Home | History | Annotate | Download | only in parser 
      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 
     37 namespace blink {
     38 
     39 enum { UninitializedDescriptor = -1 };
     40 
     41 class DescriptorParsingResult {
     42 public:
     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 
     62 private:
     63     float m_density;
     64     int m_resourceWidth;
     65     int m_resourceHeight;
     66 };
     67 
     68 class ImageCandidate {
     69 public:
     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 
    125 private:
    126     StringView m_string;
    127     float m_density;
    128     int m_resourceWidth;
    129     OriginAttribute m_originAttribute;
    130 };
    131 
    132 ImageCandidate bestFitSourceForSrcsetAttribute(float deviceScaleFactor, unsigned sourceSize, const String& srcsetAttribute);
    133 
    134 ImageCandidate bestFitSourceForImageAttributes(float deviceScaleFactor, unsigned sourceSize, const String& srcAttribute, const String& srcsetAttribute);
    135 
    136 String bestFitSourceForImageAttributes(float deviceScaleFactor, unsigned sourceSize, const String& srcAttribute, ImageCandidate& srcsetImageCandidate);
    137 
    138 }
    139 
    140 #endif
    141