add RareFlowFlags

src/components/main/layout/box_.rs

@@ -778,9 +778,9 @@ impl Box {
                         text_run: text_box.run.clone(),
                         range: text_box.range,
                         text_color: text_color,
-                        overline_color: flow_flags.overline_color,
+                        overline_color: flow_flags.overline_color(text_color),
-                        underline_color: flow_flags.underline_color,
+                        underline_color: flow_flags.underline_color(text_color),
-                        line_through_color: flow_flags.line_through_color,
+                        line_through_color: flow_flags.line_through_color(text_color),
                         flags: text_flags,
                     };
 

src/components/main/layout/flow.rs

@@ -263,6 +263,11 @@ pub struct FlowFlagsInfo{
     flags: FlowFlags,
 
     /// text-decoration colors
+    rare_flow_flags: Option<RareFlowFlags>,
+}
+
+#[deriving(Clone)]
+pub struct RareFlowFlags {
     underline_color: Color,
     overline_color: Color,
     line_through_color: Color,
@@ -296,27 +301,116 @@ impl FlowFlagsInfo {
         flags.set_override_line_through(text_decoration.line_through);
 
         // TODO(ksh8281) compute text-decoration-color,style,line
-        let underline_color = style.Color.color.to_gfx_color();
+        let rare_flow_flags = if flags.is_text_decoration_enable() {
-        let overline_color = style.Color.color.to_gfx_color();
+            Some(RareFlowFlags {
-        let line_through_color = style.Color.color.to_gfx_color();
+                underline_color: style.Color.color.to_gfx_color(),
+                overline_color: style.Color.color.to_gfx_color(),
+                line_through_color: style.Color.color.to_gfx_color(),
+            })
+        } else {
+            None
+        };
+
         FlowFlagsInfo {
             flags: flags,
-            underline_color: underline_color,
+            rare_flow_flags: rare_flow_flags,
-            overline_color: overline_color,
+        }
-            line_through_color: line_through_color,
+    }
+
+    pub fn underline_color(&self, default_color: Color) -> Color {
+        match self.rare_flow_flags {
+            Some(ref data) => {
+                data.underline_color
+            },
+            None => {
+                default_color
+            }
+        }
+    }
+
+    pub fn overline_color(&self, default_color: Color) -> Color {
+        match self.rare_flow_flags {
+            Some(ref data) => {
+                data.overline_color
+            },
+            None => {
+                default_color
+            }
+        }
+    }
+
+    pub fn line_through_color(&self, default_color: Color) -> Color {
+        match self.rare_flow_flags {
+            Some(ref data) => {
+                data.line_through_color
+            },
+            None => {
+                default_color
+            }
         }
     }
 
     /// Propagates text decoration flags from an appropriate parent flow per CSS 2.1 § 16.3.1.
     pub fn propagate_text_decoration_from_parent(&mut self, parent: FlowFlagsInfo) {
+        if !parent.flags.is_text_decoration_enable() {
+            return ;
+        }
+
+        if !self.flags.is_text_decoration_enable() && parent.flags.is_text_decoration_enable() {
+            self.rare_flow_flags = parent.rare_flow_flags.clone();
+            return ;
+        }
+
         if !self.flags.override_underline() && parent.flags.override_underline() {
-            self.underline_color = parent.underline_color;
+            match parent.rare_flow_flags {
+                Some(ref parent_data) => {
+                    match self.rare_flow_flags {
+                        Some(ref mut data) => {
+                            data.underline_color = parent_data.underline_color;
+                        },
+                        None => {
+                            fail!("if flow has text-decoration, it must have rare_flow_flags");
+                        }
+                    }
+                },
+                None => {
+                    fail!("if flow has text-decoration, it must have rare_flow_flags");
+                }
+            }
         }
         if !self.flags.override_overline() && parent.flags.override_overline() {
-            self.overline_color = parent.overline_color;
+            match parent.rare_flow_flags {
+                Some(ref parent_data) => {
+                    match self.rare_flow_flags {
+                        Some(ref mut data) => {
+                            data.overline_color = parent_data.overline_color;
+                        },
+                        None => {
+                            fail!("if flow has text-decoration, it must have rare_flow_flags");
+                        }
+                    }
+                },
+                None => {
+                    fail!("if flow has text-decoration, it must have rare_flow_flags");
+                }
+            }
         }
         if !self.flags.override_line_through() && parent.flags.override_line_through() {
-            self.line_through_color = parent.line_through_color;
+            match parent.rare_flow_flags {
+                Some(ref parent_data) => {
+                    match self.rare_flow_flags {
+                        Some(ref mut data) => {
+                            data.line_through_color = parent_data.line_through_color;
+                        },
+                        None => {
+                            fail!("if flow has text-decoration, it must have rare_flow_flags");
+                        }
+                    }
+                },
+                None => {
+                    fail!("if flow has text-decoration, it must have rare_flow_flags");
+                }
+            }
         }
         self.flags.set_text_decoration_override(parent.flags);
     }
@@ -366,6 +460,11 @@ impl FlowFlags {
     pub fn set_text_decoration_override(&mut self, parent: FlowFlags) {
         *self = FlowFlags(**self | (*parent & TEXT_DECORATION_OVERRIDE_BITMASK));
     }
+
+    #[inline]
+    pub fn is_text_decoration_enable(&self) -> bool {
+        (**self & TEXT_DECORATION_OVERRIDE_BITMASK) != 0
+    }
 }
 
 /// Data common to all flows.