[CSS Grid Layout] Handle percentages of indefinite sizes in minmax()

Source/core/rendering/RenderGrid.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 406 matching lines @@
 
 void RenderGrid::computeUsedBreadthOfGridTracks(GridTrackSizingDirection direction, GridSizingData& sizingData, LayoutUnit& availableLogicalSpace)
 {
     Vector<GridTrack>& tracks = (direction == ForColumns) ? sizingData.columnTracks : sizingData.rowTracks;
     Vector<size_t> flexibleSizedTracksIndex;
     sizingData.contentSizedTracksIndex.shrink(0);
 
     // 1. Initialize per Grid track variables.
     for (size_t i = 0; i < tracks.size(); ++i) {
         GridTrack& track = tracks[i];
-        const GridTrackSize& trackSize = gridTrackSize(direction, i);
+        GridTrackSize trackSize = gridTrackSize(direction, i);
         const GridLength& minTrackBreadth = trackSize.minTrackBreadth();
         const GridLength& maxTrackBreadth = trackSize.maxTrackBreadth();
 
         track.m_usedBreadth = computeUsedBreadthOfMinLength(direction, minTrackBreadth);
         track.m_maxBreadth = computeUsedBreadthOfMaxLength(direction, maxTrackBreadth, track.m_usedBreadth);
 
         if (track.m_maxBreadth != infinity)
             track.m_maxBreadth = std::max(track.m_maxBreadth, track.m_usedBreadth);
 
         if (trackSize.isContentSized())
@@ skipping 33 matching lines @@
     if (flexibleSizedTracksIndex.isEmpty())
         return;
 
     // 4. Grow all Grid tracks having a fraction as the MaxTrackSizingFunction.
     double normalizedFractionBreadth = 0;
     if (!hasUndefinedRemainingSpace) {
         normalizedFractionBreadth = computeNormalizedFractionBreadth(tracks, GridSpan(0, tracks.size() - 1), direction, availableLogicalSpace);
     } else {
         for (size_t i = 0; i < flexibleSizedTracksIndex.size(); ++i) {
             const size_t trackIndex = flexibleSizedTracksIndex[i];
-            const GridTrackSize& trackSize = gridTrackSize(direction, trackIndex);
+            GridTrackSize trackSize = gridTrackSize(direction, trackIndex);
             normalizedFractionBreadth = std::max(normalizedFractionBreadth, tracks[trackIndex].m_usedBreadth / trackSize.maxTrackBreadth().flex());
         }
 
         for (size_t i = 0; i < flexibleSizedTracksIndex.size(); ++i) {
             GridIterator iterator(m_grid, direction, flexibleSizedTracksIndex[i]);
             while (RenderBox* gridItem = iterator.nextGridItem()) {
                 const GridCoordinate coordinate = cachedGridCoordinate(*gridItem);
                 const GridSpan span = (direction == ForColumns) ? coordinate.columns : coordinate.rows;
 
                 // Do not include already processed items.
                 if (i > 0 && span.resolvedInitialPosition.toInt() <= flexibleSizedTracksIndex[i - 1])
                     continue;
 
                 double itemNormalizedFlexBreadth = computeNormalizedFractionBreadth(tracks, span, direction, maxContentForChild(*gridItem, direction, sizingData.columnTracks));
                 normalizedFractionBreadth = std::max(normalizedFractionBreadth, itemNormalizedFlexBreadth);
             }
         }
     }
 
     for (size_t i = 0; i < flexibleSizedTracksIndex.size(); ++i) {
         const size_t trackIndex = flexibleSizedTracksIndex[i];
-        const GridTrackSize& trackSize = gridTrackSize(direction, trackIndex);
+        GridTrackSize trackSize = gridTrackSize(direction, trackIndex);
 
         tracks[trackIndex].m_usedBreadth = std::max<LayoutUnit>(tracks[trackIndex].m_usedBreadth, normalizedFractionBreadth * trackSize.maxTrackBreadth().flex());
     }
 }
 
 LayoutUnit RenderGrid::computeUsedBreadthOfMinLength(GridTrackSizingDirection direction, const GridLength& gridLength) const
 {
     if (gridLength.isFlex())
         return 0;
 
@@ skipping 34 matching lines @@
 {
     return track1.m_normalizedFlexValue < track2.m_normalizedFlexValue;
 }
 
 double RenderGrid::computeNormalizedFractionBreadth(Vector<GridTrack>& tracks, const GridSpan& tracksSpan, GridTrackSizingDirection direction, LayoutUnit availableLogicalSpace) const
 {
     // |availableLogicalSpace| already accounts for the used breadths so no need to remove it here.
 
     Vector<GridTrackForNormalization> tracksForNormalization;
     for (GridSpan::iterator resolvedPosition = tracksSpan.begin(); resolvedPosition != tracksSpan.end(); ++resolvedPosition) {
-        const GridTrackSize& trackSize = gridTrackSize(direction, resolvedPosition.toInt());
+        GridTrackSize trackSize = gridTrackSize(direction, resolvedPosition.toInt());
         if (!trackSize.maxTrackBreadth().isFlex())
             continue;
 
         tracksForNormalization.append(GridTrackForNormalization(tracks[resolvedPosition.toInt()], trackSize.maxTrackBreadth().flex()));
     }
 
     // The function is not called if we don't have <flex> grid tracks
     ASSERT(!tracksForNormalization.isEmpty());
 
     std::sort(tracksForNormalization.begin(), tracksForNormalization.end(), sortByGridNormalizedFlexValue);
@@ skipping 17 matching lines @@
         }
 
         accumulatedFractions += track.m_flex;
         // This item was processed so we re-add its used breadth to the available space to accurately count the remaining space.
         availableLogicalSpaceIgnoringFractionTracks += track.m_track->m_usedBreadth;
     }
 
     return availableLogicalSpaceIgnoringFractionTracks / accumulatedFractions;
 }
 
-const GridTrackSize& RenderGrid::gridTrackSize(GridTrackSizingDirection direction, size_t i) const
+GridTrackSize RenderGrid::gridTrackSize(GridTrackSizingDirection direction, size_t i) const
 {
-    const Vector<GridTrackSize>& trackStyles = (direction == ForColumns) ? style()->gridTemplateColumns() : style()->gridTemplateRows();
-    if (i >= trackStyles.size())
-        return (direction == ForColumns) ? style()->gridAutoColumns() : style()->gridAutoRows();
+    bool isForColumns = direction == ForColumns;
+    const Vector<GridTrackSize>& trackStyles = isForColumns ? style()->gridTemplateColumns() : style()->gridTemplateRows();
+    const GridTrackSize& trackSize = (i >= trackStyles.size()) ? (isForColumns ? style()->gridAutoColumns() : style()->gridAutoRows()) : trackStyles[i];
 
-    const GridTrackSize& trackSize = trackStyles[i];
-    // If the logical width/height of the grid container is indefinite, percentage values are treated as <auto>.
-    if (trackSize.isPercentage()) {
-        Length logicalSize = direction == ForColumns ? style()->logicalWidth() : style()->logicalHeight();
-        if (logicalSize.isIntrinsicOrAuto()) {
-            DEFINE_STATIC_LOCAL(GridTrackSize, autoTrackSize, (Length(Auto)));
-            return autoTrackSize;
-        }
+    // If the logical width/height of the grid container is indefinite, percentage values are treated as <auto> (or in
+    // the case of minmax() as min-content for the first position and max-content for the second).
+    Length logicalSize = isForColumns ? style()->logicalWidth() : style()->logicalHeight();
+    // FIXME: isIntrinsicOrAuto() does not fulfil the 'indefinite size' description as it does not include <percentage>
+    // of indefinite sizes. This is a broather issue as Length does not have the required context to support it.
+    if (logicalSize.isIntrinsicOrAuto()) {
+        const GridLength& oldMinTrackBreadth = trackSize.minTrackBreadth();
+        const GridLength& oldMaxTrackBreadth = trackSize.maxTrackBreadth();
+        return GridTrackSize(oldMinTrackBreadth.isPercentage() ? Length(MinContent) : oldMinTrackBreadth, oldMaxTrackBreadth.isPercentage() ? Length(MaxContent) : oldMaxTrackBreadth);
     }
 
     return trackSize;
 }
 
 LayoutUnit RenderGrid::logicalHeightForChild(RenderBox& child, Vector<GridTrack>& columnTracks)
 {
     SubtreeLayoutScope layoutScope(child);
     LayoutUnit oldOverrideContainingBlockContentLogicalWidth = child.hasOverrideContainingBlockLogicalWidth() ? child.overrideContainingBlockContentLogicalWidth() : LayoutUnit();
     LayoutUnit overrideContainingBlockContentLogicalWidth = gridAreaBreadthForChild(child, ForColumns, columnTracks);
@@ skipping 94 matching lines @@
 }
 
 void RenderGrid::resolveContentBasedTrackSizingFunctionsForItems(GridTrackSizingDirection direction, GridSizingData& sizingData, RenderBox& gridItem, FilterFunction filterFunction, SizingFunction sizingFunction, AccumulatorGetter trackGetter, AccumulatorGrowFunction trackGrowthFunction)
 {
     const GridCoordinate coordinate = cachedGridCoordinate(gridItem);
     const GridResolvedPosition initialTrackPosition = (direction == ForColumns) ? coordinate.columns.resolvedInitialPosition : coordinate.rows.resolvedInitialPosition;
     const GridResolvedPosition finalTrackPosition = (direction == ForColumns) ? coordinate.columns.resolvedFinalPosition : coordinate.rows.resolvedFinalPosition;
 
     sizingData.filteredTracks.shrink(0);
     for (GridResolvedPosition trackPosition = initialTrackPosition; trackPosition <= finalTrackPosition; ++trackPosition) {
-        const GridTrackSize& trackSize = gridTrackSize(direction, trackPosition.toInt());
+        GridTrackSize trackSize = gridTrackSize(direction, trackPosition.toInt());
         if (!(trackSize.*filterFunction)())
             continue;
 
         GridTrack& track = (direction == ForColumns) ? sizingData.columnTracks[trackPosition.toInt()] : sizingData.rowTracks[trackPosition.toInt()];
         sizingData.filteredTracks.append(&track);
     }
 
     if (sizingData.filteredTracks.isEmpty())
         return;
 
@@ skipping 59 matching lines @@
         LayoutUnit growth = sizingData.distributeTrackVector[i] - (tracks[i]->*trackGetter)();
         if (growth >= 0)
             (tracks[i]->*trackGrowthFunction)(growth);
     }
 }
 
 #if ENABLE(ASSERT)
 bool RenderGrid::tracksAreWiderThanMinTrackBreadth(GridTrackSizingDirection direction, const Vector<GridTrack>& tracks)
 {
     for (size_t i = 0; i < tracks.size(); ++i) {
-        const GridTrackSize& trackSize = gridTrackSize(direction, i);
+        GridTrackSize trackSize = gridTrackSize(direction, i);
         const GridLength& minTrackBreadth = trackSize.minTrackBreadth();
         if (computeUsedBreadthOfMinLength(direction, minTrackBreadth) > tracks[i].m_usedBreadth)
             return false;
     }
     return true;
 }
 #endif
 
 void RenderGrid::ensureGridSize(size_t maximumRowIndex, size_t maximumColumnIndex)
 {
@@ skipping 639 matching lines @@
     if (isOutOfFlowPositioned())
         return "RenderGrid (positioned)";
     if (isAnonymous())
         return "RenderGrid (generated)";
     if (isRelPositioned())
         return "RenderGrid (relative positioned)";
     return "RenderGrid";
 }
 
 } // namespace blink