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