1 files changed, 164 insertions, 0 deletions
diff --git a/components/layout/util.rs b/components/layout/util.rs
new file mode 100644
index 00000000000..a0e466e8875
--- /dev/null
+++ b/components/layout/util.rs
@@ -0,0 +1,164 @@
+/* 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 construct::{ConstructionResult, NoConstructionResult};
+use incremental::RestyleDamage;
+use parallel::DomParallelInfo;
+use wrapper::{LayoutNode, TLayoutNode, ThreadSafeLayoutNode};
+
+use gfx::display_list::OpaqueNode;
+use gfx;
+use libc::uintptr_t;
+use script::dom::bindings::js::JS;
+use script::dom::bindings::utils::Reflectable;
+use script::dom::node::{Node, SharedLayoutData};
+use script::layout_interface::{LayoutChan, UntrustedNodeAddress, TrustedNodeAddress};
+use std::mem;
+use std::cell::{Ref, RefMut};
+use style::ComputedValues;
+use style;
+use sync::Arc;
+
+/// Data that layout associates with a node.
+pub struct PrivateLayoutData {
+    /// The results of CSS styling for this node's `before` pseudo-element, if any.
+    pub before_style: Option<Arc<ComputedValues>>,
+
+    /// The results of CSS styling for this node's `after` pseudo-element, if any.
+    pub after_style: Option<Arc<ComputedValues>>,
+
+    /// Description of how to account for recent style changes.
+    pub restyle_damage: Option<RestyleDamage>,
+
+    /// The current results of flow construction for this node. This is either a flow or a
+    /// `ConstructionItem`. See comments in `construct.rs` for more details.
+    pub flow_construction_result: ConstructionResult,
+
+    pub before_flow_construction_result: ConstructionResult,
+
+    pub after_flow_construction_result: ConstructionResult,
+
+    /// Information needed during parallel traversals.
+    pub parallel: DomParallelInfo,
+}
+
+impl PrivateLayoutData {
+    /// Creates new layout data.
+    pub fn new() -> PrivateLayoutData {
+        PrivateLayoutData {
+            before_style: None,
+            after_style: None,
+            restyle_damage: None,
+            flow_construction_result: NoConstructionResult,
+            before_flow_construction_result: NoConstructionResult,
+            after_flow_construction_result: NoConstructionResult,
+            parallel: DomParallelInfo::new(),
+        }
+    }
+}
+
+pub struct LayoutDataWrapper {
+    pub chan: Option<LayoutChan>,
+    pub shared_data: SharedLayoutData,
+    pub data: Box<PrivateLayoutData>,
+}
+
+/// A trait that allows access to the layout data of a DOM node.
+pub trait LayoutDataAccess {
+    /// Borrows the layout data without checks.
+    unsafe fn borrow_layout_data_unchecked(&self) -> *const Option<LayoutDataWrapper>;
+    /// Borrows the layout data immutably. Fails on a conflicting borrow.
+    fn borrow_layout_data<'a>(&'a self) -> Ref<'a,Option<LayoutDataWrapper>>;
+    /// Borrows the layout data mutably. Fails on a conflicting borrow.
+    fn mutate_layout_data<'a>(&'a self) -> RefMut<'a,Option<LayoutDataWrapper>>;
+}
+
+impl<'ln> LayoutDataAccess for LayoutNode<'ln> {
+    #[inline(always)]
+    unsafe fn borrow_layout_data_unchecked(&self) -> *const Option<LayoutDataWrapper> {
+        mem::transmute(self.get().layout_data.borrow_unchecked())
+    }
+
+    #[inline(always)]
+    fn borrow_layout_data<'a>(&'a self) -> Ref<'a,Option<LayoutDataWrapper>> {
+        unsafe {
+            mem::transmute(self.get().layout_data.borrow())
+        }
+    }
+
+    #[inline(always)]
+    fn mutate_layout_data<'a>(&'a self) -> RefMut<'a,Option<LayoutDataWrapper>> {
+        unsafe {
+            mem::transmute(self.get().layout_data.borrow_mut())
+        }
+    }
+}
+
+pub trait OpaqueNodeMethods {
+    /// Converts a DOM node (layout view) to an `OpaqueNode`.
+    fn from_layout_node(node: &LayoutNode) -> Self;
+
+    /// Converts a thread-safe DOM node (layout view) to an `OpaqueNode`.
+    fn from_thread_safe_layout_node(node: &ThreadSafeLayoutNode) -> Self;
+
+    /// Converts a DOM node (script view) to an `OpaqueNode`.
+    fn from_script_node(node: TrustedNodeAddress) -> Self;
+
+    /// Converts a DOM node to an `OpaqueNode'.
+    fn from_jsmanaged(node: &JS<Node>) -> Self;
+
+    /// Converts this node to an `UntrustedNodeAddress`. An `UntrustedNodeAddress` is just the type
+    /// of node that script expects to receive in a hit test.
+    fn to_untrusted_node_address(&self) -> UntrustedNodeAddress;
+}
+
+impl OpaqueNodeMethods for OpaqueNode {
+    fn from_layout_node(node: &LayoutNode) -> OpaqueNode {
+        unsafe {
+            OpaqueNodeMethods::from_jsmanaged(node.get_jsmanaged())
+        }
+    }
+
+    fn from_thread_safe_layout_node(node: &ThreadSafeLayoutNode) -> OpaqueNode {
+        unsafe {
+            let abstract_node = node.get_jsmanaged();
+            let ptr: uintptr_t = abstract_node.reflector().get_jsobject() as uint;
+            OpaqueNode(ptr)
+        }
+    }
+
+    fn from_script_node(node: TrustedNodeAddress) -> OpaqueNode {
+        unsafe {
+            OpaqueNodeMethods::from_jsmanaged(&JS::from_trusted_node_address(node))
+        }
+    }
+
+    fn from_jsmanaged(node: &JS<Node>) -> OpaqueNode {
+        unsafe {
+            let ptr: uintptr_t = mem::transmute(node.reflector().get_jsobject());
+            OpaqueNode(ptr)
+        }
+    }
+
+    fn to_untrusted_node_address(&self) -> UntrustedNodeAddress {
+        unsafe {
+            let OpaqueNode(addr) = *self;
+            let addr: UntrustedNodeAddress = mem::transmute(addr);
+            addr
+        }
+    }
+}
+
+/// Allows a CSS color to be converted into a graphics color.
+pub trait ToGfxColor {
+    /// Converts a CSS color to a graphics color.
+    fn to_gfx_color(&self) -> gfx::color::Color;
+}
+
+impl ToGfxColor for style::computed_values::RGBA {
+    fn to_gfx_color(&self) -> gfx::color::Color {
+        gfx::color::rgba(self.red, self.green, self.blue, self.alpha)
+    }
+}
+