Output renderer: Reverse the order of table columns when in RTL locale

When operating in a RTL locale, the last column of a table should be rendered
"first" (ie. leftmost).  This change achieves that.  In order to determine if
the locale is a RTL locale, a new translatable string is introduced.  This
string must be localised by the translator of the .po file for RTL locales. LTR
locales can leave it untranslated.

Reported by: Mohammad Haghighat <hosseinhg@hotmail.com>

diff --git a/src/output/render.c b/src/output/render.c
index c50e1121e76d573a9e72132ce9dc2dd97f06d818..b3eb6c93d459251668a8eefc4fafbef42076b92b 100644 (file)
--- a/src/output/render.c
+++ b/src/output/render.c
@@ -33,6 +33,9 @@
 #include "gl/minmax.h"
 #include "gl/xalloc.h"
 
+#include "gettext.h"
+#define _(msgid) gettext (msgid)
+
 /* This file uses TABLE_HORZ and TABLE_VERT enough to warrant abbreviating. */
 #define H TABLE_HORZ
 #define V TABLE_VERT
@@ -966,6 +969,23 @@ is_rule (int z)
   return !(z & 1);
 }
 
+bool
+render_direction_rtl (void)
+{
+  /* TRANSLATORS: Do not translate this string.  If the script of your language 
+     reads from right to left (eg Persian, Arabic, Hebrew etc), then replace 
+     this string with "output-direction-rtl".  Otherwise either leave it 
+     untranslated or copy it verbatim. */
+  const char *dir = _("output-direction-ltr");
+  if ( 0 == strcmp ("output-direction-rtl", dir))
+    return true;
+
+  if ( 0 != strcmp ("output-direction-ltr", dir))
+    fprintf (stderr, "This localisation has been incorrectly translated.  Complain to the translator.\n");
+
+  return false;
+}
+
 static void
 render_rule (const struct render_page *page, const int ofs[TABLE_N_AXES],
              const int d[TABLE_N_AXES])
@@ -1009,6 +1029,12 @@ render_rule (const struct render_page *page, const int ofs[TABLE_N_AXES],
 
       bb[H][0] = ofs[H] + page->cp[H][d[H]];
       bb[H][1] = ofs[H] + page->cp[H][d[H] + 1];
+      if (render_direction_rtl ())
+       {
+         int temp = bb[H][0];
+         bb[H][0] = page->params->size[H] - bb[H][1];
+         bb[H][1] = page->params->size[H] - temp;
+       }
       bb[V][0] = ofs[V] + page->cp[V][d[V]];
       bb[V][1] = ofs[V] + page->cp[V][d[V] + 1];
       page->params->draw_line (page->params->aux, bb, styles);
@@ -1025,6 +1051,12 @@ render_cell (const struct render_page *page, const int ofs[TABLE_N_AXES],
 
   bb[H][0] = clip[H][0] = ofs[H] + page->cp[H][cell->d[H][0] * 2 + 1];
   bb[H][1] = clip[H][1] = ofs[H] + page->cp[H][cell->d[H][1] * 2];
+  if (render_direction_rtl ())
+    {
+      int temp = bb[H][0];
+      bb[H][0] = clip[H][0] = page->params->size[H] - bb[H][1];
+      bb[H][1] = clip[H][1] = page->params->size[H] - temp;
+    }
   bb[V][0] = clip[V][0] = ofs[V] + page->cp[V][cell->d[V][0] * 2 + 1];
   bb[V][1] = clip[V][1] = ofs[V] + page->cp[V][cell->d[V][1] * 2];
 

diff --git a/src/output/render.h b/src/output/render.h
index 3e9d8a83adaf04f8c89e830e0d63d51ca555225b..ed5bb1eaf41aefd4c7386fdeb81eb9495745876e 100644 (file)
--- a/src/output/render.h
+++ b/src/output/render.h
@@ -145,4 +145,7 @@ void render_pager_draw_region (const struct render_pager *,
 int render_pager_get_size (const struct render_pager *, enum table_axis);
 int render_pager_get_best_breakpoint (const struct render_pager *, int height);
 
+bool render_direction_rtl (void);
+
+
 #endif /* output/render.h */