Open Inventor Release 2023.2.2
 
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SoEventCallback Class Reference

Node which invokes callbacks for events. More...

#include <Inventor/nodes/SoEventCallback.h>

+ Inheritance diagram for SoEventCallback:

Public Member Functions

virtual SoType getTypeId () const
 Returns the type identifier for this specific instance.
 
 SoEventCallback ()
 Constructor creates an event callback node with no event interest and a NULL path.
 
void setPath (SoPath *path)
 Sets the path which must be picked in order for the callbacks to be invoked.
 
const SoPathgetPath ()
 Gets the path which must be picked in order for the callbacks to be invoked.
 
void addEventCallback (SoType eventType, SoEventCallbackCB *f, void *userData=NULL)
 Add an event callback .
 
template<typename EventType >
void addEventCallback (SoEventCallbackCB *f, void *userData=nullptr)
 Add an event callback .
 
void removeEventCallback (SoType eventType, SoEventCallbackCB *f, void *userData=NULL)
 Removes a previously specified event callback .
 
template<typename EventType >
void removeEventCallback (SoEventCallbackCB *f, void *userData=nullptr)
 Removes a previously specified event callback .
 
SoHandleEventActiongetAction () const
 Returns the SoHandleEventAction currently traversing this node, or NULL if traversal is not taking place.
 
const SoEventgetEvent () const
 Returns the event currently being handled, or NULL if traversal is not taking place.
 
const SoPickedPointgetPickedPoint () const
 Returns pick information during SoHandleEventAction traversal, or NULL if traversal is not taking place.
 
void setHandled ()
 Tells the node the event was handled.
 
SbBool isHandled () const
 Returns whether the event has been handled.
 
void grabEvents ()
 Tells the event callback node to grab events.
 
void releaseEvents ()
 Tells the event callback node to release the grab of events.
 
- Public Member Functions inherited from SoNode
virtual void setOverride (const SbBool state)
 Turns the override flag on or off.
 
virtual SbBool isOverride () const
 Returns the state of the override flag.
 
virtual SoNodecopy (SbBool copyConnections=FALSE) const
 Creates and returns an exact copy of the node.
 
virtual SbBool affectsState () const
 Returns TRUE if a node has an effect on the state during traversal.
 
virtual void touch ()
 Marks an instance as modified, simulating a change to it.
 
- Public Member Functions inherited from SoFieldContainer
void setToDefaults ()
 Sets all fields in this object to their default values.
 
SbBool hasDefaultValues () const
 Returns TRUE if all of the object's fields have their default values.
 
SbBool fieldsAreEqual (const SoFieldContainer *fc) const
 Returns TRUE if this object's fields are exactly equal to fc's fields.
 
void copyFieldValues (const SoFieldContainer *fc, SbBool copyConnections=FALSE)
 Copies the contents of fc's fields into this object's fields.
 
SoNONUNICODE SbBool set (const char *fieldDataString)
 Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format.
 
SbBool set (const SbString &fieldDataString)
 Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format.
 
void get (SbString &fieldDataString)
 Returns the values of the fields of this object in the Open Inventor ASCII file format in the given string.
 
virtual int getFields (SoFieldList &list) const
 Appends references to all of this object's fields to resultList, and returns the number of fields appended.
 
virtual int getAllFields (SoFieldList &list) const
 Returns a list of fields, including the eventIn's and eventOut's.
 
virtual SoFieldgetField (const SbName &fieldName) const
 Returns a the field of this object whose name is fieldName.
 
virtual SoFieldgetEventIn (const SbName &fieldName) const
 Returns a the eventIn with the given name.
 
virtual SoFieldgetEventOut (const SbName &fieldName) const
 Returns the eventOut with the given name.
 
SbBool getFieldName (const SoField *field, SbName &fieldName) const
 Returns the name of the given field in the fieldName argument.
 
SbBool enableNotify (SbBool flag)
 Notification at this Field Container is enabled (if flag == TRUE) or disabled (if flag == FALSE).
 
SbBool isNotifyEnabled () const
 Notification is the process of telling interested objects that this object has changed.
 
virtual void setUserData (void *data)
 Sets application data.
 
void * getUserData (void) const
 Gets user application data.
 
- Public Member Functions inherited from SoBase
virtual SbName getName () const
 Returns the name of an instance.
 
virtual void setName (const SbName &name)
 Sets the name of an instance.
 
void setSynchronizable (const bool b)
 Sets this to be a ScaleViz synchronizable object.
 
bool isSynchronizable () const
 Gets the ScaleViz synchronizable state of this object.
 
- Public Member Functions inherited from SoRefCounter
void ref () const
 Adds a reference to an instance.
 
void unref () const
 Removes a reference from an instance.
 
void unrefNoDelete () const
 unrefNoDelete() should be called when it is desired to decrement the reference count, but not delete the instance if this brings the reference count to zero.
 
int getRefCount () const
 Returns current reference count.
 
void lock () const
 lock this instance.
 
void unlock () const
 unlock this instance.
 
- Public Member Functions inherited from SoTypedObject
SbBool isOfType (const SoType &type) const
 Returns TRUE if this object is of the type specified in type or is derived from that type.
 
template<typename TypedObjectClass >
SbBool isOfType () const
 Returns TRUE if this object is of the type of class TypedObjectClass or is derived from that class.
 

Static Public Member Functions

static SoType getClassTypeId ()
 Returns the type identifier for this class.
 
- Static Public Member Functions inherited from SoNode
static SoType getClassTypeId ()
 Returns the type identifier for this class.
 
static SoNodegetByName (const SbName &name)
 A node's name can be set using SoBase::setName().
 
static int getByName (const SbName &name, SoNodeList &list)
 A node's name can be set using SoBase::setName().
 
- Static Public Member Functions inherited from SoFieldContainer
static SoType getClassTypeId ()
 Returns the type of this class.
 
- Static Public Member Functions inherited from SoBase
static SoType getClassTypeId ()
 Returns type identifier for this class.
 
- Static Public Member Functions inherited from SoTypedObject
static SoType getClassTypeId ()
 Returns the type identifier for this class.
 

Detailed Description

Node which invokes callbacks for events.

SoEventCallback will invoke application supplied callbacks during SoHandleEventAction traversal. Methods allow the application to specify which Open Inventor events should trigger callbacks, and which path must be picked, if any, for the callback invocation to occur. The application callback is able to get information about the event and the pick detail, and may grab events, release events, and set whether the event was handled.

If you register more than one callback in an SoEventCallback node, all the callbacks will be invoked when an event occurs, even if one of the callbacks handles the event. However, if the event is handled (i.e. setHandled is called) by any of the callbacks , no subsequent node in the scene graph will see the event. Generally SoEventCallback nodes should be placed near the beginning of the scene graph, so the SoHandleEventAction does not need to traverse the rest of the scene graph if the event is handled. Note that events may be handled by other nodes in the scene graph, for example draggers and manipulators. If the event is handled before the SoEventCallback node is traversed, then none of the callbacks will be invoked.

Remember that when using the Open Inventor viewer classes, SoHandleEventAction traversal is only done when the viewer is in "selection" mode (the arrow cursor is displayed). Also note that some methods may only be called from the callback .

When invoked, this SoEventCallback node will be passed to the callback . Using this object, you can get the event being handled (getEvent()) and query what geometry is under the cursor (getPickedPoint()). These are convenient wrappers around the corresponding methods in the SoHandleEventAction (which you can get using getAction()).

Picking:
When getPickedPoint() is called, the handle event action automatically applies an SoRayPickAction to the scene graph using the cursor position in the event. The handle event action remembers the result in case another node needs pick information during the traversal. Often this is more convenient than creating and applying a pick action explicitly.

But note: The handle event action does not enable computation of normal vectors and texture coordinates in the pick action that it creates internally. If you need the normal vector at the point of intersection of the pick ray, then you must create your own pick action and apply it. In this case you can get the node to apply the pick action to by calling the handle event action's getPickRoot() method.

The application method can conveniently find out what, if any, geometry is under the cursor by querying the SoHandleEventAction (getAction()), then calling the getPickedPoint() method. The first time this method is called during a handle event traversal, the handle event action will automatically apply its internal SoRayPickAction to the scene graph returned by getPickRoot(). The result is stored in case other nodes make the same query during the same traversal. The stored result can be cleared by calling clearApplyResult().

Some, but not all, options can be modified on the internal pick action (see for example setPickRadius()). Note that the internal pick action does not compute texture coordinates or normal vector for the picked point. Thus, getPickedPoint().getNormal() returns (0,0,0) and getPickedPoint().getTextureCoords() returns (0,0,0,0).

If your application needs to apply the pick action itself, for example to set different options, get the appropriate root node by calling SoHandleEventAction::getPickRoot().

To use GPU picking on compatible shapes, it is mandatory to set the pick radius to 0, see SoHandleEventAction::setPickRadius(float radiusInPixels). Compatible shapes are described in the SoRayPickAction section Picking Algorithms.

EXAMPLE

FILE FORMAT/DEFAULT

    EventCallback {
    }

SEE ALSO

SoInteraction, SoSelection, SoHandleEventAction, SoRayPickAction, SoDragger

Definition at line 286 of file SoEventCallback.h.

Constructor & Destructor Documentation

◆ SoEventCallback()

SoEventCallback::SoEventCallback ( )

Constructor creates an event callback node with no event interest and a NULL path.

Member Function Documentation

◆ addEventCallback() [1/2]

template<typename EventType >
void SoEventCallback::addEventCallback ( SoEventCallbackCB *  f,
void *  userData = nullptr 
)
inline

Add an event callback .

Specifies the callbacks to be invoked for different event types. When invoked, the callback will be passed the userData, along with a pointer to this SoEventCallback node. For example, passing the type of SoMouseButtonEvent means callbacks will be invoked only when a mouse button is pressed or released. Passing the type of SoEvent for the eventType will cause the callback to be invoked for every event which passes through this event callback node.

Since Open Inventor 10.8

Definition at line 332 of file SoEventCallback.h.

◆ addEventCallback() [2/2]

void SoEventCallback::addEventCallback ( SoType  eventType,
SoEventCallbackCB *  f,
void *  userData = NULL 
)

Add an event callback .

Specifies the callbacks to be invoked for different event types. When invoked, the callback will be passed the userData, along with a pointer to this SoEventCallback node. For example, passing the type of SoMouseButtonEvent means callbacks will be invoked only when a mouse button is pressed or released. Passing the type of SoEvent for the eventType will cause the callback to be invoked for every event which passes through this event callback node.

◆ getAction()

SoHandleEventAction * SoEventCallback::getAction ( ) const
inline

Returns the SoHandleEventAction currently traversing this node, or NULL if traversal is not taking place.

This should be called only from callback .

Definition at line 366 of file SoEventCallback.h.

◆ getClassTypeId()

static SoType SoEventCallback::getClassTypeId ( )
static

Returns the type identifier for this class.


◆ getEvent()

const SoEvent * SoEventCallback::getEvent ( ) const
inline

Returns the event currently being handled, or NULL if traversal is not taking place.

This should be called only from callback .

Definition at line 372 of file SoEventCallback.h.

◆ getPath()

const SoPath * SoEventCallback::getPath ( )
inline

Gets the path which must be picked in order for the callbacks to be invoked.

Definition at line 308 of file SoEventCallback.h.

◆ getPickedPoint()

const SoPickedPoint * SoEventCallback::getPickedPoint ( ) const
inline

Returns pick information during SoHandleEventAction traversal, or NULL if traversal is not taking place.

This should be called only from callback .

When this method is called, an SoRayPickAction is automatically applied to the scene graph that the SoHandleEventAction is traversing, using the current event. However this is only done once for each SoHandleEventAction traversal and the result is cached for subsequent queries during the current traversal.

Note: The handle event action does not enable computation of normal vectors and texture coordinates in the pick action that it creates internally. If you need the normal vector at the point of intersection of the pick ray, then you must create your own pick action and apply it. In this case you can get the node to apply the pick action to by calling the handle event action's getPickRoot() method.

Definition at line 390 of file SoEventCallback.h.

◆ getTypeId()

virtual SoType SoEventCallback::getTypeId ( ) const
virtual

Returns the type identifier for this specific instance.

Reimplemented from SoNode.

◆ grabEvents()

void SoEventCallback::grabEvents ( )
inline

Tells the event callback node to grab events.

While grabbing, the node will consume all events; however, each callback will only be invoked for events of interest.

Definition at line 418 of file SoEventCallback.h.

◆ isHandled()

SbBool SoEventCallback::isHandled ( ) const
inline

Returns whether the event has been handled.

This should be called only from callback .

Definition at line 410 of file SoEventCallback.h.

◆ releaseEvents()

void SoEventCallback::releaseEvents ( )
inline

Tells the event callback node to release the grab of events.

Event grabbing is requested using grabEvents().

Definition at line 425 of file SoEventCallback.h.

◆ removeEventCallback() [1/2]

template<typename EventType >
void SoEventCallback::removeEventCallback ( SoEventCallbackCB *  f,
void *  userData = nullptr 
)
inline

Removes a previously specified event callback .

Since Open Inventor 10.8

Definition at line 351 of file SoEventCallback.h.

◆ removeEventCallback() [2/2]

void SoEventCallback::removeEventCallback ( SoType  eventType,
SoEventCallbackCB *  f,
void *  userData = NULL 
)

Removes a previously specified event callback .

◆ setHandled()

void SoEventCallback::setHandled ( )
inline

Tells the node the event was handled.

The callback is responsible for setting whether the event was handled or not. If there is more than one callback registered with an SoEventCallback node, all of them will be invoked, regardless of whether one has handled the event or not. This should be called only from callback .

Definition at line 403 of file SoEventCallback.h.

◆ setPath()

void SoEventCallback::setPath ( SoPath path)

Sets the path which must be picked in order for the callbacks to be invoked.

If the path is NULL, the callbacks will be invoked for every interesting event, as specified by addEventCallback(), regardless of what is picked. The setPath() method makes its own copy of the passed path.


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