content/smil/nsSMILNullType.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef NS_SMILNULLTYPE_H_
   7 #define NS_SMILNULLTYPE_H_
   8
   9 #include "mozilla/Attributes.h"
  10 #include "nsISMILType.h"
  11
  12 class nsSMILNullType : public nsISMILType
  13 {
  14 public:
  15   // Singleton for nsSMILValue objects to hold onto.
  16   static nsSMILNullType*
  17   Singleton()
  18   {
  19     static nsSMILNullType sSingleton;
  20     return &sSingleton;
  21   }
  22
  23 protected:
  24   // nsISMILType Methods
  25   // -------------------
  26   virtual void Init(nsSMILValue& aValue) const MOZ_OVERRIDE {}
  27   virtual void Destroy(nsSMILValue& aValue) const MOZ_OVERRIDE {}
  28   virtual nsresult Assign(nsSMILValue& aDest, const nsSMILValue& aSrc) const MOZ_OVERRIDE;
  29
  30   // The remaining methods should never be called, so although they're very
  31   // simple they don't need to be inline.
  32   virtual bool     IsEqual(const nsSMILValue& aLeft,
  33                            const nsSMILValue& aRight) const MOZ_OVERRIDE;
  34   virtual nsresult Add(nsSMILValue& aDest, const nsSMILValue& aValueToAdd,
  35                        uint32_t aCount) const MOZ_OVERRIDE;
  36   virtual nsresult ComputeDistance(const nsSMILValue& aFrom,
  37                                    const nsSMILValue& aTo,
  38                                    double& aDistance) const MOZ_OVERRIDE;
  39   virtual nsresult Interpolate(const nsSMILValue& aStartVal,
  40                                const nsSMILValue& aEndVal,
  41                                double aUnitDistance,
  42                                nsSMILValue& aResult) const MOZ_OVERRIDE;
  43
  44 private:
  45   // Private constructor: prevent instances beyond my singleton.
  46   MOZ_CONSTEXPR nsSMILNullType() {}
  47 };
  48
  49 #endif // NS_SMILNULLTYPE_H_