Support a part of anonymous table(step 1-1, 1-2, 2).

Not Covered: step 1-3, 1-4, 3-1, 3-2
*Spec: http://www.w3.org/TR/CSS21/tables.html#anonymous-boxes

src/components/main/layout/box_.rs

@@ -29,7 +29,7 @@ use servo_util::str::is_whitespace;
 use std::cast;
 use std::cell::RefCell;
 use std::num::Zero;
-use style::{ComputedValues, TElement, TNode};
+use style::{ComputedValues, TElement, TNode, cascade, initial_values};
 use style::computed_values::{LengthOrPercentage, LengthOrPercentageOrAuto, overflow, LPA_Auto};
 use style::computed_values::{border_style, clear, font_family, line_height, position};
 use style::computed_values::{text_align, text_decoration, vertical_align, visibility, white_space};
@@ -446,6 +446,33 @@ impl Box {
         }
     }
 
+    /// Constructs a new `Box` instance for an anonymous table object.
+    pub fn new_anonymous_table_box(node: &ThreadSafeLayoutNode, specific: SpecificBoxInfo) -> Box {
+        // CSS 2.1 § 17.2.1 This is for non-inherited properties on anonymous table boxes
+        // example:
+        //
+        //     <div style="display: table">
+        //         Foo
+        //     </div>
+        //
+        // Anonymous table boxes, TableRowBox and TableCellBox, are generated around `Foo`, but it shouldn't inherit the border.
+
+        let (node_style, _) = cascade(&[], false, Some(node.style().get()),
+                                      &initial_values(), None);
+        Box {
+            node: OpaqueNode::from_thread_safe_layout_node(node),
+            style: Arc::new(node_style),
+            border_box: RefCell::new(Au::zero_rect()),
+            border: RefCell::new(Zero::zero()),
+            padding: RefCell::new(Zero::zero()),
+            margin: RefCell::new(Zero::zero()),
+            specific: specific,
+            position_offsets: RefCell::new(Zero::zero()),
+            inline_info: RefCell::new(None),
+            new_line_pos: ~[],
+        }
+    }
+
     /// Constructs a new `Box` instance from an opaque node.
     pub fn from_opaque_node_and_style(node: OpaqueNode,
                                       style: Arc<ComputedValues>,

src/components/main/layout/construct.rs

@@ -313,15 +313,17 @@ impl<'a> FlowConstructor<'a> {
         }
     }
 
-    /// Creates an inline flow from a set of inline boxes and adds it as a child of the given flow.
+    /// Creates an inline flow from a set of inline boxes, then adds it as a child of the given flow
+    /// or pushes it onto the given flow list.
     ///
     /// `#[inline(always)]` because this is performance critical and LLVM will not inline it
     /// otherwise.
     #[inline(always)]
-    fn flush_inline_boxes_to_flow(&mut self,
+    fn flush_inline_boxes_to_flow_or_list(&mut self,
-                                  boxes: ~[Box],
+                                          boxes: ~[Box],
-                                  flow: &mut ~Flow,
+                                          flow: &mut ~Flow,
-                                  node: &ThreadSafeLayoutNode) {
+                                          flow_list: &mut ~[~Flow],
+                                          node: &ThreadSafeLayoutNode) {
         if boxes.len() == 0 {
             return
         }
@@ -330,18 +332,23 @@ impl<'a> FlowConstructor<'a> {
         TextRunScanner::new().scan_for_runs(self.font_context(), inline_flow);
         inline_flow.finish(self.layout_context);
 
-        flow.add_new_child(inline_flow)
+        if flow.need_anonymous_flow(inline_flow) {
+            flow_list.push(inline_flow)
+        } else {
+            flow.add_new_child(inline_flow)
+        }
     }
 
     /// Creates an inline flow from a set of inline boxes, if present, and adds it as a child of
-    /// the given flow.
+    /// the given flow or pushes it onto the given flow list.
-    fn flush_inline_boxes_to_flow_if_necessary(&mut self,
+    fn flush_inline_boxes_to_flow_or_list_if_necessary(&mut self,
-                                               opt_boxes: &mut Option<~[Box]>,
+                                                       opt_boxes: &mut Option<~[Box]>,
-                                               flow: &mut ~Flow,
+                                                       flow: &mut ~Flow,
-                                               node: &ThreadSafeLayoutNode) {
+                                                       flow_list: &mut ~[~Flow],
+                                                       node: &ThreadSafeLayoutNode) {
         let opt_boxes = mem::replace(opt_boxes, None);
         if opt_boxes.len() > 0 {
-            self.flush_inline_boxes_to_flow(opt_boxes.to_vec(), flow, node)
+            self.flush_inline_boxes_to_flow_or_list(opt_boxes.to_vec(), flow, flow_list, node)
         }
     }
 
@@ -358,6 +365,7 @@ impl<'a> FlowConstructor<'a> {
                                  -> ConstructionResult {
         // Gather up boxes for the inline flows we might need to create.
         let mut opt_boxes_for_inline_flow = None;
+        let mut consecutive_siblings = ~[];
         let mut first_box = true;
         // List of absolute descendants, in tree order.
         let mut abs_descendants = Descendants::new();
@@ -368,7 +376,11 @@ impl<'a> FlowConstructor<'a> {
                 FlowConstructionResult(kid_flow, kid_abs_descendants, kid_fixed_descendants) => {
                     // If kid_flow is TableCaptionFlow, kid_flow should be added under TableWrapperFlow.
                     if flow.is_table() && kid_flow.is_table_caption() {
-                        kid.set_flow_construction_result(FlowConstructionResult(kid_flow, kid_abs_descendants, kid_fixed_descendants))
+                        kid.set_flow_construction_result(FlowConstructionResult(kid_flow,
+                                                                                Descendants::new(),
+                                                                                Descendants::new()))
+                    } else if flow.need_anonymous_flow(kid_flow) {
+                        consecutive_siblings.push(kid_flow)
                     } else {
                         // Strip ignorable whitespace from the start of this flow per CSS 2.1 §
                         // 9.2.1.1.
@@ -382,13 +394,18 @@ impl<'a> FlowConstructor<'a> {
                         debug!("flushing {} inline box(es) to flow A",
                                 opt_boxes_for_inline_flow.as_ref()
                                 .map_or(0, |boxes| boxes.len()));
-                        self.flush_inline_boxes_to_flow_if_necessary(&mut opt_boxes_for_inline_flow,
+                        self.flush_inline_boxes_to_flow_or_list_if_necessary(&mut opt_boxes_for_inline_flow,
-                                &mut flow,
+                                                                             &mut flow,
-                                node);
+                                                                             &mut consecutive_siblings,
+                                                                             node);
+                        if !consecutive_siblings.is_empty() {
+                            self.generate_anonymous_missing_child(consecutive_siblings, &mut flow, node);
+                            consecutive_siblings = ~[];
+                        }
                         flow.add_new_child(kid_flow);
-                        abs_descendants.push_descendants(kid_abs_descendants);
-                        fixed_descendants.push_descendants(kid_fixed_descendants);
                     }
+                    abs_descendants.push_descendants(kid_abs_descendants);
+                    fixed_descendants.push_descendants(kid_fixed_descendants);
                 }
                 ConstructionItemConstructionResult(InlineBoxesConstructionItem(
                         InlineBoxesConstructionResult {
@@ -423,14 +440,19 @@ impl<'a> FlowConstructor<'a> {
                                        opt_boxes_for_inline_flow.as_ref()
                                                                 .map_or(0,
                                                                         |boxes| boxes.len()));
-                                self.flush_inline_boxes_to_flow_if_necessary(
+                                self.flush_inline_boxes_to_flow_or_list_if_necessary(
                                         &mut opt_boxes_for_inline_flow,
                                         &mut flow,
+                                        &mut consecutive_siblings,
                                         node);
 
                                 // Push the flow generated by the {ib} split onto our list of
                                 // flows.
-                                flow.add_new_child(kid_flow)
+                                if flow.need_anonymous_flow(kid_flow) {
+                                    consecutive_siblings.push(kid_flow)
+                                } else {
+                                    flow.add_new_child(kid_flow)
+                                }
                             }
                         }
                     }
@@ -453,9 +475,13 @@ impl<'a> FlowConstructor<'a> {
         // Perform a final flush of any inline boxes that we were gathering up to handle {ib}
         // splits, after stripping ignorable whitespace.
         strip_ignorable_whitespace_from_end(&mut opt_boxes_for_inline_flow);
-        self.flush_inline_boxes_to_flow_if_necessary(&mut opt_boxes_for_inline_flow,
+        self.flush_inline_boxes_to_flow_or_list_if_necessary(&mut opt_boxes_for_inline_flow,
-                                                     &mut flow,
+                                                             &mut flow,
-                                                     node);
+                                                             &mut consecutive_siblings,
+                                                             node);
+        if !consecutive_siblings.is_empty() {
+            self.generate_anonymous_missing_child(consecutive_siblings, &mut flow, node);
+        }
 
         // The flow is done.
         flow.finish(self.layout_context);
@@ -717,26 +743,45 @@ impl<'a> FlowConstructor<'a> {
         }
     }
 
-    fn build_table_wrapper_flow_using_children(&mut self,
+    /// TableCaptionFlow is populated underneath TableWrapperFlow
+    fn place_table_caption_under_table_wrapper(&mut self,
                                                table_wrapper_flow: &mut ~Flow,
-                                               node: &ThreadSafeLayoutNode)
+                                               node: &ThreadSafeLayoutNode) {
-                                               -> (Descendants, Descendants) {
-        // List of absolute descendants, in tree order.
-        let mut abs_descendants = Descendants::new();
-        let mut fixed_descendants = Descendants::new();
         for kid in node.children() {
             match kid.swap_out_construction_result() {
                 NoConstructionResult | ConstructionItemConstructionResult(_) => {}
-                FlowConstructionResult(kid_flow, kid_abs_descendants, kid_fixed_descendants) => {
+                FlowConstructionResult(kid_flow, _, _) => {
                     // Only kid flows with table-caption are matched here.
                     assert!(kid_flow.is_table_caption());
                     table_wrapper_flow.add_new_child(kid_flow);
-                    abs_descendants.push_descendants(kid_abs_descendants);
-                    fixed_descendants.push_descendants(kid_fixed_descendants);
                 }
             }
         }
-        (abs_descendants, fixed_descendants)
+    }
+
+    /// Generates an anonymous table flow according to CSS 2.1 § 17.2.1, step 2.
+    /// If necessary, generate recursively another anonymous table flow.
+    fn generate_anonymous_missing_child(&mut self, child_flows: ~[~Flow],
+                                        flow: &mut ~Flow, node: &ThreadSafeLayoutNode) {
+        let mut anonymous_flow = flow.generate_missing_child_flow(node);
+        let mut consecutive_siblings = ~[];
+        for kid_flow in child_flows.move_iter() {
+            if anonymous_flow.need_anonymous_flow(kid_flow) {
+                consecutive_siblings.push(kid_flow);
+                continue;
+            }
+            if !consecutive_siblings.is_empty() {
+                self.generate_anonymous_missing_child(consecutive_siblings, &mut anonymous_flow, node);
+                consecutive_siblings = ~[];
+            }
+            anonymous_flow.add_new_child(kid_flow);
+        }
+        if !consecutive_siblings.is_empty() {
+            self.generate_anonymous_missing_child(consecutive_siblings, &mut anonymous_flow, node);
+        }
+        // The flow is done.
+        anonymous_flow.finish(self.layout_context);
+        flow.add_new_child(anonymous_flow);
     }
 
     /// Builds a flow for a node with `display: table`. This yields a `TableWrapperFlow` with possibly
@@ -752,8 +797,10 @@ impl<'a> FlowConstructor<'a> {
         // We then populate the TableWrapperFlow with TableCaptionFlow, and attach
         // the TableFlow to the TableWrapperFlow
         let construction_result = self.build_flow_using_children(table_flow, node);
-        let (mut abs_descendants, mut fixed_descendants)
+        self.place_table_caption_under_table_wrapper(&mut wrapper_flow, node);
-                    = self.build_table_wrapper_flow_using_children(&mut wrapper_flow, node);
+
+        let mut abs_descendants = Descendants::new();
+        let mut fixed_descendants = Descendants::new();
 
         // NOTE: The order of captions and table are not the same order as in the DOM tree.
         // All caption blocks are placed before the table flow

src/components/main/layout/flow.rs

@@ -27,7 +27,7 @@
 
 use css::node_style::StyledNode;
 use layout::block::{BlockFlow};
-use layout::box_::Box;
+use layout::box_::{Box, TableRowBox, TableCellBox};
 use layout::context::LayoutContext;
 use layout::construct::OptVector;
 use layout::display_list_builder::{DisplayListBuilder, ExtraDisplayListData};
@@ -288,6 +288,12 @@ pub trait ImmutableFlowUtils {
     /// Returns true if this flow is one of table-related flows.
     fn is_table_kind(self) -> bool;
 
+    /// Returns true if anonymous flow is needed between this flow and child flow.
+    fn need_anonymous_flow(self, child: &Flow) -> bool;
+
+    /// Generates missing child flow of this flow.
+    fn generate_missing_child_flow(self, node: &ThreadSafeLayoutNode) -> ~Flow;
+
     /// Returns true if this flow has no children.
     fn is_leaf(self) -> bool;
 
@@ -899,6 +905,34 @@ impl<'a> ImmutableFlowUtils for &'a Flow {
         }
     }
 
+    /// Returns true if anonymous flow is needed between this flow and child flow.
+    /// Spec: http://www.w3.org/TR/CSS21/tables.html#anonymous-boxes
+    fn need_anonymous_flow(self, child: &Flow) -> bool {
+        match self.class() {
+            TableFlowClass => !child.is_proper_table_child(),
+            TableRowGroupFlowClass => !child.is_table_row(),
+            TableRowFlowClass => !child.is_table_cell(),
+            _ => false
+        }
+    }
+
+    /// Generates missing child flow of this flow.
+    fn generate_missing_child_flow(self, node: &ThreadSafeLayoutNode) -> ~Flow {
+        match self.class() {
+            TableFlowClass | TableRowGroupFlowClass => {
+                let box_ = Box::new_anonymous_table_box(node, TableRowBox);
+                ~TableRowFlow::from_node_and_box(node, box_) as ~Flow
+            },
+            TableRowFlowClass => {
+                let box_ = Box::new_anonymous_table_box(node, TableCellBox);
+                ~TableCellFlow::from_node_and_box(node, box_) as ~Flow
+            },
+            _ => {
+                fail!("no need to generate a missing child")
+            }
+        }
+    }
+
     /// Returns true if this flow has no children.
     fn is_leaf(self) -> bool {
         base(self).children.len() == 0

src/test/html/anonymous_table.html

@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Fixed Table</title>
+    <style>
+      .table {
+        display: table;
+        table-layout: fixed;
+        width: 600px;
+        border: solid black 2px;
+      }
+      .colgroup {
+        display: table-column-group;
+      }
+      .column {
+        display: table-column;
+      }
+      .row {
+        display: table-row;
+      }
+      .cell {
+        display: table-cell;
+        border: solid red 1px;
+      }
+    </style>
+  </head>
+  <body>
+    <p> This test checks Anonymous table objects(CSS 2.1, Section 17.2.1) </p>
+    <p> 1. Remove irrelevant boxes</p>
+    <p> 2. Generate missing child wrappers: `table-row`, `table-cell` </p>
+    <div class="table">
+        <span class="column"> inline child box of table-column. NOT Shown </span>
+        <span class="colgroup">
+            <span>inline child box of table-column-group</span> NOT Shown
+        </span>
+        <span class="cell">Cell1</span>
+        <span class="cell">Cell2</span>
+        <span class="row">
+            2nd Row
+            <span>Cell4</span>
+            <span class="cell">Cell3</span>
+            Cell5
+        </span>
+    </div>
+  </body>
+<html>