SMILValue.h - mozsearch

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef DOM_SMIL_SMILVALUE_H_

#define DOM_SMIL_SMILVALUE_H_

#include "mozilla/SMILNullType.h"

#include "mozilla/SMILType.h"

namespace mozilla {

/**

 * Although objects of this type are generally only created on the stack and

 * only exist during the taking of a new time sample, that's not always the

 * case. The SMILValue objects obtained from attributes' base values are

 * cached so that the SMIL engine can make certain optimizations during a

 * sample if the base value has not changed since the last sample (potentially

 * avoiding recomposing). These SMILValue objects typically live much longer

 * than a single sample.

*/

class SMILValue {

 public:

  SMILValue() : mU(), mType(SMILNullType::Singleton()) {}

  explicit SMILValue(const SMILType* aType);

  SMILValue(const SMILValue& aVal);

  ~SMILValue() { mType->Destroy(*this); }

  const SMILValue& operator=(const SMILValue& aVal);

  // Move constructor / reassignment operator:

  SMILValue(SMILValue&& aVal) noexcept;

  SMILValue& operator=(SMILValue&& aVal) noexcept;

  // Equality operators. These are allowed to be conservative (return false

  // more than you'd expect) - see comment above SMILType::IsEqual.

  bool operator==(const SMILValue& aVal) const;

  bool operator!=(const SMILValue& aVal) const { return !(*this == aVal); }

  bool IsNull() const { return (mType == SMILNullType::Singleton()); }

  nsresult Add(const SMILValue& aValueToAdd, uint32_t aCount = 1);

  nsresult SandwichAdd(const SMILValue& aValueToAdd);

  nsresult ComputeDistance(const SMILValue& aTo, double& aDistance) const;

  nsresult Interpolate(const SMILValue& aEndVal, double aUnitDistance,

                       SMILValue& aResult) const;

  union {

    bool mBool;

    uint64_t mUint;

    int64_t mInt;

    double mDouble;

    struct {

      float mAngle;

      uint16_t mUnit;

      uint16_t mOrientType;

    } mOrient;

    int32_t mIntPair[2];

    float mNumberPair[2];

    void* mPtr;

  } mU;

  const SMILType* mType;

 protected:

  void InitAndCheckPostcondition(const SMILType* aNewType);

  void DestroyAndCheckPostcondition();

  void DestroyAndReinit(const SMILType* aNewType);

};

}  // namespace mozilla

#endif  // DOM_SMIL_SMILVALUE_H_