[css-align] New CSS Value 'normal' for Content Alignment

third_party/WebKit/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 163 matching lines @@
 int LayoutFlexibleBox::baselinePosition(FontBaseline, bool, LineDirectionMode direction, LinePositionMode mode) const
 {
     ASSERT(mode == PositionOnContainingLine);
     int baseline = firstLineBoxBaseline();
     if (baseline == -1)
         baseline = synthesizedBaselineFromContentBox(*this, direction);
 
     return beforeMarginInLineDirection(direction) + baseline;
 }
 
+static const StyleContentAlignmentData& normalValueBehavior()
+{
+    // The justify-content property applies along the main axis, but since flexing
+    // in the main axis is controlled by flex, stretch behaves as flex-start (ignoring
+    // the specified fallback alignment, if any).
+    // https://drafts.csswg.org/css-align/#distribution-flex
+    static const StyleContentAlignmentData normalBehavior = {ContentPositionNormal, ContentDistributionStretch};
+    return normalBehavior;
+}
+
 int LayoutFlexibleBox::firstLineBoxBaseline() const
 {
     if (isWritingModeRoot() || m_numberOfInFlowChildrenOnFirstLine <= 0)
         return -1;
     LayoutBox* baselineChild = nullptr;
     int childNumber = 0;
     for (LayoutBox* child = m_orderIterator.first(); child; child = m_orderIterator.next()) {
         if (child->isOutOfFlowPositioned())
             continue;
         if (alignmentForChild(*child) == ItemPositionBaseline && !hasAutoMarginsInCrossAxis(*child)) {
@@ skipping 1101 matching lines @@
 {
     if (isHorizontalFlow())
         return child.styleRef().overflowY();
     return child.styleRef().overflowX();
 }
 
 void LayoutFlexibleBox::layoutAndPlaceChildren(LayoutUnit& crossAxisOffset, const OrderedFlexItemList& children, const Vector<LayoutUnit, 16>& childSizes, LayoutUnit availableFreeSpace, bool relayoutChildren, SubtreeLayoutScope& layoutScope, Vector<LineContext>& lineContexts)
 {
     ASSERT(childSizes.size() == children.size());
 
+    ContentPosition position = styleRef().resolvedJustifyContentPosition(normalValueBehavior());
+    ContentDistributionType distribution = styleRef().resolvedJustifyContentDistribution(normalValueBehavior());
+
     size_t numberOfChildrenForJustifyContent = numberOfInFlowPositionedChildren(children);
     LayoutUnit autoMarginOffset = autoMarginOffsetInMainAxis(children, availableFreeSpace);
     LayoutUnit mainAxisOffset = flowAwareBorderStart() + flowAwarePaddingStart();
-    mainAxisOffset += initialJustifyContentOffset(availableFreeSpace, style()->justifyContentPosition(), style()->justifyContentDistribution(), numberOfChildrenForJustifyContent);
+    mainAxisOffset += initialJustifyContentOffset(availableFreeSpace, position, distribution, numberOfChildrenForJustifyContent);
     if (style()->flexDirection() == FlowRowReverse)
         mainAxisOffset += isHorizontalFlow() ? verticalScrollbarWidth() : horizontalScrollbarHeight();
 
     LayoutUnit totalMainExtent = mainAxisExtent();
     LayoutUnit maxAscent, maxDescent; // Used when align-items: baseline.
     LayoutUnit maxChildCrossAxisExtent;
     size_t seenInFlowPositionedChildren = 0;
     bool shouldFlipMainAxis = !isColumnFlow() && !isLeftToRightFlow();
     for (size_t i = 0; i < children.size(); ++i) {
         LayoutBox* child = children[i];
@@ skipping 46 matching lines @@
         // In an RTL column situation, this will apply the margin-right/margin-end on the left.
         // This will be fixed later in flipForRightToLeftColumn.
         LayoutPoint childLocation(shouldFlipMainAxis ? totalMainExtent - mainAxisOffset - childMainExtent : mainAxisOffset,
             crossAxisOffset + flowAwareMarginBeforeForChild(*child));
 
         setFlowAwareLocationForChild(*child, childLocation);
         mainAxisOffset += childMainExtent + flowAwareMarginEndForChild(*child);
 
         ++seenInFlowPositionedChildren;
         if (seenInFlowPositionedChildren < numberOfChildrenForJustifyContent)
-            mainAxisOffset += justifyContentSpaceBetweenChildren(availableFreeSpace, style()->justifyContentDistribution(), numberOfChildrenForJustifyContent);
+            mainAxisOffset += justifyContentSpaceBetweenChildren(availableFreeSpace, distribution, numberOfChildrenForJustifyContent);
     }
 
     if (isColumnFlow())
         setLogicalHeight(std::max(logicalHeight(), mainAxisOffset + flowAwareBorderEnd() + flowAwarePaddingEnd() + scrollbarLogicalHeight()));
 
     if (style()->flexDirection() == FlowColumnReverse) {
         // We have to do an extra pass for column-reverse to reposition the flex items since the start depends
         // on the height of the flexbox, which we only know after we've positioned all the flex items.
         updateLogicalHeight();
         layoutColumnReverse(children, crossAxisOffset, availableFreeSpace);
     }
 
     if (m_numberOfInFlowChildrenOnFirstLine == -1)
         m_numberOfInFlowChildrenOnFirstLine = seenInFlowPositionedChildren;
     lineContexts.append(LineContext(crossAxisOffset, maxChildCrossAxisExtent, children.size(), maxAscent));
     crossAxisOffset += maxChildCrossAxisExtent;
 }
 
 void LayoutFlexibleBox::layoutColumnReverse(const OrderedFlexItemList& children, LayoutUnit crossAxisOffset, LayoutUnit availableFreeSpace)
 {
+    ContentPosition position = styleRef().resolvedJustifyContentPosition(normalValueBehavior());
+    ContentDistributionType distribution = styleRef().resolvedJustifyContentDistribution(normalValueBehavior());
+
     // This is similar to the logic in layoutAndPlaceChildren, except we place the children
     // starting from the end of the flexbox. We also don't need to layout anything since we're
     // just moving the children to a new position.
     size_t numberOfChildrenForJustifyContent = numberOfInFlowPositionedChildren(children);
     LayoutUnit mainAxisOffset = logicalHeight() - flowAwareBorderEnd() - flowAwarePaddingEnd();
-    mainAxisOffset -= initialJustifyContentOffset(availableFreeSpace, style()->justifyContentPosition(), style()->justifyContentDistribution(), numberOfChildrenForJustifyContent);
+    mainAxisOffset -= initialJustifyContentOffset(availableFreeSpace, position, distribution, numberOfChildrenForJustifyContent);
     mainAxisOffset -= isHorizontalFlow() ? verticalScrollbarWidth() : horizontalScrollbarHeight();
 
     size_t seenInFlowPositionedChildren = 0;
     for (size_t i = 0; i < children.size(); ++i) {
         LayoutBox* child = children[i];
 
         if (child->isOutOfFlowPositioned()) {
             child->layer()->setStaticBlockPosition(mainAxisOffset);
             continue;
         }
         mainAxisOffset -= mainAxisExtentForChild(*child) + flowAwareMarginEndForChild(*child);
 
         setFlowAwareLocationForChild(*child, LayoutPoint(mainAxisOffset, crossAxisOffset + flowAwareMarginBeforeForChild(*child)));
 
         mainAxisOffset -= flowAwareMarginStartForChild(*child);
 
         ++seenInFlowPositionedChildren;
         if (seenInFlowPositionedChildren < numberOfChildrenForJustifyContent)
-            mainAxisOffset -= justifyContentSpaceBetweenChildren(availableFreeSpace, style()->justifyContentDistribution(), numberOfChildrenForJustifyContent);
+            mainAxisOffset -= justifyContentSpaceBetweenChildren(availableFreeSpace, distribution, numberOfChildrenForJustifyContent);
     }
 }
 
 static LayoutUnit initialAlignContentOffset(LayoutUnit availableFreeSpace, ContentPosition alignContent, ContentDistributionType alignContentDistribution, unsigned numberOfLines)
 {
     if (numberOfLines <= 1)
         return LayoutUnit();
     if (alignContent == ContentPositionFlexEnd)
         return availableFreeSpace;
     if (alignContent == ContentPositionCenter)
@@ skipping 13 matching lines @@
         if (alignContentDistribution == ContentDistributionSpaceBetween)
             return availableFreeSpace / (numberOfLines - 1);
         if (alignContentDistribution == ContentDistributionSpaceAround || alignContentDistribution == ContentDistributionStretch)
             return availableFreeSpace / numberOfLines;
     }
     return LayoutUnit();
 }
 
 void LayoutFlexibleBox::alignFlexLines(Vector<LineContext>& lineContexts)
 {
+    ContentPosition position = styleRef().resolvedAlignContentPosition(normalValueBehavior());
+    ContentDistributionType distribution = styleRef().resolvedAlignContentDistribution(normalValueBehavior());
+
     // If we have a single line flexbox or a multiline line flexbox with only one flex line,
     // the line height is all the available space.
     // For flex-direction: row, this means we need to use the height, so we do this after calling updateLogicalHeight.
     if (lineContexts.size() == 1) {
         lineContexts[0].crossAxisExtent = crossAxisContentExtent();
         return;
     }
 
-    if (style()->alignContentPosition() == ContentPositionFlexStart)
+    if (position == ContentPositionFlexStart)
         return;
 
     LayoutUnit availableCrossAxisSpace = crossAxisContentExtent();
     for (size_t i = 0; i < lineContexts.size(); ++i)
         availableCrossAxisSpace -= lineContexts[i].crossAxisExtent;
 
     LayoutBox* child = m_orderIterator.first();
-    LayoutUnit lineOffset = initialAlignContentOffset(availableCrossAxisSpace, style()->alignContentPosition(), style()->alignContentDistribution(), lineContexts.size());
+    LayoutUnit lineOffset = initialAlignContentOffset(availableCrossAxisSpace, position, distribution, lineContexts.size());
     for (unsigned lineNumber = 0; lineNumber < lineContexts.size(); ++lineNumber) {
         lineContexts[lineNumber].crossAxisOffset += lineOffset;
         for (size_t childNumber = 0; childNumber < lineContexts[lineNumber].numberOfChildren; ++childNumber, child = m_orderIterator.next())
             adjustAlignmentForChild(*child, lineOffset);
 
-        if (style()->alignContentDistribution() == ContentDistributionStretch && availableCrossAxisSpace > 0)
+        if (distribution == ContentDistributionStretch && availableCrossAxisSpace > 0)
             lineContexts[lineNumber].crossAxisExtent += availableCrossAxisSpace / static_cast<unsigned>(lineContexts.size());
 
-        lineOffset += alignContentSpaceBetweenChildren(availableCrossAxisSpace, style()->alignContentDistribution(), lineContexts.size());
+        lineOffset += alignContentSpaceBetweenChildren(availableCrossAxisSpace, distribution, lineContexts.size());
     }
 }
 
 void LayoutFlexibleBox::adjustAlignmentForChild(LayoutBox& child, LayoutUnit delta)
 {
     if (child.isOutOfFlowPositioned()) {
         LayoutUnit staticInlinePosition = child.layer()->staticInlinePosition();
         LayoutUnit staticBlockPosition = child.layer()->staticBlockPosition();
         LayoutUnit mainAxis = isColumnFlow() ? staticBlockPosition : staticInlinePosition;
         LayoutUnit crossAxis = isColumnFlow() ? staticInlinePosition : staticBlockPosition;
@@ skipping 147 matching lines @@
             ASSERT(child);
             LayoutUnit lineCrossAxisExtent = lineContexts[lineNumber].crossAxisExtent;
             LayoutUnit originalOffset = lineContexts[lineNumber].crossAxisOffset - crossAxisStartEdge;
             LayoutUnit newOffset = contentExtent - originalOffset - lineCrossAxisExtent;
             adjustAlignmentForChild(*child, newOffset - originalOffset);
         }
     }
 }
 
 } // namespace blink