vtkRectilinearWipeWidget.h

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

  Program:   Visualization Toolkit
  Module:    vtkRectilinearWipeWidget.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   vtkRectilinearWipeWidget
 * @brief   interactively control an instance of vtkImageRectilinearWipe filter
 *
 * The vtkRectilinearWipeWidget is used to interactively control an instance
 * of vtkImageRectilinearWipe (and an associated vtkImageActor used to
 * display the rectilinear wipe). A rectilinear wipe is a 2x2 checkerboard
 * pattern created by combining two separate images, where various
 * combinations of the checker squares are possible. Using this widget, the
 * user can adjust the layout of the checker pattern, such as moving the
 * center point, moving the horizontal separator, or moving the vertical
 * separator. These capabilities are particularly useful for comparing two
 * images.
 *
 * To use this widget, specify its representation (by default the
 * representation is an instance of vtkRectilinearWipeProp). The
 * representation generally requires that you specify an instance of
 * vtkImageRectilinearWipe and an instance of vtkImageActor. Other instance
 * variables may also be required to be set -- see the documentation for
 * vtkRectilinearWipeProp (or appropriate subclass).
 *
 * By default, the widget responds to the following events:
 * <pre>
 * Selecting the center point, horizontal separator, and verticel separator:
 *   LeftButtonPressEvent - move the separators
 *   LeftButtonReleaseEvent - release the separators
 *   MouseMoveEvent - move the separators
 * </pre>
 * Selecting the center point allows you to move the horizontal and vertical
 * separators simultaneously. Otherwise only horizontal or vertical motion
 * is possible/
 *
 * Note that the event bindings described above can be changed using this
 * class's vtkWidgetEventTranslator. This class translates VTK events into
 * the vtkRectilinearWipeWidget'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 motion has been invoked
 * </pre>
 *
 * In turn, when these widget events are processed, the
 * vtkRectilinearWipeWidget invokes the following VTK events (which
 * observers can listen for):
 * <pre>
 *   vtkCommand::StartInteractionEvent (on vtkWidgetEvent::Select)
 *   vtkCommand::EndInteractionEvent (on vtkWidgetEvent::EndSelect)
 *   vtkCommand::InteractionEvent (on vtkWidgetEvent::Move)
 * </pre>
 *
 * @warning
 * The appearance of this widget is defined by its representation, including
 * any properties associated with the representation.  The widget
 * representation is a type of vtkProp that defines a particular API that
 * works with this widget. If desired, the vtkProp may be subclassed to
 * create new looks for the widget.
 *
 * @sa
 * vtkRectilinearWipeProp vtkImageRectilinearWipe vtkImageActor
 * vtkCheckerboardWidget
*/

#ifndef vtkRectilinearWipeWidget_h
#define vtkRectilinearWipeWidget_h

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

class vtkRectilinearWipeRepresentation;


class VTKINTERACTIONWIDGETS_EXPORT vtkRectilinearWipeWidget : public vtkAbstractWidget
{
public:
  /**
   * Instantiate the class.
   */
  static vtkRectilinearWipeWidget *New();

  //@{
  /**
   * Standard macros.
   */
  vtkTypeMacro(vtkRectilinearWipeWidget,vtkAbstractWidget);
  void PrintSelf(ostream& os, vtkIndent indent);
  //@}

  /**
   * 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(vtkRectilinearWipeRepresentation *r)
    {this->Superclass::SetWidgetRepresentation(reinterpret_cast<vtkWidgetRepresentation*>(r));}

  /**
   * Return the representation as a vtkRectilinearWipeRepresentation.
   */
  vtkRectilinearWipeRepresentation *GetRectilinearWipeRepresentation()
    {return reinterpret_cast<vtkRectilinearWipeRepresentation*>(this->WidgetRep);}

  /**
   * Create the default widget representation if one is not set.
   */
  virtual void CreateDefaultRepresentation();

protected:
  vtkRectilinearWipeWidget();
  ~vtkRectilinearWipeWidget();

  // These methods handle events
  static void SelectAction(vtkAbstractWidget*);
  static void MoveAction(vtkAbstractWidget*);
  static void EndSelectAction(vtkAbstractWidget*);

  // helper methods for cursor management
  void SetCursor(int state);

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

private:
  vtkRectilinearWipeWidget(const vtkRectilinearWipeWidget&) VTK_DELETE_FUNCTION;
  void operator=(const vtkRectilinearWipeWidget&) VTK_DELETE_FUNCTION;
};

#endif