2 files changed, 39 insertions, 28 deletions

diff --git a/components/layout/layout_thread.rs b/components/layout/layout_thread.rs
index a361e42fb15..1a8bdfb4a19 100644
--- a/components/layout/layout_thread.rs
+++ b/components/layout/layout_thread.rs
@@ -22,7 +22,7 @@ use euclid::size::Size2D;
 use flow::{self, Flow, ImmutableFlowUtils, MutableFlowUtils, MutableOwnedFlowUtils};
 use flow_ref::{self, FlowRef};
 use fnv::FnvHasher;
-use gfx::display_list::{ClippingRegion, DisplayList, LayerInfo};
+use gfx::display_list::{ClippingRegion, DisplayItemMetadata, DisplayList, LayerInfo};
 use gfx::display_list::{OpaqueNode, StackingContext, StackingContextId, StackingContextType};
 use gfx::font;
 use gfx::font_cache_thread::FontCacheThread;
@@ -114,6 +114,9 @@ pub struct LayoutThreadData {
     /// A queued response for the client {top, left, width, height} of a node in pixels.
     pub client_rect_response: Rect<i32>,
 
+    /// A queued response for the node at a given point
+    pub hit_test_response: (Option<DisplayItemMetadata>, bool),
+
     /// A queued response for the resolved style property of an element.
     pub resolved_style_response: Option<String>,
 
@@ -458,6 +461,7 @@ impl LayoutThread {
                     content_box_response: Rect::zero(),
                     content_boxes_response: Vec::new(),
                     client_rect_response: Rect::zero(),
+                    hit_test_response: (None, false),
                     resolved_style_response: None,
                     offset_parent_response: OffsetParentResponse::empty(),
                     margin_style_response: MarginStyleResponse::empty(),
@@ -977,6 +981,9 @@ impl LayoutThread {
                     ReflowQueryType::ContentBoxesQuery(_) => {
                         rw_data.content_boxes_response = Vec::new();
                     },
+                    ReflowQueryType::HitTestQuery(_, _) => {
+                        rw_data.hit_test_response = (None, false);
+                    },
                     ReflowQueryType::NodeGeometryQuery(_) => {
                         rw_data.client_rect_response = Rect::zero();
                     },
@@ -1119,6 +1126,18 @@ impl LayoutThread {
                     let node = unsafe { ServoLayoutNode::new(&node) };
                     rw_data.content_boxes_response = process_content_boxes_request(node, &mut root_flow);
                 },
+                ReflowQueryType::HitTestQuery(point, update_cursor) => {
+                    let point = Point2D::new(Au::from_f32_px(point.x), Au::from_f32_px(point.y));
+                    let result = match rw_data.display_list {
+                        None => panic!("Tried to hit test with no display list"),
+                        Some(ref dl) => dl.hit_test(point),
+                    };
+                    rw_data.hit_test_response = if result.len() > 0 {
+                        (Some(result[0]), update_cursor)
+                    } else {
+                        (None, update_cursor)
+                    };
+                },
                 ReflowQueryType::NodeGeometryQuery(node) => {
                     let node = unsafe { ServoLayoutNode::new(&node) };
                     rw_data.client_rect_response = process_node_geometry_request(node, &mut root_flow);
diff --git a/components/layout/query.rs b/components/layout/query.rs
index df45301106a..039de56f5c4 100644
--- a/components/layout/query.rs
+++ b/components/layout/query.rs
@@ -51,6 +51,25 @@ impl LayoutRPC for LayoutRPCImpl {
         ContentBoxesResponse(rw_data.content_boxes_response.clone())
     }
 
+    /// Requests the node containing the point of interest.
+    fn hit_test(&self) -> HitTestResponse {
+        let &LayoutRPCImpl(ref rw_data) = self;
+        let rw_data = rw_data.lock().unwrap();
+        let &(ref result, update_cursor) = &rw_data.hit_test_response;
+        if update_cursor {
+            // Compute the new cursor.
+            let cursor = match *result {
+                None => Cursor::DefaultCursor,
+                Some(dim) => dim.pointing.unwrap(),
+            };
+            let ConstellationChan(ref constellation_chan) = rw_data.constellation_chan;
+            constellation_chan.send(ConstellationMsg::SetCursor(cursor)).unwrap();
+        }
+        HitTestResponse {
+            node_address: result.map(|dim| dim.node.to_untrusted_node_address()),
+        }
+    }
+
     fn node_geometry(&self) -> NodeGeometryResponse {
         let &LayoutRPCImpl(ref rw_data) = self;
         let rw_data = rw_data.lock().unwrap();
@@ -66,33 +85,6 @@ impl LayoutRPC for LayoutRPCImpl {
         ResolvedStyleResponse(rw_data.resolved_style_response.clone())
     }
 
-    /// Requests the node containing the point of interest.
-    fn hit_test(&self, point: Point2D<f32>, update_cursor: bool) -> Result<HitTestResponse, ()> {
-        let point = Point2D::new(Au::from_f32_px(point.x), Au::from_f32_px(point.y));
-        let &LayoutRPCImpl(ref rw_data) = self;
-        let rw_data = rw_data.lock().unwrap();
-        let display_list = rw_data.display_list.as_ref().expect("Tried to hit test without a DisplayList!");
-
-        let result = display_list.hit_test(point);
-
-        if update_cursor {
-            let cursor = if !result.is_empty() {
-                result[0].pointing.unwrap()
-            } else {
-                Cursor::DefaultCursor
-            };
-
-            let ConstellationChan(ref constellation_chan) = rw_data.constellation_chan;
-            constellation_chan.send(ConstellationMsg::SetCursor(cursor)).unwrap();
-        };
-
-        if !result.is_empty() {
-            Ok(HitTestResponse(result[0].node.to_untrusted_node_address()))
-        } else {
-            Err(())
-        }
-    }
-
     fn offset_parent(&self) -> OffsetParentResponse {
         let &LayoutRPCImpl(ref rw_data) = self;
         let rw_data = rw_data.lock().unwrap();