stylo: Support lang property

components/style/build_gecko.rs

@@ -502,7 +502,7 @@ mod bindings {
             .header(add_include("mozilla/ServoBindings.h"))
             .hide_type("nsACString_internal")
             .hide_type("nsAString_internal")
-            .raw_line("pub use nsstring::{nsACString, nsAString};")
+            .raw_line("pub use nsstring::{nsACString, nsAString, nsString};")
             .raw_line("type nsACString_internal = nsACString;")
             .raw_line("type nsAString_internal = nsAString;")
             .whitelisted_function("Servo_.*")

components/style/gecko_bindings/bindings.rs

@@ -1,6 +1,6 @@
 /* automatically generated by rust-bindgen */
 
-pub use nsstring::{nsACString, nsAString};
+pub use nsstring::{nsACString, nsAString, nsString};
 type nsACString_internal = nsACString;
 type nsAString_internal = nsAString;
 use gecko_bindings::structs::mozilla::css::URLValue;
@@ -854,6 +854,14 @@ extern "C" {
 extern "C" {
     pub fn Gecko_PropertyId_IsPrefEnabled(id: nsCSSPropertyID) -> bool;
 }
+extern "C" {
+    pub fn Gecko_nsStyleFont_SetLang(font: *mut nsStyleFont,
+                                     atom: *mut nsIAtom);
+}
+extern "C" {
+    pub fn Gecko_nsStyleFont_CopyLangFrom(aFont: *mut nsStyleFont,
+                                          aSource: *const nsStyleFont);
+}
 extern "C" {
     pub fn Gecko_GetMediaFeatures() -> *const nsMediaFeature;
 }
@@ -1451,8 +1459,7 @@ extern "C" {
                                                           RawServoDeclarationBlockBorrowed,
                                                       property:
                                                           nsCSSPropertyID,
-                                                      value:
-                                                          *const nsAString_internal);
+                                                      value: *mut nsIAtom);
 }
 extern "C" {
     pub fn Servo_DeclarationBlock_SetKeywordValue(declarations:

components/style/properties/gecko.mako.rs

@@ -33,6 +33,8 @@ use gecko_bindings::bindings::Gecko_FontFamilyList_Clear;
 use gecko_bindings::bindings::Gecko_SetCursorArrayLength;
 use gecko_bindings::bindings::Gecko_SetCursorImage;
 use gecko_bindings::bindings::Gecko_NewCSSShadowArray;
+use gecko_bindings::bindings::Gecko_nsStyleFont_SetLang;
+use gecko_bindings::bindings::Gecko_nsStyleFont_CopyLangFrom;
 use gecko_bindings::bindings::Gecko_SetListStyleImage;
 use gecko_bindings::bindings::Gecko_SetListStyleImageNone;
 use gecko_bindings::bindings::Gecko_SetListStyleType;
@@ -53,7 +55,7 @@ use properties::longhands;
 use properties::{DeclaredValue, Importance, LonghandId};
 use properties::{PropertyDeclaration, PropertyDeclarationBlock, PropertyDeclarationId};
 use std::fmt::{self, Debug};
-use std::mem::{transmute, zeroed};
+use std::mem::{forget, transmute, zeroed};
 use std::ptr;
 use std::sync::Arc;
 use std::cmp;
@@ -1119,7 +1121,7 @@ fn static_assert() {
 </%self:impl_trait>
 
 <%self:impl_trait style_struct_name="Font"
-    skip_longhands="font-family font-size font-size-adjust font-weight font-synthesis"
+    skip_longhands="font-family font-size font-size-adjust font-weight font-synthesis -x-lang"
     skip_additionals="*">
 
     pub fn set_font_family(&mut self, v: longhands::font_family::computed_value::T) {
@@ -1228,6 +1230,21 @@ fn static_assert() {
         }
     }
 
+    #[allow(non_snake_case)]
+    pub fn set__x_lang(&mut self, v: longhands::_x_lang::computed_value::T) {
+        let ptr = v.0.as_ptr();
+        forget(v);
+        unsafe {
+            Gecko_nsStyleFont_SetLang(&mut self.gecko, ptr);
+        }
+    }
+
+    #[allow(non_snake_case)]
+    pub fn copy__x_lang_from(&mut self, other: &Self) {
+        unsafe {
+            Gecko_nsStyleFont_CopyLangFrom(&mut self.gecko, &other.gecko);
+        }
+    }
 </%self:impl_trait>
 
 <%def name="impl_copy_animation_value(ident, gecko_ffi_name)">

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

@@ -761,3 +761,40 @@ ${helpers.single_keyword("font-variant-position",
         }
     }
 </%helpers:longhand>
+
+<%helpers:longhand name="-x-lang" products="gecko" animatable="False" internal="True"
+                   spec="Internal (not web-exposed)"
+                   internal="True">
+    use values::HasViewportPercentage;
+    use values::computed::ComputedValueAsSpecified;
+    pub use self::computed_value::T as SpecifiedValue;
+
+    impl ComputedValueAsSpecified for SpecifiedValue {}
+    no_viewport_percentage!(SpecifiedValue);
+
+    pub mod computed_value {
+        use Atom;
+        use std::fmt;
+        use style_traits::ToCss;
+
+        impl ToCss for T {
+            fn to_css<W>(&self, _: &mut W) -> fmt::Result where W: fmt::Write {
+                Ok(())
+            }
+        }
+
+        #[derive(Clone, Debug, PartialEq)]
+        #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+        pub struct T(pub Atom);
+    }
+
+    #[inline]
+    pub fn get_initial_value() -> computed_value::T {
+        computed_value::T(atom!(""))
+    }
+
+    pub fn parse(_context: &ParserContext, _input: &mut Parser) -> Result<SpecifiedValue, ()> {
+        debug_assert!(false, "Should be set directly by presentation attributes only.");
+        Err(())
+    }
+</%helpers:longhand>

ports/geckolib/glue.rs

@@ -993,14 +993,21 @@ pub extern "C" fn Servo_DeclarationBlock_PropertyIsSet(declarations:
 }
 
 #[no_mangle]
-pub extern "C" fn Servo_DeclarationBlock_SetIdentStringValue(_:
+pub extern "C" fn Servo_DeclarationBlock_SetIdentStringValue(declarations:
                                                              RawServoDeclarationBlockBorrowed,
-                                                             _:
+                                                             property:
                                                              nsCSSPropertyID,
-                                                             _:
-                                                             *const nsAString) {
-    // 
-    error!("stylo: Don't know how to handle ident presentation attributes (-x-lang)");
+                                                             value:
+                                                             *mut nsIAtom) {
+    use style::properties::{DeclaredValue, PropertyDeclaration, LonghandId};
+    use style::properties::longhands::_x_lang::computed_value::T as Lang;
+
+    let declarations = RwLock::<PropertyDeclarationBlock>::as_arc(&declarations);
+    let long = get_longhand_from_id!(property);
+    let prop = match_wrap_declared! { long,
+        XLang => Lang(Atom::from(value)),
+    };
+    declarations.write().declarations.push((prop, Default::default()));
 }
 
 #[no_mangle]