[css-grid] Computing free space on indefinite sized grids

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

 /*
  * Copyright (C) 2011 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 517 matching lines @@
     if (cachedHasDefiniteLogicalHeight()) {
       computeTrackSizesForDefiniteSize(
           ForRows, sizingData,
           availableLogicalHeight(ExcludeMarginBorderPadding));
     } else {
       computeTrackSizesForIndefiniteSize(
           ForRows, sizingData, m_minContentHeight, m_maxContentHeight);
       sizingData.nextState();
       sizingData.sizingOperation = TrackSizing;
     }
-    setLogicalHeight(computeTrackBasedLogicalHeight(sizingData) +
-                     borderAndPaddingLogicalHeight() +
-                     scrollbarLogicalHeight());
+    LayoutUnit trackBasedLogicalHeight =
+        computeTrackBasedLogicalHeight(sizingData) +
+        borderAndPaddingLogicalHeight() + scrollbarLogicalHeight();
+    setLogicalHeight(trackBasedLogicalHeight);
 
     LayoutUnit oldClientAfterEdge = clientLogicalBottom();
     updateLogicalHeight();
 
+    // Once grid's indefinite height is resolved, we can compute the
+    // available free space for Content Alignment.
+    if (!cachedHasDefiniteLogicalHeight())
+      sizingData.freeSpace(ForRows) = logicalHeight() - trackBasedLogicalHeight;
+
     // 3- If the min-content contribution of any grid items have changed based
     // on the row sizes calculated in step 2, steps 1 and 2 are repeated with
     // the new min-content contribution (once only).
     repeatTracksSizingIfNeeded(sizingData, availableSpaceForColumns,
                                contentLogicalHeight());
 
     // Grid container should have the minimum height of a line if it's editable.
     // That doesn't affect track sizing though.
     if (hasLineIfEmpty())
       setLogicalHeight(
@@ skipping 2665 matching lines @@
   // If <content-distribution> value can't be applied, 'position' will become
   // the associated <content-position> fallback value.
   ContentAlignmentData contentAlignment = contentDistributionOffset(
       availableFreeSpace, position, distribution, numberOfGridTracks);
   if (contentAlignment.isValid())
     return contentAlignment;
 
   OverflowAlignment overflow =
       isRowAxis ? styleRef().justifyContentOverflowAlignment()
                 : styleRef().alignContentOverflowAlignment();
-  if (availableFreeSpace <= 0 && overflow == OverflowAlignmentSafe)
+  // TODO (lajava): Default value for overflow isn't exaclty as 'unsafe'.
+  // https://drafts.csswg.org/css-align/#overflow-values
+  if (availableFreeSpace == 0 ||
+      (availableFreeSpace < 0 && overflow == OverflowAlignmentSafe))
     return {LayoutUnit(), LayoutUnit()};
 
   switch (position) {
     case ContentPositionLeft:
       // The align-content's axis is always orthogonal to the inline-axis.
       return {LayoutUnit(), LayoutUnit()};
     case ContentPositionRight:
       if (isRowAxis)
         return {availableFreeSpace, LayoutUnit()};
       // The align-content's axis is always orthogonal to the inline-axis.
@@ skipping 82 matching lines @@
   if (!m_gridItemArea.isEmpty())
     GridPainter(*this).paintChildren(paintInfo, paintOffset);
 }
 
 bool LayoutGrid::cachedHasDefiniteLogicalHeight() const {
   SECURITY_DCHECK(m_hasDefiniteLogicalHeight);
   return m_hasDefiniteLogicalHeight.value();
 }
 
 }  // namespace blink