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

  Program:   ParaView
  Module:    vtkSMTransferFunctionManager.h

  Copyright (c) Kitware, Inc.
  All rights reserved.
  See Copyright.txt or http://www.paraview.org/HTML/Copyright.html for details.

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

=========================================================================*/
/**
 * @class   vtkSMTransferFunctionManager
 * @brief   manages transfer functions i.e. color
 * lookuptables and opacity piecewise functions for ParaView applications.
 *
 * vtkSMTransferFunctionManager manages transfer functions i.e. color
 * lookuptables and opacity piecewise functions for ParaView applications.
 * vtkSMTransferFunctionManager implements the ParaView specific mechanism for
 * managing such transfer function proxies where there's one transfer function
 * created and maintained per data array name.
 *
 * vtkSMTransferFunctionManager has no state. You can create as many instances as
 * per your choosing to call the methods. It uses the session proxy manager to
 * locate proxies registered using specific names under specific groups. Thus,
 * the state is maintained by the proxy manager itself.
*/

#ifndef vtkSMTransferFunctionManager_h
#define vtkSMTransferFunctionManager_h

#include "vtkPVServerManagerRenderingModule.h" // needed for export macro
#include "vtkSMObject.h"

class vtkSMProxy;
class vtkSMSessionProxyManager;

class VTKPVSERVERMANAGERRENDERING_EXPORT vtkSMTransferFunctionManager : public vtkSMObject
{
public:
  static vtkSMTransferFunctionManager* New();
  vtkTypeMacro(vtkSMTransferFunctionManager, vtkSMObject);
  void PrintSelf(ostream& os, vtkIndent indent);

  /**
   * Returns a color transfer function proxy instance for mapping a data array
   * with the given name. If none exists in the given
   * session, a new instance will be created and returned.
   */
  virtual vtkSMProxy* GetColorTransferFunction(
    const char* arrayName, vtkSMSessionProxyManager* pxm);

  /**
   * Returns a opacity transfer function proxy (aka Piecewise Function) instance
   * for mapping a data array with the given name. If
   * none exists in the given session, a new instance will be created and
   * returned.
   */
  virtual vtkSMProxy* GetOpacityTransferFunction(
    const char* arrayName, vtkSMSessionProxyManager* pxm);

  /**
   * Returns the scalar-bar (color-legend) representation corresponding to the
   * transfer function for the view (currently only render-views are supported).
   * Thus returns an existing proxy, if present, otherwise a new one is created,
   * if possible.
   */
  virtual vtkSMProxy* GetScalarBarRepresentation(
    vtkSMProxy* colorTransferFunctionProxy, vtkSMProxy* view);

  /**
   * Iterates over all "known" transfer function proxies and request each one of
   * them to update its range using data information currently available.
   * If \c extend is true, the transfer function is expanded to accommodate
   * current data range rather then resetting it to the range.
   */
  void ResetAllTransferFunctionRangesUsingCurrentData(
    vtkSMSessionProxyManager* pxm, bool extend = false);

  enum UpdateScalarBarsMode
  {
    HIDE_UNUSED_SCALAR_BARS = 0x01,
    SHOW_USED_SCALAR_BARS = 0x02
  };

  /**
   * Updates the scalar bar visibility in the view. Based on the specified mode,
   * scalars bars representing non-represented arrays can be automatically hidden;
   * and those corresponding to arrays used for coloring can be automatically shown.
   */
  virtual bool UpdateScalarBars(vtkSMProxy* viewProxy, unsigned int mode);

  /**
   * Hides the scalar bar, if any, for the lutProxy in the view if it's not
   * being used. Returns true if the scalar bar visibility was changed.
   */
  virtual bool HideScalarBarIfNotNeeded(vtkSMProxy* lutProxy, vtkSMProxy* view);

protected:
  vtkSMTransferFunctionManager();
  ~vtkSMTransferFunctionManager();

private:
  vtkSMTransferFunctionManager(const vtkSMTransferFunctionManager&) VTK_DELETE_FUNCTION;
  void operator=(const vtkSMTransferFunctionManager&) VTK_DELETE_FUNCTION;
};

#endif
