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      1 /*
      2  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  *
      8  * 1. Redistributions of source code must retain the above
      9  *    copyright notice, this list of conditions and the following
     10  *    disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above
     12  *    copyright notice, this list of conditions and the following
     13  *    disclaimer in the documentation and/or other materials
     14  *    provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     19  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
     20  * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
     21  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
     27  * OF THE POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 #ifndef Shape_h
     31 #define Shape_h
     32 
     33 #include "core/rendering/style/BasicShapes.h"
     34 #include "core/rendering/style/StyleImage.h"
     35 #include "platform/geometry/LayoutRect.h"
     36 #include "platform/text/WritingMode.h"
     37 #include "wtf/PassOwnPtr.h"
     38 #include "wtf/Vector.h"
     39 
     40 namespace WebCore {
     41 
     42 struct LineSegment {
     43     LineSegment(float logicalLeft, float logicalRight)
     44         : logicalLeft(logicalLeft)
     45         , logicalRight(logicalRight)
     46     {
     47     }
     48 
     49     float logicalLeft;
     50     float logicalRight;
     51 };
     52 
     53 typedef Vector<LineSegment> SegmentList;
     54 
     55 
     56 // A representation of a BasicShape that enables layout code to determine how to break a line up into segments
     57 // that will fit within or around a shape. The line is defined by a pair of logical Y coordinates and the
     58 // computed segments are returned as pairs of logical X coordinates. The BasicShape itself is defined in
     59 // physical coordinates.
     60 
     61 class Shape {
     62 public:
     63     static PassOwnPtr<Shape> createShape(const BasicShape*, const LayoutSize& logicalBoxSize, WritingMode, Length margin, Length padding);
     64     static PassOwnPtr<Shape> createShape(const StyleImage*, float threshold, const LayoutSize& logicalBoxSize, WritingMode, Length margin, Length padding);
     65     static PassOwnPtr<Shape> createLayoutBoxShape(const LayoutSize& logicalBoxSize, WritingMode, const Length& margin, const Length& padding);
     66 
     67     virtual ~Shape() { }
     68 
     69     virtual LayoutRect shapeMarginLogicalBoundingBox() const = 0;
     70     virtual LayoutRect shapePaddingLogicalBoundingBox() const = 0;
     71     virtual bool isEmpty() const = 0;
     72     virtual void getIncludedIntervals(LayoutUnit logicalTop, LayoutUnit logicalHeight, SegmentList&) const = 0;
     73     virtual void getExcludedIntervals(LayoutUnit logicalTop, LayoutUnit logicalHeight, SegmentList&) const = 0;
     74     virtual bool firstIncludedIntervalLogicalTop(LayoutUnit minLogicalIntervalTop, const LayoutSize& minLogicalIntervalSize, LayoutUnit& result) const = 0;
     75     bool lineOverlapsShapeMarginBounds(LayoutUnit lineTop, LayoutUnit lineHeight) const { return lineOverlapsBoundingBox(lineTop, lineHeight, shapeMarginLogicalBoundingBox()); }
     76     bool lineOverlapsShapePaddingBounds(LayoutUnit lineTop, LayoutUnit lineHeight) const { return lineOverlapsBoundingBox(lineTop, lineHeight, shapePaddingLogicalBoundingBox()); }
     77 
     78 protected:
     79     float shapeMargin() const { return m_margin; }
     80     float shapePadding() const { return m_padding; }
     81 
     82 private:
     83     bool lineOverlapsBoundingBox(LayoutUnit lineTop, LayoutUnit lineHeight, const LayoutRect& rect) const
     84     {
     85         if (rect.isEmpty())
     86             return false;
     87         return (lineTop < rect.maxY() && lineTop + lineHeight > rect.y()) || (!lineHeight && lineTop == rect.y());
     88     }
     89 
     90     WritingMode m_writingMode;
     91     float m_margin;
     92     float m_padding;
     93 };
     94 
     95 } // namespace WebCore
     96 
     97 #endif // Shape_h
     98