Auto merge of #12552 - ConnorGBrewster:history_interface, r=asajeffrey

History interface Go, Back, and Forward

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r? @asajeffrey

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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #5670 (github issue number if applicable).

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- [X] There are tests for these changes OR
- [ ] These changes do not require tests because _____

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implement go, forward, back

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components/script/dom/history.rs

@@ -0,0 +1,70 @@
+/* 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::HistoryBinding;
+use dom::bindings::codegen::Bindings::HistoryBinding::HistoryMethods;
+use dom::bindings::codegen::Bindings::LocationBinding::LocationMethods;
+use dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
+use dom::bindings::global::GlobalRef;
+use dom::bindings::js::{JS, Root};
+use dom::bindings::reflector::{Reflector, reflect_dom_object};
+use dom::window::Window;
+use msg::constellation_msg::TraversalDirection;
+use script_traits::ScriptMsg as ConstellationMsg;
+
+// https://html.spec.whatwg.org/multipage/#the-history-interface
+#[dom_struct]
+pub struct History {
+    reflector_: Reflector,
+    window: JS<Window>,
+}
+
+impl History {
+    pub fn new_inherited(window: &Window) -> History {
+        History {
+            reflector_: Reflector::new(),
+            window: JS::from_ref(&window),
+        }
+    }
+
+    pub fn new(window: &Window) -> Root<History> {
+        reflect_dom_object(box History::new_inherited(window),
+                           GlobalRef::Window(window),
+                           HistoryBinding::Wrap)
+    }
+}
+
+impl History {
+    fn traverse_history(&self, direction: TraversalDirection) {
+        let pipeline = self.window.pipeline();
+        let msg = ConstellationMsg::TraverseHistory(Some(pipeline), direction);
+        let _ = self.window.constellation_chan().send(msg);
+    }
+}
+
+impl HistoryMethods for History {
+    // https://html.spec.whatwg.org/multipage/#dom-history-go
+    fn Go(&self, delta: i32) {
+        let direction = if delta > 0 {
+            TraversalDirection::Forward(delta as usize)
+        } else if delta < 0 {
+            TraversalDirection::Back(-delta as usize)
+        } else {
+            self.window.Location().Reload();
+            return;
+        };
+
+        self.traverse_history(direction);
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-history-back
+    fn Back(&self) {
+        self.traverse_history(TraversalDirection::Back(1));
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-history-forward
+    fn Forward(&self) {
+        self.traverse_history(TraversalDirection::Forward(1));
+    }
+}

components/script/dom/mod.rs

@@ -270,6 +270,7 @@ pub mod forcetouchevent;
 pub mod formdata;
 pub mod hashchangeevent;
 pub mod headers;
+pub mod history;
 pub mod htmlanchorelement;
 pub mod htmlappletelement;
 pub mod htmlareaelement;

components/script/dom/webidls/History.webidl

@@ -0,0 +1,18 @@
+/* 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/. */
+
+// enum ScrollRestoration { "auto", "manual" };
+
+// https://html.spec.whatwg.org/multipage/#the-history-interface
+[Exposed=(Window,Worker)]
+interface History {
+  // readonly attribute unsigned long length;
+  // attribute ScrollRestoration scrollRestoration;
+  // readonly attribute any state;
+  void go(optional long delta = 0);
+  void back();
+  void forward();
+  // void pushState(any data, DOMString title, optional USVString? url = null);
+  // void replaceState(any data, DOMString title, optional USVString? url = null);
+};

components/script/dom/webidls/Window.webidl

@@ -11,7 +11,7 @@
   [Unforgeable] readonly attribute Document document;
   //         attribute DOMString name;
   [/*PutForwards=href, */Unforgeable] readonly attribute Location location;
-  //readonly attribute History history;
+  readonly attribute History history;
   //[Replaceable] readonly attribute BarProp locationbar;
   //[Replaceable] readonly attribute BarProp menubar;
   //[Replaceable] readonly attribute BarProp personalbar;

components/script/dom/window.rs

@@ -30,6 +30,7 @@ use dom::document::Document;
 use dom::element::Element;
 use dom::event::Event;
 use dom::eventtarget::EventTarget;
+use dom::history::History;
 use dom::htmliframeelement::build_mozbrowser_custom_event;
 use dom::location::Location;
 use dom::navigator::Navigator;
@@ -158,6 +159,7 @@ pub struct Window {
     #[ignore_heap_size_of = "channels are hard"]
     image_cache_chan: ImageCacheChan,
     browsing_context: MutNullableHeap<JS<BrowsingContext>>,
+    history: MutNullableHeap<JS<History>>,
     performance: MutNullableHeap<JS<Performance>>,
     navigation_start: u64,
     navigation_start_precise: f64,
@@ -475,6 +477,11 @@ impl WindowMethods for Window {
         self.browsing_context().active_document()
     }
 
+    // https://html.spec.whatwg.org/multipage/#dom-history
+    fn History(&self) -> Root<History> {
+        self.history.or_init(|| History::new(self))
+    }
+
     // https://html.spec.whatwg.org/multipage/#dom-location
     fn Location(&self) -> Root<Location> {
         self.Document().GetLocation().unwrap()
@@ -1648,6 +1655,7 @@ impl Window {
             mem_profiler_chan: mem_profiler_chan,
             time_profiler_chan: time_profiler_chan,
             devtools_chan: devtools_chan,
+            history: Default::default(),
             browsing_context: Default::default(),
             performance: Default::default(),
             navigation_start: (current_time.sec * 1000 + current_time.nsec as i64 / 1000000) as u64,