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

   Program: ParaView
   Module:    $RCSfile: pqChartPixelScale.h,v $

   Copyright (c) 2005-2008 Sandia Corporation, Kitware Inc.
   All rights reserved.

   ParaView is a free software; you can redistribute it and/or modify it
   under the terms of the ParaView license version 1.2. 

   See License_v1.2.txt for the full ParaView license.
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR
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=========================================================================*/

/// \file pqChartPixelScale.h
/// \date 7/25/2006

#ifndef _pqChartPixelScale_h
#define _pqChartPixelScale_h


#include "QtChartExport.h"

class pqChartPixelScaleInternal;
class pqChartValue;


/// \class pqChartPixelScale
/// \brief
///   The pqChartPixelScale class maps chart values to pixel locations.
class QTCHART_EXPORT pqChartPixelScale
{
public:
  enum ValueScale {
    Linear,     ///< Use a linear scale.
    Logarithmic ///< Use a logarithmic scale.
  };

public:
  pqChartPixelScale();
  ~pqChartPixelScale();

  /// \name Value Parameters
  //@{
  /// \brief
  ///   Sets the value range.
  /// \param min The minimum value.
  /// \param max The maximum value.
  /// \return
  ///   True if the pixel-value scale changed.
  bool setValueRange(const pqChartValue &min, const pqChartValue &max);

  /// \brief
  ///   Gets the value range.
  /// \param range Used to return the difference between the minimum
  ///   and maximum values.
  void getValueRange(pqChartValue &range) const;

  /// \brief
  ///   Sets the minimum value.
  /// \param min The minimum value.
  /// \return
  ///   True if the pixel-value scale changed.
  bool setMinValue(const pqChartValue &min);

  /// \brief
  ///   Gets the minimum value.
  /// \return
  ///   The minimum value.
  const pqChartValue &getMinValue() const;

  /// \brief
  ///   Sets the maximum value.
  /// \param max The maximum value.
  /// \return
  ///   True if the pixel-value scale changed.
  bool setMaxValue(const pqChartValue &max);

  /// \brief
  ///   Gets the maximum value.
  /// \return
  ///   The maximum value.
  const pqChartValue &getMaxValue() const;
  //@}

  /// \name Pixel Parameters
  //@{
  /// \brief
  ///   Sets the pixel range.
  /// \param min The minimum pixel location.
  /// \param max The maximum pixel location.
  /// \return
  ///   True if the pixel-value scale changed.
  bool setPixelRange(int min, int max);

  /// \brief
  ///   Gets the pixel range.
  ///
  /// The pixel range is always returned as a positive number.
  ///
  /// \return 
  ///   The difference between the minimum and maximum pixels.
  int getPixelRange() const;

  /// \brief
  ///   Sets the minimum pixel location.
  /// \param min The minimum pixel location.
  /// \return
  ///   True if the pixel-value scale changed.
  bool setMinPixel(int min);

  /// \brief
  ///   Gets the minimum pixel location.
  /// \return
  ///   The minimum pixel location.
  int getMinPixel() const;

  /// \brief
  ///   Sets the maximum pixel location.
  /// \param max The maximum pixel location.
  /// \return
  ///   True if the pixel-value scale changed.
  bool setMaxPixel(int max);

  /// \brief
  ///   Gets the maximum pixel location.
  /// \return
  ///   The maximum pixel location.
  int getMaxPixel() const;
  //@}

  /// \name Pixel to Value Mapping
  //@{
  /// \brief
  ///   Maps a value to a pixel.
  /// \param value The data value.
  /// \return
  ///   The pixel location for the given value.
  /// \sa pqChartPixelScale::isValid(),
  ///     pqChartPixelScale::getValue(int)
  int getPixel(const pqChartValue &value) const;

  /// \brief
  ///   Maps a value to a pixel.
  /// \param value The data value.
  /// \return
  ///   The pixel location for the given value.
  /// \sa pqChartPixelScale::isValid(),
  ///     pqChartPixelScale::getValue(int)
  float getPixelF(const pqChartValue &value) const;

  /// \brief
  ///   Maps a pixel to a value.
  /// \param pixel The pixel location.
  /// \param value Used to return the value equivalent to the pixel
  ///   location.
  /// \sa pqChartPixelScale::isValid(),
  ///     pqChartPixelScale::getPixel(const pqChartValue &)
  void getValue(int pixel, pqChartValue &value) const;

  /// \brief
  ///   Used to determine if the pixel/value mapping is valid.
  /// \return
  ///   True if the pixel/value mapping is valid.
  bool isValid() const;

  /// \brief
  ///   Used to determine if zero is in the value range.
  /// \return
  ///   True if zero is in the value range.
  bool isZeroInRange() const;

  /// \brief
  ///   Sets the scale type.
  /// \param scale The new scale type.
  void setScaleType(ValueScale scale);

  /// \brief
  ///   Gets the scale type.
  /// \return
  ///   The current scale type.
  ValueScale getScaleType() const;

  /// \brief
  ///   Gets wether or not logarithmic scale can be used.
  /// \return
  ///   True if logarithmic scale can be used.
  bool isLogScaleAvailable() const;
  //@}

public:
  static bool isLogScaleValid(const pqChartValue &min,
      const pqChartValue &max);

public:
  static const double MinLogValue;     ///< Stores the log scale minimum.

private:
  pqChartPixelScaleInternal *Internal; ///< Stores the pixel/range mapping.
};

#endif
