qtOperationLauncher.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_extension_qtOperationLauncher_h
#define smtk_extension_qtOperationLauncher_h
 
#include "smtk/extension/qt/Exports.h"
 
#include "smtk/attribute/Attribute.h"
#include "smtk/attribute/Resource.h"
 
#include "smtk/common/ThreadPool.h"
 
#include "smtk/operation/Operation.h"
 
#include <QObject>
#include <QString>
 
#include <future>
 
namespace smtk
{
namespace extension
{
 
class Launcher;
 
class SMTKQTEXT_EXPORT ResultHandler : public QObject
{
  Q_OBJECT
 
public:
  explicit ResultHandler();
  smtk::operation::Operation::Result waitForResult();
  std::shared_future<smtk::operation::Operation::Result>& future() { return m_future; }
 
Q_SIGNALS:
  void resultReady(smtk::operation::Operation::Result result);
 
private:
  friend class qtOperationLauncher;
  friend class Launcher;
  std::shared_future<smtk::operation::Operation::Result> m_future;
};
 
class SMTKQTEXT_EXPORT qtOperationLauncher : public QObject
{
  Q_OBJECT
 
public:
  static constexpr const char* const type_name = "smtk::extension::qtOperationLauncher";
 
  std::shared_ptr<ResultHandler> operator()(const smtk::operation::Operation::Ptr& operation);
 
  int activeOperations() const { return m_operationCount; }
 
  static bool setBusyCursorBehavior(bool enabled);
 
Q_SIGNALS:
  void operationHasResult(QString parametersName, QString resultName, QPrivateSignal);
 
private:
  smtk::operation::Operation::Result run(smtk::operation::Operation::Ptr operation);
 
  void decrementCount(smtk::operation::Operation::Result result);
 
  smtk::common::ThreadPool<smtk::operation::Operation::Result> m_threadPool;
 
  std::atomic<int> m_operationCount{ 0 };
  static bool s_busyCursorEnabled;
};
 
namespace qt
{
class Launcher
{
public:
  Launcher()
    : m_launcher(new qtOperationLauncher)
  {
  }
 
  Launcher(const Launcher&)
    : m_launcher(new qtOperationLauncher)
  {
  }
 
  Launcher(Launcher&& other) noexcept
    : m_launcher{ other.m_launcher }
  {
    other.m_launcher = nullptr;
  }
 
  Launcher& operator=(Launcher&& other) noexcept
  {
    if (&other != this)
    {
      delete m_launcher;
      m_launcher = other.m_launcher;
      other.m_launcher = nullptr;
    }
    return *this;
  }
 
  ~Launcher() { delete m_launcher; }
 
  std::shared_future<smtk::operation::Operation::Result> operator()(
    const smtk::operation::Operation::Ptr& operation)
  {
    auto resHandler = (*m_launcher)(operation);
    return resHandler->future();
  }
 
  qtOperationLauncher* get() const { return m_launcher; }
 
private:
  qtOperationLauncher* m_launcher;
};
} // namespace qt
} // namespace extension
} // namespace smtk
 
#endif