// SPDX-FileCopyrightText: Copyright (c) Kitware Inc.
// SPDX-License-Identifier: BSD-3-Clause
/**
 * @class   vtkPVKeyFrame
 *
 * Base class for key frames.
 * A key frame is responsible to interpolate the curve
 * between it self and a consequent key frame. A new subclass is
 * needed for each type of interpolation available between two
 * key frames. This class can be instantiated to create a no-action key
 * frame.
 */

#ifndef vtkPVKeyFrame_h
#define vtkPVKeyFrame_h

#include "vtkObject.h"
#include "vtkRemotingAnimationModule.h" // needed for export macro

class vtkPVKeyFrameInternals;
class vtkPVAnimationCue;
struct vtkClientServerID;

class VTKREMOTINGANIMATION_EXPORT vtkPVKeyFrame : public vtkObject
{
public:
  vtkTypeMacro(vtkPVKeyFrame, vtkObject);
  void PrintSelf(ostream& os, vtkIndent indent) override;
  static vtkPVKeyFrame* New();

  ///@{
  /**
   * Key time is the time at which this key frame is
   * associated. KeyTime ranges from [0,1], where 0 is the
   * start time of the cue for which this is a key frame and
   * 1 is that cue's end time.
   */
  vtkSetMacro(KeyTime, double);
  vtkGetMacro(KeyTime, double);
  ///@}

  ///@{
  /**
   * Get/Set the animated value at this key frame.
   * Note that is the number of values is adjusted to fit the index
   * specified in SetKeyValue.
   */
  virtual void SetKeyValue(double val) { this->SetKeyValue(0, val); }
  virtual void SetKeyValue(unsigned int index, double val);
  double GetKeyValue() { return this->GetKeyValue(0); }
  double GetKeyValue(unsigned int index);
  ///@}

  /**
   * Removes all key values.
   */
  virtual void RemoveAllKeyValues();

  ///@{
  /**
   * Set/Get the number of key values this key frame currently stores.
   */
  unsigned int GetNumberOfKeyValues();
  virtual void SetNumberOfKeyValues(unsigned int num);
  ///@}

  /**
   * This method will do the actual interpolation.
   * currenttime is normalized to the time range between
   * this key frame and the next key frame.
   */
  virtual void UpdateValue(double currenttime, vtkPVAnimationCue* cue, vtkPVKeyFrame* next);

protected:
  vtkPVKeyFrame();
  ~vtkPVKeyFrame() override;

  double KeyTime;
  vtkPVKeyFrameInternals* Internals;

private:
  vtkPVKeyFrame(const vtkPVKeyFrame&) = delete;
  void operator=(const vtkPVKeyFrame&) = delete;
};

#endif
