[LayoutNG] Inline margin/border/padding, inter-item breaking, and tests

third_party/WebKit/Source/core/layout/ng/ng_length_utils.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_length_utils.h"
 
 #include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_constraint_space_builder.h"
 #include "core/layout/ng/ng_fragment.h"
 #include "core/style/ComputedStyle.h"
@@ skipping 378 matching lines @@
       LengthResolveType::kMarginBorderPaddingSize);
   padding.block_start = ResolveInlineLength(
       constraint_space, style, empty_sizes, style.PaddingBefore(),
       LengthResolveType::kMarginBorderPaddingSize);
   padding.block_end = ResolveInlineLength(
       constraint_space, style, empty_sizes, style.PaddingAfter(),
       LengthResolveType::kMarginBorderPaddingSize);
   return padding;
 }
 
+LayoutUnit ComputeMarginBorderPaddingInlineStart(

[cbiesinger, 2017/05/22 19:02:58]

I'd rather not add functions like these; why not use:

  (ComputeMargins() + ComputeBorders() + ComputePadding()).inline_start?

NGBoxStrut has an operator+ for that specific purpose.

[kojii, 2017/05/22 19:22:42]

It computes 4 values and discard 3 out of that. I'm ok to add 6 functions
(margin/border/padding * start/end) and the caller to sum them. Is that better?

Or is computing unnecessary 3 values ok?

[kojii, 2017/05/22 19:26:31]

BTW, you might know but in case, the legacy has MarginBorderPaddingLogicalLeft()
etc. for inline, because when inline, inline direction and block direction are
used in different phases.
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/layout/li...

+    const NGConstraintSpace& constraint_space,
+    const ComputedStyle& style) {
+  MinMaxContentSize empty_sizes;
+  return ResolveInlineLength(constraint_space, style, empty_sizes,
+                             style.MarginStart(),
+                             LengthResolveType::kMarginBorderPaddingSize) +
+         LayoutUnit(style.BorderStartWidth()) +
+         ResolveInlineLength(constraint_space, style, empty_sizes,
+                             style.PaddingStart(),
+                             LengthResolveType::kMarginBorderPaddingSize);
+}
+
+LayoutUnit ComputeMarginBorderPaddingInlineEnd(
+    const NGConstraintSpace& constraint_space,
+    const ComputedStyle& style) {
+  MinMaxContentSize empty_sizes;
+  return ResolveInlineLength(constraint_space, style, empty_sizes,
+                             style.MarginEnd(),
+                             LengthResolveType::kMarginBorderPaddingSize) +
+         LayoutUnit(style.BorderEndWidth()) +
+         ResolveInlineLength(constraint_space, style, empty_sizes,
+                             style.PaddingEnd(),
+                             LengthResolveType::kMarginBorderPaddingSize);
+}
+
 void ApplyAutoMargins(const NGConstraintSpace& constraint_space,
                       const ComputedStyle& style,
                       const LayoutUnit& inline_size,
                       NGBoxStrut* margins) {
   DCHECK(margins) << "Margins cannot be NULL here";
   const LayoutUnit used_space = inline_size + margins->InlineSum();
   const LayoutUnit available_space =
       constraint_space.AvailableSize().inline_size - used_space;
   if (available_space < LayoutUnit())
     return;
@@ skipping 11 matching lines @@
                              Optional<LayoutUnit> min,
                              Optional<LayoutUnit> max) {
   if (max && length > max.value())
     length = max.value();
   if (min && length < min.value())
     length = min.value();
   return length;
 }
 
 }  // namespace blink