Auto merge of #13056 - KiChjang:transition-event, r=mbrubeck

Implement transition event and infrastructure

Fixes #10245.

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/13056)
<!-- Reviewable:end -->

components/script/dom/bindings/js.rs

@@ -451,6 +451,14 @@ impl<T: Reflectable> LayoutJS<T> {
         debug_assert!(thread_state::get().is_layout());
         *self.ptr
     }
+
+    /// Returns a reference to the interior of this JS object. This method is
+    /// safe to call because it originates from the layout thread, and it cannot
+    /// mutate DOM nodes.
+    pub fn get_for_script(&self) -> &T {
+        debug_assert!(thread_state::get().is_script());
+        unsafe { &**self.ptr }
+    }
 }
 
 /// Get a reference out of a rooted value.

components/script/dom/macros.rs

@@ -472,6 +472,7 @@ macro_rules! global_event_handlers(
         event_handler!(suspend, GetOnsuspend, SetOnsuspend);
         event_handler!(timeupdate, GetOntimeupdate, SetOntimeupdate);
         event_handler!(toggle, GetOntoggle, SetOntoggle);
+        event_handler!(transitionend, GetOntransitionend, SetOntransitionend);
         event_handler!(volumechange, GetOnvolumechange, SetOnvolumechange);
         event_handler!(waiting, GetOnwaiting, SetOnwaiting);
     )

components/script/dom/mod.rs

@@ -404,6 +404,7 @@ pub mod textencoder;
 pub mod touch;
 pub mod touchevent;
 pub mod touchlist;
+pub mod transitionevent;
 pub mod treewalker;
 pub mod uievent;
 pub mod url;

components/script/dom/transitionevent.rs

@@ -0,0 +1,76 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use dom::bindings::codegen::Bindings::EventBinding::EventMethods;
+use dom::bindings::codegen::Bindings::TransitionEventBinding;
+use dom::bindings::codegen::Bindings::TransitionEventBinding::{TransitionEventInit, TransitionEventMethods};
+use dom::bindings::error::Fallible;
+use dom::bindings::inheritance::Castable;
+use dom::bindings::js::Root;
+use dom::bindings::num::Finite;
+use dom::bindings::reflector::reflect_dom_object;
+use dom::bindings::str::DOMString;
+use dom::event::Event;
+use dom::globalscope::GlobalScope;
+use string_cache::Atom;
+
+#[dom_struct]
+pub struct TransitionEvent {
+    event: Event,
+    property_name: Atom,
+    elapsed_time: Finite<f32>,
+    pseudo_element: DOMString,
+}
+
+impl TransitionEvent {
+    pub fn new_inherited(init: &TransitionEventInit) -> TransitionEvent {
+        TransitionEvent {
+            event: Event::new_inherited(),
+            property_name: Atom::from(init.propertyName.clone()),
+            elapsed_time: init.elapsedTime.clone(),
+            pseudo_element: init.pseudoElement.clone()
+        }
+    }
+
+    pub fn new(global: &GlobalScope,
+               type_: Atom,
+               init: &TransitionEventInit) -> Root<TransitionEvent> {
+        let ev = reflect_dom_object(box TransitionEvent::new_inherited(init),
+                                    global,
+                                    TransitionEventBinding::Wrap);
+        {
+            let event = ev.upcast::<Event>();
+            event.init_event(type_, init.parent.bubbles, init.parent.cancelable);
+        }
+        ev
+    }
+
+    pub fn Constructor(global: &GlobalScope,
+                       type_: DOMString,
+                       init: &TransitionEventInit) -> Fallible<Root<TransitionEvent>> {
+        Ok(TransitionEvent::new(global, Atom::from(type_), init))
+    }
+}
+
+impl TransitionEventMethods for TransitionEvent {
+    // https://drafts.csswg.org/css-transitions/#Events-TransitionEvent-propertyName
+    fn PropertyName(&self) -> DOMString {
+        DOMString::from(&*self.property_name)
+    }
+
+    // https://drafts.csswg.org/css-transitions/#Events-TransitionEvent-elapsedTime
+    fn ElapsedTime(&self) -> Finite<f32> {
+        self.elapsed_time.clone()
+    }
+
+    // https://drafts.csswg.org/css-transitions/#Events-TransitionEvent-pseudoElement
+    fn PseudoElement(&self) -> DOMString {
+        self.pseudo_element.clone()
+    }
+
+    // https://dom.spec.whatwg.org/#dom-event-istrusted
+    fn IsTrusted(&self) -> bool {
+        self.upcast::<Event>().IsTrusted()
+    }
+}

components/script/dom/webidls/EventHandler.webidl

@@ -89,6 +89,11 @@ interface GlobalEventHandlers {
            attribute EventHandler onwaiting;
 };
 
+// https://drafts.csswg.org/css-transitions/#interface-globaleventhandlers-idl
+partial interface GlobalEventHandlers {
+           attribute EventHandler ontransitionend;
+};
+
 // https://html.spec.whatwg.org/multipage/#windoweventhandlers
 [NoInterfaceObject, Exposed=(Window,Worker)]
 interface WindowEventHandlers {

components/script/dom/webidls/TransitionEvent.webidl

@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+/*
+ * For more information on this interface please see
+ * https://dom.spec.whatwg.org/#event
+ */
+
+[Constructor(DOMString type, optional TransitionEventInit transitionEventInitDict),
+ Exposed=Window]
+interface TransitionEvent : Event {
+  readonly attribute DOMString          propertyName;
+  readonly attribute float              elapsedTime;
+  readonly attribute DOMString          pseudoElement;
+};
+
+dictionary TransitionEventInit : EventInit {
+  DOMString propertyName = "";
+  float elapsedTime = 0.0;
+  DOMString pseudoElement = "";
+};