Auto merge of #12458 - Manishearth:style-gecko-only, r=emilio

Cleanups in autoarray helper

Addresses @emilio's comments from #11851

- Replace gecko_autoarray_longhand with vector_longhand, make it configurable
- Allow for empty vectors, use empty vector longhand in box-shadow

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components/style/properties/helpers.mako.rs

@@ -37,12 +37,18 @@
 // and handle the empty case correctly
 <%doc>
     To be used in cases where we have a grammar like
-    "<thing> [ , <thing> ]*", but only support a single value
-    in servo
+    "<thing> [ , <thing> ]*". `gecko_only` should be set
+    to True for cases where Servo takes a single value
+    and Stylo supports vector values.
+
+    Setting allow_empty to False allows for cases where the vector
+    is empty. The grammar for these is usually "none | <thing> [ , <thing> ]*".
+    We assume that the default/initial value is an empty vector for these.
+    `initial_value` need not be defined for these.
 </%doc>
-<%def name="gecko_autoarray_longhand(name, **kwargs)">
+<%def name="vector_longhand(name, gecko_only=False, allow_empty=False, **kwargs)">
     <%call expr="longhand(name, **kwargs)">
-        % if product == "gecko":
+        % if product == "gecko" or not gecko_only:
             use cssparser::ToCss;
             use std::fmt;
 
@@ -63,10 +69,17 @@
 
             impl ToCss for computed_value::T {
                 fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
-                    if !self.0.is_empty() {
-                        try!(self.0[0].to_css(dest));
+                    let mut iter = self.0.iter();
+                    if let Some(val) = iter.next() {
+                        try!(val.to_css(dest));
+                    } else {
+                        % if allow_empty:
+                            try!(dest.write_str("none"));
+                        % else:
+                            error!("Found empty value for property ${name}");
+                        % endif
                     }
-                    for i in self.0.iter().skip(1) {
+                    for i in iter {
                         try!(dest.write_str(", "));
                         try!(i.to_css(dest));
                     }
@@ -80,10 +93,17 @@
 
             impl ToCss for SpecifiedValue {
                 fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
-                    if !self.0.is_empty() {
-                        try!(self.0[0].to_css(dest))
+                    let mut iter = self.0.iter();
+                    if let Some(val) = iter.next() {
+                        try!(val.to_css(dest));
+                    } else {
+                        % if allow_empty:
+                            try!(dest.write_str("none"));
+                        % else:
+                            error!("Found empty value for property ${name}");
+                        % endif
                     }
-                    for i in self.0.iter().skip(1) {
+                    for i in iter {
                         try!(dest.write_str(", "));
                         try!(i.to_css(dest));
                     }
@@ -91,12 +111,26 @@
                 }
             }
             pub fn get_initial_value() -> computed_value::T {
-                computed_value::T(vec![single_value::get_initial_value()])
+                % if allow_empty:
+                    computed_value::T(vec![])
+                % else:
+                    computed_value::T(vec![single_value::get_initial_value()])
+                % endif
             }
             pub fn parse(context: &ParserContext, input: &mut Parser) -> Result<SpecifiedValue, ()> {
-                input.parse_comma_separated(|parser| {
-                    single_value::parse(context, parser)
-                }).map(|ok| SpecifiedValue(ok))
+                % if allow_empty:
+                    if input.try(|input| input.expect_ident_matching("none")).is_ok() {
+                        Ok(SpecifiedValue(Vec::new()))
+                    } else {
+                        input.parse_comma_separated(|parser| {
+                            single_value::parse(context, parser)
+                        }).map(SpecifiedValue)
+                    }
+                % else:
+                    input.parse_comma_separated(|parser| {
+                        single_value::parse(context, parser)
+                    }).map(SpecifiedValue)
+                % endif
             }
             impl ToComputedValue for SpecifiedValue {
                 type ComputedValue = computed_value::T;

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

@@ -16,7 +16,7 @@ use properties::longhands::line_height::computed_value::T as LineHeight;
 use properties::longhands::text_shadow::computed_value::T as TextShadowList;
 use properties::longhands::text_shadow::computed_value::TextShadow;
 use properties::longhands::box_shadow::computed_value::T as BoxShadowList;
-use properties::longhands::box_shadow::computed_value::BoxShadow;
+use properties::longhands::box_shadow::single_value::computed_value::T as BoxShadow;
 use properties::longhands::transform::computed_value::ComputedMatrix;
 use properties::longhands::transform::computed_value::ComputedOperation as TransformOperation;
 use properties::longhands::transform::computed_value::T as TransformList;

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

@@ -10,7 +10,7 @@ ${helpers.predefined_type("background-color", "CSSColor",
     "::cssparser::Color::RGBA(::cssparser::RGBA { red: 0., green: 0., blue: 0., alpha: 0. }) /* transparent */",
     animatable=True)}
 
-<%helpers:gecko_autoarray_longhand name="background-image" animatable="False">
+<%helpers:vector_longhand gecko_only="True" name="background-image" animatable="False">
     use cssparser::ToCss;
     use std::fmt;
     use values::specified::Image;
@@ -70,7 +70,7 @@ ${helpers.predefined_type("background-color", "CSSColor",
             }
         }
     }
-</%helpers:gecko_autoarray_longhand>
+</%helpers:vector_longhand>
 
 <%helpers:longhand name="background-position" animatable="True">
         use cssparser::ToCss;

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

@@ -12,18 +12,14 @@ ${helpers.predefined_type("opacity",
                           "1.0",
                           animatable=True)}
 
-<%helpers:longhand name="box-shadow" animatable="True">
+<%helpers:vector_longhand name="box-shadow" allow_empty="True" animatable="True">
     use cssparser::{self, ToCss};
     use std::fmt;
     use values::LocalToCss;
 
     #[derive(Debug, Clone, PartialEq)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-    pub struct SpecifiedValue(Vec<SpecifiedBoxShadow>);
-
-    #[derive(Debug, Clone, PartialEq)]
-    #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-    pub struct SpecifiedBoxShadow {
+    pub struct SpecifiedValue {
         pub offset_x: specified::Length,
         pub offset_y: specified::Length,
         pub blur_radius: specified::Length,
@@ -33,23 +29,6 @@ ${helpers.predefined_type("opacity",
     }
 
     impl ToCss for SpecifiedValue {
-        fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
-            let mut iter = self.0.iter();
-            if let Some(shadow) = iter.next() {
-                try!(shadow.to_css(dest));
-            } else {
-                try!(dest.write_str("none"));
-                return Ok(())
-            }
-            for shadow in iter {
-                try!(dest.write_str(", "));
-                try!(shadow.to_css(dest));
-            }
-            Ok(())
-        }
-    }
-
-    impl ToCss for SpecifiedBoxShadow {
         fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
             if self.inset {
                 try!(dest.write_str("inset "));
@@ -75,13 +54,9 @@ ${helpers.predefined_type("opacity",
         use std::fmt;
         use values::computed;
 
-        #[derive(Clone, PartialEq, Debug)]
-        #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-        pub struct T(pub Vec<BoxShadow>);
-
         #[derive(Clone, PartialEq, Copy, Debug)]
         #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-        pub struct BoxShadow {
+        pub struct T {
             pub offset_x: Au,
             pub offset_y: Au,
             pub blur_radius: Au,
@@ -92,23 +67,6 @@ ${helpers.predefined_type("opacity",
     }
 
     impl ToCss for computed_value::T {
-        fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
-            let mut iter = self.0.iter();
-            if let Some(shadow) = iter.next() {
-                try!(shadow.to_css(dest));
-            } else {
-                try!(dest.write_str("none"));
-                return Ok(())
-            }
-            for shadow in iter {
-                try!(dest.write_str(", "));
-                try!(shadow.to_css(dest));
-            }
-            Ok(())
-        }
-    }
-
-    impl ToCss for computed_value::BoxShadow {
         fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
             if self.inset {
                 try!(dest.write_str("inset "));
@@ -126,44 +84,26 @@ ${helpers.predefined_type("opacity",
         }
     }
 
-    #[inline]
-    pub fn get_initial_value() -> computed_value::T {
-        computed_value::T(Vec::new())
-    }
-
-    pub fn parse(_context: &ParserContext, input: &mut Parser) -> Result<SpecifiedValue, ()> {
-        if input.try(|input| input.expect_ident_matching("none")).is_ok() {
-            Ok(SpecifiedValue(Vec::new()))
-        } else {
-            input.parse_comma_separated(parse_one_box_shadow).map(SpecifiedValue)
-        }
-    }
-
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
 
         #[inline]
         fn to_computed_value<Cx: TContext>(&self, context: &Cx) -> computed_value::T {
-            computed_value::T(self.0.iter().map(|value| compute_one_box_shadow(value, context)).collect())
+            computed_value::T {
+                offset_x: self.offset_x.to_computed_value(context),
+                offset_y: self.offset_y.to_computed_value(context),
+                blur_radius: self.blur_radius.to_computed_value(context),
+                spread_radius: self.spread_radius.to_computed_value(context),
+                color: self.color
+                            .as_ref()
+                            .map(|color| color.parsed)
+                            .unwrap_or(cssparser::Color::CurrentColor),
+                inset: self.inset,
+            }
         }
     }
 
-    pub fn compute_one_box_shadow<Cx: TContext>(value: &SpecifiedBoxShadow, context: &Cx)
-                                  -> computed_value::BoxShadow {
-        computed_value::BoxShadow {
-            offset_x: value.offset_x.to_computed_value(context),
-            offset_y: value.offset_y.to_computed_value(context),
-            blur_radius: value.blur_radius.to_computed_value(context),
-            spread_radius: value.spread_radius.to_computed_value(context),
-            color: value.color
-                        .as_ref()
-                        .map(|color| color.parsed)
-                        .unwrap_or(cssparser::Color::CurrentColor),
-            inset: value.inset,
-        }
-    }
-
-    pub fn parse_one_box_shadow(input: &mut Parser) -> Result<SpecifiedBoxShadow, ()> {
+    pub fn parse(_context: &ParserContext, input: &mut Parser) -> Result<SpecifiedValue, ()> {
         use app_units::Au;
         let mut lengths = [specified::Length::Absolute(Au(0)); 4];
         let mut lengths_parsed = false;
@@ -213,7 +153,7 @@ ${helpers.predefined_type("opacity",
             return Err(())
         }
 
-        Ok(SpecifiedBoxShadow {
+        Ok(SpecifiedValue {
             offset_x: lengths[0],
             offset_y: lengths[1],
             blur_radius: lengths[2],
@@ -222,7 +162,7 @@ ${helpers.predefined_type("opacity",
             inset: inset,
         })
     }
-</%helpers:longhand>
+</%helpers:vector_longhand>
 
 // FIXME: This prop should be animatable
 <%helpers:longhand name="clip" animatable="False">