1/*
2 * Copyright (C) 2013 Apple Inc. All rights reserved.
3 * Copyright (C) 2013 Google Inc. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met:
8 *
9 *     * Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *     * Redistributions in binary form must reproduce the above
12 * copyright notice, this list of conditions and the following disclaimer
13 * in the documentation and/or other materials provided with the
14 * distribution.
15 *     * Neither the name of Google Inc. nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#ifndef HTMLSrcsetParser_h
33#define HTMLSrcsetParser_h
34
35#include "wtf/text/WTFString.h"
36
37namespace blink {
38
39enum { UninitializedDescriptor = -1 };
40
41class DescriptorParsingResult {
42public:
43    DescriptorParsingResult()
44        : m_density(UninitializedDescriptor)
45        , m_resourceWidth(UninitializedDescriptor)
46        , m_resourceHeight(UninitializedDescriptor)
47    {
48    }
49
50    bool hasDensity() const { return m_density >= 0; }
51    bool hasWidth() const { return m_resourceWidth >= 0; }
52    bool hasHeight() const { return m_resourceHeight >= 0; }
53
54    float density() const { ASSERT(hasDensity()); return m_density; }
55    unsigned resourceWidth() const { ASSERT(hasWidth()); return m_resourceWidth; }
56    unsigned resourceHeight() const { ASSERT(hasHeight()); return m_resourceHeight; }
57
58    void setResourceWidth(int width) { ASSERT(width >= 0); m_resourceWidth = (unsigned)width; }
59    void setResourceHeight(int height) { ASSERT(height >= 0); m_resourceHeight = (unsigned)height; }
60    void setDensity(float densityToSet) { ASSERT(densityToSet >= 0); m_density = densityToSet; }
61
62private:
63    float m_density;
64    int m_resourceWidth;
65    int m_resourceHeight;
66};
67
68class ImageCandidate {
69public:
70    enum OriginAttribute {
71        SrcsetOrigin,
72        SrcOrigin
73    };
74
75    ImageCandidate()
76        : m_density(1.0)
77        , m_resourceWidth(UninitializedDescriptor)
78        , m_originAttribute(SrcsetOrigin)
79    {
80    }
81
82    ImageCandidate(const String& source, unsigned start, unsigned length, const DescriptorParsingResult& result, OriginAttribute originAttribute)
83        : m_string(source.createView(start, length))
84        , m_density(result.hasDensity()?result.density():UninitializedDescriptor)
85        , m_resourceWidth(result.hasWidth()?result.resourceWidth():UninitializedDescriptor)
86        , m_originAttribute(originAttribute)
87    {
88    }
89
90    String toString() const
91    {
92        return String(m_string.toString());
93    }
94
95    AtomicString url() const
96    {
97        return AtomicString(m_string.toString());
98    }
99
100    void setDensity(float factor)
101    {
102        m_density = factor;
103    }
104
105    float density() const
106    {
107        return m_density;
108    }
109
110    int resourceWidth() const
111    {
112        return m_resourceWidth;
113    }
114
115    bool srcOrigin() const
116    {
117        return (m_originAttribute == SrcOrigin);
118    }
119
120    inline bool isEmpty() const
121    {
122        return m_string.isEmpty();
123    }
124
125private:
126    StringView m_string;
127    float m_density;
128    int m_resourceWidth;
129    OriginAttribute m_originAttribute;
130};
131
132ImageCandidate bestFitSourceForSrcsetAttribute(float deviceScaleFactor, unsigned sourceSize, const String& srcsetAttribute);
133
134ImageCandidate bestFitSourceForImageAttributes(float deviceScaleFactor, unsigned sourceSize, const String& srcAttribute, const String& srcsetAttribute);
135
136String bestFitSourceForImageAttributes(float deviceScaleFactor, unsigned sourceSize, const String& srcAttribute, ImageCandidate& srcsetImageCandidate);
137
138}
139
140#endif
141