Move fragment navigation into Document object

Move the `check_and_scroll_fragment()` method into Document, make the
mothod set the fragment of url after navigation, and use the
`perform_a_scroll()` method to scroll rather than an individual
method. Also removes the broken `Window.fragment` fields.

4 files changed, 61 insertions, 82 deletions

diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 4d3513b6d96..fac64cbc965 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -18,7 +18,7 @@ use dom::bindings::codegen::Bindings::NodeBinding::NodeMethods;
 use dom::bindings::codegen::Bindings::NodeFilterBinding::NodeFilter;
 use dom::bindings::codegen::Bindings::PerformanceBinding::PerformanceMethods;
 use dom::bindings::codegen::Bindings::TouchBinding::TouchMethods;
-use dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
+use dom::bindings::codegen::Bindings::WindowBinding::{ScrollBehavior, WindowMethods};
 use dom::bindings::codegen::UnionTypes::NodeOrString;
 use dom::bindings::error::{Error, ErrorResult, Fallible};
 use dom::bindings::inheritance::{Castable, ElementTypeId, HTMLElementTypeId, NodeTypeId};
@@ -600,6 +600,45 @@ impl Document {
         }
     }
 
+    /// https://html.spec.whatwg.org/multipage/#scroll-to-the-fragment-identifier
+    pub fn check_and_scroll_fragment(&self, fragment: &str) {
+        let target = self.find_fragment_node(fragment);
+
+        // Step 1
+        self.set_target_element(target.r());
+
+        let point = if fragment.is_empty() || fragment.to_lowercase() == "top" {
+            // FIXME(stshine): this should be the origin of the stacking context space,
+            // which may differ under the influence of writing mode.
+            Some((0.0, 0.0))
+        } else {
+            target.r().map(|element| {
+                // FIXME(#8275, pcwalton): This is pretty bogus when multiple layers
+                // are involved. Really what needs to happen is that this needs to go
+                // through layout to ask which layer the element belongs to, and have
+                // it send the scroll message to the compositor.
+                let rect = element.upcast::<Node>().bounding_content_box();
+
+                // In order to align with element edges, we snap to unscaled pixel
+                // boundaries, since the paint thread currently does the same for
+                // drawing elements. This is important for pages that require pixel
+                // perfect scroll positioning for proper display (like Acid2). Since
+                // we don't have the device pixel ratio here, this might not be
+                // accurate, but should work as long as the ratio is a whole number.
+                // Once #8275 is fixed this should actually take into account the
+                // real device pixel ratio.
+                (rect.origin.x.to_nearest_px() as f32,
+                 rect.origin.y.to_nearest_px() as f32)
+            })
+        };
+
+        if let Some((x, y)) = point {
+            // Step 3
+            self.window.perform_a_scroll(x, y, ScrollBehavior::Instant,
+                                         target.r());
+        }
+    }
+
     fn get_anchor_by_name(&self, name: &str) -> Option<Root<Element>> {
         let check_anchor = |node: &HTMLAnchorElement| {
             let elem = node.upcast::<Element>();
diff --git a/components/script/dom/location.rs b/components/script/dom/location.rs
index c992486b8d1..576a1d1b005 100644
--- a/components/script/dom/location.rs
+++ b/components/script/dom/location.rs
@@ -40,7 +40,7 @@ impl Location {
                          setter: fn(&mut ServoUrl, USVString)) {
         let mut url = self.window.get_url();
         setter(&mut url, value);
-        self.window.load_url(url, false, None);
+        self.window.load_url(url, false, false, None);
     }
 }
 
@@ -51,7 +51,7 @@ impl LocationMethods for Location {
         //       _entry settings object_.
         let base_url = self.window.get_url();
         if let Ok(url) = base_url.join(&url.0) {
-            self.window.load_url(url, false, None);
+            self.window.load_url(url, false, false, None);
             Ok(())
         } else {
             Err(Error::Syntax)
@@ -60,7 +60,8 @@ impl LocationMethods for Location {
 
     // https://html.spec.whatwg.org/multipage/#dom-location-reload
     fn Reload(&self) {
-        self.window.load_url(self.get_url(), true, None);
+        self.window.load_url(self.get_url(), true, true, None);
+    }
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-location-hash
@@ -109,7 +110,7 @@ impl LocationMethods for Location {
     // https://html.spec.whatwg.org/multipage/#dom-location-href
     fn SetHref(&self, value: USVString) {
         if let Ok(url) = self.window.get_url().join(&value.0) {
-            self.window.load_url(url, false, None);
+            self.window.load_url(url, false, false, None);
         }
     }
 
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index 066643f3fb1..6e946fe3eac 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -103,6 +103,7 @@ use time;
 use timers::{IsInterval, TimerCallback};
 #[cfg(any(target_os = "macos", target_os = "linux", target_os = "windows"))]
 use tinyfiledialogs::{self, MessageBoxIcon};
+use url::Position;
 use util::geometry::{self, max_rect};
 use util::opts;
 use util::prefs::PREFS;
@@ -205,9 +206,6 @@ pub struct Window {
     #[ignore_heap_size_of = "channels are hard"]
     bluetooth_thread: IpcSender<BluetoothRequest>,
 
-    /// Pending scroll to fragment event, if any
-    fragment_name: DOMRefCell<Option<String>>,
-
     /// An enlarged rectangle around the page contents visible in the viewport, used
     /// to prevent creating display list items for content that is far away from the viewport.
     page_clip_rect: Cell<Rect<Au>>,
@@ -1331,13 +1329,24 @@ impl Window {
     }
 
     /// Commence a new URL load which will either replace this window or scroll to a fragment.
-    pub fn load_url(&self, url: ServoUrl, replace: bool, referrer_policy: Option<ReferrerPolicy>) {
+    pub fn load_url(&self, url: ServoUrl, replace: bool, force_reload: bool,
+                    referrer_policy: Option<ReferrerPolicy>) {
         let doc = self.Document();
         let referrer_policy = referrer_policy.or(doc.get_referrer_policy());
 
+        // https://html.spec.whatwg.org/multipage/#navigating-across-documents
+        if !force_reload && url.as_url().unwrap()[..Position::AfterQuery] == doc.url().as_url().unwrap()[..Position::AfterQuery] {
+            // Step 5
+            if let Some(fragment) = url.fragment() {
+                doc.check_and_scroll_fragment(fragment);
+                doc.set_url(url.clone());
+                return
+            }
+        }
+
         self.main_thread_script_chan().send(
             MainThreadScriptMsg::Navigate(self.upcast::<GlobalScope>().pipeline_id(),
-                LoadData::new(url, referrer_policy, Some(doc.url().clone())),
+                LoadData::new(url, referrer_policy, Some(doc.url())),
                 replace)).unwrap();
     }
 
@@ -1348,14 +1357,6 @@ impl Window {
                     ReflowReason::Timer);
     }
 
-    pub fn set_fragment_name(&self, fragment: Option<String>) {
-        *self.fragment_name.borrow_mut() = fragment;
-    }
-
-    pub fn steal_fragment_name(&self) -> Option<String> {
-        self.fragment_name.borrow_mut().take()
-    }
-
     pub fn set_window_size(&self, size: WindowSizeData) {
         self.window_size.set(Some(size));
     }
diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index 1d434f591b8..a5452bc38ec 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -59,7 +59,6 @@ use euclid::Rect;
 use euclid::point::Point2D;
 use hyper::header::{ContentType, HttpDate, LastModified};
 use hyper::header::ReferrerPolicy as ReferrerPolicyHeader;
-use hyper::method::Method;
 use hyper::mime::{Mime, SubLevel, TopLevel};
 use hyper_serde::Serde;
 use ipc_channel::ipc::{self, IpcSender};
@@ -91,7 +90,6 @@ use script_traits::CompositorEvent::{KeyEvent, MouseButtonEvent, MouseMoveEvent,
 use script_traits::CompositorEvent::{TouchEvent, TouchpadPressureEvent};
 use script_traits::webdriver_msg::WebDriverScriptCommand;
 use servo_url::ServoUrl;
-use std::borrow::ToOwned;
 use std::cell::Cell;
 use std::collections::{hash_map, HashMap, HashSet};
 use std::option::Option;
@@ -1231,20 +1229,8 @@ impl ScriptThread {
         self.dom_manipulation_task_source.queue(handler, doc.window().upcast()).unwrap();
 
         if let Some(fragment) = doc.url().fragment() {
-            self.check_and_scroll_fragment(fragment, pipeline, &doc);
-        }
-    }
-
-    fn check_and_scroll_fragment(&self, fragment: &str, pipeline_id: PipelineId, doc: &Document) {
-        match doc.find_fragment_node(fragment) {
-            Some(ref node) => {
-                doc.set_target_element(Some(&node));
-                self.scroll_fragment_point(pipeline_id, &node);
-            }
-            None => {
-                doc.set_target_element(None);
-            }
-        }
+            doc.check_and_scroll_fragment(fragment);
+        };
     }
 
     fn collect_reports(&self, reports_chan: ReportsChan) {
@@ -1826,26 +1812,6 @@ impl ScriptThread {
         }
     }
 
-    fn scroll_fragment_point(&self, pipeline_id: PipelineId, element: &Element) {
-        // FIXME(#8275, pcwalton): This is pretty bogus when multiple layers are involved.
-        // Really what needs to happen is that this needs to go through layout to ask which
-        // layer the element belongs to, and have it send the scroll message to the
-        // compositor.
-        let rect = element.upcast::<Node>().bounding_content_box();
-
-        // In order to align with element edges, we snap to unscaled pixel boundaries, since the
-        // paint thread currently does the same for drawing elements. This is important for pages
-        // that require pixel perfect scroll positioning for proper display (like Acid2). Since we
-        // don't have the device pixel ratio here, this might not be accurate, but should work as
-        // long as the ratio is a whole number. Once #8275 is fixed this should actually take into
-        // account the real device pixel ratio.
-        let point = Point2D::new(rect.origin.x.to_nearest_px() as f32,
-                                 rect.origin.y.to_nearest_px() as f32);
-
-        let message = ConstellationMsg::ScrollFragmentPoint(pipeline_id, point, false);
-        self.constellation_chan.send(message).unwrap();
-    }
-
     /// Reflows non-incrementally, rebuilding the entire layout tree in the process.
     fn rebuild_and_force_reflow(&self, document: &Document, reason: ReflowReason) {
         let window = window_from_node(&*document);
@@ -1987,25 +1953,6 @@ impl ScriptThread {
                               frame_id: Option<FrameId>,
                               load_data: LoadData,
                               replace: bool) {
-        // Step 7.
-        {
-            let nurl = &load_data.url;
-            if let Some(fragment) = nurl.fragment() {
-                let document = match self.documents.borrow().find_document(parent_pipeline_id) {
-                    Some(document) => document,
-                    None => return warn!("Message sent to closed pipeline {}.", parent_pipeline_id),
-                };
-                let nurl = nurl.as_url().unwrap();
-                if let Some(url) = document.url().as_url() {
-                    if &url[..Position::AfterQuery] == &nurl[..Position::AfterQuery] &&
-                        load_data.method == Method::Get {
-                        self.check_and_scroll_fragment(fragment, parent_pipeline_id, &document);
-                        return;
-                    }
-                }
-            }
-        }
-
         match frame_id {
             Some(frame_id) => {
                 if let Some(iframe) = self.documents.borrow().find_iframe(parent_pipeline_id, frame_id) {
@@ -2032,13 +1979,6 @@ impl ScriptThread {
                             ReflowQueryType::NoQuery,
                             ReflowReason::WindowResize);
 
-        let fragment_node = window.steal_fragment_name()
-                                  .and_then(|name| document.find_fragment_node(&*name));
-        match fragment_node {
-            Some(ref node) => self.scroll_fragment_point(pipeline_id, &node),
-            None => {}
-        }
-
         // http://dev.w3.org/csswg/cssom-view/#resizing-viewports
         if size_type == WindowSizeType::Resize {
             let uievent = UIEvent::new(&window,
@@ -2118,8 +2058,6 @@ impl ScriptThread {
 
         // https://html.spec.whatwg.org/multipage/#the-end steps 3-4.
         document.process_deferred_scripts();
-
-        window.set_fragment_name(final_url.fragment().map(str::to_owned));
     }
 
     fn handle_css_error_reporting(&self, pipeline_id: PipelineId, filename: String,