CTK/Libs/Core/ctkWorkflowTransitions.h

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

  Library:   CTK
 
  Copyright (c) 2010  Kitware Inc.

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

      http://www.commontk.org/LICENSE

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

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

#ifndef __ctkWorkflowTransition_h
#define __ctkWorkflowTransition_h

// Qt includes
#include <QEvent>
#include <QAbstractTransition>
#include <QString>

// CTK includes
#include "CTKCoreExport.h"

/// \brief Custom transitions for use with ctkWorkflow.
///
/// ctkWorkflowIntrastepTransition: for transition between states of the same step.  The transition
/// occurs only when the transition event's EventTransitionType matches the transition's
/// TransitionType).
///
/// ctkWorkflowInterstepTransition: for transition between states of different steps (i.e. when
/// transitioning between steps).  The transition occurs only when the transition event's
/// EventTransitionType matches the transition's TransitionType, and when the transition event's
/// EventId matches the transition's Id.
///
/// Example:
/// \code
/// ctkWorkflowInterstepTransition *transition = new
/// ctkWorkflowInterstepTransition(ctkWorkflowInterstepTransition::TransitionToNextStep, "branchId");
///
/// workflow.postEvent(new
/// ctkWorkflowInterstepTransition(ctkWorkflowInterstepTransition::TransitionToNextStep, "branchId")
/// \endcode

//-----------------------------------------------------------------------------
struct CTK_CORE_EXPORT ctkWorkflowIntrastepTransitionEvent : public QEvent
{

  /// EventTransitionType is the value of a transition event, used to conditionally trigger transitions
  ctkWorkflowIntrastepTransitionEvent(int newTransitionType)
    : QEvent(QEvent::Type(getWorkflowIntrastepTransitionEventType())),
      EventTransitionType(newTransitionType){}

  /// Reserve a custom event type, ensuring that we are not re-using an
  /// event type that was previously used
  static inline int getWorkflowIntrastepTransitionEventType()
  {
    static int workflowIntrastepTransitionEventType = QEvent::registerEventType(QEvent::User+1);
    return workflowIntrastepTransitionEventType;
  }

  int EventTransitionType;
};

//-----------------------------------------------------------------------------
class CTK_CORE_EXPORT ctkWorkflowIntrastepTransition : public QAbstractTransition
{
  Q_OBJECT

public:

  enum IntrastepTransitionType
  {
    ValidationTransition = 0,
    ValidationFailedTransition
  };

  ctkWorkflowIntrastepTransition(IntrastepTransitionType newTransitionType)
    : TransitionType(newTransitionType){}

  IntrastepTransitionType transitionType() {return this->TransitionType;}

protected:
  virtual bool eventTest(QEvent* e)
  {
    // check the event type
    if (e->type() != ctkWorkflowIntrastepTransitionEvent::getWorkflowIntrastepTransitionEventType())
      {
      return false;
      }

    // check the event value (i.e. the TransitionType)
    ctkWorkflowIntrastepTransitionEvent* workflowEvent = static_cast<ctkWorkflowIntrastepTransitionEvent*>(e);

    return (this->TransitionType == workflowEvent->EventTransitionType);
  }

  void onTransition(QEvent*){}

private:
  IntrastepTransitionType TransitionType;

};

//-----------------------------------------------------------------------------
struct CTK_CORE_EXPORT ctkWorkflowInterstepTransitionEvent : public QEvent
{

  /// EventTransitionType is the value of a transition event, used to conditionally trigger transitions
  ctkWorkflowInterstepTransitionEvent(int newTransitionType)
    : QEvent(QEvent::Type(getWorkflowInterstepTransitionEventType())),
      EventTransitionType(newTransitionType){}
  ctkWorkflowInterstepTransitionEvent(int newTransitionType, const QString& newId)
    : QEvent(QEvent::Type(getWorkflowInterstepTransitionEventType())),
    EventTransitionType(newTransitionType),
    EventId(newId){}

  /// Reserve a custom event type, ensuring that we are not re-using an
  /// event type that was previously used
  static inline int getWorkflowInterstepTransitionEventType()
  {
    static int workflowInterstepTransitionEventType = QEvent::registerEventType(QEvent::User+1);
    return workflowInterstepTransitionEventType;
  }

  int     EventTransitionType;
  QString EventId;
};

//-----------------------------------------------------------------------------
class CTK_CORE_EXPORT ctkWorkflowInterstepTransition : public QAbstractTransition
{
  Q_OBJECT

public:

  enum InterstepTransitionType
  {
    TransitionToNextStep = 0,
    TransitionToPreviousStep,
    StartingWorkflow,
    StoppingWorkflow,
    TransitionToPreviousStartingStepAfterSuccessfulGoToFinishStep
  };

  ctkWorkflowInterstepTransition(InterstepTransitionType newTransitionType)
    : TransitionType(newTransitionType){}
  ctkWorkflowInterstepTransition(InterstepTransitionType newTransitionType, const QString& newId)
    : TransitionType(newTransitionType),
    Id(newId) {}

  InterstepTransitionType transitionType() {return this->TransitionType;}
  QString& id() {return this->Id;}

protected:
  virtual bool eventTest(QEvent* e)
  {
    // check the event type
    if (e->type() != ctkWorkflowInterstepTransitionEvent::getWorkflowInterstepTransitionEventType())
      {
      return false;
      }

    // check the event value (i.e. the TransitionType)
    ctkWorkflowInterstepTransitionEvent* workflowEvent = static_cast<ctkWorkflowInterstepTransitionEvent*>(e);

    return (this->TransitionType == workflowEvent->EventTransitionType
            && this->Id == workflowEvent->EventId); 
  }

  void onTransition(QEvent*){}

private:
  InterstepTransitionType TransitionType;
  QString                 Id;

};

#endif