third_party/WebKit/Source/core/html/parser/HTMLSrcsetParser.h

   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 "core/CoreExport.h"
  36 #include "wtf/Allocator.h"
  37 #include "wtf/text/WTFString.h"
  38
  39 namespace blink {
  40
  41 class Document;
  42
  43 enum { UninitializedDescriptor = -1 };
  44
  45 class DescriptorParsingResult {
  46     STACK_ALLOCATED();
  47 public:
  48     DescriptorParsingResult()
  49         : m_density(UninitializedDescriptor)
  50         , m_resourceWidth(UninitializedDescriptor)
  51         , m_resourceHeight(UninitializedDescriptor)
  52     {
  53     }
  54
  55     bool hasDensity() const { return m_density >= 0; }
  56     bool hasWidth() const { return m_resourceWidth >= 0; }
  57     bool hasHeight() const { return m_resourceHeight >= 0; }
  58
  59     float density() const { ASSERT(hasDensity()); return m_density; }
  60     unsigned resourceWidth() const { ASSERT(hasWidth()); return m_resourceWidth; }
  61     unsigned resourceHeight() const { ASSERT(hasHeight()); return m_resourceHeight; }
  62
  63     void setResourceWidth(int width) { ASSERT(width >= 0); m_resourceWidth = (unsigned)width; }
  64     void setResourceHeight(int height) { ASSERT(height >= 0); m_resourceHeight = (unsigned)height; }
  65     void setDensity(float densityToSet) { ASSERT(densityToSet >= 0); m_density = densityToSet; }
  66
  67 private:
  68     float m_density;
  69     int m_resourceWidth;
  70     int m_resourceHeight;
  71 };
  72
  73 class ImageCandidate {
  74     ALLOW_ONLY_INLINE_ALLOCATION();
  75 public:
  76     enum OriginAttribute {
  77         SrcsetOrigin,
  78         SrcOrigin
  79     };
  80
  81     ImageCandidate()
  82         : m_density(1.0)
  83         , m_resourceWidth(UninitializedDescriptor)
  84         , m_originAttribute(SrcsetOrigin)
  85     {
  86     }
  87
  88     ImageCandidate(const String& source, unsigned start, unsigned length, const DescriptorParsingResult& result, OriginAttribute originAttribute)
  89         : m_string(source.createView(start, length))
  90         , m_density(result.hasDensity()?result.density():UninitializedDescriptor)
  91         , m_resourceWidth(result.hasWidth()?result.resourceWidth():UninitializedDescriptor)
  92         , m_originAttribute(originAttribute)
  93     {
  94     }
  95
  96     String toString() const
  97     {
  98         return String(m_string.toString());
  99     }
 100
 101     AtomicString url() const
 102     {
 103         return AtomicString(m_string.toString());
 104     }
 105
 106     void setDensity(float factor)
 107     {
 108         m_density = factor;
 109     }
 110
 111     float density() const
 112     {
 113         return m_density;
 114     }
 115
 116     int resourceWidth() const
 117     {
 118         return m_resourceWidth;
 119     }
 120
 121     bool srcOrigin() const
 122     {
 123         return (m_originAttribute == SrcOrigin);
 124     }
 125
 126     inline bool isEmpty() const
 127     {
 128         return m_string.isEmpty();
 129     }
 130
 131 private:
 132     StringView m_string;
 133     float m_density;
 134     int m_resourceWidth;
 135     OriginAttribute m_originAttribute;
 136 };
 137
 138 ImageCandidate bestFitSourceForSrcsetAttribute(float deviceScaleFactor, float sourceSize, const String& srcsetAttribute, Document* = nullptr);
 139
 140 CORE_EXPORT ImageCandidate bestFitSourceForImageAttributes(float deviceScaleFactor, float sourceSize, const String& srcAttribute, const String& srcsetAttribute, Document* = nullptr);
 141
 142 String bestFitSourceForImageAttributes(float deviceScaleFactor, float sourceSize, const String& srcAttribute, ImageCandidate& srcsetImageCandidate);
 143
 144 }
 145
 146 #endif