.TH "SoCallback" 3 "Sat Oct 12 2013" "Version 4.0.0a" "Coin" \" -*- nroff -*- .ad l .nh .SH NAME SoCallback \- .PP The \fBSoCallback\fP class is a node type which provides a means of setting callback hooks in the scene graph\&. .PP By inserting \fBSoCallback\fP nodes in a scene graph, the application programmer can set up functions to be executed at certain points in the traversal\&. .SH SYNOPSIS .br .PP .PP \fC#include \fP .PP Inherits \fBSoNode\fP\&. .SS "Public Member Functions" .in +1c .ti -1c .RI "virtual \fBSoType\fP \fBgetTypeId\fP (void) const " .br .RI "\fIReturns the type identification of an object derived from a class inheriting \fBSoBase\fP\&. This is used for run-time type checking and 'downward' casting\&. \fP" .ti -1c .RI "\fBSoCallback\fP (void)" .br .ti -1c .RI "void \fBsetCallback\fP (\fBSoCallbackCB\fP *function, void *userdata=NULL)" .br .ti -1c .RI "virtual void \fBdoAction\fP (\fBSoAction\fP *action)" .br .ti -1c .RI "virtual void \fBcallback\fP (\fBSoCallbackAction\fP *action)" .br .ti -1c .RI "virtual void \fBGLRender\fP (\fBSoGLRenderAction\fP *action)" .br .ti -1c .RI "virtual void \fBgetBoundingBox\fP (\fBSoGetBoundingBoxAction\fP *action)" .br .ti -1c .RI "virtual void \fBgetMatrix\fP (\fBSoGetMatrixAction\fP *action)" .br .ti -1c .RI "virtual void \fBhandleEvent\fP (\fBSoHandleEventAction\fP *action)" .br .ti -1c .RI "virtual void \fBpick\fP (\fBSoPickAction\fP *action)" .br .ti -1c .RI "virtual void \fBsearch\fP (\fBSoSearchAction\fP *action)" .br .ti -1c .RI "virtual void \fBwrite\fP (\fBSoWriteAction\fP *action)" .br .ti -1c .RI "virtual void \fBgetPrimitiveCount\fP (\fBSoGetPrimitiveCountAction\fP *action)" .br .in -1c .SS "Static Public Member Functions" .in +1c .ti -1c .RI "static \fBSoType\fP \fBgetClassTypeId\fP (void)" .br .RI "\fIThis static method returns the \fBSoType\fP object associated with objects of this class\&. \fP" .ti -1c .RI "static void \fBinitClass\fP (void)" .br .RI "\fISets up initialization for data common to all instances of this class, like submitting necessary information to the Coin type system\&. \fP" .in -1c .SS "Protected Member Functions" .in +1c .ti -1c .RI "virtual const \fBSoFieldData\fP * \fBgetFieldData\fP (void) const " .br .ti -1c .RI "virtual \fB~SoCallback\fP ()" .br .ti -1c .RI "virtual void \fBcopyContents\fP (const \fBSoFieldContainer\fP *from, SbBool copyconnections)" .br .in -1c .SS "Static Protected Member Functions" .in +1c .ti -1c .RI "static const \fBSoFieldData\fP ** \fBgetFieldDataPtr\fP (void)" .br .in -1c .SS "Additional Inherited Members" .SH "Detailed Description" .PP The \fBSoCallback\fP class is a node type which provides a means of setting callback hooks in the scene graph\&. .PP By inserting \fBSoCallback\fP nodes in a scene graph, the application programmer can set up functions to be executed at certain points in the traversal\&. The callback function will be executed during traversal of \fIany\fP action, so check the type of the \fIaction\fP argument of the callback function if you only want to run your code at specific actions\&. .PP \fBFILE FORMAT/DEFAULTS:\fP .PP .nf Callback { } .fi .PP .SH "Constructor & Destructor Documentation" .PP .SS "SoCallback::SoCallback (void)" Constructor\&. .SS "SoCallback::~SoCallback ()\fC [protected]\fP, \fC [virtual]\fP" Destructor\&. .SH "Member Function Documentation" .PP .SS "\fBSoType\fP SoCallback::getTypeId (void) const\fC [virtual]\fP" .PP Returns the type identification of an object derived from a class inheriting \fBSoBase\fP\&. This is used for run-time type checking and 'downward' casting\&. Usage example: .PP .PP .nf void foo(SoNode * node) { if (node->getTypeId() == SoFile::getClassTypeId()) { SoFile * filenode = (SoFile *)node; // safe downward cast, knows the type } } .fi .PP .PP For application programmers wanting to extend the library with new nodes, engines, nodekits, draggers or others: this method needs to be overridden in \fIall\fP subclasses\&. This is typically done as part of setting up the full type system for extension classes, which is usually accomplished by using the pre-defined macros available through for instance \fBInventor/nodes/SoSubNode\&.h\fP (SO_NODE_INIT_CLASS and SO_NODE_CONSTRUCTOR for node classes), Inventor/engines/SoSubEngine\&.h (for engine classes) and so on\&. .PP For more information on writing Coin extensions, see the class documentation of the toplevel superclasses for the various class groups\&. .PP Implements \fBSoBase\fP\&. .SS "const \fBSoFieldData\fP ** SoCallback::getFieldDataPtr (void)\fC [static]\fP, \fC [protected]\fP" \fIThis API member is considered internal to the library, as it is not likely to be of interest to the application programmer\&.\fP .PP Reimplemented from \fBSoNode\fP\&. .SS "const \fBSoFieldData\fP * SoCallback::getFieldData (void) const\fC [protected]\fP, \fC [virtual]\fP" Returns a pointer to the class-wide field data storage object for this instance\&. If no fields are present, returns \fCNULL\fP\&. .PP Reimplemented from \fBSoFieldContainer\fP\&. .SS "void SoCallback::setCallback (\fBSoCallbackCB\fP *function, void *userdata = \fCNULL\fP)" Set up the \fIfunction\fP to call at traversal of this node\&. \fIuserdata\fP will be passed back as the first argument of the callback \fIfunction\fP\&. Setting \fIfunction\fP to NULL removes the previously set callback function\&. .PP If you want a callback only for a specific action, you must (in your callback function) remember to check which action invoked the callback, for instance like this: .PP .PP .nf void mycallback(void * userdata, SoAction * action) { if (action->isOfType(SoGLRenderAction::getClassTypeId())) { // do stuff specific for GL rendering here\&. } } .fi .PP .PP Please note that \fBSoCallback\fP nodes under a Separator might be included in a cache\&. Cached nodes are not traversed, and you'll not receive any callbacks\&. If you want to make sure that your callback is called every time the scene graph is rendered, you must invalidate the render cache in your callback: .PP .PP .nf void mycallback(void * userdata, SoAction * action) { if (action->isOfType(SoGLRenderAction::getClassTypeId())) { SoCacheElement::invalidate(action->getState()); } } .fi .PP .PP If you want to invalidate all caches (for instance also the bounding box cache), you can do this in your callback: .PP .PP .nf void mycallback(void * userdata, SoAction * action) { SoState * state = action->getState(); if (state->isElementEnabled(SoCacheElement::getClassStackIndex())) { SoCacheElement::invalidate(state); } } .fi .PP .SS "void SoCallback::doAction (\fBSoAction\fP *action)\fC [virtual]\fP" This function performs the typical operation of a node for any action\&. .PP Reimplemented from \fBSoNode\fP\&. .SS "void SoCallback::callback (\fBSoCallbackAction\fP *action)\fC [virtual]\fP" Action method for \fBSoCallbackAction\fP\&. .PP Simply updates the state according to how the node behaves for the render action, so the application programmer can use the \fBSoCallbackAction\fP for extracting information about the scene graph\&. .PP Reimplemented from \fBSoNode\fP\&. .SS "void SoCallback::GLRender (\fBSoGLRenderAction\fP *action)\fC [virtual]\fP" Action method for the \fBSoGLRenderAction\fP\&. .PP This is called during rendering traversals\&. Nodes influencing the rendering state in any way or who wants to throw geometry primitives at OpenGL overrides this method\&. .PP Reimplemented from \fBSoNode\fP\&. .SS "void SoCallback::getBoundingBox (\fBSoGetBoundingBoxAction\fP *action)\fC [virtual]\fP" Action method for the \fBSoGetBoundingBoxAction\fP\&. .PP Calculates bounding box and center coordinates for node and modifies the values of the \fIaction\fP to encompass the bounding box for this node and to shift the center point for the scene more towards the one for this node\&. .PP Nodes influencing how geometry nodes calculates their bounding box also overrides this method to change the relevant state variables\&. .PP Reimplemented from \fBSoNode\fP\&. .SS "void SoCallback::getMatrix (\fBSoGetMatrixAction\fP *action)\fC [virtual]\fP" Action method for \fBSoGetMatrixAction\fP\&. .PP Updates \fIaction\fP by accumulating with the transformation matrix of this node (if any)\&. .PP Reimplemented from \fBSoNode\fP\&. .SS "void SoCallback::handleEvent (\fBSoHandleEventAction\fP *action)\fC [virtual]\fP" Action method for \fBSoHandleEventAction\fP\&. .PP Inspects the event data from \fIaction\fP, and processes it if it is something which this node should react to\&. .PP Nodes influencing relevant state variables for how event handling is done also overrides this method\&. .PP Reimplemented from \fBSoNode\fP\&. .SS "void SoCallback::pick (\fBSoPickAction\fP *action)\fC [virtual]\fP" Action method for \fBSoPickAction\fP\&. .PP Does common processing for \fBSoPickAction\fP \fIaction\fP instances\&. .PP Reimplemented from \fBSoNode\fP\&. .SS "void SoCallback::search (\fBSoSearchAction\fP *action)\fC [virtual]\fP" Action method for \fBSoSearchAction\fP\&. .PP Compares the search criteria from the \fIaction\fP to see if this node is a match\&. Searching is done by matching up \fIall\fP criteria set up in the \fBSoSearchAction\fP -- if \fIany\fP of the requested criteria is a miss, the search is not deemed successful for the node\&. .PP \fBSee Also:\fP .RS 4 \fBSoSearchAction\fP .RE .PP .PP Reimplemented from \fBSoNode\fP\&. .SS "void SoCallback::write (\fBSoWriteAction\fP *action)\fC [virtual]\fP" Action method for \fBSoWriteAction\fP\&. .PP Writes out a node object, and any connected nodes, engines etc, if necessary\&. .PP Reimplemented from \fBSoNode\fP\&. .SS "void SoCallback::getPrimitiveCount (\fBSoGetPrimitiveCountAction\fP *action)\fC [virtual]\fP" Action method for the \fBSoGetPrimitiveCountAction\fP\&. .PP Calculates the number of triangle, line segment and point primitives for the node and adds these to the counters of the \fIaction\fP\&. .PP Nodes influencing how geometry nodes calculates their primitive count also overrides this method to change the relevant state variables\&. .PP Reimplemented from \fBSoNode\fP\&. .SS "void SoCallback::copyContents (const \fBSoFieldContainer\fP *from, SbBoolcopyconnections)\fC [protected]\fP, \fC [virtual]\fP" Makes a deep copy of all data of \fIfrom\fP into this instance, \fIexcept\fP external scenegraph references if \fIcopyconnections\fP is \fCFALSE\fP\&. .PP This is the method that should be overridden by extension node / engine / dragger / whatever subclasses which needs to account for internal data that are not handled automatically\&. .PP For copying nodes from application code, you should not invoke this function directly, but rather call the \fBSoNode::copy()\fP function: .PP .PP .nf SoNode * mynewnode = templatenode->copy(); .fi .PP .PP The same also goes for engines\&. .PP Make sure that when you override the \fBcopyContents()\fP method in your extension class that you also make it call upwards to it's parent superclass in the inheritance hierarchy, as \fBcopyContents()\fP in for instance \fBSoNode\fP and \fBSoFieldContainer\fP does important work\&. It should go something like this: .PP .PP .nf void MyCoinExtensionNode::copyContents(const SoFieldContainer * from, SbBool copyconnections) { // let parent superclasses do their thing (copy fields, copy // instance name, etc etc) SoNode::copyContents(from, copyconnections); // [\&.\&.then copy internal data\&.\&.] } .fi .PP .PP Reimplemented from \fBSoNode\fP\&. .SH "Author" .PP Generated automatically by Doxygen for Coin from the source code\&.