3 files changed, 103 insertions, 0 deletions

diff --git a/components/script_layout_interface/Cargo.toml b/components/script_layout_interface/Cargo.toml
index 79d0c10682c..a4ace11ae26 100644
--- a/components/script_layout_interface/Cargo.toml
+++ b/components/script_layout_interface/Cargo.toml
@@ -9,8 +9,10 @@ name = "script_layout_interface"
 path = "lib.rs"
 
 [dependencies]
+app_units = {version = "0.2.3", features = ["plugins"]}
 bitflags = "0.7"
 canvas_traits = {path = "../canvas_traits"}
+euclid = {version = "0.6.4", features = ["plugins"]}
 gfx_traits = {path = "../gfx_traits"}
 heapsize = "0.3.0"
 heapsize_plugin = "0.1.2"
@@ -19,6 +21,7 @@ libc = "0.2"
 msg = {path = "../msg"}
 plugins = {path = "../plugins"}
 range = {path = "../range"}
+script_traits = {path = "../script_traits"}
 selectors = {version = "0.6", features = ["heap_size"]}
 string_cache = {version = "0.2.20", features = ["heap_size"]}
 style = {path = "../style"}
diff --git a/components/script_layout_interface/lib.rs b/components/script_layout_interface/lib.rs
index d9037311f6a..123792a6c6f 100644
--- a/components/script_layout_interface/lib.rs
+++ b/components/script_layout_interface/lib.rs
@@ -14,17 +14,20 @@
 #![plugin(heapsize_plugin)]
 #![plugin(plugins)]
 
+extern crate app_units;
 #[allow(unused_extern_crates)]
 #[macro_use]
 extern crate bitflags;
 extern crate canvas_traits;
 extern crate core;
+extern crate euclid;
 extern crate gfx_traits;
 extern crate heapsize;
 extern crate ipc_channel;
 extern crate libc;
 extern crate msg;
 extern crate range;
+extern crate script_traits;
 extern crate selectors;
 #[macro_use(atom, ns)]
 extern crate string_cache;
@@ -32,6 +35,7 @@ extern crate style;
 extern crate url;
 
 pub mod restyle_damage;
+pub mod rpc;
 pub mod wrapper_traits;
 
 use canvas_traits::CanvasMsg;
diff --git a/components/script_layout_interface/rpc.rs b/components/script_layout_interface/rpc.rs
new file mode 100644
index 00000000000..21cac2a19c2
--- /dev/null
+++ b/components/script_layout_interface/rpc.rs
@@ -0,0 +1,96 @@
+/* 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 app_units::Au;
+use euclid::point::Point2D;
+use euclid::rect::Rect;
+use gfx_traits::LayerId;
+use script_traits::UntrustedNodeAddress;
+use style::properties::longhands::{margin_top, margin_right, margin_bottom, margin_left, overflow_x};
+
+/// Synchronous messages that script can send to layout.
+///
+/// In general, you should use messages to talk to Layout. Use the RPC interface
+/// if and only if the work is
+///
+///   1) read-only with respect to LayoutThreadData,
+///   2) small,
+///   3) and really needs to be fast.
+pub trait LayoutRPC {
+    /// Requests the dimensions of the content box, as in the `getBoundingClientRect()` call.
+    fn content_box(&self) -> ContentBoxResponse;
+    /// Requests the dimensions of all the content boxes, as in the `getClientRects()` call.
+    fn content_boxes(&self) -> ContentBoxesResponse;
+    /// Requests the geometry of this node. Used by APIs such as `clientTop`.
+    fn node_geometry(&self) -> NodeGeometryResponse;
+    /// Requests the overflow-x and overflow-y of this node. Used by `scrollTop` etc.
+    fn node_overflow(&self) -> NodeOverflowResponse;
+    /// Requests the scroll geometry of this node. Used by APIs such as `scrollTop`.
+    fn node_scroll_area(&self) -> NodeGeometryResponse;
+    /// Requests the layer id of this node. Used by APIs such as `scrollTop`
+    fn node_layer_id(&self) -> NodeLayerIdResponse;
+    /// Requests the node containing the point of interest
+    fn hit_test(&self) -> HitTestResponse;
+    /// Query layout for the resolved value of a given CSS property
+    fn resolved_style(&self) -> ResolvedStyleResponse;
+    fn offset_parent(&self) -> OffsetParentResponse;
+    /// Query layout for the resolve values of the margin properties for an element.
+    fn margin_style(&self) -> MarginStyleResponse;
+
+    fn nodes_from_point(&self, point: Point2D<f32>) -> Vec<UntrustedNodeAddress>;
+}
+
+pub struct ContentBoxResponse(pub Rect<Au>);
+
+pub struct ContentBoxesResponse(pub Vec<Rect<Au>>);
+
+pub struct NodeGeometryResponse {
+    pub client_rect: Rect<i32>,
+}
+
+pub struct NodeOverflowResponse(pub Option<Point2D<overflow_x::computed_value::T>>);
+
+pub struct NodeLayerIdResponse {
+    pub layer_id: LayerId,
+}
+
+pub struct HitTestResponse {
+    pub node_address: Option<UntrustedNodeAddress>,
+}
+
+pub struct ResolvedStyleResponse(pub Option<String>);
+
+#[derive(Clone)]
+pub struct OffsetParentResponse {
+    pub node_address: Option<UntrustedNodeAddress>,
+    pub rect: Rect<Au>,
+}
+
+impl OffsetParentResponse {
+    pub fn empty() -> OffsetParentResponse {
+        OffsetParentResponse {
+            node_address: None,
+            rect: Rect::zero(),
+        }
+    }
+}
+
+#[derive(Clone)]
+pub struct MarginStyleResponse {
+    pub top: margin_top::computed_value::T,
+    pub right: margin_right::computed_value::T,
+    pub bottom: margin_bottom::computed_value::T,
+    pub left: margin_left::computed_value::T,
+}
+
+impl MarginStyleResponse {
+    pub fn empty() -> MarginStyleResponse {
+        MarginStyleResponse {
+            top: margin_top::computed_value::T::Auto,
+            right: margin_right::computed_value::T::Auto,
+            bottom: margin_bottom::computed_value::T::Auto,
+            left: margin_left::computed_value::T::Auto,
+        }
+    }
+}