Manager.h

//=========================================================================
//  Copyright (c) Kitware, Inc.
//  All rights reserved.
//  See LICENSE.txt 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.
//=========================================================================
#ifndef smtk_geometry_Manager_h
#define smtk_geometry_Manager_h
 
#include "smtk/geometry/Backend.h"
#include "smtk/geometry/Resource.h"
 
#include "smtk/resource/Manager.h"
#include "smtk/resource/Observer.h"
 
#include "smtk/common/TypeName.h"
#include "smtk/common/UUID.h"
 
#include "smtk/CoreExports.h"
#include "smtk/PublicPointerDefs.h"
#include "smtk/SharedFromThis.h"
#include "smtk/SystemConfig.h"
 
#include <functional>
#include <string>
#include <typeinfo>
#include <unordered_map>
 
namespace smtk
{
namespace geometry
{
class SMTKCORE_EXPORT Manager : smtkEnableSharedPtr(Manager)
{
public:
  smtkTypedefs(smtk::geometry::Manager);
  smtkCreateMacro(Manager);
 
  virtual ~Manager() = default;
 
  template<typename Backend>
  bool registerBackend()
  {
    auto entry = std::make_shared<Backend>();
    if (m_backends.find(entry->index()) == m_backends.end())
    {
      m_backends[entry->index()] = entry;
      if (auto resourceManager = m_resourceManager.lock())
      {
        this->constructGeometry(resourceManager, *entry);
      }
      return true;
    }
    return false;
  }
 
  template<typename Backend>
  bool unregisterBackend()
  {
    Backend entry;
    auto it = m_backends.find(entry.index());
    if (it == m_backends.end())
    {
      return false;
    }
    m_backends.erase(it);
    return true;
  }
 
  void visitBackends(std::function<void(const Backend&)> visitor) const;
 
  void registerResourceManager(const smtk::resource::Manager::Ptr& manager);
 
protected:
  void constructGeometry(
    const std::shared_ptr<smtk::resource::Manager>& resourceManager,
    Backend& backend);
 
private:
  Manager() = default;
 
  std::weak_ptr<smtk::resource::Manager> m_resourceManager;
  smtk::resource::Observers::Key m_resourceObserverKey;
  std::map<Backend::index_t, std::shared_ptr<Backend>> m_backends;
};
 
} // namespace geometry
} // namespace smtk
 
#endif // smtk_geometry_Manager_h