[css-flexbox] Implementing new CSS Box Alignment values

Source/core/layout/LayoutFlexibleBox.cpp

Index: Source/core/layout/LayoutFlexibleBox.cpp
diff --git a/Source/core/layout/LayoutFlexibleBox.cpp b/Source/core/layout/LayoutFlexibleBox.cpp
index 0a676c9316df5f2186bf503278dda462b71ce7a6..f0977885e5615063f700b0c17b16b8c5a1fec265 100644
--- a/Source/core/layout/LayoutFlexibleBox.cpp
+++ b/Source/core/layout/LayoutFlexibleBox.cpp
@@ -1348,15 +1348,35 @@ void LayoutFlexibleBox::alignChildren(const Vector<LineContext>& lineContexts)
                     minMarginAfterBaseline = std::min(minMarginAfterBaseline, availableAlignmentSpaceForChild(lineCrossAxisExtent, *child) - startOffset);
                 break;
             }
-            case ItemPositionLastBaseline:
-            case ItemPositionSelfStart:
-            case ItemPositionSelfEnd:
-            case ItemPositionStart:
-            case ItemPositionEnd:
+            case ItemPositionSelfStart: {
+                bool hasSameCrossStartEdges = hasOrthogonalFlow(*child) ? child->styleRef().isLeftToRightDirection() == styleRef().isLeftToRightDirection() : child->styleRef().isFlippedBlocksWritingMode() == styleRef().isFlippedBlocksWritingMode();
+                if (!hasSameCrossStartEdges)
+                    adjustAlignmentForChild(*child, availableAlignmentSpaceForChild(lineCrossAxisExtent, *child));
+                break;
+            }
+            case ItemPositionSelfEnd: {
+                bool hasSameCrossStartEdges = hasOrthogonalFlow(*child) ? child->styleRef().isLeftToRightDirection() == styleRef().isLeftToRightDirection() : child->styleRef().isFlippedBlocksWritingMode() == styleRef().isFlippedBlocksWritingMode();
+                if (hasSameCrossStartEdges)
+                    adjustAlignmentForChild(*child, availableAlignmentSpaceForChild(lineCrossAxisExtent, *child));
+                break;
+            }
             case ItemPositionLeft:
+                // Cross-axis is only parallel to container's inline-axis when column-flow is used.
+                if (isColumnFlow() && !style()->isLeftToRightDirection())
+                    adjustAlignmentForChild(*child, availableAlignmentSpaceForChild(lineCrossAxisExtent, *child));
+                break;
             case ItemPositionRight:
-                // FIXME: File a bug about implementing that. The extended grammar
-                // is not enabled by default so we shouldn't hit this codepath.
+                // Cross-axis is only parallel to container's inline-axis when column-flow is used.
+                if (isColumnFlow() && style()->isLeftToRightDirection())
+                    adjustAlignmentForChild(*child, availableAlignmentSpaceForChild(lineCrossAxisExtent, *child));
+                break;
+            case ItemPositionStart:

[cbiesinger, 2015/08/11 23:04:58]

Ah, you're right about start vs flex-start, thanks for the explanation!

But in that case, to make it clearer what's happening, please move this up to
the case for flex start and add a comment, e.g.:

  case ItemPositionStart:
  case ItemPositionFlexStart:
      // We treat flex-start the same as start because alignmentForChild fixed
it up appropriately
      break;

Similar for end.

+                break;
+            case ItemPositionEnd:
+                adjustAlignmentForChild(*child, availableAlignmentSpaceForChild(lineCrossAxisExtent, *child));
+                break;
+            case ItemPositionLastBaseline: // TODO (lajava): This feature is at-risk of being dropped during the CR period.
+            default:
                 ASSERT_NOT_REACHED();
                 break;
             }