tidy and test fixes

components/style/properties/data.py

@@ -20,6 +20,7 @@ SYSTEM_FONT_LONGHANDS = """font_family font_size font_style
                            font_variant_ligatures font_variant_east_asian
                            font_variant_numeric font_language_override""".split()
 
+
 def maybe_moz_logical_alias(product, side, prop):
     if product == "gecko" and side[1]:
         axis, dir = side[0].split("-")
@@ -38,9 +39,10 @@ def to_rust_ident(name):
 def to_camel_case(ident):
     return re.sub("(^|_|-)([a-z])", lambda m: m.group(2).upper(), ident.strip("_").strip("-"))
 
+
 def to_camel_case_lower(ident):
     camel = to_camel_case(ident)
-    return  camel[0].lower() + camel[1:]
+    return camel[0].lower() + camel[1:]
 
 
 def parse_aliases(value):

components/style/properties/gecko.mako.rs

@@ -95,6 +95,7 @@ pub struct ComputedValues {
     /// When this is Some, we compute font sizes by computing the keyword against
     /// the generic font, and then multiplying it by the ratio.
     pub font_size_keyword: Option<(longhands::font_size::KeywordSize, f32)>,
+    /// The cached system font. See longhand/font.mako.rs
     pub cached_system_font: Option<longhands::system_font::ComputedSystemFont>,
 }
 

components/style/properties/helpers/animated_properties.mako.rs

@@ -411,7 +411,8 @@ impl AnimationValue {
     }
 
     /// Construct an AnimationValue from a property declaration
-    pub fn from_declaration(decl: &PropertyDeclaration, context: &mut Context, initial: &ComputedValues) -> Option<Self> {
+    pub fn from_declaration(decl: &PropertyDeclaration, context: &mut Context,
+                            initial: &ComputedValues) -> Option<Self> {
         use error_reporting::StdoutErrorReporter;
         use properties::LonghandId;
         use properties::DeclaredValue;

components/style/properties/longhand/font.mako.rs

@@ -45,12 +45,12 @@
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
 
-        fn to_computed_value(&self, context: &Context) -> computed_value::T {
+        fn to_computed_value(&self, _context: &Context) -> computed_value::T {
             match *self {
                 SpecifiedValue::Value(v) => v,
                 SpecifiedValue::System(_) => {
                     <%self:nongecko_unreachable>
-                        context.style.cached_system_font.as_ref().unwrap().${name}
+                        _context.style.cached_system_font.as_ref().unwrap().${name}
                     </%self:nongecko_unreachable>
                 }
             }
@@ -62,7 +62,7 @@
     }
 </%def>
 
-<%helpers:longhand name="font-family" animation_type="none" need_index="True"
+<%helpers:longhand name="font-family" animation_type="none" need_index="True"  boxed="${product == 'gecko'}"
                    spec="https://drafts.csswg.org/css-fonts/#propdef-font-family">
     use properties::longhands::system_font::SystemFont;
     use self::computed_value::{FontFamily, FamilyName};
@@ -1850,7 +1850,8 @@ ${helpers.single_keyword_system("font-variant-position",
     }
 </%helpers:longhand>
 
-<%helpers:longhand name="font-language-override" products="gecko" animation_type="none" extra_prefixes="moz"
+<%helpers:longhand name="font-language-override" products="gecko" animation_type="none"
+                   extra_prefixes="moz" boxed="True"
                    spec="https://drafts.csswg.org/css-fonts-3/#propdef-font-language-override">
     use properties::longhands::system_font::SystemFont;
     use std::fmt;
@@ -1938,7 +1939,7 @@ ${helpers.single_keyword_system("font-variant-position",
         type ComputedValue = computed_value::T;
 
         #[inline]
-        fn to_computed_value(&self, context: &Context) -> computed_value::T {
+        fn to_computed_value(&self, _context: &Context) -> computed_value::T {
             use std::ascii::AsciiExt;
             match *self {
                 SpecifiedValue::Normal => computed_value::T(0),
@@ -1955,7 +1956,7 @@ ${helpers.single_keyword_system("font-variant-position",
                 }
                 SpecifiedValue::System(_) => {
                     <%self:nongecko_unreachable>
-                        context.style.cached_system_font.as_ref().unwrap().font_language_override
+                        _context.style.cached_system_font.as_ref().unwrap().font_language_override
                     </%self:nongecko_unreachable>
                 }
             }
@@ -2180,6 +2181,21 @@ ${helpers.single_keyword("-moz-math-variant",
 
 % if product == "gecko":
     pub mod system_font {
+        //! We deal with system fonts here
+        //!
+        //! System fonts can only be set as a group via the font shorthand.
+        //! They resolve at compute time (not parse time -- this lets the
+        //! browser respond to changes to the OS font settings).
+        //!
+        //! While Gecko handles these as a separate property and keyword
+        //! values on each property indicating that the font should be picked
+        //! from the -x-system-font property, we avoid this. Instead,
+        //! each font longhand has a special SystemFont variant which contains
+        //! the specified system font. When the cascade function (in helpers)
+        //! detects that a value has a system font, it will resolve it, and
+        //! cache it on the ComputedValues. After this, it can be just fetched
+        //! whenever a font longhand on the same element needs the system font.
+
         use app_units::Au;
         use cssparser::Parser;
         use properties::longhands;
@@ -2270,7 +2286,8 @@ ${helpers.single_keyword("-moz-math-variant",
                     font_family: longhands::font_family::computed_value::T(family),
                     font_size: Au(system.size),
                     font_weight: weight,
-                    font_size_adjust: longhands::font_size_adjust::computed_value::T::from_gecko_adjust(system.sizeAdjust),
+                    font_size_adjust: longhands::font_size_adjust::computed_value
+                                               ::T::from_gecko_adjust(system.sizeAdjust),
                     % for kwprop in kw_font_props:
                         ${kwprop}: longhands::${kwprop}::computed_value::T::from_gecko_keyword(
                             system.${to_camel_case_lower(kwprop.replace('font_', ''))}
@@ -2279,7 +2296,8 @@ ${helpers.single_keyword("-moz-math-variant",
                             % endif
                         ),
                     % endfor
-                    font_language_override: longhands::font_language_override::computed_value::T(system.languageOverride),
+                    font_language_override: longhands::font_language_override::computed_value
+                                                     ::T(system.languageOverride),
                     system_font: *self,
                 };
                 unsafe { bindings::Gecko_nsFont_Destroy(&mut system); }

components/style/properties/shorthand/font.mako.rs

@@ -19,6 +19,7 @@
                     spec="https://drafts.csswg.org/css-fonts-3/#propdef-font">
     use properties::longhands::{font_family, font_style, font_weight, font_stretch};
     use properties::longhands::{font_size, line_height, font_variant_caps};
+    #[cfg(feature = "gecko")]
     use properties::longhands::system_font::SystemFont;
     <%
         gecko_sub_properties = "kerning language_override size_adjust \
@@ -31,7 +32,7 @@
             use properties::longhands::font_${prop};
         % endfor
     % endif
-    use properties::longhands::font_family::SpecifiedValue as FontFamily;
+    use self::font_family::SpecifiedValue as FontFamily;
 
     pub fn parse_value(context: &ParserContext, input: &mut Parser) -> Result<Longhands, ()> {
         let mut nb_normals = 0;
@@ -114,13 +115,13 @@
         })
     }
 
-    enum CheckSystemResult {
-        AllSystem(SystemFont),
-        SomeSystem,
-        None
-    }
-
     % if product == "gecko":
+        enum CheckSystemResult {
+            AllSystem(SystemFont),
+            SomeSystem,
+            None
+        }
+
         impl<'a> LonghandsToSerialize<'a> {
             /// Check if some or all members are system fonts
             fn check_system(&self) -> CheckSystemResult {