Double border support

src/components/gfx/render_context.rs

@@ -159,6 +159,9 @@ impl<'a> RenderContext<'a>  {
             border_style::solid                        => {
                 self.draw_solid_border_segment(direction,bounds,border,color_select);
             }
+            border_style::double                       => {
+                self.draw_double_border_segment(direction, bounds, border, color_select);
+            }
             border_style::groove | border_style::ridge => {
                 self.draw_groove_ridge_border_segment(direction, bounds, border, color_select, style_select);
             }
@@ -182,6 +185,9 @@ impl<'a> RenderContext<'a>  {
             border_style::solid                        => {
                 self.draw_solid_border_segment(Right,bounds,border,color);
             }
+            border_style::double                       => {
+                self.draw_double_border_segment(Right, bounds, border, color);
+            }
             border_style::groove | border_style::ridge => {
                 self.draw_groove_ridge_border_segment(Right, bounds, border, color, style);
             }
@@ -329,6 +335,18 @@ impl<'a> RenderContext<'a>  {
         return Color(color.r * scale_factor, color.g * scale_factor, color.b * scale_factor, color.a);
     }
 
+    fn draw_double_border_segment(&self, direction: Direction, bounds: &Rect<Au>, border: SideOffsets2D<f32>, color: Color) {
+        let scaled_border       = SideOffsets2D::new((1.0/3.0) * border.top,
+                                                     (1.0/3.0) * border.right,
+                                                     (1.0/3.0) * border.bottom,
+                                                     (1.0/3.0) * border.left);
+        let inner_scaled_bounds = self.get_scaled_bounds(bounds, border, 2.0/3.0);
+        // draw the outer portion of the double border.
+        self.draw_solid_border_segment(direction, bounds, scaled_border, color);
+        // draw the inner portion of the double border.
+        self.draw_border_path(inner_scaled_bounds, direction, scaled_border, color);
+    }
+
     fn draw_groove_ridge_border_segment(&self,
                                         direction: Direction,
                                         bounds:    &Rect<Au>,

src/components/style/properties.rs.mako

@@ -221,8 +221,7 @@ pub mod longhands {
         ${predefined_type("border-%s-color" % side, "CSSColor", "CurrentColor")}
     % endfor
 
-    //  double
-    ${single_keyword("border-top-style", values="none solid dotted dashed hidden groove ridge inset outset")}
+    ${single_keyword("border-top-style", values="none solid double dotted dashed hidden groove ridge inset outset")}
 
     % for side in ["right", "bottom", "left"]:
         <%self:longhand name="border-${side}-style", no_super="True">

src/test/html/test_border.html

@@ -16,6 +16,11 @@
     border-width: 10px;
     border-color: yellow green red black;
 }
+#double{
+    border-style: double;
+    border-width: 10px;
+    border-color: yellow green red black;
+}
 #dashed{
     border-style: dashed;
     border-width: 10px;
@@ -67,6 +72,7 @@
 <div id="none"> none test.</div>
 <div id="hidden"> hidden test.</div>
 <div id="solid"> solid test</div>
+<div id="double"> double test</div>
 <div id="dashed"> dashed test</div>
 <div id="dotted"> dotted test</div>
 <div id="groove"> groove test</div>

src/test/ref/borders_a.html

@@ -12,6 +12,11 @@
     border-width: 10px;
     border-color: green red yellow black;
 }
+#double{
+    border-style: double;
+    border-width: 10px;
+    border-color: yellow;
+}
 #solid{
     border-style: solid;
     border-width: 10px;
@@ -65,6 +70,7 @@
 <div id="none"></div>
 <div id="hidden"></div>
 <div id="solid"></div>
+<div id="double"></div>
 <div id="dashed"></div>
 <div id="dotted"></div>
 <div id="groove"></div>