style: Add support for disabled document colors.

components/style/animation.rs

@@ -19,6 +19,7 @@ use properties::longhands::animation_iteration_count::single_value::computed_val
 use properties::longhands::animation_play_state::computed_value::single_value::T as AnimationPlayState;
 use properties::longhands::transition_timing_function::single_value::computed_value::StartEnd;
 use properties::longhands::transition_timing_function::single_value::computed_value::T as TransitionTimingFunction;
+use rule_tree::CascadeLevel;
 use std::sync::mpsc::Sender;
 use stylearc::Arc;
 use timer::Timer;
@@ -472,7 +473,8 @@ fn compute_style_for_animation_step(context: &SharedStyleContext,
                             .all(|&(_, importance)| importance == Importance::Normal));
 
             let iter = || {
-                guard.declarations().iter().rev().map(|&(ref decl, _importance)| decl)
+                guard.declarations().iter().rev()
+                     .map(|&(ref decl, _importance)| (decl, CascadeLevel::Animations))
             };
 
             // This currently ignores visited styles, which seems acceptable,

components/style/gecko/media_queries.rs

@@ -6,9 +6,10 @@
 
 use app_units::Au;
 use context::QuirksMode;
-use cssparser::{CssStringWriter, Parser, Token};
+use cssparser::{CssStringWriter, Parser, RGBA, Token};
 use euclid::Size2D;
 use font_metrics::get_metrics_provider_for_product;
+use gecko::values::convert_nscolor_to_rgba;
 use gecko_bindings::bindings;
 use gecko_bindings::structs::{nsCSSKeyword, nsCSSProps_KTableEntry, nsCSSValue, nsCSSUnit, nsStringBuffer};
 use gecko_bindings::structs::{nsMediaExpression_Range, nsMediaFeature};
@@ -134,6 +135,16 @@ impl Device {
                         Au((*self.pres_context).mVisibleArea.height))
         })
     }
+
+    /// Returns whether document colors are enabled.
+    pub fn use_document_colors(&self) -> bool {
+        unsafe { (*self.pres_context).mUseDocumentColors() != 0 }
+    }
+
+    /// Returns the default background color.
+    pub fn default_background_color(&self) -> RGBA {
+        convert_nscolor_to_rgba(unsafe { (*self.pres_context).mBackgroundColor })
+    }
 }
 
 /// A expression for gecko contains a reference to the media feature, the value

components/style/properties/data.py

@@ -150,7 +150,8 @@ class Longhand(object):
                  need_clone=False, need_index=False, gecko_ffi_name=None, depend_on_viewport_size=False,
                  allowed_in_keyframe_block=True, complex_color=False, cast_type='u8',
                  has_uncacheable_values=False, logical=False, alias=None, extra_prefixes=None, boxed=False,
-                 flags=None, allowed_in_page_rule=False, allow_quirks=False, vector=False):
+                 flags=None, allowed_in_page_rule=False, allow_quirks=False, ignored_when_colors_disabled=False,
+                 vector=False):
         self.name = name
         if not spec:
             raise TypeError("Spec should be specified for %s" % name)
@@ -177,6 +178,7 @@ class Longhand(object):
         self.flags = flags.split() if flags else []
         self.allowed_in_page_rule = arg_to_bool(allowed_in_page_rule)
         self.allow_quirks = allow_quirks
+        self.ignored_when_colors_disabled = ignored_when_colors_disabled
         self.is_vector = vector
 
         # https://drafts.csswg.org/css-animations/#keyframes

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

@@ -12,6 +12,7 @@ ${helpers.predefined_type("background-color", "CSSColor",
     spec="https://drafts.csswg.org/css-backgrounds/#background-color",
     animation_value_type="IntermediateColor",
     complex_color=True,
+    ignored_when_colors_disabled=True,
     allow_quirks=True)}
 
 ${helpers.predefined_type("background-image", "ImageLayer",
@@ -20,7 +21,8 @@ ${helpers.predefined_type("background-image", "ImageLayer",
     spec="https://drafts.csswg.org/css-backgrounds/#the-background-image",
     vector="True",
     animation_value_type="none",
-    has_uncacheable_values="True" if product == "gecko" else "False")}
+    has_uncacheable_values="True" if product == "gecko" else "False",
+    ignored_when_colors_disabled="True")}
 
 % for (axis, direction, initial) in [("x", "Horizontal", "left"), ("y", "Vertical", "top")]:
     ${helpers.predefined_type("background-position-" + axis, "position::" + direction + "Position",

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

@@ -22,7 +22,8 @@
                               spec=maybe_logical_spec(side, "color"),
                               animation_value_type="IntermediateColor",
                               logical=side[1],
-                              allow_quirks=not side[1])}
+                              allow_quirks=not side[1],
+                              ignored_when_colors_disabled=True)}
 
     ${helpers.predefined_type("border-%s-style" % side[0], "BorderStyle",
                               "specified::BorderStyle::none",
@@ -59,7 +60,8 @@ ${helpers.gecko_keyword_conversion(Keyword('border-style',
 % for side in PHYSICAL_SIDES:
     <%helpers:longhand name="-moz-border-${side}-colors" animation_value_type="none"
                        spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/-moz-border-*-colors)"
-                       products="gecko">
+                       products="gecko"
+                       ignored_when_colors_disabled="True">
         use std::fmt;
         use style_traits::ToCss;
         use values::specified::CSSColor;

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

@@ -10,6 +10,7 @@
 
 <%helpers:longhand name="color" need_clone="True"
                    animation_value_type="IntermediateRGBA"
+                   ignored_when_colors_disabled="True"
                    spec="https://drafts.csswg.org/css-color/#color">
     use cssparser::RGBA;
     use std::fmt;

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

@@ -52,6 +52,7 @@ ${helpers.predefined_type("column-rule-color", "CSSColor",
                           initial_specified_value="specified::CSSColor::currentcolor()",
                           products="gecko", animation_value_type="IntermediateColor", extra_prefixes="moz",
                           complex_color=True, need_clone=True,
+                          ignored_when_colors_disabled=True,
                           spec="https://drafts.csswg.org/css-multicol/#propdef-column-rule-color")}
 
 ${helpers.single_keyword("column-span", "none all",

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

@@ -17,6 +17,7 @@ ${helpers.predefined_type("opacity",
 <%helpers:vector_longhand name="box-shadow" allow_empty="True"
                           animation_value_type="IntermediateBoxShadowList"
                           extra_prefixes="webkit"
+                          ignored_when_colors_disabled="True"
                           spec="https://drafts.csswg.org/css-backgrounds/#box-shadow">
     use std::fmt;
     use style_traits::ToCss;

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

@@ -680,6 +680,7 @@ ${helpers.single_keyword("text-align-last",
 
 <%helpers:longhand name="text-shadow"
                    animation_value_type="IntermediateTextShadowList",
+                   ignored_when_colors_disabled="True",
                    spec="https://drafts.csswg.org/css-text-decor/#propdef-text-shadow">
     use cssparser;
     use std::fmt;
@@ -1117,6 +1118,7 @@ ${helpers.predefined_type("text-emphasis-color", "CSSColor",
                           initial_specified_value="specified::CSSColor::currentcolor()",
                           products="gecko", animation_value_type="IntermediateColor",
                           complex_color=True, need_clone=True,
+                          ignored_when_colors_disabled=True,
                           spec="https://drafts.csswg.org/css-text-decor/#propdef-text-emphasis-color")}
 
 
@@ -1135,6 +1137,7 @@ ${helpers.predefined_type(
     "CSSParserColor::CurrentColor",
     products="gecko", animation_value_type="IntermediateColor",
     complex_color=True, need_clone=True,
+    ignored_when_colors_disabled=True,
     spec="https://compat.spec.whatwg.org/#the-webkit-text-fill-color")}
 
 ${helpers.predefined_type(
@@ -1143,6 +1146,7 @@ ${helpers.predefined_type(
     initial_specified_value="specified::CSSColor::currentcolor()",
     products="gecko", animation_value_type="IntermediateColor",
     complex_color=True, need_clone=True,
+    ignored_when_colors_disabled=True,
     spec="https://compat.spec.whatwg.org/#the-webkit-text-stroke-color")}
 
 ${helpers.predefined_type("-webkit-text-stroke-width", "BorderWidth", "Au::from_px(0)",

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

@@ -13,6 +13,7 @@
 ${helpers.predefined_type("outline-color", "CSSColor", "computed::CSSColor::CurrentColor",
                           initial_specified_value="specified::CSSColor::currentcolor()",
                           animation_value_type="IntermediateColor", complex_color=True, need_clone=True,
+                          ignored_when_colors_disabled=True,
                           spec="https://drafts.csswg.org/css-ui/#propdef-outline-color")}
 
 <%helpers:longhand name="outline-style" need_clone="True" animation_value_type="none"

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

@@ -184,4 +184,5 @@ ${helpers.predefined_type("caret-color",
                           spec="https://drafts.csswg.org/css-ui/#caret-color",
                           animation_value_type="Either<IntermediateColor, Auto>",
                           boxed=True,
+                          ignored_when_colors_disabled=True,
                           products="gecko")}

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

@@ -284,6 +284,7 @@ ${helpers.predefined_type(
     complex_color=True,
     products="gecko",
     animation_value_type="IntermediateColor",
+    ignored_when_colors_disabled=True,
     spec="https://drafts.csswg.org/css-text-decor/#propdef-text-decoration-color")}
 
 <%helpers:longhand name="initial-letter"

components/style/properties/properties.mako.rs

@@ -37,9 +37,10 @@ use shared_lock::StylesheetGuards;
 use style_traits::{HasViewportPercentage, ToCss};
 use stylesheets::{CssRuleType, MallocSizeOf, MallocSizeOfFn, Origin, UrlExtraData};
 #[cfg(feature = "servo")] use values::Either;
+use values::specified::Color;
 use values::computed;
 use cascade_info::CascadeInfo;
-use rule_tree::StrongRuleNode;
+use rule_tree::{CascadeLevel, StrongRuleNode};
 use style_adjuster::StyleAdjuster;
 #[cfg(feature = "servo")] use values::specified::BorderStyle;
 
@@ -591,6 +592,15 @@ impl LonghandId {
         )
     }
 
+    /// Returns true if the property is one that is ignored when document
+    /// colors are disabled.
+    fn is_ignored_when_document_colors_disabled(&self) -> bool {
+        matches!(*self,
+            ${" | ".join([("LonghandId::" + p.camel_case)
+                          for p in data.longhands if p.ignored_when_colors_disabled])}
+        )
+    }
+
     /// The computed value of some properties depends on the (sometimes
     /// computed) value of *other* properties.
     ///
@@ -2499,8 +2509,9 @@ pub fn cascade(device: &Device,
 
     let iter_declarations = || {
         rule_node.self_and_ancestors().flat_map(|node| {
+            let cascade_level = node.cascade_level();
             let declarations = match node.style_source() {
-                Some(source) => source.read(node.cascade_level().guard(guards)).declarations(),
+                Some(source) => source.read(cascade_level.guard(guards)).declarations(),
                 // The root node has no style source.
                 None => &[]
             };
@@ -2511,7 +2522,7 @@ pub fn cascade(device: &Device,
                 .rev()
                 .filter_map(move |&(ref declaration, declaration_importance)| {
                     if declaration_importance == node_importance {
-                        Some(declaration)
+                        Some((declaration, cascade_level))
                     } else {
                         None
                     }
@@ -2547,13 +2558,13 @@ pub fn apply_declarations<'a, F, I>(device: &Device,
                                     quirks_mode: QuirksMode)
                                     -> ComputedValues
     where F: Fn() -> I,
-          I: Iterator<Item = &'a PropertyDeclaration>,
+          I: Iterator<Item = (&'a PropertyDeclaration, CascadeLevel)>,
 {
     let default_style = device.default_computed_values();
     let inherited_custom_properties = inherited_style.custom_properties();
     let mut custom_properties = None;
     let mut seen_custom = HashSet::new();
-    for declaration in iter_declarations() {
+    for (declaration, _cascade_level) in iter_declarations() {
         if let PropertyDeclaration::Custom(ref name, ref value) = *declaration {
             ::custom_properties::cascade(
                 &mut custom_properties, &inherited_custom_properties,
@@ -2601,6 +2612,14 @@ pub fn apply_declarations<'a, F, I>(device: &Device,
         quirks_mode: quirks_mode,
     };
 
+    let ignore_colors = !device.use_document_colors();
+    let default_background_color_decl = if ignore_colors {
+        let color = device.default_background_color();
+        Some(PropertyDeclaration::BackgroundColor(Color::RGBA(color).into()))
+    } else {
+        None
+    };
+
     // Set computed values, overwriting earlier declarations for the same
     // property.
     //
@@ -2625,7 +2644,8 @@ pub fn apply_declarations<'a, F, I>(device: &Device,
             let mut font_size = None;
             let mut font_family = None;
         % endif
-        for declaration in iter_declarations() {
+        for (declaration, cascade_level) in iter_declarations() {
+            let mut declaration = declaration;
             let longhand_id = match declaration.id() {
                 PropertyDeclarationId::Longhand(id) => id,
                 PropertyDeclarationId::Custom(..) => continue,
@@ -2639,6 +2659,28 @@ pub fn apply_declarations<'a, F, I>(device: &Device,
                 continue
             }
 
+            // When document colors are disabled, skip properties that are
+            // marked as ignored in that mode, if they come from a UA or
+            // user style sheet.
+            if ignore_colors &&
+               longhand_id.is_ignored_when_document_colors_disabled() &&
+               !matches!(cascade_level,
+                         CascadeLevel::UANormal |
+                         CascadeLevel::UserNormal |
+                         CascadeLevel::UserImportant |
+                         CascadeLevel::UAImportant) {
+                if let PropertyDeclaration::BackgroundColor(ref color) = *declaration {
+                    // Treat background-color a bit differently.  If the specified
+                    // color is anything other than a fully transparent color, convert
+                    // it into the Device's default background color.
+                    if color.is_non_transparent() {
+                        declaration = default_background_color_decl.as_ref().unwrap();
+                    }
+                } else {
+                    continue
+                }
+            }
+
             if
                 % if category_to_cascade_now == "early":
                     !

components/style/servo/media_queries.rs

@@ -6,7 +6,7 @@
 
 use app_units::Au;
 use context::QuirksMode;
-use cssparser::Parser;
+use cssparser::{Parser, RGBA};
 use euclid::{Size2D, TypedSize2D};
 use font_metrics::ServoMetricsProvider;
 use media_queries::MediaType;
@@ -96,6 +96,16 @@ impl Device {
     pub fn media_type(&self) -> MediaType {
         self.media_type.clone()
     }
+
+    /// Returns whether document colors are enabled.
+    pub fn use_document_colors(&self) -> bool {
+        true
+    }
+
+    /// Returns the default background color.
+    pub fn default_background_color(&self) -> RGBA {
+        RGBA::new(255, 255, 255, 255)
+    }
 }
 
 /// A expression kind servo understands and parses.

components/style/values/specified/mod.rs

@@ -178,6 +178,15 @@ impl CSSColor {
             authored: None,
         })
     }
+
+    /// Returns false if the color is completely transparent, and
+    /// true otherwise.
+    pub fn is_non_transparent(&self) -> bool {
+        match self.parsed {
+            Color::RGBA(rgba) if rgba.alpha == 0 => false,
+            _ => true,
+        }
+    }
 }
 
 no_viewport_percentage!(CSSColor);