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  #include "qvariantanimation.h"
  #include "qvariantanimation_p.h"
  
  #include <QtCore/qrect.h>
  #include <QtCore/qline.h>
  #include <QtCore/qmutex.h>
  
  #include <algorithm>
  
  #ifndef QT_NO_ANIMATION
  
  QT_BEGIN_NAMESPACE
  
  /*!
      \class QVariantAnimation
      \inmodule QtCore
      \ingroup animation
      \brief The QVariantAnimation class provides a base class for animations.
      \since 4.6
  
      This class is part of \l{The Animation Framework}. It serves as a
      base class for property and item animations, with functions for
      shared functionality.
  
      The class performs interpolation over
      \l{QVariant}s, but leaves using the interpolated values to its
      subclasses. Currently, Qt provides QPropertyAnimation, which
      animates Qt \l{Qt's Property System}{properties}. See the
      QPropertyAnimation class description if you wish to animate such
      properties.
  
      You can then set start and end values for the property by calling
      setStartValue() and setEndValue(), and finally call start() to
      start the animation. QVariantAnimation will interpolate the
      property of the target object and emit valueChanged(). To react to
      a change in the current value you have to reimplement the
      updateCurrentValue() virtual function or connect to said signal.
  
      It is also possible to set values at specified steps situated
      between the start and end value. The interpolation will then
      touch these points at the specified steps. Note that the start and
      end values are defined as the key values at 0.0 and 1.0.
  
      There are two ways to affect how QVariantAnimation interpolates
      the values. You can set an easing curve by calling
      setEasingCurve(), and configure the duration by calling
      setDuration(). You can change how the \l{QVariant}s are interpolated
      by creating a subclass of QVariantAnimation, and reimplementing
      the virtual interpolated() function.
  
      Subclassing QVariantAnimation can be an alternative if you have
      \l{QVariant}s that you do not wish to declare as Qt properties.
      Note, however, that you in most cases will be better off declaring
      your QVariant as a property.
  
      Not all QVariant types are supported. Below is a list of currently
      supported QVariant types:
  
      \list
          \li \l{QMetaType::}{Int}
          \li \l{QMetaType::}{UInt}
          \li \l{QMetaType::}{Double}
          \li \l{QMetaType::}{Float}
          \li \l{QMetaType::}{QLine}
          \li \l{QMetaType::}{QLineF}
          \li \l{QMetaType::}{QPoint}
          \li \l{QMetaType::}{QPointF}
          \li \l{QMetaType::}{QSize}
          \li \l{QMetaType::}{QSizeF}
          \li \l{QMetaType::}{QRect}
          \li \l{QMetaType::}{QRectF}
          \li \l{QMetaType::}{QColor}
      \endlist
  
      If you need to interpolate other variant types, including custom
      types, you have to implement interpolation for these yourself.
      To do this, you can register an interpolator function for a given
      type. This function takes 3 parameters: the start value, the end value,
      and the current progress.
  
      Example:
      \code
          QVariant myColorInterpolator(const QColor &start, const QColor &end, qreal progress)
          {
              ...
              return QColor(...);
          }
          ...
          qRegisterAnimationInterpolator<QColor>(myColorInterpolator);
      \endcode
  
      Another option is to reimplement interpolated(), which returns
      interpolation values for the value being interpolated.
  
      \omit We need some snippets around here. \endomit
  
      \sa QPropertyAnimation, QAbstractAnimation, {The Animation Framework}
  */
  
  /*!
      \fn void QVariantAnimation::valueChanged(const QVariant &value)
  
      QVariantAnimation emits this signal whenever the current \a value changes.
  
      \sa currentValue, startValue, endValue
  */
  
  /*!
      This virtual function is called every time the animation's current
      value changes. The \a value argument is the new current value.
  
      The base class implementation does nothing.
  
      \sa currentValue
  */
  void QVariantAnimation::updateCurrentValue(const QVariant &) {}
  
  static bool animationValueLessThan(const QVariantAnimation::KeyValue &p1, const QVariantAnimation::KeyValue &p2)
  {
      return p1.first < p2.first;
  }
  
  static QVariant defaultInterpolator(const void *, const void *, qreal)
  {
      return QVariant();
  }
  
  template<> Q_INLINE_TEMPLATE QRect _q_interpolate(const QRect &f, const QRect &t, qreal progress)
  {
      QRect ret;
      ret.setCoords(_q_interpolate(f.left(), t.left(), progress),
                    _q_interpolate(f.top(), t.top(), progress),
                    _q_interpolate(f.right(), t.right(), progress),
                    _q_interpolate(f.bottom(), t.bottom(), progress));
      return ret;
  }
  
  template<> Q_INLINE_TEMPLATE QRectF _q_interpolate(const QRectF &f, const QRectF &t, qreal progress)
  {
      qreal x1, y1, w1, h1;
      f.getRect(&x1, &y1, &w1, &h1);
      qreal x2, y2, w2, h2;
      t.getRect(&x2, &y2, &w2, &h2);
      return QRectF(_q_interpolate(x1, x2, progress), _q_interpolate(y1, y2, progress),
                    _q_interpolate(w1, w2, progress), _q_interpolate(h1, h2, progress));
  }
  
  template<> Q_INLINE_TEMPLATE QLine _q_interpolate(const QLine &f, const QLine &t, qreal progress)
  {
      return QLine( _q_interpolate(f.p1(), t.p1(), progress), _q_interpolate(f.p2(), t.p2(), progress));
  }
  
  template<> Q_INLINE_TEMPLATE QLineF _q_interpolate(const QLineF &f, const QLineF &t, qreal progress)
  {
      return QLineF( _q_interpolate(f.p1(), t.p1(), progress), _q_interpolate(f.p2(), t.p2(), progress));
  }
  
  QVariantAnimationPrivate::QVariantAnimationPrivate() : duration(250), interpolator(&defaultInterpolator)
  { }
  
  void QVariantAnimationPrivate::convertValues(int t)
  {
      //this ensures that all the keyValues are of type t
      for (int i = 0; i < keyValues.count(); ++i) {
          QVariantAnimation::KeyValue &pair = keyValues[i];
          pair.second.convert(t);
      }
      //we also need update to the current interval if needed
      currentInterval.start.second.convert(t);
      currentInterval.end.second.convert(t);
  
      //... and the interpolator
      updateInterpolator();
  }
  
  void QVariantAnimationPrivate::updateInterpolator()
  {
      int type = currentInterval.start.second.userType();
      if (type == currentInterval.end.second.userType())
          interpolator = getInterpolator(type);
      else
          interpolator = 0;
  
      //we make sure that the interpolator is always set to something
      if (!interpolator)
          interpolator = &defaultInterpolator;
  }
  
  /*!
      \internal
      The goal of this function is to update the currentInterval member. As a consequence, we also
      need to update the currentValue.
      Set \a force to true to always recalculate the interval.
  */
  void QVariantAnimationPrivate::recalculateCurrentInterval(bool force/*=false*/)
  {
      // can't interpolate if we don't have at least 2 values
      if ((keyValues.count() + (defaultStartEndValue.isValid() ? 1 : 0)) < 2)
          return;
  
      const qreal endProgress = (direction == QAbstractAnimation::Forward) ? qreal(1) : qreal(0);
      const qreal progress = easing.valueForProgress(((duration == 0) ? endProgress : qreal(currentTime) / qreal(duration)));
  
      //0 and 1 are still the boundaries
      if (force || (currentInterval.start.first > 0 && progress < currentInterval.start.first)
          || (currentInterval.end.first < 1 && progress > currentInterval.end.first)) {
          //let's update currentInterval
          QVariantAnimation::KeyValues::const_iterator it = std::lower_bound(keyValues.constBegin(),
                                                                             keyValues.constEnd(),
                                                                             qMakePair(progress, QVariant()),
                                                                             animationValueLessThan);
          if (it == keyValues.constBegin()) {
              //the item pointed to by it is the start element in the range
              if (it->first == 0 && keyValues.count() > 1) {
                  currentInterval.start = *it;
                  currentInterval.end = *(it+1);
              } else {
                  currentInterval.start = qMakePair(qreal(0), defaultStartEndValue);
                  currentInterval.end = *it;
              }
          } else if (it == keyValues.constEnd()) {
              --it; //position the iterator on the last item
              if (it->first == 1 && keyValues.count() > 1) {
                  //we have an end value (item with progress = 1)
                  currentInterval.start = *(it-1);
                  currentInterval.end = *it;
              } else {
                  //we use the default end value here
                  currentInterval.start = *it;
                  currentInterval.end = qMakePair(qreal(1), defaultStartEndValue);
              }
          } else {
              currentInterval.start = *(it-1);
              currentInterval.end = *it;
          }
  
          // update all the values of the currentInterval
          updateInterpolator();
      }
      setCurrentValueForProgress(progress);
  }
  
  void QVariantAnimationPrivate::setCurrentValueForProgress(const qreal progress)
  {
      Q_Q(QVariantAnimation);
  
      const qreal startProgress = currentInterval.start.first;
      const qreal endProgress = currentInterval.end.first;
      const qreal localProgress = (progress - startProgress) / (endProgress - startProgress);
  
      QVariant ret = q->interpolated(currentInterval.start.second,
                                     currentInterval.end.second,
                                     localProgress);
      qSwap(currentValue, ret);
      q->updateCurrentValue(currentValue);
      static QBasicAtomicInt changedSignalIndex = Q_BASIC_ATOMIC_INITIALIZER(0);
      if (!changedSignalIndex.load()) {
          //we keep the mask so that we emit valueChanged only when needed (for performance reasons)
          changedSignalIndex.testAndSetRelaxed(0, signalIndex("valueChanged(QVariant)"));
      }
      if (isSignalConnected(changedSignalIndex.load()) && currentValue != ret) {
          //the value has changed
          emit q->valueChanged(currentValue);
      }
  }
  
  QVariant QVariantAnimationPrivate::valueAt(qreal step) const
  {
      QVariantAnimation::KeyValues::const_iterator result =
          std::lower_bound(keyValues.constBegin(), keyValues.constEnd(), qMakePair(step, QVariant()), animationValueLessThan);
      if (result != keyValues.constEnd() && !animationValueLessThan(qMakePair(step, QVariant()), *result))
          return result->second;
  
      return QVariant();
  }
  
  void QVariantAnimationPrivate::setValueAt(qreal step, const QVariant &value)
  {
      if (step < qreal(0.0) || step > qreal(1.0)) {
          qWarning("QVariantAnimation::setValueAt: invalid step = %f", step);
          return;
      }
  
      QVariantAnimation::KeyValue pair(step, value);
  
      QVariantAnimation::KeyValues::iterator result = std::lower_bound(keyValues.begin(), keyValues.end(), pair, animationValueLessThan);
      if (result == keyValues.end() || result->first != step) {
          keyValues.insert(result, pair);
      } else {
          if (value.isValid())
              result->second = value; // replaces the previous value
          else
              keyValues.erase(result); // removes the previous value
      }
  
      recalculateCurrentInterval(/*force=*/true);
  }
  
  void QVariantAnimationPrivate::setDefaultStartEndValue(const QVariant &value)
  {
      defaultStartEndValue = value;
      recalculateCurrentInterval(/*force=*/true);
  }
  
  /*!
      Construct a QVariantAnimation object. \a parent is passed to QAbstractAnimation's
      constructor.
  */
  QVariantAnimation::QVariantAnimation(QObject *parent) : QAbstractAnimation(*new QVariantAnimationPrivate, parent)
  {
  }
  
  /*!
      \internal
  */
  QVariantAnimation::QVariantAnimation(QVariantAnimationPrivate &dd, QObject *parent) : QAbstractAnimation(dd, parent)
  {
  }
  
  /*!
      Destroys the animation.
  */
  QVariantAnimation::~QVariantAnimation()
  {
  }
  
  /*!
      \property QVariantAnimation::easingCurve
      \brief the easing curve of the animation
  
      This property defines the easing curve of the animation. By
      default, a linear easing curve is used, resulting in linear
      interpolation. Other curves are provided, for instance,
      QEasingCurve::InCirc, which provides a circular entry curve.
      Another example is QEasingCurve::InOutElastic, which provides an
      elastic effect on the values of the interpolated variant.
  
      QVariantAnimation will use the QEasingCurve::valueForProgress() to
      transform the "normalized progress" (currentTime / totalDuration)
      of the animation into the effective progress actually
      used by the animation. It is this effective progress that will be
      the progress when interpolated() is called. Also, the steps in the
      keyValues are referring to this effective progress.
  
      The easing curve is used with the interpolator, the interpolated()
      virtual function, and the animation's duration to control how the
      current value changes as the animation progresses.
  */
  QEasingCurve QVariantAnimation::easingCurve() const
  {
      Q_D(const QVariantAnimation);
      return d->easing;
  }
  
  void QVariantAnimation::setEasingCurve(const QEasingCurve &easing)
  {
      Q_D(QVariantAnimation);
      d->easing = easing;
      d->recalculateCurrentInterval();
  }
  
  typedef QVector<QVariantAnimation::Interpolator> QInterpolatorVector;
  Q_GLOBAL_STATIC(QInterpolatorVector, registeredInterpolators)
  static QBasicMutex registeredInterpolatorsMutex;
  
  /*!
      \fn void qRegisterAnimationInterpolator(QVariant (*func)(const T &from, const T &to, qreal progress))
      \relates QVariantAnimation
      \threadsafe
  
      Registers a custom interpolator \a func for the template type \c{T}.
      The interpolator has to be registered before the animation is constructed.
      To unregister (and use the default interpolator) set \a func to 0.
   */
  
  /*!
      \internal
      \typedef QVariantAnimation::Interpolator
  
      This is a typedef for a pointer to a function with the following
      signature:
      \code
      QVariant myInterpolator(const QVariant &from, const QVariant &to, qreal progress);
      \endcode
  
  */
  
  /*!
   * \internal
   * Registers a custom interpolator \a func for the specific \a interpolationType.
   * The interpolator has to be registered before the animation is constructed.
   * To unregister (and use the default interpolator) set \a func to 0.
   */
  void QVariantAnimation::registerInterpolator(QVariantAnimation::Interpolator func, int interpolationType)
  {
      // will override any existing interpolators
      QInterpolatorVector *interpolators = registeredInterpolators();
      // When built on solaris with GCC, the destructors can be called
      // in such an order that we get here with interpolators == NULL,
      // to continue causes the app to crash on exit with a SEGV
      if (interpolators) {
          QMutexLocker locker(&registeredInterpolatorsMutex);
          if (int(interpolationType) >= interpolators->count())
              interpolators->resize(int(interpolationType) + 1);
          interpolators->replace(interpolationType, func);
      }
  }
  
  
  template<typename T> static inline QVariantAnimation::Interpolator castToInterpolator(QVariant (*func)(const T &from, const T &to, qreal progress))
  {
       return reinterpret_cast<QVariantAnimation::Interpolator>(func);
  }
  
  QVariantAnimation::Interpolator QVariantAnimationPrivate::getInterpolator(int interpolationType)
  {
      {
          QInterpolatorVector *interpolators = registeredInterpolators();
          QMutexLocker locker(&registeredInterpolatorsMutex);
          QVariantAnimation::Interpolator ret = 0;
          if (interpolationType < interpolators->count()) {
              ret = interpolators->at(interpolationType);
              if (ret) return ret;
          }
      }
  
      switch(interpolationType)
      {
      case QMetaType::Int:
          return castToInterpolator(_q_interpolateVariant<int>);
      case QMetaType::UInt:
          return castToInterpolator(_q_interpolateVariant<uint>);
      case QMetaType::Double:
          return castToInterpolator(_q_interpolateVariant<double>);
      case QMetaType::Float:
          return castToInterpolator(_q_interpolateVariant<float>);
      case QMetaType::QLine:
          return castToInterpolator(_q_interpolateVariant<QLine>);
      case QMetaType::QLineF:
          return castToInterpolator(_q_interpolateVariant<QLineF>);
      case QMetaType::QPoint:
          return castToInterpolator(_q_interpolateVariant<QPoint>);
      case QMetaType::QPointF:
          return castToInterpolator(_q_interpolateVariant<QPointF>);
      case QMetaType::QSize:
          return castToInterpolator(_q_interpolateVariant<QSize>);
      case QMetaType::QSizeF:
          return castToInterpolator(_q_interpolateVariant<QSizeF>);
      case QMetaType::QRect:
          return castToInterpolator(_q_interpolateVariant<QRect>);
      case QMetaType::QRectF:
          return castToInterpolator(_q_interpolateVariant<QRectF>);
      default:
          return 0; //this type is not handled
      }
  }
  
  /*!
      \property QVariantAnimation::duration
      \brief the duration of the animation
  
      This property describes the duration in milliseconds of the
      animation. The default duration is 250 milliseconds.
  
      \sa QAbstractAnimation::duration()
   */
  int QVariantAnimation::duration() const
  {
      Q_D(const QVariantAnimation);
      return d->duration;
  }
  
  void QVariantAnimation::setDuration(int msecs)
  {
      Q_D(QVariantAnimation);
      if (msecs < 0) {
          qWarning("QVariantAnimation::setDuration: cannot set a negative duration");
          return;
      }
      if (d->duration == msecs)
          return;
      d->duration = msecs;
      d->recalculateCurrentInterval();
  }
  
  /*!
      \property QVariantAnimation::startValue
      \brief the optional start value of the animation
  
      This property describes the optional start value of the animation. If
      omitted, or if a null QVariant is assigned as the start value, the
      animation will use the current position of the end when the animation
      is started.
  
      \sa endValue
  */
  QVariant QVariantAnimation::startValue() const
  {
      return keyValueAt(0);
  }
  
  void QVariantAnimation::setStartValue(const QVariant &value)
  {
      setKeyValueAt(0, value);
  }
  
  /*!
      \property QVariantAnimation::endValue
      \brief the end value of the animation
  
      This property describes the end value of the animation.
  
      \sa startValue
   */
  QVariant QVariantAnimation::endValue() const
  {
      return keyValueAt(1);
  }
  
  void QVariantAnimation::setEndValue(const QVariant &value)
  {
      setKeyValueAt(1, value);
  }
  
  
  /*!
      Returns the key frame value for the given \a step. The given \a step
      must be in the range 0 to 1. If there is no KeyValue for \a step,
      it returns an invalid QVariant.
  
      \sa keyValues(), setKeyValueAt()
  */
  QVariant QVariantAnimation::keyValueAt(qreal step) const
  {
      return d_func()->valueAt(step);
  }
  
  /*!
      \typedef QVariantAnimation::KeyValue
  
      This is a typedef for QPair<qreal, QVariant>.
  */
  /*!
      \typedef QVariantAnimation::KeyValues
  
      This is a typedef for QVector<KeyValue>
  */
  
  /*!
      Creates a key frame at the given \a step with the given \a value.
      The given \a step must be in the range 0 to 1.
  
      \sa setKeyValues(), keyValueAt()
  */
  void QVariantAnimation::setKeyValueAt(qreal step, const QVariant &value)
  {
      d_func()->setValueAt(step, value);
  }
  
  /*!
      Returns the key frames of this animation.
  
      \sa keyValueAt(), setKeyValues()
  */
  QVariantAnimation::KeyValues QVariantAnimation::keyValues() const
  {
      return d_func()->keyValues;
  }
  
  /*!
      Replaces the current set of key frames with the given \a keyValues.
      the step of the key frames must be in the range 0 to 1.
  
      \sa keyValues(), keyValueAt()
  */
  void QVariantAnimation::setKeyValues(const KeyValues &keyValues)
  {
      Q_D(QVariantAnimation);
      d->keyValues = keyValues;
      std::sort(d->keyValues.begin(), d->keyValues.end(), animationValueLessThan);
      d->recalculateCurrentInterval(/*force=*/true);
  }
  
  /*!
      \property QVariantAnimation::currentValue
      \brief the current value of the animation.
  
      This property describes the current value; an interpolated value
      between the \l{startValue}{start value} and the \l{endValue}{end
      value}, using the current time for progress. The value itself is
      obtained from interpolated(), which is called repeatedly as the
      animation is running.
  
      QVariantAnimation calls the virtual updateCurrentValue() function
      when the current value changes. This is particularly useful for
      subclasses that need to track updates. For example,
      QPropertyAnimation uses this function to animate Qt \l{Qt's
      Property System}{properties}.
  
      \sa startValue, endValue
  */
  QVariant QVariantAnimation::currentValue() const
  {
      Q_D(const QVariantAnimation);
      if (!d->currentValue.isValid())
          const_cast<QVariantAnimationPrivate*>(d)->recalculateCurrentInterval();
      return d->currentValue;
  }
  
  /*!
      \reimp
   */
  bool QVariantAnimation::event(QEvent *event)
  {
      return QAbstractAnimation::event(event);
  }
  
  /*!
      \reimp
  */
  void QVariantAnimation::updateState(QAbstractAnimation::State newState,
                                      QAbstractAnimation::State oldState)
  {
      Q_UNUSED(oldState);
      Q_UNUSED(newState);
  }
  
  /*!
  
      This virtual function returns the linear interpolation between
      variants \a from and \a to, at \a progress, usually a value
      between 0 and 1. You can reimplement this function in a subclass
      of QVariantAnimation to provide your own interpolation algorithm.
  
      Note that in order for the interpolation to work with a
      QEasingCurve that return a value smaller than 0 or larger than 1
      (such as QEasingCurve::InBack) you should make sure that it can
      extrapolate. If the semantic of the datatype does not allow
      extrapolation this function should handle that gracefully.
  
      You should call the QVariantAnimation implementation of this
      function if you want your class to handle the types already
      supported by Qt (see class QVariantAnimation description for a
      list of supported types).
  
      \sa QEasingCurve
   */
  QVariant QVariantAnimation::interpolated(const QVariant &from, const QVariant &to, qreal progress) const
  {
      return d_func()->interpolator(from.constData(), to.constData(), progress);
  }
  
  /*!
      \reimp
   */
  void QVariantAnimation::updateCurrentTime(int)
  {
      d_func()->recalculateCurrentInterval();
  }
  
  QT_END_NAMESPACE
  
  #include "moc_qvariantanimation.cpp"
  
  #endif //QT_NO_ANIMATION
  