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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 blink {
     43 
     44 struct LineSegment {
     45     LineSegment()
     46         : logicalLeft(0)
     47         , logicalRight(0)
     48         , isValid(false)
     49     {
     50     }
     51 
     52     LineSegment(float logicalLeft, float logicalRight)
     53         : logicalLeft(logicalLeft)
     54         , logicalRight(logicalRight)
     55         , isValid(true)
     56     {
     57     }
     58 
     59     float logicalLeft;
     60     float logicalRight;
     61     bool isValid;
     62 };
     63 
     64 // A representation of a BasicShape that enables layout code to determine how to break a line up into segments
     65 // that will fit within or around a shape. The line is defined by a pair of logical Y coordinates and the
     66 // computed segments are returned as pairs of logical X coordinates. The BasicShape itself is defined in
     67 // physical coordinates.
     68 
     69 class Shape {
     70 public:
     71     struct DisplayPaths {
     72         Path shape;
     73         Path marginShape;
     74     };
     75     static PassOwnPtr<Shape> createShape(const BasicShape*, const LayoutSize& logicalBoxSize, WritingMode, float margin);
     76     static PassOwnPtr<Shape> createRasterShape(Image*, float threshold, const LayoutRect& imageRect, const LayoutRect& marginRect, WritingMode, float margin);
     77     static PassOwnPtr<Shape> createEmptyRasterShape(WritingMode, float margin);
     78     static PassOwnPtr<Shape> createLayoutBoxShape(const RoundedRect&, WritingMode, float margin);
     79 
     80     virtual ~Shape() { }
     81 
     82     virtual LayoutRect shapeMarginLogicalBoundingBox() const = 0;
     83     virtual bool isEmpty() const = 0;
     84     virtual LineSegment getExcludedInterval(LayoutUnit logicalTop, LayoutUnit logicalHeight) const = 0;
     85 
     86     bool lineOverlapsShapeMarginBounds(LayoutUnit lineTop, LayoutUnit lineHeight) const { return lineOverlapsBoundingBox(lineTop, lineHeight, shapeMarginLogicalBoundingBox()); }
     87     virtual void buildDisplayPaths(DisplayPaths&) const = 0;
     88 
     89 protected:
     90     float shapeMargin() const { return m_margin; }
     91 
     92 private:
     93     bool lineOverlapsBoundingBox(LayoutUnit lineTop, LayoutUnit lineHeight, const LayoutRect& rect) const
     94     {
     95         if (rect.isEmpty())
     96             return false;
     97         return (lineTop < rect.maxY() && lineTop + lineHeight > rect.y()) || (!lineHeight && lineTop == rect.y());
     98     }
     99 
    100     WritingMode m_writingMode;
    101     float m_margin;
    102 };
    103 
    104 } // namespace blink
    105 
    106 #endif // Shape_h
    107