third_party/WebKit/Source/wtf/text/TextPosition.h

   1 /*
   2  * Copyright (C) 2010, Google Inc. 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  * 1.  Redistributions of source code must retain the above copyright
   8  *     notice, this list of conditions and the following disclaimer.
   9  * 2.  Redistributions in binary form must reproduce the above copyright
  10  *     notice, this list of conditions and the following disclaimer in the
  11  *     documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  16  * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  17  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  18  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  19  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  20  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  22  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  23  */
  24
  25 #ifndef TextPosition_h
  26 #define TextPosition_h
  27
  28 #include "wtf/Assertions.h"
  29 #include "wtf/Vector.h"
  30 #include "wtf/WTFExport.h"
  31 #include "wtf/text/WTFString.h"
  32
  33 namespace WTF {
  34
  35 // An abstract number of element in a sequence. The sequence has a first element.
  36 // This type should be used instead of integer because 2 contradicting traditions can
  37 // call a first element '0' or '1' which makes integer type ambiguous.
  38 class OrdinalNumber {
  39 public:
  40     static OrdinalNumber fromZeroBasedInt(int zeroBasedInt) { return OrdinalNumber(zeroBasedInt); }
  41     static OrdinalNumber fromOneBasedInt(int oneBasedInt) { return OrdinalNumber(oneBasedInt - 1); }
  42     OrdinalNumber() : m_zeroBasedValue(0) { }
  43
  44     int zeroBasedInt() const { return m_zeroBasedValue; }
  45     int oneBasedInt() const { return m_zeroBasedValue + 1; }
  46
  47     bool operator==(OrdinalNumber other) const { return m_zeroBasedValue == other.m_zeroBasedValue; }
  48     bool operator!=(OrdinalNumber other) const { return !((*this) == other); }
  49
  50     static OrdinalNumber first() { return OrdinalNumber(0); }
  51     static OrdinalNumber beforeFirst() { return OrdinalNumber(-1); }
  52
  53 private:
  54     OrdinalNumber(int zeroBasedInt) : m_zeroBasedValue(zeroBasedInt) { }
  55     int m_zeroBasedValue;
  56 };
  57
  58
  59 // TextPosition structure specifies coordinates within an text resource. It is used mostly
  60 // for saving script source position.
  61 class TextPosition {
  62 public:
  63     TextPosition(OrdinalNumber line, OrdinalNumber column)
  64         : m_line(line)
  65         , m_column(column)
  66     {
  67     }
  68     TextPosition() { }
  69     bool operator==(const TextPosition& other) const { return m_line == other.m_line && m_column == other.m_column; }
  70     bool operator!=(const TextPosition& other) const { return !((*this) == other); }
  71     WTF_EXPORT OrdinalNumber toOffset(const Vector<unsigned>&);
  72
  73     // A 'minimum' value of position, used as a default value.
  74     static TextPosition minimumPosition() { return TextPosition(OrdinalNumber::first(), OrdinalNumber::first()); }
  75
  76     // A value with line value less than a minimum; used as an impossible position.
  77     static TextPosition belowRangePosition() { return TextPosition(OrdinalNumber::beforeFirst(), OrdinalNumber::beforeFirst()); }
  78
  79     // A value corresponding to a position with given offset within text having the specified line ending offsets.
  80     WTF_EXPORT static TextPosition fromOffsetAndLineEndings(unsigned, const Vector<unsigned>&);
  81
  82     OrdinalNumber m_line;
  83     OrdinalNumber m_column;
  84 };
  85
  86 WTF_EXPORT PassOwnPtr<Vector<unsigned>> lineEndings(const String&);
  87
  88 } // namespace WTF
  89
  90 using WTF::OrdinalNumber;
  91
  92 using WTF::TextPosition;
  93
  94 using WTF::lineEndings;
  95
  96 #endif // TextPosition_h