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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/geometry/RoundedRect.h"
     37 #include "platform/graphics/Path.h"
     38 #include "platform/text/WritingMode.h"
     39 #include "wtf/PassOwnPtr.h"
     40 #include "wtf/Vector.h"
     41 
     42 namespace WebCore {
     43 
     44 struct LineSegment {
     45     LineSegment(float logicalLeft, float logicalRight)
     46         : logicalLeft(logicalLeft)
     47         , logicalRight(logicalRight)
     48     {
     49     }
     50 
     51     float logicalLeft;
     52     float logicalRight;
     53 };
     54 
     55 typedef Vector<LineSegment> SegmentList;
     56 
     57 
     58 // A representation of a BasicShape that enables layout code to determine how to break a line up into segments
     59 // that will fit within or around a shape. The line is defined by a pair of logical Y coordinates and the
     60 // computed segments are returned as pairs of logical X coordinates. The BasicShape itself is defined in
     61 // physical coordinates.
     62 
     63 class Shape {
     64 public:
     65     struct DisplayPaths {
     66         Path shape;
     67         Path marginShape;
     68     };
     69     static PassOwnPtr<Shape> createShape(const BasicShape*, const LayoutSize& logicalBoxSize, WritingMode, float margin);
     70     static PassOwnPtr<Shape> createRasterShape(Image*, float threshold, const LayoutRect& imageRect, const LayoutRect& marginRect, WritingMode, float margin);
     71     static PassOwnPtr<Shape> createLayoutBoxShape(const RoundedRect&, WritingMode, float margin);
     72 
     73     virtual ~Shape() { }
     74 
     75     virtual LayoutRect shapeMarginLogicalBoundingBox() const = 0;
     76     virtual bool isEmpty() const = 0;
     77     virtual void getExcludedIntervals(LayoutUnit logicalTop, LayoutUnit logicalHeight, SegmentList&) const = 0;
     78 
     79     bool lineOverlapsShapeMarginBounds(LayoutUnit lineTop, LayoutUnit lineHeight) const { return lineOverlapsBoundingBox(lineTop, lineHeight, shapeMarginLogicalBoundingBox()); }
     80     virtual void buildDisplayPaths(DisplayPaths&) const = 0;
     81 
     82 protected:
     83     float shapeMargin() const { return m_margin; }
     84 
     85 private:
     86     bool lineOverlapsBoundingBox(LayoutUnit lineTop, LayoutUnit lineHeight, const LayoutRect& rect) const
     87     {
     88         if (rect.isEmpty())
     89             return false;
     90         return (lineTop < rect.maxY() && lineTop + lineHeight > rect.y()) || (!lineHeight && lineTop == rect.y());
     91     }
     92 
     93     WritingMode m_writingMode;
     94     float m_margin;
     95 };
     96 
     97 } // namespace WebCore
     98 
     99 #endif // Shape_h
    100