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SoHandleEventAction Class Reference

The SoHandleEventAction class distributes user events to the scene. More...

#include <Inventor/actions/SoHandleEventAction.h>

Inheritance diagram for SoHandleEventAction:

Public Member Functions

virtual SoType getTypeId (void) const
 SoHandleEventAction (const SbViewportRegion &viewportregion)
virtual ~SoHandleEventAction (void)
void setViewportRegion (const SbViewportRegion &newregion)
const SbViewportRegiongetViewportRegion (void) const
void setEvent (const SoEvent *ev)
const SoEventgetEvent (void) const
void setHandled (void)
SbBool isHandled (void) const
void setGrabber (SoNode *node)
void releaseGrabber (void)
SoNodegetGrabber (void) const
void setPickRoot (SoNode *node)
SoNodegetPickRoot (void) const
void setPickRadius (const float radiusinpixels)
float getPickRadius (void) const
const SoPickedPointgetPickedPoint (void)
const SoPickedPointListgetPickedPointList (void)
- Public Member Functions inherited from SoAction
virtual ~SoAction (void)
virtual SbBool isOfType (SoType type) const
virtual void apply (SoNode *root)
virtual void apply (SoPath *path)
virtual void apply (const SoPathList &pathlist, SbBool obeysrules=FALSE)
void apply (SoAction *beingApplied)
virtual void invalidateState (void)
AppliedCode getWhatAppliedTo (void) const
SoNodegetNodeAppliedTo (void) const
SoPathgetPathAppliedTo (void) const
const SoPathListgetPathListAppliedTo (void) const
const SoPathListgetOriginalPathListAppliedTo (void) const
SbBool isLastPathListAppliedTo (void) const
PathCode getPathCode (int &numindices, const int *&indices)
void traverse (SoNode *const node)
SbBool hasTerminated (void) const
const SoPathgetCurPath (void)
SoStategetState (void) const
PathCode getCurPathCode (void) const
virtual SoNodegetCurPathTail (void)
void usePathCode (int &numindices, const int *&indices)
void pushCurPath (const int childindex, SoNode *node=NULL)
void popCurPath (const PathCode prevpathcode)
void pushCurPath (void)
void popPushCurPath (const int childindex, SoNode *node=NULL)
void popCurPath (void)
void switchToPathTraversal (SoPath *path)
void switchToNodeTraversal (SoNode *node)

Static Public Member Functions

static SoType getClassTypeId (void)
static void addMethod (const SoType type, SoActionMethod method)
static void enableElement (const SoType type, const int stackindex)
static void initClass (void)
- Static Public Member Functions inherited from SoAction
static void initClass (void)
static void initClasses (void)
static SoType getClassTypeId (void)
static void nullAction (SoAction *action, SoNode *node)

Protected Member Functions

virtual const SoEnabledElementsListgetEnabledElements (void) const
virtual void beginTraversal (SoNode *node)
- Protected Member Functions inherited from SoAction
 SoAction (void)
virtual void endTraversal (SoNode *node)
void setTerminated (const SbBool flag)
virtual SbBool shouldCompactPathList (void) const

Static Protected Member Functions

static SoEnabledElementsListgetClassEnabledElements (void)
static SoActionMethodListgetClassActionMethods (void)
- Static Protected Member Functions inherited from SoAction
static SoEnabledElementsListgetClassEnabledElements (void)
static SoActionMethodListgetClassActionMethods (void)

Additional Inherited Members

- Public Types inherited from SoAction
enum  AppliedCode { NODE = 0, PATH = 1, PATH_LIST = 2 }
enum  PathCode { NO_PATH = 0, IN_PATH = 1, BELOW_PATH = 2, OFF_PATH = 3 }
- Protected Attributes inherited from SoAction

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

Constructor & Destructor Documentation

◆ SoHandleEventAction()

SoHandleEventAction::SoHandleEventAction ( const SbViewportRegion viewportregion)


SoHandleEventAction needs a viewportregion to pass on to the ray pick action instance it uses for being able to track objects under the mouse cursor.

◆ ~SoHandleEventAction()

SoHandleEventAction::~SoHandleEventAction ( void  )


Member Function Documentation

◆ getTypeId()

SoType SoHandleEventAction::getTypeId ( void  ) const

Returns the type identification of an action derived from a class inheriting SoAction. This is used for runtime type checking and "downward" casting.

Usage example:

void bar(SoAction * action)
if (action->getTypeId() == SoGLRenderAction::getClassTypeId()) {
// safe downward cast, know the type
SoGLRenderAction * glrender = (SoGLRenderAction *)action;
return; // ignore if not render action

For application programmers wanting to extend the library with new actions: this method needs to be overridden in all subclasses. This is typically done as part of setting up the full type system for extension classes, which is usually accomplished by using the predefined macros available through Inventor/nodes/SoSubAction.h: SO_ACTION_SOURCE, SO_ACTION_INIT_CLASS and SO_ACTION_CONSTRUCTOR.

For more information on writing Coin extensions, see the SoAction class documentation.

Returns the actual type id of an object derived from a class inheriting SoAction. Needs to be overridden in all subclasses.

Implements SoAction.

◆ addMethod()

void SoHandleEventAction::addMethod ( const SoType  type,
SoActionMethod  method 

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

◆ enableElement()

void SoHandleEventAction::enableElement ( const SoType  type,
const int  stackindex 

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

◆ getEnabledElements()

const SoEnabledElementsList & SoHandleEventAction::getEnabledElements ( void  ) const

Returns a list of the elements used by action instances of this class upon traversal operations.

Reimplemented from SoAction.

◆ setViewportRegion()

void SoHandleEventAction::setViewportRegion ( const SbViewportRegion newregion)

Set a new viewport region, replacing the one passed in the constructor.

◆ getViewportRegion()

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();

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();

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().

◆ setEvent()

void SoHandleEventAction::setEvent ( const SoEvent ev)

Set the event to distribute to the nodes of the scene.

◆ getEvent()

const SoEvent * SoHandleEventAction::getEvent ( void  ) const

Returns the event this action is handling.

◆ setHandled()

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

◆ setGrabber()

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 invocations are just applied directly on the grabber node, using SoHandleEventAction methods like getCurPath() will return bogus data.

◆ releaseGrabber()

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

◆ getGrabber()

SoNode * SoHandleEventAction::getGrabber ( void  ) const

Returns the grabber node, or NULL if no grabber is active.

◆ setPickRoot()

void SoHandleEventAction::setPickRoot ( SoNode node)

Sets the root node that is used for the pick action tracking the cursor.

◆ getPickRoot()

SoNode * SoHandleEventAction::getPickRoot ( void  ) const

Returns the root node that is used by nodes that is tracking the cursor.

◆ setPickRadius()

void SoHandleEventAction::setPickRadius ( const float  radiusinpixels)

Sets the pick radius for cursor tracking.

◆ getPickRadius()

float SoHandleEventAction::getPickRadius ( void  ) const

Gets the pick radius for cursor tracking.

◆ getPickedPoint()

const SoPickedPoint * SoHandleEventAction::getPickedPoint ( void  )

Returns the SoPickedPoint information for the intersection point below the cursor.

◆ getPickedPointList()

const SoPickedPointList & SoHandleEventAction::getPickedPointList ( void  )

Returns a list of all intersection points below the mouse cursor.

◆ beginTraversal()

void SoHandleEventAction::beginTraversal ( SoNode node)

This virtual method is called from SoAction::apply(), and is the entry point for the actual scene graph 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 scene graph traversal.

Reimplemented from SoAction.

The documentation for this class was generated from the following files: