third_party/WebKit/Source/core/style/BorderImageLength.h

/*
 * Copyright (c) 2013, Opera Software ASA. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 */

#ifndef BorderImageLength_h
#define BorderImageLength_h

#include "platform/Length.h"
#include "wtf/Allocator.h"

namespace blink {

// Represents an individual computed border image width or outset.
//
// http://www.w3.org/TR/css3-background/#border-image-width
// http://www.w3.org/TR/css3-background/#border-image-outset
class BorderImageLength {
  DISALLOW_NEW();

 public:
  BorderImageLength(double number) : m_number(number), m_type(NumberType) {}

  BorderImageLength(const Length& length)
      : m_length(length), m_number(0), m_type(LengthType) {}

  bool isNumber() const { return m_type == NumberType; }
  bool isLength() const { return m_type == LengthType; }

  const Length& length() const {
    ASSERT(isLength());
    return m_length;
  }
  Length& length() {
    ASSERT(isLength());
    return m_length;
  }

  double number() const {
    ASSERT(isNumber());
    return m_number;
  }

  bool operator==(const BorderImageLength& other) const {
    return m_type == other.m_type && m_length == other.m_length &&
           m_number == other.m_number;
  }

  bool isZero() const {
    if (isLength())
      return m_length.isZero();

    ASSERT(isNumber());
    return !m_number;
  }

 private:
  // Ideally we would put the 2 following fields in a union, but Length has a
  // constructor, a destructor and a copy assignment which isn't allowed.
  Length m_length;
  double m_number;
  enum { LengthType, NumberType } m_type;
};

}  // namespace blink

#endif  // BorderImageLength_h