[CSS Grid Layout] Replace the usage of pointers to functions

Source/core/layout/LayoutGrid.h

 /*
  * 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 81 matching lines @@
     void placeAutoMajorAxisItemsOnGrid(const Vector<LayoutBox*>&);
     void placeAutoMajorAxisItemOnGrid(LayoutBox&, std::pair<size_t, size_t>& autoPlacementCursor);
     GridTrackSizingDirection autoPlacementMajorAxisDirection() const;
     GridTrackSizingDirection autoPlacementMinorAxisDirection() const;
 
     void layoutGridItems();
     void layoutPositionedObjects(bool relayoutChildren, PositionedLayoutBehavior = DefaultLayout);
     void offsetAndBreadthForPositionedChild(const LayoutBox&, GridTrackSizingDirection, bool startIsAuto, bool endIsAuto, LayoutUnit& offset, LayoutUnit& breadth);
     void populateGridPositions(const GridSizingData&);
 
-    typedef LayoutUnit (LayoutGrid::* SizingFunction)(LayoutBox&, GridTrackSizingDirection, Vector<GridTrack>&);
-    typedef const LayoutUnit& (GridTrack::* AccumulatorGetter)() const;
-    typedef bool (GridTrackSize::* FilterFunction)() const;
+    enum TrackSizeRestriction {
+        AllowInfinity,
+        ForbidInfinity,
+    };
+    enum TrackSizeComputationPhase {
+        ResolveIntrinsicMinimums,
+        ResolveMaxContentMinimums,
+        ResolveIntrinsicMaximums,
+        ResolveMaxContentMaximums,
+        MaximizeTracks,
+    };
+    static const LayoutUnit& trackSizeForTrackSizeComputationPhase(TrackSizeComputationPhase, GridTrack&, TrackSizeRestriction);

[cbiesinger, 2015/04/30 23:33:01]

So the patch looks good except that I don't see any place where you pass in
AllowInfinity here? What am I missing?

[dsinclair, 2015/05/08 15:50:28]

Can GridTrack be const?

[svillar, 2015/05/11 07:11:45]

Acknowledged.

+    static bool shouldProcessTrackForTrackSizeComputationPhase(TrackSizeComputationPhase, const GridTrackSize&);

[dsinclair, 2015/05/08 15:50:27]

These are only called in this class, and don't seem like they use class
knowledge, can they be moved to an anonymous namespace inside the .cpp file?

[svillar, 2015/05/11 07:11:45]

Sure.

+    static bool trackShouldGrowBeyondGrowthLimitsForTrackSizeComputationPhase(TrackSizeComputationPhase, const GridTrackSize&);
+    static void updateTrackSizeForTrackSizeComputationPhase(TrackSizeComputationPhase, GridTrack&);

[dsinclair, 2015/05/08 15:50:28]

Can GridTrack be const?

[svillar, 2015/05/11 07:11:45]

Acknowledged.

     typedef struct GridItemsSpanGroupRange GridItemsSpanGroupRange;
+    LayoutUnit currentItemSizeForTrackSizeComputationPhase(TrackSizeComputationPhase, LayoutBox&, GridTrackSizingDirection, Vector<GridTrack>& columnTracks);
     void resolveContentBasedTrackSizingFunctionsForNonSpanningItems(GridTrackSizingDirection, const GridCoordinate&, LayoutBox& gridItem, GridTrack&, Vector<GridTrack>& columnTracks);
-    void resolveContentBasedTrackSizingFunctionsForItems(GridTrackSizingDirection, GridSizingData&, const GridItemsSpanGroupRange&, FilterFunction, SizingFunction, AccumulatorGetter, AccumulatorGrowFunction, FilterFunction growAboveMaxBreadthFilterFunction = nullptr);
-    void distributeSpaceToTracks(Vector<GridTrack*>&, const Vector<GridTrack*>* growBeyondGrowthLimitsTracks, AccumulatorGetter, GridSizingData&, LayoutUnit& availableLogicalSpace);
+    template <TrackSizeComputationPhase> void resolveContentBasedTrackSizingFunctionsForItems(GridTrackSizingDirection, GridSizingData&, const GridItemsSpanGroupRange&);
+    template <TrackSizeComputationPhase> void distributeSpaceToTracks(Vector<GridTrack*>&, const Vector<GridTrack*>* growBeyondGrowthLimitsTracks, GridSizingData&, LayoutUnit& availableLogicalSpace);

[dsinclair, 2015/05/08 15:50:27]

Why template these and not just pass in TrackSizeComputationPhase as a
parameter?

[svillar, 2015/05/11 07:11:45]

The reason why I used templates is because we always explicitly call them with a
given phase, it isn't that we compute a parameter and pass it to the function. 

They will obviously be equivalent but having a template makes IMO it more
explicit the four phases of the computation.

 
     double computeNormalizedFractionBreadth(Vector<GridTrack>&, const GridSpan& tracksSpan, GridTrackSizingDirection, LayoutUnit availableLogicalSpace) const;
 
     GridTrackSize gridTrackSize(GridTrackSizingDirection, size_t) const;
 
     LayoutUnit logicalHeightForChild(LayoutBox&, Vector<GridTrack>&);
     LayoutUnit minContentForChild(LayoutBox&, GridTrackSizingDirection, Vector<GridTrack>& columnTracks);
     LayoutUnit maxContentForChild(LayoutBox&, GridTrackSizingDirection, Vector<GridTrack>& columnTracks);
     LayoutUnit startOfColumnForChild(const LayoutBox& child) const;
     LayoutUnit endOfColumnForChild(const LayoutBox& child) const;
@@ skipping 52 matching lines @@
     OrderIterator m_orderIterator;
     Vector<LayoutBox*> m_gridItemsOverflowingGridArea;
     HashMap<const LayoutBox*, size_t> m_gridItemsIndexesMap;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutGrid, isLayoutGrid());
 
 } // namespace blink
 
 #endif // LayoutGrid_h