Implement setting element style properties. Improve serialization to return initial values when unspecified.

components/style/lib.rs

@@ -43,6 +43,7 @@ pub use selector_matching::{matches, matches_simple_selector, common_style_affec
 pub use selector_matching::{rare_style_affecting_attributes};
 pub use selector_matching::{RECOMMENDED_SELECTOR_BLOOM_FILTER_SIZE, SELECTOR_WHITESPACE};
 pub use properties::{cascade, cascade_anonymous, computed, longhands_from_shorthand};
+pub use properties::is_supported_property;
 pub use properties::{PropertyDeclaration, ComputedValues, computed_values, style_structs};
 pub use properties::{PropertyDeclarationBlock, parse_style_attribute};  // Style attributes
 pub use properties::{CSSFloat, DeclaredValue, PropertyDeclarationParseResult};

components/style/properties/common_types.rs

@@ -650,6 +650,15 @@ pub mod computed {
         Percentage(CSSFloat),
         Auto,
     }
+    impl fmt::Show for LengthOrPercentageOrAuto {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            match self {
+                &LengthOrPercentageOrAuto::Length(length) => write!(f, "{}", length),
+                &LengthOrPercentageOrAuto::Percentage(percentage) => write!(f, "{}%", percentage),
+                &LengthOrPercentageOrAuto::Auto => write!(f, "auto"),
+            }
+        }
+    }
     #[allow(non_snake_case)]
     pub fn compute_LengthOrPercentageOrAuto(value: specified::LengthOrPercentageOrAuto,
                                             context: &Context) -> LengthOrPercentageOrAuto {
@@ -669,6 +678,15 @@ pub mod computed {
         Percentage(CSSFloat),
         None,
     }
+    impl fmt::Show for LengthOrPercentageOrNone {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            match self {
+                &LengthOrPercentageOrNone::Length(length) => write!(f, "{}", length),
+                &LengthOrPercentageOrNone::Percentage(percentage) => write!(f, "{}%", percentage),
+                &LengthOrPercentageOrNone::None => write!(f, "none"),
+            }
+        }
+    }
     #[allow(non_snake_case)]
     pub fn compute_LengthOrPercentageOrNone(value: specified::LengthOrPercentageOrNone,
                                             context: &Context) -> LengthOrPercentageOrNone {
@@ -689,6 +707,15 @@ pub mod computed {
         LinearGradient(LinearGradient),
     }
 
+    impl fmt::Show for Image {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            match self {
+                &Image::Url(ref url) => write!(f, "url({})", url),
+                &Image::LinearGradient(ref grad) => write!(f, "linear-gradient({})", grad),
+            }
+        }
+    }
+
     /// Computed values for a CSS linear gradient.
     #[deriving(Clone, PartialEq)]
     pub struct LinearGradient {
@@ -699,6 +726,16 @@ pub mod computed {
         pub stops: Vec<ColorStop>,
     }
 
+    impl fmt::Show for LinearGradient {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            let _ = write!(f, "{}", self.angle_or_corner);
+            for stop in self.stops.iter() {
+                let _ = write!(f, ", {}", stop);
+            }
+            Ok(())
+        }
+    }
+
     /// Computed values for one color stop in a linear gradient.
     #[deriving(Clone, PartialEq)]
     pub struct ColorStop {
@@ -710,6 +747,16 @@ pub mod computed {
         pub position: Option<LengthOrPercentage>,
     }
 
+    impl fmt::Show for ColorStop {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            let _ = write!(f, "{}", self.color);
+            self.position.map(|pos| {
+                let _ = write!(f, " {}", pos);
+            });
+            Ok(())
+        }
+    }
+
     impl LinearGradient {
         pub fn compute(value: specified::LinearGradient, context: &Context) -> LinearGradient {
             let specified::LinearGradient {

components/style/properties/mod.rs.mako

@@ -593,12 +593,22 @@ pub mod longhands {
         }
         pub mod computed_value {
             use super::super::{Au, CSSFloat};
+            use std::fmt;
             #[deriving(PartialEq, Clone)]
             pub enum T {
                 Normal,
                 Length(Au),
                 Number(CSSFloat),
             }
+            impl fmt::Show for T {
+                fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                    match self {
+                        &T::Normal => write!(f, "normal"),
+                        &T::Length(length) => write!(f, "{}%", length),
+                        &T::Number(number) => write!(f, "{}", number),
+                    }
+                }
+            }
         }
         #[inline]
         pub fn get_initial_value() -> computed_value::T { T::Normal }
@@ -656,6 +666,7 @@ pub mod longhands {
         }
         pub mod computed_value {
             use super::super::{Au, CSSFloat};
+            use std::fmt;
             #[allow(non_camel_case_types)]
             #[deriving(PartialEq, Clone)]
             pub enum T {
@@ -665,6 +676,17 @@ pub mod longhands {
                 Length(Au),
                 Percentage(CSSFloat),
             }
+            impl fmt::Show for T {
+                fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                    match self {
+                        % for keyword in vertical_align_keywords:
+                            &T::${to_rust_ident(keyword)} => write!(f, "${keyword}"),
+                        % endfor
+                        &T::Length(length) => write!(f, "{}", length),
+                        &T::Percentage(number) => write!(f, "{}%", number),
+                    }
+                }
+            }
         }
         #[inline]
         pub fn get_initial_value() -> computed_value::T { T::baseline }
@@ -1143,12 +1165,22 @@ pub mod longhands {
             }
         }
         pub mod computed_value {
+            use std::fmt;
             #[deriving(PartialEq, Clone)]
             pub enum T {
                 % for weight in range(100, 901, 100):
                     Weight${weight},
                 % endfor
             }
+            impl fmt::Show for T {
+                fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                    match self {
+                        % for weight in range(100, 901, 100):
+                            &T::Weight${weight} => write!(f, "{}", ${weight}i),
+                        % endfor
+                    }
+                }
+            }
             impl T {
                 pub fn is_bold(self) -> bool {
                     match self {
@@ -1672,6 +1704,7 @@ pub mod longhands {
         pub mod computed_value {
             use super::super::Au;
             use super::super::super::computed;
+            use std::fmt;
 
             pub type T = Vec<BoxShadow>;
 
@@ -1684,6 +1717,17 @@ pub mod longhands {
                 pub color: computed::CSSColor,
                 pub inset: bool,
             }
+
+            impl fmt::Show for BoxShadow {
+                fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                    if self.inset {
+                        let _ = write!(f, "inset ");
+                    }
+                    let _ = write!(f, "{} {} {} {} {}", self.offset_x, self.offset_y,
+                                   self.blur_radius, self.spread_radius, self.color);
+		    Ok(())
+                }
+            }
         }
 
         #[inline]
@@ -2456,7 +2500,8 @@ impl<T: Show> DeclaredValue<T> {
     pub fn specified_value(&self) -> Option<String> {
         match self {
             &DeclaredValue::SpecifiedValue(ref inner) => Some(format!("{}", inner)),
-            _ => None,
+            &DeclaredValue::Initial => None,
+            &DeclaredValue::Inherit => Some("inherit".to_string()),
         }
     }
 }
@@ -2488,14 +2533,16 @@ impl PropertyDeclaration {
         }
     }
 
-    pub fn value(&self) -> Option<String> {
+    pub fn value(&self) -> String {
         match self {
             % for property in LONGHANDS:
                 % if property.derived_from is None:
-                    &PropertyDeclaration::${property.camel_case}Declaration(ref value) => value.specified_value(),
+                    &PropertyDeclaration::${property.camel_case}Declaration(ref value) =>
+                        value.specified_value()
+                             .unwrap_or_else(|| format!("{}", longhands::${property.ident}::get_initial_value())),
 		% endif
             % endfor
-            _ => None,
+            decl => panic!("unsupported property declaration: {}", decl.name()),
         }
     }
 
@@ -3144,6 +3191,18 @@ pub fn cascade_anonymous(parent_style: &ComputedValues) -> ComputedValues {
     result
 }
 
+pub fn is_supported_property(property: &str) -> bool {
+    match property {
+        % for property in SHORTHANDS:
+            "${property.name}" => true,
+        % endfor
+        % for property in LONGHANDS:
+            "${property.name}" => true,
+        % endfor
+        _ => false,
+    }
+}
+
 pub fn longhands_from_shorthand(shorthand: &str) -> Option<Vec<String>> {
     match shorthand {
         % for property in SHORTHANDS: