[css-grid] Implementation of Baseline Self-Alignment

third_party/WebKit/Source/core/layout/GridTrackSizingAlgorithm.cpp

 // Copyright 2017 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/GridTrackSizingAlgorithm.h"
 
 #include "core/frame/FrameView.h"
 #include "core/layout/Grid.h"
 #include "core/layout/LayoutGrid.h"
 #include "platform/LengthFunctions.h"
@@ skipping 258 matching lines @@
                                                   LayoutUnit(-1));
     setGridItemNeedsLayout(child);
   }
 
   // We need to clear the stretched height to properly compute logical height
   // during layout.
   if (child.needsLayout())
     child.clearOverrideLogicalContentHeight();
 
   child.layoutIfNeeded();
+  GridAxis baselineAxis =
+      layoutGrid()->isOrthogonalChild(child) ? GridRowAxis : GridColumnAxis;
+  if (layoutGrid()->isBaselineAlignmentForChild(child, baselineAxis) &&
+      layoutGrid()->isBaselineContextComputed(baselineAxis)) {
+    auto& group = layoutGrid()->getBaselineGroupForChild(child, baselineAxis);
+    return group.maxAscent() + group.maxDescent();
+  }
   return child.logicalHeight() + child.marginLogicalHeight();
 }
 
 DISABLE_CFI_PERF
 LayoutUnit GridTrackSizingAlgorithmStrategy::minContentForChild(
     LayoutBox& child) const {
   GridTrackSizingDirection childInlineDirection =
       flowAwareDirectionForChild(layoutGrid(), child, ForColumns);
   if (direction() == childInlineDirection) {
     // If |child| has a relative logical width, we shouldn't let it override its
     // intrinsic width, which is what we are interested in here. Thus we need to
     // set the inline-axis override size to -1 (no possible resolution).
     if (shouldClearOverrideContainingBlockContentSizeForChild(child,
                                                               ForColumns)) {
       setOverrideContainingBlockContentSizeForChild(child, childInlineDirection,
                                                     LayoutUnit(-1));
     }
 
     // FIXME: It's unclear if we should return the intrinsic width or the
     // preferred width.
     // See http://lists.w3.org/Archives/Public/www-style/2013Jan/0245.html
     LayoutUnit marginLogicalWidth =
         child.needsLayout() ? computeMarginLogicalSizeForChild(
                                   InlineDirection, layoutGrid(), child)
                             : child.marginLogicalWidth();
     return child.minPreferredLogicalWidth() + marginLogicalWidth;
   }
 
+  if (direction() == ForColumns &&
+      m_algorithm.m_sizingOperation == IntrinsicSizeComputation) {
+    DCHECK(layoutGrid()->isOrthogonalChild(child));
+    if (layoutGrid()->isBaselineAlignmentForChild(child, GridRowAxis) &&
+        layoutGrid()->isBaselineContextComputed(GridRowAxis)) {
+      auto& group = layoutGrid()->getBaselineGroupForChild(child, GridRowAxis);
+      return group.maxAscent() + group.maxDescent();
+    }
+  }
+
   if (updateOverrideContainingBlockContentSizeForChild(child,
                                                        childInlineDirection))
     setGridItemNeedsLayout(child);
   return logicalHeightForChild(child);
 }
 
 DISABLE_CFI_PERF
 LayoutUnit GridTrackSizingAlgorithmStrategy::maxContentForChild(
     LayoutBox& child) const {
   GridTrackSizingDirection childInlineDirection =
@@ skipping 1106 matching lines @@
   DCHECK(m_algorithm.isValidTransition());
   DCHECK(!m_algorithm.m_needsSetup);
 }
 
 GridTrackSizingAlgorithm::StateMachine::~StateMachine() {
   m_algorithm.advanceNextState();
   m_algorithm.m_needsSetup = true;
 }
 
 }  // namespace blink