/*=========================================================================

  Library:   CTK

  Copyright (c) Kitware Inc. 
  All rights reserved.
  Distributed under a BSD License. See LICENSE.txt file.

  This software is distributed "AS IS" WITHOUT ANY WARRANTY; without even
  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the above copyright notice for more information.

=========================================================================*/

// QT includes
#include <QDebug>
#include <QHBoxLayout>

// CTK includes
#include "ctkDoubleSlider.h"

// STD includes
#include <limits>

//-----------------------------------------------------------------------------
class ctkDoubleSliderPrivate: public ctkPrivate<ctkDoubleSlider>
{
  public:
  ctkDoubleSliderPrivate();
  int toInt(double _value)const;
  double fromInt(int _value)const;
  void init();
  void updateOffset(double value);

  QSlider*    Slider;
  double      Minimum;
  double      Maximum;
  // we should have a Offset and SliderPositionOffset (and MinimumOffset?)
  double      Offset;
  double      SingleStep;
  double      Value;
};

// --------------------------------------------------------------------------
ctkDoubleSliderPrivate::ctkDoubleSliderPrivate()
{
  this->Slider = 0;
  this->Minimum = 0.;
  this->Maximum = 100.;
  this->Offset = 0.;
  this->SingleStep = 1.;
  this->Value = 0.;
}

// --------------------------------------------------------------------------
void ctkDoubleSliderPrivate::init()
{
  CTK_P(ctkDoubleSlider);
  this->Slider = new QSlider(p);
  QHBoxLayout* l = new QHBoxLayout(p);
  l->addWidget(this->Slider);
  l->setContentsMargins(0,0,0,0);
  
  this->Minimum = this->Slider->minimum();
  this->Maximum = this->Slider->maximum();
  this->SingleStep = this->Slider->singleStep();
  this->Value = this->Slider->value();

  p->connect(this->Slider, SIGNAL(valueChanged(int)), p, SLOT(onValueChanged(int)));
  p->connect(this->Slider, SIGNAL(sliderMoved(int)), p, SLOT(onSliderMoved(int)));
  p->connect(this->Slider, SIGNAL(sliderPressed()), p, SIGNAL(sliderPressed()));
  p->connect(this->Slider, SIGNAL(sliderReleased()), p, SIGNAL(sliderReleased()));
}
  
// --------------------------------------------------------------------------
int ctkDoubleSliderPrivate::toInt(double doubleValue)const
{
  double tmp = doubleValue / this->SingleStep;
  static const double minInt = std::numeric_limits<int>::min();
  static const double maxInt = std::numeric_limits<int>::max();
#ifndef QT_NO_DEBUG
  if (tmp < minInt || tmp > maxInt)
    {
    qWarning("ctkDoubleSliderPrivate::toInt value out of bounds !");
    }
#endif
  tmp = qBound(minInt, tmp, maxInt);
  int intValue = qRound(tmp);
  //qDebug() << __FUNCTION__ << doubleValue << tmp << intValue;
  return intValue;
}

// --------------------------------------------------------------------------
double ctkDoubleSliderPrivate::fromInt(int intValue)const
{
  double doubleValue = this->SingleStep * (this->Offset + intValue) ;
  //qDebug() << __FUNCTION__ << intValue << doubleValue;
  return doubleValue;
}

// --------------------------------------------------------------------------
void ctkDoubleSliderPrivate::updateOffset(double value)
{
  this->Offset = (value / this->SingleStep) - this->toInt(value);
}

// --------------------------------------------------------------------------
ctkDoubleSlider::ctkDoubleSlider(QWidget* _parent) : Superclass(_parent)
{
  CTK_INIT_PRIVATE(ctkDoubleSlider);
  ctk_d()->init();
}

// --------------------------------------------------------------------------
ctkDoubleSlider::ctkDoubleSlider(Qt::Orientation _orientation, QWidget* _parent)
  : Superclass(_parent)
{
  CTK_INIT_PRIVATE(ctkDoubleSlider);
  ctk_d()->init();
  this->setOrientation(_orientation);
}

// --------------------------------------------------------------------------
ctkDoubleSlider::~ctkDoubleSlider()
{
}

// --------------------------------------------------------------------------
void ctkDoubleSlider::setMinimum(double min)
{
  CTK_D(ctkDoubleSlider);
  d->Minimum = min;
  if (d->Minimum >= d->Value)
    {
    d->updateOffset(d->Minimum);
    }
  d->Slider->setMinimum(d->toInt(min));
}

// --------------------------------------------------------------------------
void ctkDoubleSlider::setMaximum(double max)
{
  CTK_D(ctkDoubleSlider);
  d->Maximum = max;
  if (d->Maximum <= d->Value)
    {
    d->updateOffset(d->Maximum);
    }
  d->Slider->setMaximum(d->toInt(max));
}

// --------------------------------------------------------------------------
void ctkDoubleSlider::setRange(double min, double max)
{
  CTK_D(ctkDoubleSlider);
  d->Minimum = min;
  d->Maximum = max;
  
  if (d->Minimum >= d->Value)
    {
    d->updateOffset(d->Minimum);
    }
  if (d->Maximum <= d->Value)
    {
    d->updateOffset(d->Maximum);
    }
  
  d->Slider->setRange(d->toInt(min), d->toInt(max));
}

// --------------------------------------------------------------------------
double ctkDoubleSlider::minimum()const
{
  CTK_D(const ctkDoubleSlider);
  return d->Minimum;
}

// --------------------------------------------------------------------------
double ctkDoubleSlider::maximum()const
{
  CTK_D(const ctkDoubleSlider);
  return d->Maximum;
}

// --------------------------------------------------------------------------
double ctkDoubleSlider::sliderPosition()const
{
  CTK_D(const ctkDoubleSlider);
  return d->fromInt(d->Slider->sliderPosition());
}

// --------------------------------------------------------------------------
void ctkDoubleSlider::setSliderPosition(double newSliderPosition)
{
  CTK_D(ctkDoubleSlider);
  d->Slider->setSliderPosition(d->toInt(newSliderPosition));
}

// --------------------------------------------------------------------------
double ctkDoubleSlider::value()const
{
  CTK_D(const ctkDoubleSlider);
  return d->Value;
}

// --------------------------------------------------------------------------
void ctkDoubleSlider::setValue(double newValue)
{
  CTK_D(ctkDoubleSlider);
  newValue = qBound(d->Minimum, newValue, d->Maximum);
  d->updateOffset(newValue);
  int newIntValue = d->toInt(newValue);
  if (newIntValue != d->Slider->value())
    {
    // d->Slider will emit a valueChanged signal that is connected to
    // ctkDoubleSlider::onValueChanged
    d->Slider->setValue(newIntValue);
    }
  else
    {
    double oldValue = d->Value;
    d->Value = newValue;
    // don't emit a valuechanged signal if the new value is quite 
    // similar to the old value.
    if (qAbs(newValue - oldValue) > (d->SingleStep * 0.000000001))
      {
      emit this->valueChanged(newValue);
      }
    }
}

// --------------------------------------------------------------------------
double ctkDoubleSlider::singleStep()const
{
  CTK_D(const ctkDoubleSlider);
  return d->SingleStep;
}

// --------------------------------------------------------------------------
void ctkDoubleSlider::setSingleStep(double newStep)
{
  CTK_D(ctkDoubleSlider);
  d->SingleStep = newStep;
  // update the new values of the QSlider
  double _value = d->Value;
  d->updateOffset(_value);
  bool oldBlockSignals = this->blockSignals(true);
  this->setRange(d->Minimum, d->Maximum);
  d->Slider->setValue(d->toInt(_value));
  d->Value = _value;
  this->blockSignals(oldBlockSignals);
}

// --------------------------------------------------------------------------
double ctkDoubleSlider::tickInterval()const
{
  CTK_D(const ctkDoubleSlider);
  return d->fromInt(d->Slider->tickInterval());
}

// --------------------------------------------------------------------------
void ctkDoubleSlider::setTickInterval(double newTickInterval)
{
  CTK_D(ctkDoubleSlider);
  d->Slider->setTickInterval(d->toInt(newTickInterval));
}

// --------------------------------------------------------------------------
bool ctkDoubleSlider::hasTracking()const
{
  CTK_D(const ctkDoubleSlider);
  return d->Slider->hasTracking();
}

// --------------------------------------------------------------------------
void ctkDoubleSlider::setTracking(bool enable)
{
  CTK_D(ctkDoubleSlider);
  d->Slider->setTracking(enable);
}

// --------------------------------------------------------------------------
void ctkDoubleSlider::triggerAction( QAbstractSlider::SliderAction action)
{
  CTK_D(ctkDoubleSlider);
  d->Slider->triggerAction(action);
}

// --------------------------------------------------------------------------
Qt::Orientation ctkDoubleSlider::orientation()const
{
  CTK_D(const ctkDoubleSlider);
  return d->Slider->orientation();
}

// --------------------------------------------------------------------------
void ctkDoubleSlider::setOrientation(Qt::Orientation newOrientation)
{
  CTK_D(ctkDoubleSlider);
  d->Slider->setOrientation(newOrientation);
}

// --------------------------------------------------------------------------
void ctkDoubleSlider::onValueChanged(int newValue)
{
  CTK_D(ctkDoubleSlider);
  double doubleNewValue = d->fromInt(newValue);
/*
  qDebug() << "onValueChanged: " << newValue << "->"<< d->fromInt(newValue+d->Offset) 
           << " old: " << d->Value << "->" << d->toInt(d->Value) 
           << "offset:" << d->Offset << doubleNewValue;
*/
  if (d->Value == doubleNewValue)
    {
    return;
    }
  d->Value = doubleNewValue;
  emit this->valueChanged(d->Value);
}

// --------------------------------------------------------------------------
void ctkDoubleSlider::onSliderMoved(int newPosition)
{
  CTK_D(const ctkDoubleSlider);
  emit this->sliderMoved(d->fromInt(newPosition));
}