NAME
SoHandleEventAction -
The SoHandleEventAction class distributes user events to the scene.
This is the action used by the GUI viewer classes to pass interaction
events from the window system to the nodes in the scene graph.
SYNOPSIS
#include <Inventor/actions/SoHandleEventAction.h>
Inherits SoAction.
Public Member Functions
SoHandleEventAction (const SbViewportRegion &viewportregion)
virtual ~SoHandleEventAction (void)
void setViewportRegion (const SbViewportRegion &newregion)
const SbViewportRegion & getViewportRegion (void) const
void setEvent (const SoEvent *ev)
const SoEvent * getEvent (void) const
void setHandled (void)
SbBool isHandled (void) const
void setGrabber (SoNode *node)
void releaseGrabber (void)
SoNode * getGrabber (void) const
void setPickRoot (SoNode *node)
SoNode * getPickRoot (void) const
void setPickRadius (const float radiusinpixels)
const SoPickedPoint * getPickedPoint (void)
const SoPickedPointList & getPickedPointList (void)
Static Public Member Functions
static void initClass (void)
Protected Member Functions
virtual void beginTraversal (SoNode *node)
Detailed Description
The SoHandleEventAction class distributes user events to the scene.
This is the action used by the GUI viewer classes to pass interaction
events from the window system to the nodes in the scene graph.
SoHandleEventAction also provides the functionality for tracking the
object currently under the cursor, and functionality for ’grabbing’ the
event focus.
See also:
SoEvent
Constructor & Destructor Documentation
SoHandleEventAction::SoHandleEventAction (const SbViewportRegion &
viewportregion) Constructor.
SoHandleEventAction needs a viewportregion to pass on to the raypick
action instance it uses for being able to track objects under the mouse
cursor.
SoHandleEventAction::~SoHandleEventAction (void) [virtual] Destructor.
Member Function Documentation
void SoHandleEventAction::initClass (void) [static] Initializes the run-
time type system for this class, and sets up the enabled elements and
action method list.
Reimplemented from SoAction.
void SoHandleEventAction::setViewportRegion (const SbViewportRegion &
newregion) Set a new viewport region, replacing the one passed in the
constructor.
const SbViewportRegion & SoHandleEventAction::getViewportRegion (void)
const Returns the viewport region this action instance is using.
Advanced Usage:
You can also get the viewport region by accessing it through its
element on the traversal state. You do that the following way:
#include <Inventor/elements/SoViewportRegionElement.h>
SoState * state = action->getState();
SbViewportRegion vp = SoViewportRegionElement::get(state);
The reason for explaining this is that you can use this generic
technique when you need access to state information when you can’t seem
to find the accessor function you need in the action implementation.
You can use it to for instance retrieve the view volume information,
for which there are no accessor methods:
#include <Inventor/elements/SoViewVolumeElement.h>
SoState * state = action->getState();
SbViewVolume vv = SoViewVolumeElement::get(state);
When you do this on arbitrary action instances, you need to make sure
that the given element is enabled for the action before you try to use
it. The relevant functions for this are SoState::isElementEnabled() and
SoElement::getClassStackIndex().
void SoHandleEventAction::setEvent (const SoEvent * ev) Set the event to
distribute to the nodes of the scene.
const SoEvent * SoHandleEventAction::getEvent (void) const Returns the
event this action is handling.
void SoHandleEventAction::setHandled (void) Marks the action instance as
handled, hence terminates the action.
The action is only marked as handled when a node in the graph ’grabs’
the event this action is carrying, so the handled flag will be FALSE
after traversal if no nodes wanted the event.
See also:
isHandled()
SbBool SoHandleEventAction::isHandled (void) const Returns whether or not
the event has been handled by a node during scene graph traversal.
See also:
setHandled()
void SoHandleEventAction::setGrabber (SoNode * node) Set a node pointer
which will get all future events handled by this action until
releaseGrabber() is called.
Note that since later SoHandleEventAction invokations are just applied
directly on the grabber node, using SoHandleEventAction methods like
getCurPath() will return bogus data.
void SoHandleEventAction::releaseGrabber (void) Don’t send the events to a
’grabber’ node anymore, use the default behavior of the action and pass
them along to the scene graph again.
See also:
setGrabber()
SoNode * SoHandleEventAction::getGrabber (void) const Returns the grabber
node, or NULL if no grabber is active.
void SoHandleEventAction::setPickRoot (SoNode * node) Sets the root node
that is used for the pick action tracking the cursor.
SoNode * SoHandleEventAction::getPickRoot (void) const Returns the root
node that is used by nodes that is tracking the cursor.
void SoHandleEventAction::setPickRadius (const float radiusinpixels) Sets
the pick radius for cursor tracking.
const SoPickedPoint * SoHandleEventAction::getPickedPoint (void) Returns
the SoPickedPoint information for the intersection point below the
cursor.
const SoPickedPointList & SoHandleEventAction::getPickedPointList (void)
Returns a list of all intersection points below the mouse cursor.
void SoHandleEventAction::beginTraversal (SoNode * node) [protected,
virtual] This virtual method is called from SoAction::apply(), and is
the entry point for the actual scenegraph traversal.
It can be overridden to initialize the action at traversal start, for
specific initializations in the action subclasses inheriting SoAction.
Default method just calls traverse(), which any overridden
implementation of the method must do too (or call
SoAction::beginTraversal()) to trigger the scenegraph traversal.
Reimplemented from SoAction.
Author
Generated automatically by Doxygen for Coin from the source code.