src/third_party/WebKit/Source/core/rendering/style/GridCoordinate.h

   1 /*
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   3  *
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   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
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   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
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  16  * this software without specific prior written permission.
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  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #ifndef GridCoordinate_h
  32 #define GridCoordinate_h
  33
  34 #include "core/rendering/style/GridResolvedPosition.h"
  35 #include "wtf/HashMap.h"
  36 #include "wtf/PassOwnPtr.h"
  37 #include "wtf/text/WTFString.h"
  38
  39 namespace blink {
  40
  41 // A span in a single direction (either rows or columns). Note that |resolvedInitialPosition|
  42 // and |resolvedFinalPosition| are grid areas' indexes, NOT grid lines'. Iterating over the
  43 // span should include both |resolvedInitialPosition| and |resolvedFinalPosition| to be correct.
  44 struct GridSpan {
  45     static PassOwnPtr<GridSpan> create(const GridResolvedPosition& resolvedInitialPosition, const GridResolvedPosition& resolvedFinalPosition)
  46     {
  47         return adoptPtr(new GridSpan(resolvedInitialPosition, resolvedFinalPosition));
  48     }
  49
  50     static PassOwnPtr<GridSpan> createWithSpanAgainstOpposite(const GridResolvedPosition& resolvedOppositePosition, const GridPosition& position, GridPositionSide side)
  51     {
  52         // 'span 1' is contained inside a single grid track regardless of the direction.
  53         // That's why the CSS span value is one more than the offset we apply.
  54         size_t positionOffset = position.spanPosition() - 1;
  55         if (side == ColumnStartSide || side == RowStartSide) {
  56             GridResolvedPosition initialResolvedPosition = GridResolvedPosition(std::max<int>(0, resolvedOppositePosition.toInt() - positionOffset));
  57             return GridSpan::create(initialResolvedPosition, resolvedOppositePosition);
  58         }
  59
  60         return GridSpan::create(resolvedOppositePosition, GridResolvedPosition(resolvedOppositePosition.toInt() + positionOffset));
  61     }
  62
  63     static PassOwnPtr<GridSpan> createWithNamedSpanAgainstOpposite(const GridResolvedPosition& resolvedOppositePosition, const GridPosition& position, GridPositionSide side, const Vector<size_t>& gridLines)
  64     {
  65         if (side == RowStartSide || side == ColumnStartSide)
  66             return createWithInitialNamedSpanAgainstOpposite(resolvedOppositePosition, position, gridLines);
  67
  68         return createWithFinalNamedSpanAgainstOpposite(resolvedOppositePosition, position, gridLines);
  69     }
  70
  71     static PassOwnPtr<GridSpan> createWithInitialNamedSpanAgainstOpposite(const GridResolvedPosition& resolvedOppositePosition, const GridPosition& position, const Vector<size_t>& gridLines)
  72     {
  73         // The grid line inequality needs to be strict (which doesn't match the after / end case) because |resolvedOppositePosition|
  74         // is already converted to an index in our grid representation (ie one was removed from the grid line to account for the side).
  75         size_t firstLineBeforeOppositePositionIndex = 0;
  76         const size_t* firstLineBeforeOppositePosition = std::lower_bound(gridLines.begin(), gridLines.end(), resolvedOppositePosition.toInt());
  77         if (firstLineBeforeOppositePosition != gridLines.end()) {
  78             if (*firstLineBeforeOppositePosition > resolvedOppositePosition.toInt() && firstLineBeforeOppositePosition != gridLines.begin())
  79                 --firstLineBeforeOppositePosition;
  80
  81             firstLineBeforeOppositePositionIndex = firstLineBeforeOppositePosition - gridLines.begin();
  82         }
  83
  84         size_t gridLineIndex = std::max<int>(0, firstLineBeforeOppositePositionIndex - position.spanPosition() + 1);
  85         GridResolvedPosition resolvedGridLinePosition = GridResolvedPosition(gridLines[gridLineIndex]);
  86         if (resolvedGridLinePosition > resolvedOppositePosition)
  87             resolvedGridLinePosition = resolvedOppositePosition;
  88         return GridSpan::create(resolvedGridLinePosition, resolvedOppositePosition);
  89     }
  90
  91     static PassOwnPtr<GridSpan> createWithFinalNamedSpanAgainstOpposite(const GridResolvedPosition& resolvedOppositePosition, const GridPosition& position, const Vector<size_t>& gridLines)
  92     {
  93         size_t firstLineAfterOppositePositionIndex = gridLines.size() - 1;
  94         const size_t* firstLineAfterOppositePosition = std::upper_bound(gridLines.begin(), gridLines.end(), resolvedOppositePosition.toInt());
  95         if (firstLineAfterOppositePosition != gridLines.end())
  96             firstLineAfterOppositePositionIndex = firstLineAfterOppositePosition - gridLines.begin();
  97
  98         size_t gridLineIndex = std::min(gridLines.size() - 1, firstLineAfterOppositePositionIndex + position.spanPosition() - 1);
  99         GridResolvedPosition resolvedGridLinePosition = GridResolvedPosition::adjustGridPositionForAfterEndSide(gridLines[gridLineIndex]);
 100         if (resolvedGridLinePosition < resolvedOppositePosition)
 101             resolvedGridLinePosition = resolvedOppositePosition;
 102         return GridSpan::create(resolvedOppositePosition, resolvedGridLinePosition);
 103     }
 104
 105     GridSpan(const GridResolvedPosition& resolvedInitialPosition, const GridResolvedPosition& resolvedFinalPosition)
 106         : resolvedInitialPosition(resolvedInitialPosition)
 107         , resolvedFinalPosition(resolvedFinalPosition)
 108     {
 109         ASSERT(resolvedInitialPosition <= resolvedFinalPosition);
 110     }
 111
 112     bool operator==(const GridSpan& o) const
 113     {
 114         return resolvedInitialPosition == o.resolvedInitialPosition && resolvedFinalPosition == o.resolvedFinalPosition;
 115     }
 116
 117     size_t integerSpan() const
 118     {
 119         return resolvedFinalPosition.toInt() - resolvedInitialPosition.toInt() + 1;
 120     }
 121
 122     GridResolvedPosition resolvedInitialPosition;
 123     GridResolvedPosition resolvedFinalPosition;
 124
 125     typedef GridResolvedPosition iterator;
 126
 127     iterator begin() const
 128     {
 129         return resolvedInitialPosition;
 130     }
 131
 132     iterator end() const
 133     {
 134         return resolvedFinalPosition.next();
 135     }
 136 };
 137
 138 // This represents a grid area that spans in both rows' and columns' direction.
 139 struct GridCoordinate {
 140     // HashMap requires a default constuctor.
 141     GridCoordinate()
 142         : columns(0, 0)
 143         , rows(0, 0)
 144     {
 145     }
 146
 147     GridCoordinate(const GridSpan& r, const GridSpan& c)
 148         : columns(c)
 149         , rows(r)
 150     {
 151     }
 152
 153     bool operator==(const GridCoordinate& o) const
 154     {
 155         return columns == o.columns && rows == o.rows;
 156     }
 157
 158     bool operator!=(const GridCoordinate& o) const
 159     {
 160         return !(*this == o);
 161     }
 162
 163     GridResolvedPosition positionForSide(GridPositionSide side) const
 164     {
 165         switch (side) {
 166         case ColumnStartSide:
 167             return columns.resolvedInitialPosition;
 168         case ColumnEndSide:
 169             return columns.resolvedFinalPosition;
 170         case RowStartSide:
 171             return rows.resolvedInitialPosition;
 172         case RowEndSide:
 173             return rows.resolvedFinalPosition;
 174         }
 175         ASSERT_NOT_REACHED();
 176         return 0;
 177     }
 178
 179     GridSpan columns;
 180     GridSpan rows;
 181 };
 182
 183 typedef HashMap<String, GridCoordinate> NamedGridAreaMap;
 184
 185 } // namespace blink
 186
 187 #endif // GridCoordinate_h