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
42namespace blink {
43
44struct 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
69class Shape {
70public:
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
89protected:
90    float shapeMargin() const { return m_margin; }
91
92private:
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