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

  Program:   ParaView
  Module:    vtkSMGlobalPropertiesProxy.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.

=========================================================================*/
// .NAME vtkSMGlobalPropertiesProxy - proxy that adds support for linking
// properties with other proxies designed for use-cases like color-palettes.
// .SECTION Description
// vtkSMGlobalPropertiesProxy can be thought of as a proxy which provides API to
// link its properties with any arbitrary proxy unidirectionally, so that if the
// property value on this proxy changes, the linked property on every other
// proxy is updated. However if the linked property (or target property) is
// modified externally, then the link is automatically broken.
//
// This is suitable adding ability for color palettes. Using XML hints in the
// proxy definition, one can write application code that setups links with a
// proxy and the color palette proxy (as done in
// vtkSMParaViewPipelineController). Now as long as the user doesn't modify
// the linked properties, the color palette can be changed and it will reflect
// on all linked properties.
//
// vtkSMParaViewPipelineController uses the property level hint
// <GlobalPropertyLink /> to define such links e.g.
//    \code
//    <DoubleVectorProperty name="Background" ... >
//         ...
//      <Hints>
//        <GlobalPropertyLink type="ColorPalette" property="BackgroundColor" />
//      </Hints>
//    </DoubleVectorProperty>
//    \endcode
//
// While vtkSMParaViewPipelineController currently only respects
// hints on the property, we can in future add support for respecting hints at
// the proxy level if needed.

#ifndef vtkSMGlobalPropertiesProxy_h
#define vtkSMGlobalPropertiesProxy_h

#include "vtkSMProxy.h"
#include "vtkPVServerManagerCoreModule.h" //needed for exports

class VTKPVSERVERMANAGERCORE_EXPORT vtkSMGlobalPropertiesProxy : public vtkSMProxy
{
public:
  static vtkSMGlobalPropertiesProxy* New();
  vtkTypeMacro(vtkSMGlobalPropertiesProxy, vtkSMProxy);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Set up a property link with the given property on the proxy with the
  // specified property on this proxy. The link is automatically broken if the
  // target property is modified outside by someone other than this
  // vtkSMGlobalPropertiesProxy instance or when the targetProxy is destroyed.
  bool Link(const char* propertyname,
    vtkSMProxy* targetProxy, const char* targetPropertyName);

  // Description:
  // Unlink a property link,
  bool Unlink(const char* propertyname,
    vtkSMProxy* targetProxy, const char* targetPropertyName);

  // Description:
  // Remove all links.
  void RemoveAllLinks();

  // Description:
  // If a link between the target and a property on this proxy exists, returns
  // the name of that property else NULL.
  const char* GetLinkedPropertyName(vtkSMProxy* targetProxy, const char* targetPropertyName);

  // Description:
  // Overridden to save link state.
  virtual vtkPVXMLElement* SaveXMLState(vtkPVXMLElement* root, vtkSMPropertyIterator* iter);
  using Superclass::SaveXMLState;

  // Description:
  // Overridden to load links state.
  virtual int LoadXMLState(vtkPVXMLElement* element, vtkSMProxyLocator* locator);

protected:
  vtkSMGlobalPropertiesProxy();
  ~vtkSMGlobalPropertiesProxy();

  // Description:
  // Overridden to propagate the modification to the linked properties.
  virtual void SetPropertyModifiedFlag(const char* name, int flag);

  // Description:
  // Called when a target properties is modified.
  void TargetPropertyModified(vtkObject*, unsigned long, void*);

private:
  vtkSMGlobalPropertiesProxy(const vtkSMGlobalPropertiesProxy&); // Not implemented
  void operator=(const vtkSMGlobalPropertiesProxy&); // Not implemented

  class vtkInternals;
  vtkInternals* Internals;

};

#endif
