// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
#include "vtkSliderWidget.h"
#include "vtkCallbackCommand.h"
#include "vtkCommand.h"
#include "vtkEvent.h"
#include "vtkObjectFactory.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkRenderer.h"
#include "vtkSliderRepresentation3D.h"
#include "vtkWidgetCallbackMapper.h"
#include "vtkWidgetEvent.h"
#include "vtkWidgetEventTranslator.h"

VTK_ABI_NAMESPACE_BEGIN
vtkStandardNewMacro(vtkSliderWidget);

//------------------------------------------------------------------------------
vtkSliderWidget::vtkSliderWidget()
{
  // Set the initial state
  this->WidgetState = vtkSliderWidget::Start;

  // Assign initial values
  this->AnimationMode = vtkSliderWidget::Jump;
  this->NumberOfAnimationSteps = 24;

  // Okay, define the events
  this->CallbackMapper->SetCallbackMethod(
    vtkCommand::LeftButtonPressEvent, vtkWidgetEvent::Select, this, vtkSliderWidget::SelectAction);
  this->CallbackMapper->SetCallbackMethod(
    vtkCommand::MouseMoveEvent, vtkWidgetEvent::Move, this, vtkSliderWidget::MoveAction);
  this->CallbackMapper->SetCallbackMethod(vtkCommand::LeftButtonReleaseEvent,
    vtkWidgetEvent::EndSelect, this, vtkSliderWidget::EndSelectAction);
}

//------------------------------------------------------------------------------
void vtkSliderWidget::CreateDefaultRepresentation()
{
  if (!this->WidgetRep)
  {
    this->WidgetRep = vtkSliderRepresentation3D::New();
  }
}

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

  double eventPos[2];
  eventPos[0] = self->Interactor->GetEventPosition()[0];
  eventPos[1] = self->Interactor->GetEventPosition()[1];

  // Okay, make sure that the pick is in the current renderer
  if (!self->CurrentRenderer ||
    !self->CurrentRenderer->IsInViewport(
      static_cast<int>(eventPos[0]), static_cast<int>(eventPos[1])))
  {
    self->WidgetState = vtkSliderWidget::Start;
    return;
  }

  // See if the widget has been selected. StartWidgetInteraction records the
  // starting point of the motion.
  self->WidgetRep->StartWidgetInteraction(eventPos);
  int interactionState = self->WidgetRep->GetInteractionState();
  if (interactionState == vtkSliderRepresentation::Outside)
  {
    return;
  }

  // We are definitely selected
  self->GrabFocus(self->EventCallbackCommand);
  if (interactionState == vtkSliderRepresentation::Slider)
  {
    self->WidgetState = vtkSliderWidget::Sliding;
  }
  else
  {
    self->WidgetState = vtkSliderWidget::Animating;
  }

  // Highlight as necessary
  self->WidgetRep->Highlight(1);

  // start the interaction
  self->EventCallbackCommand->SetAbortFlag(1);
  self->StartInteraction();
  self->InvokeEvent(vtkCommand::StartInteractionEvent, nullptr);
  self->Render();
}

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

  // See whether we're active
  if (self->WidgetState == vtkSliderWidget::Start ||
    self->WidgetState == vtkSliderWidget::Animating)
  {
    return;
  }

  // Definitely moving the slider, get the updated position
  double eventPos[2];
  eventPos[0] = self->Interactor->GetEventPosition()[0];
  eventPos[1] = self->Interactor->GetEventPosition()[1];
  self->WidgetRep->WidgetInteraction(eventPos);

  // Interact, if desired
  self->EventCallbackCommand->SetAbortFlag(1);
  self->InvokeEvent(vtkCommand::InteractionEvent, nullptr);
  self->Render();
}

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

  if (self->WidgetState == vtkSliderWidget::Start)
  {
    return;
  }

  // If animating we do it and return
  if (self->WidgetState == vtkSliderWidget::Animating)
  {
    self->AnimateSlider(self->WidgetRep->GetInteractionState());
  }

  // Highlight if necessary
  self->WidgetRep->Highlight(0);

  // The state returns to unselected
  self->WidgetState = vtkSliderWidget::Start;
  self->ReleaseFocus();

  // Complete interaction
  self->EventCallbackCommand->SetAbortFlag(1);
  self->EndInteraction();
  self->InvokeEvent(vtkCommand::EndInteractionEvent, nullptr);
  self->Render();
}

//------------------------------------------------------------------------------
void vtkSliderWidget::AnimateSlider(int selectionState)
{
  // Get the representation and grab some information
  vtkSliderRepresentation* sliderRep = reinterpret_cast<vtkSliderRepresentation*>(this->WidgetRep);

  // If the slider bead has been selected, then nothing happens
  if (selectionState == vtkSliderRepresentation::Outside ||
    selectionState == vtkSliderRepresentation::Slider)
  {
    return;
  }

  // Depending on animation mode, we'll jump to the pick point or
  // animate towards it.
  double minValue = sliderRep->GetMinimumValue();
  double maxValue = sliderRep->GetMaximumValue();
  double pickedT = sliderRep->GetPickedT();

  if (this->AnimationMode == vtkSliderWidget::Jump)
  {
    if (selectionState == vtkSliderRepresentation::Tube)
    {
      sliderRep->SetValue(minValue + pickedT * (maxValue - minValue));
    }

    else if (selectionState == vtkSliderRepresentation::LeftCap)
    {
      sliderRep->SetValue(minValue);
    }

    else if (selectionState == vtkSliderRepresentation::RightCap)
    {
      sliderRep->SetValue(maxValue);
    }
    sliderRep->BuildRepresentation();
    this->InvokeEvent(vtkCommand::InteractionEvent, nullptr);
  }

  else if (this->AnimationMode == vtkSliderWidget::Animate)
  {
    double targetValue = minValue, originalValue = sliderRep->GetValue();
    if (selectionState == vtkSliderRepresentation::Tube)
    {
      targetValue = minValue + pickedT * (maxValue - minValue);
    }

    else if (selectionState == vtkSliderRepresentation::LeftCap)
    {
      targetValue = minValue;
    }

    else if (selectionState == vtkSliderRepresentation::RightCap)
    {
      targetValue = maxValue;
    }

    // Okay, animate the slider
    double value;
    for (int i = 0; i < this->NumberOfAnimationSteps; i++)
    {
      value = originalValue +
        (static_cast<double>(i + 1) / this->NumberOfAnimationSteps) * (targetValue - originalValue);
      sliderRep->SetValue(value);
      sliderRep->BuildRepresentation();
      this->InvokeEvent(vtkCommand::InteractionEvent, nullptr);
      this->Render();
    }
  }

  this->WidgetState = vtkSliderWidget::Start;
}

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

  os << indent << "Animation Mode: ";
  switch (this->AnimationMode)
  {
    case vtkSliderWidget::Jump:
      os << "Jump\n";
      break;
    case vtkSliderWidget::Animate:
      os << "Animate\n";
      break;
    default:
      os << "AnimateOff\n";
  }

  os << indent << "Number of Animation Steps: " << this->NumberOfAnimationSteps << "\n";
}
VTK_ABI_NAMESPACE_END
