dom/smil/SMILValue.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_SMILValue_h
   8 #define mozilla_SMILValue_h
   9
  10 #include "mozilla/SMILNullType.h"
  11 #include "mozilla/SMILType.h"
  12
  13 namespace mozilla {
  14
  15 /**
  16  * Although objects of this type are generally only created on the stack and
  17  * only exist during the taking of a new time sample, that's not always the
  18  * case. The SMILValue objects obtained from attributes' base values are
  19  * cached so that the SMIL engine can make certain optimizations during a
  20  * sample if the base value has not changed since the last sample (potentially
  21  * avoiding recomposing). These SMILValue objects typically live much longer
  22  * than a single sample.
  23  */
  24 class SMILValue {
  25  public:
  26   SMILValue() : mU(), mType(SMILNullType::Singleton()) {}
  27   explicit SMILValue(const SMILType* aType);
  28   SMILValue(const SMILValue& aVal);
  29
  30   ~SMILValue() { mType->Destroy(*this); }
  31
  32   const SMILValue& operator=(const SMILValue& aVal);
  33
  34   // Move constructor / reassignment operator:
  35   SMILValue(SMILValue&& aVal);
  36   SMILValue& operator=(SMILValue&& aVal);
  37
  38   // Equality operators. These are allowed to be conservative (return false
  39   // more than you'd expect) - see comment above SMILType::IsEqual.
  40   bool operator==(const SMILValue& aVal) const;
  41   bool operator!=(const SMILValue& aVal) const { return !(*this == aVal); }
  42
  43   bool IsNull() const { return (mType == SMILNullType::Singleton()); }
  44
  45   nsresult Add(const SMILValue& aValueToAdd, uint32_t aCount = 1);
  46   nsresult SandwichAdd(const SMILValue& aValueToAdd);
  47   nsresult ComputeDistance(const SMILValue& aTo, double& aDistance) const;
  48   nsresult Interpolate(const SMILValue& aEndVal, double aUnitDistance,
  49                        SMILValue& aResult) const;
  50
  51   union {
  52     bool mBool;
  53     uint64_t mUint;
  54     int64_t mInt;
  55     double mDouble;
  56     struct {
  57       float mAngle;
  58       uint16_t mUnit;
  59       uint16_t mOrientType;
  60     } mOrient;
  61     int32_t mIntPair[2];
  62     float mNumberPair[2];
  63     void* mPtr;
  64   } mU;
  65   const SMILType* mType;
  66
  67  protected:
  68   void InitAndCheckPostcondition(const SMILType* aNewType);
  69   void DestroyAndCheckPostcondition();
  70   void DestroyAndReinit(const SMILType* aNewType);
  71 };
  72
  73 }  // namespace mozilla
  74
  75 #endif  // mozilla_SMILValue_h