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

  Program:   Visualization Toolkit
  Module:    $RCSfile: vtkLineWidget2.h,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.

=========================================================================*/
// .NAME vtkLineWidget2 - 3D widget for manipulating a finite, straight line
// .SECTION Description
// This 3D widget defines a straight line that can be interactively placed in
// a scene. The widget is assumed to consist of two parts: 1) two end points
// and 2) a straight line connecting the two points. (The representation
// paired with this widget determines the actual geometry of the widget.) The
// positioning of the two end points is facilitated by using vtkHandleWidgets
// to position the points.
//
// To use this widget, you generally pair it with a vtkLineRepresentation
// (or a subclass). Variuos options are available in the representation for 
// controlling how the widget appears, and how the widget functions.
//
// .SECTION 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 two end points are selected:
//   LeftButtonPressEvent - activate the associated handle widget
//   LeftButtonReleaseEvent - release the handle widget associated with the point
//   MouseMoveEvent - move the point
// If the line is selected:
//   LeftButtonPressEvent - activate a handle widget accociated with the line 
//   LeftButtonReleaseEvent - release the handle widget associated with the line
//   MouseMoveEvent - translate the line
// 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>
//
// Note that the event bindings described above can be changed using this
// class's vtkWidgetEventTranslator. This class translates VTK events 
// into the vtkLineWidget2's widget events:
// <pre>
//   vtkWidgetEvent::Select -- some part of the widget has been selected
//   vtkWidgetEvent::EndSelect -- the selection process has completed
//   vtkWidgetEvent::Move -- a request for slider motion has been invoked
// </pre>
//
// In turn, when these widget events are processed, the vtkLineWidget2
// 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>
//

// .SECTION Caveats
// Note that the widget can be picked even when it is "behind"
// other actors.  This is an intended feature and not a bug.
// 
// This class, and vtkLineRepresentation, are next generation VTK widgets. An
// earlier version of this functionality was defined in the class
// vtkLineWidget.

// .SECTION See Also
// vtkLineRepresentation vtkLineWidget vtk3DWidget vtkImplicitPlaneWidget
// vtkImplicitPlaneWidget2

#ifndef __vtkLineWidget2_h
#define __vtkLineWidget2_h

#include "vtkAbstractWidget.h"

class vtkLineRepresentation;
class vtkHandleWidget;


class VTK_WIDGETS_EXPORT vtkLineWidget2 : public vtkAbstractWidget
{
public:
  // Description:
  // Instantiate the object.
  static vtkLineWidget2 *New();

  // Description:
  // Standard vtkObject methods
  vtkTypeRevisionMacro(vtkLineWidget2,vtkAbstractWidget);
  void PrintSelf(ostream& os, vtkIndent indent);

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

  // Description:
  // 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(vtkLineRepresentation *r)
    {this->Superclass::SetWidgetRepresentation(reinterpret_cast<vtkWidgetRepresentation*>(r));}
  
  // Description:
  // Create the default widget representation if one is not set. 
  void CreateDefaultRepresentation();

  // Description:
  // Methods to change the whether the widget responds to interaction.
  // Overridden to pass the state to component widgets.
  virtual void SetProcessEvents(int);

protected:
  vtkLineWidget2();
  ~vtkLineWidget2();

//BTX - manage the state of the widget
  int WidgetState;
  enum _WidgetState {Start=0,Active};
//ETX
  int CurrentHandle;
    
  // These methods handle events
  static void SelectAction(vtkAbstractWidget*);
  static void TranslateAction(vtkAbstractWidget*);
  static void ScaleAction(vtkAbstractWidget*);
  static void EndSelectAction(vtkAbstractWidget*);
  static void MoveAction(vtkAbstractWidget*);

  // The positioning handle widgets
  vtkHandleWidget *Point1Widget; //first end point
  vtkHandleWidget *Point2Widget; //second end point
  vtkHandleWidget *LineHandle; //used when selecting the line

private:
  vtkLineWidget2(const vtkLineWidget2&);  //Not implemented
  void operator=(const vtkLineWidget2&);  //Not implemented
};

#endif
