Move NGConstraintSpace utility methods to a separate file

third_party/WebKit/Source/core/layout/ng/ng_block_layout_algorithm.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/layout/ng/ng_block_layout_algorithm.h"
 
 #include "core/layout/ng/ng_absolute_utils.h"
 #include "core/layout/ng/ng_block_break_token.h"
 #include "core/layout/ng/ng_block_child_iterator.h"
 #include "core/layout/ng/ng_box_fragment.h"
 #include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_constraint_space_builder.h"
 #include "core/layout/ng/ng_floats_utils.h"
 #include "core/layout/ng/ng_fragment.h"
 #include "core/layout/ng/ng_fragment_builder.h"
 #include "core/layout/ng/ng_inline_node.h"
 #include "core/layout/ng/ng_layout_opportunity_iterator.h"
 #include "core/layout/ng/ng_length_utils.h"
 #include "core/layout/ng/ng_line_builder.h"
 #include "core/layout/ng/ng_out_of_flow_layout_part.h"
+#include "core/layout/ng/ng_space_utils.h"
 #include "core/style/ComputedStyle.h"
 #include "platform/LengthFunctions.h"
 #include "wtf/Optional.h"
 
 namespace blink {
 namespace {
 
 // Whether child's constraint space should shrink to its intrinsic width.
 // This is needed for buttons, select, input, floats and orthogonal children.
 // See LayoutBox::sizesLogicalWidthToFitContent for the rationale behind this.
 bool ShouldShrinkToFit(const NGConstraintSpace& parent_space,
                        const ComputedStyle& child_style) {
   NGWritingMode child_writing_mode =
       FromPlatformWritingMode(child_style.getWritingMode());
   // Whether the child and the containing block are parallel to each other.
   // Example: vertical-rl and vertical-lr
   bool is_in_parallel_flow =
       IsParallelWritingMode(parent_space.WritingMode(), child_writing_mode);
 
   return child_style.display() == EDisplay::kInlineBlock ||
          child_style.isFloating() || !is_in_parallel_flow;
 }
 
-// Returns max of 2 {@code WTF::Optional} values.
-template <typename T>
-WTF::Optional<T> OptionalMax(const WTF::Optional<T>& value1,
-                             const WTF::Optional<T>& value2) {
-  if (value1 && value2) {
-    return std::max(value1.value(), value2.value());
-  } else if (value1) {
-    return value1;
-  }
-  return value2;
-}
-
-WTF::Optional<LayoutUnit> GetClearanceOffset(
-    const std::shared_ptr<NGExclusions>& exclusions,
-    const ComputedStyle& style) {
-  const NGExclusion* right_exclusion = exclusions->last_right_float;
-  const NGExclusion* left_exclusion = exclusions->last_left_float;
-
-  WTF::Optional<LayoutUnit> left_offset;
-  if (left_exclusion) {
-    left_offset = left_exclusion->rect.BlockEndOffset();
-  }
-  WTF::Optional<LayoutUnit> right_offset;
-  if (right_exclusion) {
-    right_offset = right_exclusion->rect.BlockEndOffset();
-  }
-
-  switch (style.clear()) {
-    case EClear::kNone:
-      return WTF::nullopt;  // nothing to do here.
-    case EClear::kLeft:
-      return left_offset;
-    case EClear::kRight:
-      return right_offset;
-    case EClear::kBoth:
-      return OptionalMax<LayoutUnit>(left_offset, right_offset);
-    default:
-      ASSERT_NOT_REACHED();
-  }
-  return WTF::nullopt;
-}
-
 // Positions pending floats stored on the fragment builder starting from
 // {@code origin_point_block_offset}.
 void PositionPendingFloats(const LayoutUnit origin_point_block_offset,
                            NGConstraintSpace* new_parent_space,
                            NGFragmentBuilder* builder) {
   DCHECK(builder->BfcOffset()) << "Parent BFC offset should be known here";
   LayoutUnit bfc_block_offset = builder->BfcOffset().value().block_offset;
 
   for (auto& floating_object : builder->UnpositionedFloats()) {
     const auto* float_space = floating_object->space.get();
     const NGConstraintSpace* original_parent_space =
         floating_object->original_parent_space.get();
 
     NGLogicalOffset origin_point = {float_space->BfcOffset().inline_offset,
                                     origin_point_block_offset};
     NGLogicalOffset from_offset = {
         original_parent_space->BfcOffset().inline_offset, bfc_block_offset};
 
     NGLogicalOffset float_fragment_offset = PositionFloat(
         origin_point, from_offset, floating_object.get(), new_parent_space);
     builder->AddFloatingObject(floating_object, float_fragment_offset);
   }
   builder->MutableUnpositionedFloats().clear();
 }
 
-// Whether an in-flow block-level child creates a new formatting context.
-//
-// This will *NOT* check the following cases:
-//  - The child is out-of-flow, e.g. floating or abs-pos.
-//  - The child is a inline-level, e.g. "display: inline-block".
-//  - The child establishes a new formatting context, but should be a child of
-//    another layout algorithm, e.g. "display: table-caption" or flex-item.
-bool IsNewFormattingContextForInFlowBlockLevelChild(
-    const NGConstraintSpace& space,
-    const ComputedStyle& style) {
-  // TODO(layout-dev): This doesn't capture a few cases which can't be computed
-  // directly from style yet:
-  //  - The child is a <fieldset>.
-  //  - "column-span: all" is set on the child (requires knowledge that we are
-  //    in a multi-col formatting context).
-  //    (https://drafts.csswg.org/css-multicol-1/#valdef-column-span-all)
-
-  if (style.specifiesColumns() || style.containsPaint() ||
-      style.containsLayout())
-    return true;
-
-  if (!style.isOverflowVisible())
-    return true;
-
-  EDisplay display = style.display();
-  if (display == EDisplay::kGrid || display == EDisplay::kFlex ||
-      display == EDisplay::kWebkitBox)
-    return true;
-
-  if (space.WritingMode() != FromPlatformWritingMode(style.getWritingMode()))
-    return true;
-
-  return false;
-}
-
 // Whether we've run out of space in this flow. If so, there will be no work
 // left to do for this block in this fragmentainer.
 bool IsOutOfSpace(const NGConstraintSpace& space, LayoutUnit content_size) {
   return space.HasBlockFragmentation() &&
          content_size >= space.FragmentainerSpaceAvailable();
 }
 
 }  // namespace
 
 NGBlockLayoutAlgorithm::NGBlockLayoutAlgorithm(
@@ skipping 447 matching lines @@
       DCHECK(builder_.BfcOffset());
       space_available -= curr_bfc_offset_.block_offset;
     }
   }
   space_builder_.SetFragmentainerSpaceAvailable(space_available);
 
   return space_builder_.ToConstraintSpace(
       FromPlatformWritingMode(child_style.getWritingMode()));
 }
 }  // namespace blink