[css-flexbox] Implementing new CSS Box Alignment values

Source/core/layout/LayoutFlexibleBox.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1330 matching lines @@
                 // FIXME: If we get here in columns, we want the use the descent, except we currently can't get the ascent/descent of orthogonal children.
                 // https://bugs.webkit.org/show_bug.cgi?id=98076
                 LayoutUnit ascent = marginBoxAscentForChild(*child);
                 LayoutUnit startOffset = maxAscent - ascent;
                 adjustAlignmentForChild(*child, startOffset);
 
                 if (style()->flexWrap() == FlexWrapReverse)
                     minMarginAfterBaseline = std::min(minMarginAfterBaseline, availableAlignmentSpaceForChild(lineCrossAxisExtent, *child) - startOffset);
                 break;
             }
-            case ItemPositionLastBaseline:
-            case ItemPositionSelfStart:
-            case ItemPositionSelfEnd:
+            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:
+                // 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:
-            case ItemPositionLeft:
-            case ItemPositionRight:
-                // FIXME: File a bug about implementing that. The extended grammar
-                // is not enabled by default so we shouldn't hit this codepath.
+                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;
             }
         }
         minMarginAfterBaselines.append(minMarginAfterBaseline);
     }
 
     if (style()->flexWrap() != FlexWrapReverse)
         return;
 
@@ skipping 74 matching lines @@
             ASSERT(child);
             LayoutUnit lineCrossAxisExtent = lineContexts[lineNumber].crossAxisExtent;
             LayoutUnit originalOffset = lineContexts[lineNumber].crossAxisOffset - crossAxisStartEdge;
             LayoutUnit newOffset = contentExtent - originalOffset - lineCrossAxisExtent;
             adjustAlignmentForChild(*child, newOffset - originalOffset);
         }
     }
 }
 
 }