Implement strike-through and overline on NextStep (Bug#8863).

* src/nsfont.m (nsfont_open): Use underline position provided by font,
instead of hard-coded value of 2.
(nsfont_draw): Call ns_draw_text_decoration instead.

* src/nsterm.h: Add declaration for ns_draw_text_decoration.

* src/nsterm.m (ns_draw_text_decoration): New function for drawing
underline, overline, and strike-through.
(ns_dumpglyphs_image, ns_dumpglyphs_stretch): Add call to
ns_draw_text_decoration.  Change treatment of cursor drawing to
accomodate underlining, etc.

4 files changed, 195 insertions, 63 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index e821b75f4c8..24b36e7ff61 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,19 @@
+2011-07-26  Alp Aker  <alp.tekin.aker@gmail.com>
+
+        Implement strike-through and overline on NextStep (Bug#8863).
+
+        * nsfont.m (nsfont_open): Use underline position provided by font,
+        instead of hard-coded value of 2.
+        (nsfont_draw): Call ns_draw_text_decoration instead.
+
+        * nsterm.h: Add declaration for ns_draw_text_decoration.
+
+        * nsterm.m (ns_draw_text_decoration): New function for drawing
+        underline, overline, and strike-through.
+        (ns_dumpglyphs_image, ns_dumpglyphs_stretch): Add call to
+        ns_draw_text_decoration.  Change treatment of cursor drawing to
+        accomodate underlining, etc.
+
 2011-07-28  Eli Zaretskii  <eliz@gnu.org>
 
         * buffer.c (init_buffer_once): Set bidi-display-reordering to t by
diff --git a/src/nsfont.m b/src/nsfont.m
index 76c70aadf9f..3720e9a4615 100644
--- a/src/nsfont.m
+++ b/src/nsfont.m
@@ -845,7 +845,7 @@ nsfont_open (FRAME_PTR f, Lisp_Object font_entity, int pixel_size)
     expand = 0.0;
     hshrink = 1.0;
 
-    font_info->underpos = 2; /*[sfont underlinePosition] is often clipped out */
+    font_info->underpos = [sfont underlinePosition];
     font_info->underwidth = [sfont underlineThickness];
     font_info->size = font->pixel_size;
     font_info->voffset = lrint (hshrink * [sfont ascender] + expand * hd / 2);
@@ -1196,20 +1196,7 @@ nsfont_draw (struct glyph_string *s, int from, int to, int x, int y,
 /*[context GSSetTextDrawingMode: GSTextFill]; /// not implemented yet */
       }
 
-    /* do underline */
-    if (face->underline_p)
-      {
-        if (face->underline_color != 0)
-          [ns_lookup_indexed_color (face->underline_color, s->f) set];
-        else
-          [col set];
-        DPSmoveto (context, r.origin.x, r.origin.y + font->underpos);
-        DPSlineto (context, r.origin.x+r.size.width, r.origin.y+font->underpos);
-        if (face->underline_color != 0)
-          [col set];
-      }
-    else
-      [col set];
+    [col set];
 
     /* draw with DPSxshow () */
     DPSmoveto (context, r.origin.x, r.origin.y);
@@ -1255,23 +1242,7 @@ nsfont_draw (struct glyph_string *s, int from, int to, int x, int y,
         CGContextSetTextDrawingMode (gcontext, kCGTextFill);
       }
 
-    if (face->underline_p)
-      {
-        if (face->underline_color != 0)
-          [ns_lookup_indexed_color (face->underline_color, s->f) set];
-        else
-          [col set];
-        CGContextBeginPath (gcontext);
-        CGContextMoveToPoint (gcontext,
-                              r.origin.x, r.origin.y + font->underpos);
-        CGContextAddLineToPoint (gcontext, r.origin.x + r.size.width,
-                                r.origin.y + font->underpos);
-        CGContextStrokePath (gcontext);
-        if (face->underline_color != 0)
-          [col set];
-      }
-    else
-      [col set];
+    [col set];
 
     CGContextSetTextPosition (gcontext, r.origin.x, r.origin.y);
     CGContextShowGlyphsWithAdvances (gcontext, s->char2b + s->cmp_from,
@@ -1287,6 +1258,10 @@ nsfont_draw (struct glyph_string *s, int from, int to, int x, int y,
     CGContextRestoreGState (gcontext);
   }
 #endif  /* NS_IMPL_COCOA */
+
+  /* Draw underline, overline, strike-through. */
+  ns_draw_text_decoration (s, face, col, r.size.width, r.origin.x);
+
   return to-from;
 }
 
diff --git a/src/nsterm.h b/src/nsterm.h
index f419391a11e..227429ed515 100644
--- a/src/nsterm.h
+++ b/src/nsterm.h
@@ -825,6 +825,13 @@ extern unsigned long ns_get_rgb_color (struct frame *f,
                                        float r, float g, float b, float a);
 extern NSPoint last_mouse_motion_position;
 
+/* From nsterm.m, needed in nsfont.m. */
+#ifdef __OBJC__
+extern void
+ns_draw_text_decoration (struct glyph_string *s, struct face *face,
+                         NSColor *defaultCol, CGFloat width, CGFloat x);
+#endif
+
 #ifdef NS_IMPL_GNUSTEP
 extern char gnustep_base_version[];  /* version tracking */
 #endif
diff --git a/src/nsterm.m b/src/nsterm.m
index e45dc1a902d..e9e7dcc0804 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -263,8 +263,6 @@ static void ns_condemn_scroll_bars (struct frame *f);
 static void ns_judge_scroll_bars (struct frame *f);
 void x_set_frame_alpha (struct frame *f);
 
-/* FIXME: figure out what to do with underline_minimum_offset. */
-
 
 /* ==========================================================================
 
@@ -2597,6 +2595,107 @@ ns_get_glyph_string_clip_rect (struct glyph_string *s, NativeRectangle *nr)
   return n;
 }
 
+void
+ns_draw_text_decoration (struct glyph_string *s, struct face *face,
+                         NSColor *defaultCol, CGFloat width, CGFloat x)
+/* --------------------------------------------------------------------------
+   Draw underline, overline, and strike-through on glyph string s.
+   -------------------------------------------------------------------------- */
+{
+  if (s->for_overlaps)
+    return;
+
+  /* Do underline. */
+  if (face->underline_p)
+    {
+      NSRect r;
+      unsigned long thickness, position;
+
+      /* If the prev was underlined, match its appearance. */
+      if (s->prev && s->prev->face->underline_p
+          && s->prev->underline_thickness > 0)
+        {
+          thickness = s->prev->underline_thickness;
+          position = s->prev->underline_position;
+        }
+      else
+        {
+          struct font *font;
+          unsigned long descent;
+
+          font=s->font;
+          descent = s->y + s->height - s->ybase;
+
+          /* Use underline thickness of font, defaulting to 1. */
+          thickness = (font && font->underline_thickness > 0)
+            ? font->underline_thickness : 1;
+
+          /* Determine the offset of underlining from the baseline. */
+          if (x_underline_at_descent_line)
+            position = descent - thickness;
+          else if (x_use_underline_position_properties
+                   && font && font->underline_position >= 0)
+            position = font->underline_position;
+          else if (font)
+            position = lround (font->descent / 2);
+          else
+            position = underline_minimum_offset;
+
+          position = max (position, underline_minimum_offset);
+
+          /* Ensure underlining is not cropped. */
+          if (descent <= position)
+            {
+              position = descent - 1;
+              thickness = 1;
+            }
+          else if (descent < position + thickness)
+            thickness = 1;
+        }
+
+      s->underline_thickness = thickness;
+      s->underline_position = position;
+
+      r = NSMakeRect (x, s->ybase + position, width, thickness);
+
+      if (face->underline_defaulted_p)
+        [defaultCol set];
+      else
+        [ns_lookup_indexed_color (face->underline_color, s->f) set];
+      NSRectFill (r);
+    }
+
+  /* Do overline. We follow other terms in using a thickness of 1
+     and ignoring overline_margin. */
+  if (face->overline_p)
+    {
+      NSRect r;
+      r = NSMakeRect (x, s->y, width, 1);
+
+      if (face->overline_color_defaulted_p)
+        [defaultCol set];
+      else
+        [ns_lookup_indexed_color (face->overline_color, s->f) set];
+      NSRectFill (r);
+    }
+
+  /* Do strike-through.  We follow other terms for thickness and
+     vertical position.*/
+  if (face->strike_through_p)
+    {
+      NSRect r;
+      unsigned long dy;
+
+      dy = lrint ((s->height - 1) / 2);
+      r = NSMakeRect (x, s->y + dy, width, 1);
+
+      if (face->strike_through_color_defaulted_p)
+        [defaultCol set];
+      else
+        [ns_lookup_indexed_color (face->strike_through_color, s->f) set];
+      NSRectFill (r);
+    }
+}
 
 static void
 ns_draw_box (NSRect r, float thickness, NSColor *col, char left_p, char right_p)
@@ -2854,6 +2953,7 @@ ns_dumpglyphs_image (struct glyph_string *s, NSRect r)
   char raised_p;
   NSRect br;
   struct face *face;
+  NSColor *tdCol;
 
   NSTRACE (ns_dumpglyphs_image);
 
@@ -2882,10 +2982,7 @@ ns_dumpglyphs_image (struct glyph_string *s, NSRect r)
   else
     face = FACE_FROM_ID (s->f, s->first_glyph->face_id);
 
-  if (s->hl == DRAW_CURSOR)
-      [FRAME_CURSOR_COLOR (s->f) set];
-  else
-    [ns_lookup_indexed_color (NS_FACE_BACKGROUND (face), s->f) set];
+  [ns_lookup_indexed_color (NS_FACE_BACKGROUND (face), s->f) set];
 
   if (bg_height > s->slice.height || s->img->hmargin || s->img->vmargin
       || s->img->mask || s->img->pixmap == 0 || s->width != s->background_width)
@@ -2923,6 +3020,27 @@ ns_dumpglyphs_image (struct glyph_string *s, NSRect r)
     [img compositeToPoint: NSMakePoint (x, y + s->slice.height)
                 operation: NSCompositeSourceOver];
 
+  if (s->hl == DRAW_CURSOR)
+    {
+    [FRAME_CURSOR_COLOR (s->f) set];
+    if (s->w->phys_cursor_type == FILLED_BOX_CURSOR)
+      tdCol = ns_lookup_indexed_color (NS_FACE_BACKGROUND (face), s->f);
+    else
+      /* Currently on NS img->mask is always 0. Since
+         get_window_cursor_type specifies a hollow box cursor when on
+         a non-masked image we never reach this clause. But we put it
+         in in antipication of better support for image masks on
+         NS. */
+      tdCol = ns_lookup_indexed_color (NS_FACE_FOREGROUND (face), s->f);
+    }
+  else
+    {
+      tdCol = ns_lookup_indexed_color (NS_FACE_FOREGROUND (face), s->f);
+    }
+
+  /* Draw underline, overline, strike-through. */
+  ns_draw_text_decoration (s, face, tdCol, br.size.width, br.origin.x);
+
   /* Draw relief, if requested */
   if (s->img->relief || s->hl ==DRAW_IMAGE_RAISED || s->hl ==DRAW_IMAGE_SUNKEN)
     {
@@ -2967,12 +3085,27 @@ ns_dumpglyphs_stretch (struct glyph_string *s)
   NSRect r[2];
   int n, i;
   struct face *face;
+  NSColor *fgCol, *bgCol;
 
   if (!s->background_filled_p)
     {
       n = ns_get_glyph_string_clip_rect (s, r);
       *r = NSMakeRect (s->x, s->y, s->background_width, s->height);
 
+      ns_focus (s->f, r, n);
+
+      if (s->hl == DRAW_MOUSE_FACE)
+       {
+         face = FACE_FROM_ID (s->f, MOUSE_HL_INFO (s->f)->mouse_face_face_id);
+         if (!face)
+           face = FACE_FROM_ID (s->f, MOUSE_FACE_ID);
+       }
+      else
+       face = FACE_FROM_ID (s->f, s->first_glyph->face_id);
+
+      bgCol = ns_lookup_indexed_color (NS_FACE_BACKGROUND (face), s->f);
+      fgCol = ns_lookup_indexed_color (NS_FACE_FOREGROUND (face), s->f);
+
       for (i=0; i<n; i++)
         {
           if (!s->row->full_width_p)
@@ -2998,30 +3131,37 @@ ns_dumpglyphs_stretch (struct glyph_string *s)
                                       FRAME_PIXEL_WIDTH (s->f));
             }
 
+          [bgCol set];
+
           /* NOTE: under NS this is NOT used to draw cursors, but we must avoid
              overwriting cursor (usually when cursor on a tab) */
           if (s->hl == DRAW_CURSOR)
             {
-              r[i].origin.x += s->width;
-              r[i].size.width -= s->width;
-            }
-        }
+              CGFloat x, width;
 
-      ns_focus (s->f, r, n);
+              x = r[i].origin.x;
+              width = s->w->phys_cursor_width;
+              r[i].size.width -= width;
+              r[i].origin.x += width;
 
-      if (s->hl == DRAW_MOUSE_FACE)
-       {
-         face = FACE_FROM_ID (s->f, MOUSE_HL_INFO (s->f)->mouse_face_face_id);
-         if (!face)
-           face = FACE_FROM_ID (s->f, MOUSE_FACE_ID);
-       }
-      else
-       face = FACE_FROM_ID (s->f, s->first_glyph->face_id);
+              NSRectFill (r[i]);
 
-      [ns_lookup_indexed_color (NS_FACE_BACKGROUND (face), s->f) set];
+              /* Draw overlining, etc. on the cursor. */
+              if (s->w->phys_cursor_type == FILLED_BOX_CURSOR)
+                ns_draw_text_decoration (s, face, bgCol, width, x);
+              else
+                ns_draw_text_decoration (s, face, fgCol, width, x);
+            }
+          else
+            {
+              NSRectFill (r[i]);
+            }
 
-      NSRectFill (r[0]);
-      NSRectFill (r[1]);
+          /* Draw overlining, etc. on the stretch glyph (or the part
+             of the stretch glyph after the cursor). */
+          ns_draw_text_decoration (s, face, fgCol, r[i].size.width,
+                                   r[i].origin.x);
+        }
       ns_unfocus (s->f);
       s->background_filled_p = 1;
     }
@@ -6556,23 +6696,17 @@ Only works on OSX 10.6 or later.  */);
   Vx_toolkit_scroll_bars = Qnil;
 #endif
 
-  /* these are unsupported but we need the declarations to avoid whining
-     messages from cus-start.el */
   DEFVAR_BOOL ("x-use-underline-position-properties",
                x_use_underline_position_properties,
-     doc: /* NOT SUPPORTED UNDER NS.
-*Non-nil means make use of UNDERLINE_POSITION font properties.
+     doc: /*Non-nil means make use of UNDERLINE_POSITION font properties.
 A value of nil means ignore them.  If you encounter fonts with bogus
 UNDERLINE_POSITION font properties, for example 7x13 on XFree prior
-to 4.1, set this to nil.
-
-NOTE: Not supported on Mac yet.  */);
+to 4.1, set this to nil. */);
   x_use_underline_position_properties = 0;
 
   DEFVAR_BOOL ("x-underline-at-descent-line",
                x_underline_at_descent_line,
-     doc: /* NOT SUPPORTED UNDER NS.
-*Non-nil means to draw the underline at the same place as the descent line.
+     doc: /* Non-nil means to draw the underline at the same place as the descent line.
 A value of nil means to draw the underline according to the value of the
 variable `x-use-underline-position-properties', which is usually at the
 baseline level.  The default value is nil.  */);