Implement ScrollTop and ScrollLeft getters:

Add new compositor message to get scroll_offset;
Add new layout query for computed value of overflow-x/y;
Implement layer_id method for ThreadSafeLayoutNode;
Add new layout query for layer_id;
Implement script interface for getting scrollTop and scrollLeft, as well as relavant helper functions.

1 files changed, 22 insertions, 0 deletions

diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index 8a3affefe06..75c7089fac3 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -74,6 +74,7 @@ use std::sync::{Arc, Mutex};
 use string_cache::Atom;
 use style::context::ReflowGoal;
 use style::error_reporting::ParseErrorReporter;
+use style::properties::longhands::{overflow_x};
 use style::selector_impl::PseudoElement;
 use task_source::TaskSource;
 use task_source::dom_manipulation::{DOMManipulationTaskSource, DOMManipulationTask};
@@ -1122,6 +1123,25 @@ impl Window {
         self.layout_rpc.node_scroll_area().client_rect
     }
 
+    pub fn overflow_query(&self, node: TrustedNodeAddress) -> Point2D<overflow_x::computed_value::T> {
+        self.reflow(ReflowGoal::ForScriptQuery,
+                    ReflowQueryType::NodeOverflowQuery(node),
+                    ReflowReason::Query);
+        self.layout_rpc.node_overflow().0.unwrap()
+    }
+
+    pub fn scroll_offset_query(&self, node: TrustedNodeAddress) -> Point2D<f32> {
+        self.reflow(ReflowGoal::ForScriptQuery,
+                    ReflowQueryType::NodeLayerIdQuery(node),
+                    ReflowReason::Query);
+        let layer_id = self.layout_rpc.node_layer_id().layer_id;
+        let pipeline_id = self.id;
+
+        let (send, recv) = ipc::channel::<Point2D<f32>>().unwrap();
+        self.compositor.send(ScriptToCompositorMsg::GetScrollOffset(pipeline_id, layer_id, send)).unwrap();
+        recv.recv().unwrap_or(Point2D::zero())
+    }
+
     pub fn resolved_style_query(&self,
                             element: TrustedNodeAddress,
                             pseudo: Option<PseudoElement>,
@@ -1476,6 +1496,8 @@ fn debug_reflow_events(id: PipelineId, goal: &ReflowGoal, query_type: &ReflowQue
         ReflowQueryType::ContentBoxesQuery(_n) => "\tContentBoxesQuery",
         ReflowQueryType::HitTestQuery(_n, _o) => "\tHitTestQuery",
         ReflowQueryType::NodeGeometryQuery(_n) => "\tNodeGeometryQuery",
+        ReflowQueryType::NodeLayerIdQuery(_n) => "\tNodeLayerIdQuery",
+        ReflowQueryType::NodeOverflowQuery(_n) => "\tNodeOverFlowQuery",
         ReflowQueryType::NodeScrollGeometryQuery(_n) => "\tNodeScrollGeometryQuery",
         ReflowQueryType::ResolvedStyleQuery(_, _, _) => "\tResolvedStyleQuery",
         ReflowQueryType::OffsetParentQuery(_n) => "\tOffsetParentQuery",