the recent term_flushln() rewrite.
No functional change yet, but to be used by upcoming commits.

1 files changed, 16 insertions, 2 deletions

diff --git a/usr.bin/mandoc/term.c b/usr.bin/mandoc/term.c
index f1a790fe643..ceebbb86141 100644
--- a/usr.bin/mandoc/term.c
+++ b/usr.bin/mandoc/term.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: term.c,v 1.138 2019/01/03 19:59:11 schwarze Exp $ */
+/*	$OpenBSD: term.c,v 1.139 2019/01/04 03:20:44 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2019 Ingo Schwarze <schwarze@openbsd.org>
@@ -133,13 +133,27 @@ term_flushln(struct termp *p)
 		/*
 		 * Figure out how much text will fit in the field.
 		 * If there is whitespace only, print nothing.
-		 * Otherwise, print the field content.
 		 */
 
 		term_fill(p, &nbr, &vbr, vtarget);
 		if (nbr == 0)
 			break;
 
+		/*
+		 * With the CENTER or RIGHT flag, increase the indentation
+		 * to center the text between the left and right margins
+		 * or to adjust it to the right margin, respectively.
+		 */
+
+		if (vbr < vtarget) {
+			if (p->flags & TERMP_CENTER)
+				vbl += (vtarget - vbr) / 2;
+			else if (p->flags & TERMP_RIGHT)
+				vbl += vtarget - vbr;
+		}
+
+		/* Finally, print the field content. */
+
 		term_field(p, vbl, nbr, vbr, vtarget);
 
 		/*