NAME

       SoHandleEventAction — allows nodes in a graph to receive input events

INHERITS FROM

       SoAction > SoHandleEventAction

SYNOPSIS

       #include <Inventor/actions/SoHandleEventAction.h>

          Methods from class SoHandleEventAction:

                                SoHandleEventAction(const SbViewportRegion &viewportRegion)
     void                       setViewportRegion(const SbViewportRegion &newRegion)
     const SbViewportRegion &   getViewportRegion() const
     void                       setEvent(const SoEvent *ev)
     const SoEvent *            getEvent() const
     void                       setHandled()
     SbBool                     isHandled() const
     void                       setGrabber(SoNode *node)
     void                       releaseGrabber()
     SoNode *                   getGrabber() const
     void                       setPickRoot(SoNode *node)
     SoNode *                   getPickRoot() const
     void                       setPickRadius(float radiusInPixels)
     const SoPickedPoint *      getPickedPoint()
     const SoPickedPointList &  getPickedPointList()

          Methods from class SoAction:

     virtual void        apply(SoNode *node)
     virtual void        apply(SoPath *path)
     virtual void        apply(const SoPathList &pathList, SbBool obeysRules = FALSE)
     static SoType       getClassTypeId()
     virtual SoType      getTypeId()
     virtual SbBool      isOfType(SoType type)
     virtual void        invalidateState()

DESCRIPTION

       This  class  is used to allow nodes in a scene graph to handle input events. It is usually invoked from a
       component derived from SoXtRenderArea when the component receives a window system event.

       Manipulator, dragger and selection nodes respond to and process events. Most other group nodes just  pass
       the  event  to  their children, while most other nodes simply ignore the action entirely. Once a node has
       indicated to the action that it has handled the event, traversal stops.

       A node that handles an event can also grab future events. Once it has done so, all events  will  be  sent
       directly to that node, with no traversal taking place, until the node releases the grab.

METHODS

                                SoHandleEventAction(const SbViewportRegion &viewportRegion)
          Constructor takes viewport region to use; this is needed to perform a pick operation when requested.

     void                       setViewportRegion(const SbViewportRegion &newRegion)
     const SbViewportRegion &   getViewportRegion() const
          Sets/returns current viewport region to use for action.

     void                       setEvent(const SoEvent *ev)
     const SoEvent *            getEvent() const
          Sets/returns the event being handled.

     void                       setHandled()
     SbBool                     isHandled() const
          Sets/returns whether any node has yet handled the event.

     void                       setGrabber(SoNode *node)
          Initiates  grabbing  of  future  events.  All  events will be sent to the given node until the grab is
          released.

     void                       releaseGrabber()
          Releases the grab.

     SoNode *                   getGrabber() const
          Returns the node that is currently grabbing events, or NULL if there is none.

     void                       setPickRoot(SoNode *node)
     SoNode *                   getPickRoot() const
          Sets/returns the root node used for initiating a pick action for those nodes that want to know what is
          under the cursor.

     void                       setPickRadius(float radiusInPixels)
          Set the radius (in pixels) around the viewport-space point through which the ray passes when doing ray
          picking. Ray picking is performed when getPickedPoint()  is called. The pick radius set here  is  used
          when testing the ray against lines and points.

     const SoPickedPoint *      getPickedPoint()
          Returns  the  frontmost  object  hit  (as  an  SoPickedPoint)  by performing a pick based on the mouse
          location specified in the event for which the action is being applied. The first time this  is  called
          for  a  particular  event,  a SoRayPickAction is applied to find this object; subsequent calls for the
          same event return the same information. The storage for the picked point remains valid as long as  the
          action is not re-applied or deleted.

     const SoPickedPointList &  getPickedPointList()
          Returns a list of objects intersected by a picking operation, sorted from nearest to farthest.

SEE ALSO

       SoEvent, SoPickedPoint, SoRayPickAction

                                                                                      SoHandleEventAction(3IV)()