auto merge of #5400 : pcwalton/servo/transitions-redux, r=glennw

Transition events are not yet supported, and the only animatable
properties are `top`, `right`, `bottom`, and `left`. However, all other
features of transitions are supported. There are no automated tests at
present because I'm not sure how best to test it, but three manual tests
are included.

r? @glennw

components/script/dom/webidls/CSSStyleDeclaration.webidl

@@ -186,4 +186,10 @@ partial interface CSSStyleDeclaration {
   [TreatNullAs=EmptyString] attribute DOMString zIndex;
 
   [TreatNullAs=EmptyString] attribute DOMString imageRendering;
+
+  [TreatNullAs=EmptyString] attribute DOMString transition;
+  [TreatNullAs=EmptyString] attribute DOMString transitionDuration;
+  [TreatNullAs=EmptyString] attribute DOMString transitionTimingFunction;
+  [TreatNullAs=EmptyString] attribute DOMString transitionProperty;
+  [TreatNullAs=EmptyString] attribute DOMString transitionDelay;
 };

components/script/dom/window.rs

@@ -27,7 +27,7 @@ use dom::performance::Performance;
 use dom::screen::Screen;
 use dom::storage::Storage;
 use layout_interface::{ReflowGoal, ReflowQueryType, LayoutRPC, LayoutChan, Reflow, Msg};
-use layout_interface::{ContentBoxResponse, ContentBoxesResponse};
+use layout_interface::{ContentBoxResponse, ContentBoxesResponse, ScriptReflow};
 use page::Page;
 use script_task::{TimerSource, ScriptChan};
 use script_task::ScriptMsg;
@@ -564,17 +564,19 @@ impl<'a> WindowHelpers for JSRef<'a, Window> {
         }
 
         // Send new document and relevant styles to layout.
-        let reflow = box Reflow {
+        let reflow = box ScriptReflow {
+            reflow_info: Reflow {
+                goal: goal,
+                url: self.get_url(),
+                iframe: self.parent_info.is_some(),
+                page_clip_rect: self.page_clip_rect.get(),
+            },
             document_root: root.to_trusted_node_address(),
-            url: self.get_url(),
-            iframe: self.parent_info.is_some(),
-            goal: goal,
             window_size: window_size,
             script_chan: self.control_chan.clone(),
             script_join_chan: join_chan,
             id: last_reflow_id.get(),
             query_type: query_type,
-            page_clip_rect: self.page_clip_rect.get(),
         };
 
         let LayoutChan(ref chan) = self.layout_chan;

components/script/layout_interface.rs

@@ -10,14 +10,16 @@ use dom::node::LayoutData;
 
 use geom::point::Point2D;
 use geom::rect::Rect;
+use libc::uintptr_t;
 use msg::constellation_msg::{PipelineExitType, WindowSizeData};
 use profile::mem::{Reporter, ReportsChan};
 use script_traits::{ScriptControlChan, OpaqueScriptLayoutChannel, UntrustedNodeAddress};
 use std::any::Any;
 use std::sync::mpsc::{channel, Receiver, Sender};
 use std::boxed::BoxAny;
-use style::stylesheets::Stylesheet;
+use style::animation::PropertyAnimation;
 use style::media_queries::MediaQueryList;
+use style::stylesheets::Stylesheet;
 use url::Url;
 use util::geometry::Au;
 
@@ -35,11 +37,14 @@ pub enum Msg {
     SetQuirksMode,
 
     /// Requests a reflow.
-    Reflow(Box<Reflow>),
+    Reflow(Box<ScriptReflow>),
 
     /// Get an RPC interface.
     GetRPC(Sender<Box<LayoutRPC + Send>>),
 
+    /// Requests that the layout task render the next frame of all animations.
+    TickAnimations,
+
     /// Destroys layout data associated with a DOM node.
     ///
     /// TODO(pcwalton): Maybe think about batching to avoid message traffic.
@@ -100,14 +105,22 @@ pub enum ReflowQueryType {
 
 /// Information needed for a reflow.
 pub struct Reflow {
-    /// The document node.
-    pub document_root: TrustedNodeAddress,
     /// The goal of reflow: either to render to the screen or to flush layout info for script.
     pub goal: ReflowGoal,
     /// The URL of the page.
     pub url: Url,
     /// Is the current reflow of an iframe, as opposed to a root window?
     pub iframe: bool,
+    ///  A clipping rectangle for the page, an enlarged rectangle containing the viewport.
+    pub page_clip_rect: Rect<Au>,
+}
+
+/// Information needed for a script-initiated reflow.
+pub struct ScriptReflow {
+    /// General reflow data.
+    pub reflow_info: Reflow,
+    /// The document node.
+    pub document_root: TrustedNodeAddress,
     /// The channel through which messages can be sent back to the script task.
     pub script_chan: ScriptControlChan,
     /// The current window size.
@@ -118,8 +131,6 @@ pub struct Reflow {
     pub id: u32,
     /// The type of query if any to perform during this reflow.
     pub query_type: ReflowQueryType,
-    ///  A clipping rectangle for the page, an enlarged rectangle containing the viewport.
-    pub page_clip_rect: Rect<Au>,
 }
 
 /// Encapsulates a channel to the layout task.
@@ -165,3 +176,28 @@ impl ScriptLayoutChan for OpaqueScriptLayoutChannel {
         *receiver.downcast::<Receiver<Msg>>().unwrap()
     }
 }
+
+/// Type of an opaque node.
+pub type OpaqueNode = uintptr_t;
+
+/// State relating to an animation.
+#[derive(Copy, Clone)]
+pub struct Animation {
+    /// An opaque reference to the DOM node participating in the animation.
+    pub node: OpaqueNode,
+    /// A description of the property animation that is occurring.
+    pub property_animation: PropertyAnimation,
+    /// The start time of the animation, as returned by `time::precise_time_s()`.
+    pub start_time: f64,
+    /// The end time of the animation, as returned by `time::precise_time_s()`.
+    pub end_time: f64,
+}
+
+impl Animation {
+    /// Returns the duration of this animation in seconds.
+    #[inline]
+    pub fn duration(&self) -> f64 {
+        self.end_time - self.start_time
+    }
+}
+