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

  Program:   Visualization Toolkit
  Module:    vtkTensorWidget.h

  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.

=========================================================================*/
/**
 * @class   vtkTensorWidget
 * @brief   3D widget for manipulating a tensor glyph
 *
 * This 3D widget interacts with a vtkTensorRepresentation class (i.e., it
 * handles the events that drive its corresponding representation). The
 * widget is assumed to operate on a single 3x3 real, symmetric tensor
 * located at a specified position. The tensor implicitly defines three
 * orthogonal eigenvectors which indicate the orientation and relative
 * scaling of the widget's representation.
 *
 * The widget has the appearance of an oriented box with seven handles: one
 * at the center of the box, and six located at the center of each face. The
 * box can be translated by selecting its center handle; rotated by selecting
 * and rotating one of the box faces around the box center; and scaled (in a
 * particular direction) by selecting the face handles (located on each face)
 * and moving the faces in/out in the direction of the face normal. Uniform
 * scaling is also possible by (default) using the right mouse button (unless
 * the binding has been redefined).
 *
 * To use this widget, you generally pair it with a
 * vtkTensorRepresentation (or a subclass). Various options are
 * available in the representation for controlling the widgets' size and
 * position; how the widget appears; and how the widget functions.
 *
 * @par Event Bindings:
 * By default, the widget responds to the following VTK events (i.e., it
 * watches the vtkRenderWindowInteractor for these events):
 * <pre>
 * If one of the seven handles are selected:
 *   LeftButtonPressEvent - select the appropriate handle
 *   LeftButtonReleaseEvent - release the currently selected handle
 *   MouseMoveEvent - move the handle
 * If one of the faces is selected:
 *   LeftButtonPressEvent - select a box face
 *   LeftButtonReleaseEvent - release the box face
 *   MouseMoveEvent - rotate the box
 * In all the cases, independent of what is picked, the widget responds to the
 * following VTK events:
 *   MiddleButtonPressEvent - translate the widget
 *   MiddleButtonReleaseEvent - release the widget
 *   RightButtonPressEvent - scale the widget's representation
 *   RightButtonReleaseEvent - stop scaling the widget
 *   MouseMoveEvent - scale (if right button) or move (if middle button) the widget
 * </pre>
 *
 * @par Event Bindings:
 * Note that the event bindings described above can be changed using this
 * class's vtkWidgetEventTranslator. This class translates VTK events
 * into the vtkTensorWidget's widget events:
 * <pre>
 *   vtkWidgetEvent::Select -- some part of the widget has been selected
 *   vtkWidgetEvent::EndSelect -- the selection process has completed
 *   vtkWidgetEvent::Scale -- some part of the widget has been selected
 *   vtkWidgetEvent::EndScale -- the selection process has completed
 *   vtkWidgetEvent::Translate -- some part of the widget has been selected
 *   vtkWidgetEvent::EndTranslate -- the selection process has completed
 *   vtkWidgetEvent::Move -- a request for motion has been invoked
 * </pre>
 *
 * @par Event Bindings:
 * In turn, when these widget events are processed, the vtkTensorWidget
 * invokes the following VTK events on itself (which observers can listen for):
 * <pre>
 *   vtkCommand::StartInteractionEvent (on vtkWidgetEvent::Select)
 *   vtkCommand::EndInteractionEvent (on vtkWidgetEvent::EndSelect)
 *   vtkCommand::InteractionEvent (on vtkWidgetEvent::Move)
 * </pre>
 *
 *
 * @sa
 * vtkTensorRepresentation vtkBoxWidget2
 */

#ifndef vtkTensorWidget_h
#define vtkTensorWidget_h

#include "vtkAbstractWidget.h"
#include "vtkInteractionWidgetsModule.h" // For export macro

class vtkTensorRepresentation;

class VTKINTERACTIONWIDGETS_EXPORT vtkTensorWidget : public vtkAbstractWidget
{
public:
  //@{
  /**
   * Standard methods for instantiation, type information, and printing.
   */
  static vtkTensorWidget* New();
  vtkTypeMacro(vtkTensorWidget, vtkAbstractWidget);
  void PrintSelf(ostream& os, vtkIndent indent) override;
  //@}

  /**
   * Specify an instance of vtkWidgetRepresentation used to represent this
   * widget in the scene. Note that the representation is a subclass of vtkProp
   * so it can be added to the renderer independent of the widget.
   */
  void SetRepresentation(vtkTensorRepresentation* r)
  {
    this->Superclass::SetWidgetRepresentation(reinterpret_cast<vtkWidgetRepresentation*>(r));
  }

  //@{
  /**
   * Control the behavior of the widget (i.e., how it processes
   * events). Translation, rotation, scaling and face movement can all be
   * enabled and disabled. Scaling refers to scaling of the whole widget at
   * once, (default is through right mouse button) while face movement refers
   * to scaling of the widget one face (axis) at a time (default through
   * grabbing one of the representation spherical handles).
   */
  vtkSetMacro(TranslationEnabled, vtkTypeBool);
  vtkGetMacro(TranslationEnabled, vtkTypeBool);
  vtkBooleanMacro(TranslationEnabled, vtkTypeBool);
  vtkSetMacro(ScalingEnabled, vtkTypeBool);
  vtkGetMacro(ScalingEnabled, vtkTypeBool);
  vtkBooleanMacro(ScalingEnabled, vtkTypeBool);
  vtkSetMacro(RotationEnabled, vtkTypeBool);
  vtkGetMacro(RotationEnabled, vtkTypeBool);
  vtkBooleanMacro(RotationEnabled, vtkTypeBool);
  vtkSetMacro(MoveFacesEnabled, vtkTypeBool);
  vtkGetMacro(MoveFacesEnabled, vtkTypeBool);
  vtkBooleanMacro(MoveFacesEnabled, vtkTypeBool);
  //@}

  /**
   * Create the default widget representation if one is not set. By default,
   * this is an instance of the vtkTensorRepresentation class.
   */
  void CreateDefaultRepresentation() override;

  /**
   * Override superclasses' SetEnabled() method because the line
   * widget must enable its internal handle widgets.
   */
  void SetEnabled(int enabling) override;

protected:
  vtkTensorWidget();
  ~vtkTensorWidget() override;

  // Manage the state of the widget
  int WidgetState;
  enum _WidgetState
  {
    Start = 0,
    Active
  };

  // These methods handle events
  static void SelectAction(vtkAbstractWidget*);
  static void EndSelectAction(vtkAbstractWidget*);
  static void TranslateAction(vtkAbstractWidget*);
  static void ScaleAction(vtkAbstractWidget*);
  static void MoveAction(vtkAbstractWidget*);
  static void SelectAction3D(vtkAbstractWidget*);
  static void EndSelectAction3D(vtkAbstractWidget*);
  static void MoveAction3D(vtkAbstractWidget*);
  static void StepAction3D(vtkAbstractWidget*);

  // Control whether scaling, rotation, and translation are supported
  vtkTypeBool TranslationEnabled;
  vtkTypeBool ScalingEnabled;
  vtkTypeBool RotationEnabled;
  vtkTypeBool MoveFacesEnabled;

  vtkCallbackCommand* KeyEventCallbackCommand;
  static void ProcessKeyEvents(vtkObject*, unsigned long, void*, void*);

private:
  vtkTensorWidget(const vtkTensorWidget&) = delete;
  void operator=(const vtkTensorWidget&) = delete;
};

#endif
