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

  Program:   Visualization Toolkit
  Module:    vtkAngleWidget.cxx,v

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm 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.

=========================================================================*/
#include "vtkAngleWidget.h"
#include "vtkAngleRepresentation2D.h"
#include "vtkCallbackCommand.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkObjectFactory.h"
#include "vtkRenderer.h"
#include "vtkHandleWidget.h"
#include "vtkHandleRepresentation.h"
#include "vtkCoordinate.h"
#include "vtkWidgetCallbackMapper.h"
#include "vtkWidgetEvent.h"
#include "vtkWidgetEventTranslator.h"

vtkStandardNewMacro(vtkAngleWidget);

// The angle widget observes the handles.
// Here we create the command/observer classes to respond to the
// slider widgets.
class vtkAngleWidgetCallback : public vtkCommand
{
public:
  static vtkAngleWidgetCallback *New()
    { return new vtkAngleWidgetCallback; }
  void Execute(vtkObject*, unsigned long eventId, void*) override
  {
      switch (eventId)
      {
        case vtkCommand::StartInteractionEvent:
          this->AngleWidget->StartAngleInteraction(this->HandleNumber);
          break;
        case vtkCommand::InteractionEvent:
          this->AngleWidget->AngleInteraction(this->HandleNumber);
          break;
        case vtkCommand::EndInteractionEvent:
          this->AngleWidget->EndAngleInteraction(this->HandleNumber);
          break;
      }
  }
  int HandleNumber;
  vtkAngleWidget *AngleWidget;
};


//----------------------------------------------------------------------
vtkAngleWidget::vtkAngleWidget()
{
  this->ManagesCursor = 0;

  this->WidgetState = vtkAngleWidget::Start;
  this->CurrentHandle = 0;

  // The widgets for moving the end points. They observe this widget (i.e.,
  // this widget is the parent to the handles).
  this->Point1Widget = vtkHandleWidget::New();
  this->Point1Widget->SetParent(this);
  this->CenterWidget = vtkHandleWidget::New();
  this->CenterWidget->SetParent(this);
  this->Point2Widget = vtkHandleWidget::New();
  this->Point2Widget->SetParent(this);

  // Set up the callbacks on the two handles
  this->AngleWidgetCallback1 = vtkAngleWidgetCallback::New();
  this->AngleWidgetCallback1->HandleNumber = 0;
  this->AngleWidgetCallback1->AngleWidget = this;
  this->Point1Widget->AddObserver(vtkCommand::StartInteractionEvent, this->AngleWidgetCallback1,
                                  this->Priority);
  this->Point1Widget->AddObserver(vtkCommand::InteractionEvent, this->AngleWidgetCallback1,
                                  this->Priority);
  this->Point1Widget->AddObserver(vtkCommand::EndInteractionEvent, this->AngleWidgetCallback1,
                                  this->Priority);

  // Set up the callbacks on the two handles
  this->AngleWidgetCenterCallback = vtkAngleWidgetCallback::New();
  this->AngleWidgetCenterCallback->HandleNumber = 1;
  this->AngleWidgetCenterCallback->AngleWidget = this;
  this->CenterWidget->AddObserver(vtkCommand::StartInteractionEvent, this->AngleWidgetCenterCallback,
                                  this->Priority);
  this->CenterWidget->AddObserver(vtkCommand::InteractionEvent, this->AngleWidgetCenterCallback,
                                  this->Priority);
  this->CenterWidget->AddObserver(vtkCommand::EndInteractionEvent, this->AngleWidgetCenterCallback,
                                  this->Priority);

  this->AngleWidgetCallback2 = vtkAngleWidgetCallback::New();
  this->AngleWidgetCallback2->HandleNumber = 2;
  this->AngleWidgetCallback2->AngleWidget = this;
  this->Point2Widget->AddObserver(vtkCommand::StartInteractionEvent, this->AngleWidgetCallback2,
                                  this->Priority);
  this->Point2Widget->AddObserver(vtkCommand::InteractionEvent, this->AngleWidgetCallback2,
                                  this->Priority);
  this->Point2Widget->AddObserver(vtkCommand::EndInteractionEvent, this->AngleWidgetCallback2,
                                  this->Priority);


  // These are the event callbacks supported by this widget
  this->CallbackMapper->SetCallbackMethod(vtkCommand::LeftButtonPressEvent,
                                          vtkWidgetEvent::AddPoint,
                                          this, vtkAngleWidget::AddPointAction);
  this->CallbackMapper->SetCallbackMethod(vtkCommand::MouseMoveEvent,
                                          vtkWidgetEvent::Move,
                                          this, vtkAngleWidget::MoveAction);
  this->CallbackMapper->SetCallbackMethod(vtkCommand::LeftButtonReleaseEvent,
                                          vtkWidgetEvent::EndSelect,
                                          this, vtkAngleWidget::EndSelectAction);
}

//----------------------------------------------------------------------
vtkAngleWidget::~vtkAngleWidget()
{
  this->Point1Widget->RemoveObserver(this->AngleWidgetCallback1);
  this->Point1Widget->Delete();
  this->AngleWidgetCallback1->Delete();

  this->CenterWidget->RemoveObserver(this->AngleWidgetCenterCallback);
  this->CenterWidget->Delete();
  this->AngleWidgetCenterCallback->Delete();

  this->Point2Widget->RemoveObserver(this->AngleWidgetCallback2);
  this->Point2Widget->Delete();
  this->AngleWidgetCallback2->Delete();
}

//----------------------------------------------------------------------
void vtkAngleWidget::CreateDefaultRepresentation()
{
  if ( ! this->WidgetRep )
  {
    this->WidgetRep = vtkAngleRepresentation2D::New();
  }
  reinterpret_cast<vtkAngleRepresentation*>(this->WidgetRep)->
    InstantiateHandleRepresentation();
}

//----------------------------------------------------------------------
void vtkAngleWidget::SetEnabled(int enabling)
{
  // The handle widgets are not actually enabled until they are placed.
  // The handle widgets take their representation from the vtkAngleRepresentation.
  if ( enabling )
  {
    if ( this->WidgetState == vtkAngleWidget::Start )
    {
      if (this->WidgetRep)
      {
        reinterpret_cast<vtkAngleRepresentation*>(this->WidgetRep)->
          Ray1VisibilityOff();
        reinterpret_cast<vtkAngleRepresentation*>(this->WidgetRep)->
          Ray2VisibilityOff();
        reinterpret_cast<vtkAngleRepresentation*>(this->WidgetRep)->
          ArcVisibilityOff();
      }
    }
    else
    {
      if (this->WidgetRep)
      {
        reinterpret_cast<vtkAngleRepresentation*>(this->WidgetRep)->
          Ray1VisibilityOn();
        reinterpret_cast<vtkAngleRepresentation*>(this->WidgetRep)->
          Ray2VisibilityOn();
        reinterpret_cast<vtkAngleRepresentation*>(this->WidgetRep)->
          ArcVisibilityOn();
      }

      // The interactor must be set prior to enabling the widget.
      if (this->Interactor)
      {
        this->Point1Widget->SetInteractor(this->Interactor);
        this->CenterWidget->SetInteractor(this->Interactor);
        this->Point2Widget->SetInteractor(this->Interactor);
      }

      this->Point1Widget->SetEnabled(1);
      this->CenterWidget->SetEnabled(1);
      this->Point2Widget->SetEnabled(1);
    }
  }


  if ( enabling ) //----------------
  {
    if ( this->Enabled ) //already enabled, just return
    {
      return;
    }

    if ( ! this->Interactor )
    {
      vtkErrorMacro(<<"The interactor must be set prior to enabling the widget");
      return;
    }

    int X=this->Interactor->GetEventPosition()[0];
    int Y=this->Interactor->GetEventPosition()[1];

    if ( ! this->CurrentRenderer )
    {
      this->SetCurrentRenderer(this->Interactor->FindPokedRenderer(X,Y));

      if (this->CurrentRenderer == nullptr)
      {
        return;
      }
    }

    // We're ready to enable
    this->Enabled = 1;
    this->CreateDefaultRepresentation();
    this->WidgetRep->SetRenderer(this->CurrentRenderer);

    // listen for the events found in the EventTranslator
    if ( ! this->Parent )
    {
      this->EventTranslator->AddEventsToInteractor(this->Interactor,
        this->EventCallbackCommand,this->Priority);
    }
    else
    {
      this->EventTranslator->AddEventsToParent(this->Parent,
        this->EventCallbackCommand,this->Priority);
    }

    if ( this->ManagesCursor )
    {
      this->WidgetRep->ComputeInteractionState(X, Y);
      this->SetCursor(this->WidgetRep->GetInteractionState());
    }

    vtkAngleRepresentation *rep =
        static_cast<vtkAngleRepresentation*>(this->WidgetRep);

    // Set the renderer, representation and interactor on the child widgets.
    if (this->Point1Widget)
    {
      this->Point1Widget->SetRepresentation(rep->GetPoint1Representation());
      this->Point1Widget->SetInteractor(this->Interactor);
      this->Point1Widget->GetRepresentation()->SetRenderer(
        this->CurrentRenderer);
    }

    if (this->CenterWidget)
    {
      this->CenterWidget->SetRepresentation(rep->GetCenterRepresentation());
      this->CenterWidget->SetInteractor(this->Interactor);
      this->CenterWidget->GetRepresentation()->SetRenderer(
        this->CurrentRenderer);
    }

    if (this->Point2Widget)
    {
      this->Point2Widget->SetRepresentation(rep->GetPoint2Representation());
      this->Point2Widget->SetInteractor(this->Interactor);
      this->Point2Widget->GetRepresentation()->SetRenderer(
        this->CurrentRenderer);
    }

    if (rep)
    {
      rep->SetRay1Visibility(
          this->WidgetState != vtkAngleWidget::Start ? 1 : 0);
      rep->SetRay2Visibility(
          this->WidgetState != vtkAngleWidget::Start ? 1 : 0);
      rep->SetArcVisibility(
          this->WidgetState != vtkAngleWidget::Start ? 1 : 0);
    }


    if ( this->WidgetState != vtkAngleWidget::Start )
    {
      if (this->Point1Widget)
      {
        this->Point1Widget->SetEnabled(1);
      }
      if (this->CenterWidget)
      {
        this->CenterWidget->SetEnabled(1);
      }
      if (this->Point2Widget)
      {
        this->Point2Widget->SetEnabled(1);
      }
    }

    this->WidgetRep->BuildRepresentation();
    this->CurrentRenderer->AddViewProp(this->WidgetRep);

    this->InvokeEvent(vtkCommand::EnableEvent,nullptr);
  }

  else //disabling------------------
  {
    if ( ! this->Enabled ) //already disabled, just return
    {
      return;
    }

    this->Enabled = 0;

    // don't listen for events any more
    if ( ! this->Parent )
    {
      this->Interactor->RemoveObserver(this->EventCallbackCommand);
    }
    else
    {
      this->Parent->RemoveObserver(this->EventCallbackCommand);
    }

    this->CurrentRenderer->RemoveViewProp(this->WidgetRep);


    if (vtkAngleRepresentation *rep =
        static_cast<vtkAngleRepresentation*>(this->WidgetRep))
    {
      rep->Ray1VisibilityOff();
      rep->Ray2VisibilityOff();
      rep->ArcVisibilityOff();
    }

    if (this->Point1Widget)
    {
      this->Point1Widget->SetEnabled(0);
    }

    if (this->CenterWidget)
    {
      this->CenterWidget->SetEnabled(0);
    }

    if (this->Point2Widget)
    {
      this->Point2Widget->SetEnabled(0);
    }

    this->InvokeEvent(vtkCommand::DisableEvent,nullptr);
    this->SetCurrentRenderer(nullptr);
  }


  // Should only render if there is no parent
  if ( this->Interactor && !this->Parent )
  {
    this->Interactor->Render();
  }
}

//----------------------------------------------------------------------
int vtkAngleWidget::IsAngleValid()
{
  if ( this->WidgetState == vtkAngleWidget::Manipulate ||
       (this->WidgetState == vtkAngleWidget::Define && this->CurrentHandle == 2) )
  {
    return 1;
  }
  else
  {
    return 0;
  }
}

// The following methods are the callbacks that the angle widget responds to.
//-------------------------------------------------------------------------
void vtkAngleWidget::AddPointAction(vtkAbstractWidget *w)
{
  vtkAngleWidget *self = reinterpret_cast<vtkAngleWidget*>(w);
  int X = self->Interactor->GetEventPosition()[0];
  int Y = self->Interactor->GetEventPosition()[1];

  // If we are placing the first point it's easy
  if ( self->WidgetState == vtkAngleWidget::Start )
  {
    self->GrabFocus(self->EventCallbackCommand);
    self->WidgetState = vtkAngleWidget::Define;
    self->InvokeEvent(vtkCommand::StartInteractionEvent,nullptr);
    double e[2];
    e[0] = static_cast<double>(X);
    e[1] = static_cast<double>(Y);
    reinterpret_cast<vtkAngleRepresentation*>(self->WidgetRep)->StartWidgetInteraction(e);
    self->CurrentHandle = 0;
    self->InvokeEvent(vtkCommand::PlacePointEvent,&(self->CurrentHandle));
    reinterpret_cast<vtkAngleRepresentation*>(self->WidgetRep)->Ray1VisibilityOn();
    self->Point1Widget->SetEnabled(1);
    self->CurrentHandle++;
  }

  // If defining we are placing the second or third point
  else if ( self->WidgetState == vtkAngleWidget::Define )
  {
    self->InvokeEvent(vtkCommand::PlacePointEvent,&(self->CurrentHandle));
    if ( self->CurrentHandle == 1 )
    {
      double e[2];
      e[0] = static_cast<double>(X);
      e[1] = static_cast<double>(Y);
      reinterpret_cast<vtkAngleRepresentation*>(self->WidgetRep)->CenterWidgetInteraction(e);
      self->CurrentHandle++;
      self->CenterWidget->SetEnabled(1);
      reinterpret_cast<vtkAngleRepresentation*>(self->WidgetRep)->Ray2VisibilityOn();
      reinterpret_cast<vtkAngleRepresentation*>(self->WidgetRep)->ArcVisibilityOn();
    }
    else if ( self->CurrentHandle == 2 )
    {
      self->WidgetState = vtkAngleWidget::Manipulate;
      self->Point2Widget->SetEnabled(1);
      self->CurrentHandle = (-1);
      self->ReleaseFocus();
      self->InvokeEvent(vtkCommand::EndInteractionEvent,nullptr);
    }
  }

  // Maybe we are trying to manipulate the widget handles
  else //if ( self->WidgetState == vtkAngleWidget::Manipulate )
  {
    int state = self->WidgetRep->ComputeInteractionState(X,Y);
    if ( state == vtkAngleRepresentation::Outside )
    {
      self->CurrentHandle = (-1);
      return;
    }

    self->GrabFocus(self->EventCallbackCommand);
    if ( state == vtkAngleRepresentation::NearP1 )
    {
      self->CurrentHandle = 0;
    }
    else if ( state == vtkAngleRepresentation::NearCenter )
    {
      self->CurrentHandle = 1;
    }
    else if ( state == vtkAngleRepresentation::NearP2 )
    {
      self->CurrentHandle = 2;
    }
    self->InvokeEvent(vtkCommand::LeftButtonPressEvent,nullptr);
  }

  self->EventCallbackCommand->SetAbortFlag(1);
  self->Render();
}

//-------------------------------------------------------------------------
void vtkAngleWidget::MoveAction(vtkAbstractWidget *w)
{
  vtkAngleWidget *self = reinterpret_cast<vtkAngleWidget*>(w);

  // Do nothing if outside
  if ( self->WidgetState == vtkAngleWidget::Start )
  {
    return;
  }

  // Delegate the event consistent with the state
  if ( self->WidgetState == vtkAngleWidget::Define )
  {
    int X = self->Interactor->GetEventPosition()[0];
    int Y = self->Interactor->GetEventPosition()[1];
    double e[2];
    e[0] = static_cast<double>(X);
    e[1] = static_cast<double>(Y);
    if ( self->CurrentHandle == 1 )
    {
      reinterpret_cast<vtkAngleRepresentation*>(self->WidgetRep)->
        CenterWidgetInteraction(e);
    }
    else
    {
      reinterpret_cast<vtkAngleRepresentation*>(self->WidgetRep)->
        WidgetInteraction(e);
    }
    self->InvokeEvent(vtkCommand::InteractionEvent,nullptr);
    self->EventCallbackCommand->SetAbortFlag(1);
  }

  else //must be moving a handle, invoke a event for the handle widgets
  {
    self->InvokeEvent(vtkCommand::MouseMoveEvent, nullptr);
  }

  self->WidgetRep->BuildRepresentation();
  self->Render();
}

//-------------------------------------------------------------------------
void vtkAngleWidget::EndSelectAction(vtkAbstractWidget *w)
{
  vtkAngleWidget *self = reinterpret_cast<vtkAngleWidget*>(w);

  // Do nothing if outside
  if ( self->WidgetState == vtkAngleWidget::Start ||
       self->WidgetState == vtkAngleWidget::Define ||
       self->CurrentHandle < 0 )
  {
    return;
  }

  self->ReleaseFocus();
  self->InvokeEvent(vtkCommand::LeftButtonReleaseEvent,nullptr);
  self->CurrentHandle = (-1);
  self->WidgetRep->BuildRepresentation();
  self->EventCallbackCommand->SetAbortFlag(1);
  self->Render();
}

// These are callbacks that are active when the user is manipulating the
// handles of the angle widget.
//----------------------------------------------------------------------
void vtkAngleWidget::StartAngleInteraction(int)
{
  this->Superclass::StartInteraction();
  this->InvokeEvent(vtkCommand::StartInteractionEvent,nullptr);
}

//----------------------------------------------------------------------
void vtkAngleWidget::AngleInteraction(int)
{
  this->InvokeEvent(vtkCommand::InteractionEvent,nullptr);
}

//----------------------------------------------------------------------
void vtkAngleWidget::EndAngleInteraction(int)
{
  this->Superclass::EndInteraction();

  this->InvokeEvent(vtkCommand::EndInteractionEvent,nullptr);
}

//----------------------------------------------------------------------
void vtkAngleWidget::SetProcessEvents(int pe)
{
  this->Superclass::SetProcessEvents(pe);

  //Pass pe flag to component widgets.
  this->Point1Widget->SetProcessEvents(pe);
  this->CenterWidget->SetProcessEvents(pe);
  this->Point2Widget->SetProcessEvents(pe);
}

//----------------------------------------------------------------------
void vtkAngleWidget::SetWidgetStateToStart()
{
  this->WidgetState = vtkAngleWidget::Start;
  this->CurrentHandle = -1;
  this->ReleaseFocus();
  this->GetRepresentation()->BuildRepresentation(); // update this->Angle
  this->SetEnabled(this->GetEnabled()); // show/hide the handles properly
}

//----------------------------------------------------------------------
void vtkAngleWidget::SetWidgetStateToManipulate()
{
  this->WidgetState = vtkAngleWidget::Manipulate;
  this->CurrentHandle = -1;
  this->ReleaseFocus();
  this->GetRepresentation()->BuildRepresentation(); // update this->Angle
  this->SetEnabled(this->GetEnabled()); // show/hide the handles properly
}

//----------------------------------------------------------------------
void vtkAngleWidget::PrintSelf(ostream& os, vtkIndent indent)
{
  //Superclass typedef defined in vtkTypeMacro() found in vtkSetGet.h
  this->Superclass::PrintSelf(os,indent);
}