From 2f2e7da7b83ac875fae35059bfb4df6effdf3cd2 Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@cs.stanford.edu>
Date: Mon, 15 Sep 2014 22:48:00 -0700
Subject: [PATCH] render: Center and emphasize table titles.

Before applying, this needs to distinguish between tables that will be
rendered as one piece (where the title should be centered across the
table) and tables that will be broken up (where the title should be
centered across the first fragment of the table).
---
 src/output/render.c | 42 +++++++++++++++++++++++++++++++++++++++---
 1 file changed, 39 insertions(+), 3 deletions(-)

diff --git a/src/output/render.c b/src/output/render.c
index d282a8fce6..0585d23622 100644
--- a/src/output/render.c
+++ b/src/output/render.c
@@ -933,6 +933,33 @@ render_page_get_size (const struct render_page *page, enum table_axis axis)
   return page->cp[axis][page->n[axis] * 2 + 1];
 }
 
+/* If PAGE is smaller than SIZE along AXIS, inserts extra space to increase
+   its size to SIZE. */
+void
+render_page_stretch (struct render_page *page, enum table_axis axis,
+                     int size)
+{
+  int extra = size - render_page_get_size (page, axis);
+  if (extra > 0)
+    {
+      int n = page->n[axis];
+      int error = 0;
+      int adjust = 0;
+      int i;
+
+      for (i = 2; i <= 2 * n + 1; i++)
+        {
+          if (!(i & 1))
+            {
+              error += extra;
+              adjust += error / n;
+              error %= n;
+            }
+          page->cp[axis][i] += adjust;
+        }
+    }
+}
+
 int
 render_page_get_best_breakpoint (const struct render_page *page, int height)
 {
@@ -1416,7 +1443,7 @@ struct render_pager
     struct render_break y_break;
   };
 
-static const struct render_page *
+static struct render_page *
 render_pager_add_table (struct render_pager *p, struct table *table)
 {
   struct render_page *page;
@@ -1489,18 +1516,27 @@ render_pager_create (const struct render_params *params,
   const char *caption = table_item_get_caption (table_item);
   const char *title = table_item_get_title (table_item);
   const struct render_page *body_page;
+  struct render_page *title_page;
   struct render_pager *p;
 
   p = xzalloc (sizeof *p);
   p->params = params;
 
   /* Title. */
-  if (title)
-    render_pager_add_table (p, table_from_string (TAB_LEFT, title));
+  title_page = (title
+                ? render_pager_add_table (
+                  p, table_from_string (TAB_CENTER | TAB_EMPH, title))
+                : NULL);
 
   /* Body. */
   body_page = render_pager_add_table (p, table_ref (table_item_get_table (
                                                       table_item)));
+  if (title_page && body_page)
+    {
+      int body_page_size = render_page_get_size (body_page, H);
+      render_page_stretch (title_page, H,
+                           MIN (body_page_size, params->size[H]));
+    }
 
   /* Caption. */
   if (caption)
-- 
2.30.2