style: Add a generic way to deal with lists of values, ditch all uses…

… of as_servo in style/animations.rs

components/style/animation.rs

@@ -253,10 +253,10 @@ impl PropertyAnimation {
                                               new_style: &mut C)
                                               -> Vec<PropertyAnimation> {
         let mut result = vec![];
-        let box_style = new_style.as_servo().get_box();
-        let transition_property = box_style.transition_property.0[transition_index];
-        let timing_function = *box_style.transition_timing_function.0.get_mod(transition_index);
-        let duration = *box_style.transition_duration.0.get_mod(transition_index);
+        let box_style = new_style.get_box();
+        let transition_property = box_style.transition_property_at(transition_index);
+        let timing_function = box_style.transition_timing_function_mod(transition_index);
+        let duration = box_style.transition_duration_mod(transition_index);
 
 
         if transition_property != TransitionProperty::All {
@@ -333,23 +333,6 @@ impl PropertyAnimation {
     }
 }
 
-/// Accesses an element of an array, "wrapping around" using modular arithmetic. This is needed
-/// to handle [repeatable lists][lists] of differing lengths.
-///
-/// [lists]: https://drafts.csswg.org/css-transitions/#animtype-repeatable-list
-pub trait GetMod {
-    type Item;
-    fn get_mod(&self, i: usize) -> &Self::Item;
-}
-
-impl<T> GetMod for Vec<T> {
-    type Item = T;
-    #[inline]
-    fn get_mod(&self, i: usize) -> &T {
-        &(*self)[i % self.len()]
-    }
-}
-
 /// Inserts transitions into the queue of running animations as applicable for
 /// the given style difference. This is called from the layout worker threads.
 /// Returns true if any animations were kicked off and false otherwise.
@@ -362,7 +345,7 @@ pub fn start_transitions_if_applicable<Impl: SelectorImplExt>(new_animations_sen
                                                               new_style: &mut Arc<Impl::ComputedValues>)
                                                               -> bool {
     let mut had_animations = false;
-    for i in 0..new_style.get_box().transition_count() {
+    for i in 0..new_style.get_box().transition_property_count() {
         // Create any property animations, if applicable.
         let property_animations = PropertyAnimation::from_transition(i, old_style, Arc::make_mut(new_style));
         for property_animation in property_animations {
@@ -372,14 +355,14 @@ pub fn start_transitions_if_applicable<Impl: SelectorImplExt>(new_animations_sen
             property_animation.update(Arc::get_mut(new_style).unwrap(), 0.0);
 
             // Kick off the animation.
+            let box_style = new_style.get_box();
             let now = time::precise_time_s();
-            let box_style = new_style.as_servo().get_box();
             let start_time =
-                now + (box_style.transition_delay.0.get_mod(i).seconds() as f64);
+                now + (box_style.transition_delay_mod(i).seconds() as f64);
             new_animations_sender
                 .lock().unwrap()
                 .send(Animation::Transition(node, start_time, AnimationFrame {
-                    duration: box_style.transition_duration.0.get_mod(i).seconds() as f64,
+                    duration: box_style.transition_duration_mod(i).seconds() as f64,
                     property_animation: property_animation,
                 }, /* is_expired = */ false)).unwrap();
 
@@ -427,10 +410,10 @@ pub fn maybe_start_animations<Impl: SelectorImplExt>(context: &SharedStyleContex
         return false;
     }
 
-    let box_style = new_style.as_servo().get_box();
-    for (i, name) in box_style.animation_name.0.iter().enumerate() {
+    let box_style = new_style.get_box();
+    for (i, name) in box_style.animation_name_iter().enumerate() {
         debug!("maybe_start_animations: name={}", name);
-        let total_duration = box_style.animation_duration.0.get_mod(i).seconds();
+        let total_duration = box_style.animation_duration_mod(i).seconds();
         if total_duration == 0. {
             continue
         }
@@ -446,16 +429,16 @@ pub fn maybe_start_animations<Impl: SelectorImplExt>(context: &SharedStyleContex
                 continue;
             }
 
-            let delay = box_style.animation_delay.0.get_mod(i).seconds();
+            let delay = box_style.animation_delay_mod(i).seconds();
             let now = time::precise_time_s();
             let animation_start = now + delay as f64;
-            let duration = box_style.animation_duration.0.get_mod(i).seconds();
-            let iteration_state = match *box_style.animation_iteration_count.0.get_mod(i) {
+            let duration = box_style.animation_duration_mod(i).seconds();
+            let iteration_state = match box_style.animation_iteration_count_mod(i) {
                 AnimationIterationCount::Infinite => KeyframesIterationState::Infinite,
                 AnimationIterationCount::Number(n) => KeyframesIterationState::Finite(0, n),
             };
 
-            let animation_direction = *box_style.animation_direction.0.get_mod(i);
+            let animation_direction = box_style.animation_direction_mod(i);
 
             let initial_direction = match animation_direction {
                 AnimationDirection::normal |
@@ -464,7 +447,7 @@ pub fn maybe_start_animations<Impl: SelectorImplExt>(context: &SharedStyleContex
                 AnimationDirection::alternate_reverse => AnimationDirection::reverse,
             };
 
-            let running_state = match *box_style.animation_play_state.0.get_mod(i) {
+            let running_state = match box_style.animation_play_state_mod(i) {
                 AnimationPlayState::paused => KeyframesRunningState::Paused(0.),
                 AnimationPlayState::running => KeyframesRunningState::Running,
             };
@@ -556,9 +539,9 @@ where Impl: SelectorImplExt,
 
             debug_assert!(!animation.steps.is_empty());
 
-            let maybe_index = style.as_servo()
-                                   .get_box().animation_name.0.iter()
-                                   .position(|animation_name| name == animation_name);
+            let maybe_index = style.get_box()
+                                   .animation_name_iter()
+                                   .position(|animation_name| *name == animation_name);
 
             let index = match maybe_index {
                 Some(index) => index,
@@ -568,7 +551,7 @@ where Impl: SelectorImplExt,
                 }
             };
 
-            let total_duration = style.as_servo().get_box().animation_duration.0.get_mod(index).seconds() as f64;
+            let total_duration = style.get_box().animation_duration_mod(index).seconds() as f64;
             if total_duration == 0. {
                 debug!("update_style_for_animation: zero duration for animation {:?}", name);
                 return;
@@ -648,9 +631,9 @@ where Impl: SelectorImplExt,
 
             // NB: The spec says that the timing function can be overwritten
             // from the keyframe style.
-            let mut timing_function = *style.as_servo().get_box().animation_timing_function.0.get_mod(index);
-            if !from_style.as_servo().get_box().animation_timing_function.0.is_empty() {
-                timing_function = from_style.as_servo().get_box().animation_timing_function.0[0];
+            let mut timing_function = style.get_box().animation_timing_function_mod(index);
+            if from_style.get_box().animation_timing_function_count() != 0 {
+                timing_function = from_style.get_box().animation_timing_function_at(0);
             }
 
             let target_style = compute_style_for_animation_step(context,

components/style/properties/data.py

@@ -47,7 +47,7 @@ def gecko_constant(self, value):
 class Longhand(object):
     def __init__(self, style_struct, name, animatable=None, derived_from=None, keyword=None,
                  predefined_type=None, custom_cascade=False, experimental=False, internal=False,
-                 need_clone=False, gecko_ffi_name=None):
+                 need_clone=False, need_index=False, gecko_ffi_name=None):
         self.name = name
         self.keyword = keyword
         self.predefined_type = predefined_type
@@ -58,6 +58,7 @@ def __init__(self, style_struct, name, animatable=None, derived_from=None, keywo
         self.custom_cascade = custom_cascade
         self.internal = internal
         self.need_clone = need_clone
+        self.need_index = need_index
         self.gecko_ffi_name = gecko_ffi_name or "m" + self.camel_case
         self.derived_from = (derived_from or "").split()
 

components/style/properties/helpers.mako.rs

@@ -225,6 +225,8 @@
                 }
             }
 
+            pub use self::${to_camel_case(name)} as SingleComputedValue;
+
             define_css_keyword_enum! { ${to_camel_case(name)}:
                 % for value in data.longhands_by_name[name].keyword.values_for(product):
                     "${value}" => ${to_rust_ident(value)},

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

@@ -7,8 +7,7 @@
 
 <% data.new_style_struct("Box",
                          inherited=False,
-                         gecko_name="Display",
-                         additional_methods=[Method("transition_count", "usize")]) %>
+                         gecko_name="Display") %>
 
 // TODO(SimonSapin): don't parse `inline-table`, since we don't support it
 <%helpers:longhand name="display"
@@ -285,7 +284,9 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
 </%helpers:longhand>
 
 // TODO(pcwalton): Multiple transitions.
-<%helpers:longhand name="transition-duration" animatable="False">
+<%helpers:longhand name="transition-duration"
+                   need_index="True"
+                   animatable="False">
     use values::computed::ComputedValueAsSpecified;
     use values::specified::Time;
 
@@ -343,7 +344,9 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
 
 // TODO(pcwalton): Lots more timing functions.
 // TODO(pcwalton): Multiple transitions.
-<%helpers:longhand name="transition-timing-function" animatable="False">
+<%helpers:longhand name="transition-timing-function"
+                   need_index="True"
+                   animatable="False">
     use self::computed_value::{StartEnd, TransitionTimingFunction};
 
     use euclid::point::Point2D;
@@ -541,7 +544,9 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
     }
 </%helpers:longhand>
 
-<%helpers:longhand name="transition-property" animatable="False">
+<%helpers:longhand name="transition-property"
+                   need_index="True"
+                   animatable="False">
     pub use self::computed_value::SingleComputedValue as SingleSpecifiedValue;
     pub use self::computed_value::T as SpecifiedValue;
 
@@ -592,14 +597,17 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
     }
 </%helpers:longhand>
 
-<%helpers:longhand name="transition-delay" animatable="False">
+<%helpers:longhand name="transition-delay"
+                   need_index="True"
+                   animatable="False">
     pub use properties::longhands::transition_duration::{SingleSpecifiedValue, SpecifiedValue};
     pub use properties::longhands::transition_duration::{computed_value};
     pub use properties::longhands::transition_duration::{get_initial_single_value};
     pub use properties::longhands::transition_duration::{get_initial_value, parse, parse_one};
 </%helpers:longhand>
 
 <%helpers:longhand name="animation-name"
+                   need_index="True"
                    animatable="False">
     use values::computed::ComputedValueAsSpecified;
 
@@ -608,6 +616,8 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
         use std::fmt;
         use string_cache::Atom;
 
+        pub use string_cache::Atom as SingleComputedValue;
+
         #[derive(Debug, Clone, PartialEq, HeapSizeOf)]
         pub struct T(pub Vec<Atom>);
 
@@ -647,26 +657,32 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
 </%helpers:longhand>
 
 <%helpers:longhand name="animation-duration"
+                   need_index="True"
                    animatable="False">
     pub use super::transition_duration::computed_value;
     pub use super::transition_duration::{parse, get_initial_value};
     pub use super::transition_duration::SpecifiedValue;
 </%helpers:longhand>
 
 <%helpers:longhand name="animation-timing-function"
+                   need_index="True"
                    animatable="False">
     pub use super::transition_timing_function::computed_value;
     pub use super::transition_timing_function::{parse, get_initial_value};
     pub use super::transition_timing_function::SpecifiedValue;
 </%helpers:longhand>
 
-<%helpers:longhand name="animation-iteration-count" animatable="False">
+<%helpers:longhand name="animation-iteration-count"
+                   need_index="True"
+                   animatable="False">
     use values::computed::ComputedValueAsSpecified;
 
     pub mod computed_value {
         use cssparser::ToCss;
         use std::fmt;
 
+        pub use self::AnimationIterationCount as SingleComputedValue;
+
         #[derive(Debug, Clone, PartialEq, HeapSizeOf)]
         pub enum AnimationIterationCount {
             Number(u32),
@@ -731,18 +747,22 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
 
 ${helpers.keyword_list("animation-direction",
                        "normal reverse alternate alternate-reverse",
+                       need_index=True,
                        animatable=False)}
 
 ${helpers.keyword_list("animation-play-state",
                        "running paused",
                        need_clone=True,
+                       need_index=True,
                        animatable=False)}
 
 ${helpers.keyword_list("animation-fill-mode",
                        "none forwards backwards both",
+                       need_index=True,
                        animatable=False)}
 
 <%helpers:longhand name="animation-delay"
+                   need_index="True"
                    animatable="False">
     pub use super::transition_duration::computed_value;
     pub use super::transition_duration::{parse, get_initial_value};

components/style/properties/properties.mako.rs

@@ -1082,12 +1082,61 @@ pub mod style_struct_traits {
                     #[allow(non_snake_case)]
                     fn clone_${longhand.ident}(&self) -> longhands::${longhand.ident}::computed_value::T;
                 % endif
+                % if longhand.need_index:
+                    #[allow(non_snake_case)]
+                    fn ${longhand.ident}_count(&self) -> usize;
+
+                    #[allow(non_snake_case)]
+                    fn ${longhand.ident}_at(&self, index: usize)
+                        -> longhands::${longhand.ident}::computed_value::SingleComputedValue;
+
+                    #[allow(non_snake_case)]
+                    #[inline]
+                    fn ${longhand.ident}_iter<'a>(&'a self)
+                        -> ${longhand.camel_case}Iter<'a, Self> {
+                        ${longhand.camel_case}Iter {
+                            style_struct: self,
+                            current: 0,
+                            max: self.${longhand.ident}_count(),
+                        }
+                    }
+
+                    #[allow(non_snake_case)]
+                    #[inline]
+                    fn ${longhand.ident}_mod(&self, index: usize)
+                        -> longhands::${longhand.ident}::computed_value::SingleComputedValue {
+                        self.${longhand.ident}_at(index % self.${longhand.ident}_count())
+                    }
+                % endif
             % endfor
             % for additional in style_struct.additional_methods:
                 #[allow(non_snake_case)]
                 ${additional.declare()}
             % endfor
         }
+
+        % for longhand in style_struct.longhands:
+            % if longhand.need_index:
+                pub struct ${longhand.camel_case}Iter<'a, S: ${style_struct.trait_name} + 'static> {
+                    style_struct: &'a S,
+                    current: usize,
+                    max: usize,
+                }
+
+                impl<'a, S: ${style_struct.trait_name} + 'static> Iterator for ${longhand.camel_case}Iter<'a, S> {
+                    type Item = longhands::${longhand.ident}::computed_value::SingleComputedValue;
+
+                    fn next(&mut self) -> Option<Self::Item> {
+                        self.current += 1;
+                        if self.current <= self.max {
+                            Some(self.style_struct.${longhand.ident}_at(self.current - 1))
+                        } else {
+                            None
+                        }
+                    }
+                }
+            % endif
+        % endfor
     % endfor
 }
 
@@ -1140,18 +1189,24 @@ pub mod style_structs {
                         self.${longhand.ident}.clone()
                     }
                 % endif
+
+                % if longhand.need_index:
+                    fn ${longhand.ident}_count(&self) -> usize {
+                        self.${longhand.ident}.0.len()
+                    }
+
+                    fn ${longhand.ident}_at(&self, index: usize)
+                        -> longhands::${longhand.ident}::computed_value::SingleComputedValue {
+                        self.${longhand.ident}.0[index].clone()
+                    }
+                % endif
             % endfor
             % if style_struct.trait_name == "Border":
                 % for side in ["top", "right", "bottom", "left"]:
                     fn border_${side}_has_nonzero_width(&self) -> bool {
                         self.border_${side}_width != ::app_units::Au(0)
                     }
                 % endfor
-            % elif style_struct.trait_name == "Box":
-                #[inline]
-                fn transition_count(&self) -> usize {
-                    self.transition_property.0.len()
-                }
             % elif style_struct.trait_name == "Font":
                 fn compute_font_hash(&mut self) {
                     // Corresponds to the fields in `gfx::font_template::FontTemplateDescriptor`.