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SoAction Class Reference

The SoAction class is the base class for all traversal actions. More...

#include <Inventor/actions/SoAction.h>

Inheritance diagram for SoAction::

List of all members.

Public Types
enum	AppliedCode { NODE = 0, PATH = 1, PATH_LIST = 2 }
enum	PathCode { NO_PATH = 0, IN_PATH = 1, BELOW_PATH = 2, OFF_PATH = 3 }
Public Methods
virtual	~SoAction ()
virtual SoType	getTypeId (void) const=0
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)
virtual void	invalidateState (void)
AppliedCode	getWhatAppliedTo (void) const
SoNode *	getNodeAppliedTo (void) const
SoPath *	getPathAppliedTo (void) const
const SoPathList *	getPathListAppliedTo (void) const
const SoPathList *	getOriginalPathListAppliedTo (void) const
SbBool	isLastPathListAppliedTo (void) const
PathCode	getPathCode (int &numindices, const int *&indices)
void	traverse (SoNode *const node)
SbBool	hasTerminated (void) const
const SoPath *	getCurPath (void)
SoState *	getState (void) const
PathCode	getCurPathCode (void) const
virtual SoNode *	getCurPathTail (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 Methods
void	initClass (void)
void	initClasses (void)
SoType	getClassTypeId (void)
void	nullAction (SoAction *action, SoNode *node)
Protected Methods
	SoAction (void)
virtual void	beginTraversal (SoNode *node)
virtual void	endTraversal (SoNode *node)
void	setTerminated (const SbBool flag)
virtual const SoEnabledElementsList &	getEnabledElements (void) const
virtual SbBool	shouldCompactPathList (void) const
Static Protected Methods
SoEnabledElementsList *	getClassEnabledElements (void)
SoActionMethodList *	getClassActionMethods (void)
Protected Attributes
SoState *	state
SoActionMethodList *	traversalMethods

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Detailed Description

The SoAction class is the base class for all traversal actions.

Applying actions is the basic mechanism in Coin for executing various operations on scene graphs or paths within scene graphs, including search operations, rendering, interaction through picking, etc.

The basic operation is to instantiate an action, set it up with miscellaneous parameters if necessary, then "apply it" to the root node of the scenegraph (or sub-graph of a scenegraph). The action then traverses the scenegraph from the root node, depth-first and left-to-right, applying it's specific processing at the nodes where it is applicable.

   int write_scenegraph(const char * filename, SoNode * root)
   {
     SoOutput output;
     if (output.openFile(filename)) return 0;
     SoWriteAction wa(&output);
     wa.apply(root);
     return 1;
   }

See the various built-in actions for further information (ie the subclasses of this class), or look at the example code applications of the Coin library to see how actions are generally used.

For extending the Coin library with your own action classes, we strongly recommend that you make yourself acquainted with the excellent «The Inventor Toolmaker» book (ISBN 0-201-62493-1), which describes the tasks involved in detail. Reading the sourcecode of the built-in action classes in Coin should also provide very helpful.

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Member Enumeration Documentation

enum SoAction::AppliedCode

Enumerated values for what the action was applied to.

enum SoAction::PathCode

Enumerated values for how the action is applied to a scene graph.

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Constructor & Destructor Documentation

SoAction::~SoAction (  void )  [virtual]

Destructor, free resources.

SoAction::SoAction (  void )  [protected]

Default constructor, does all necessary toplevel initialization.

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Member Function Documentation

void SoAction::initClass (  void )  [static]

Initializes the run-time type system for this class, and sets up the enabled elements and action method list. Reimplemented in SoGetMatrixAction, SoSearchAction, SoGLRenderAction, SoCallbackAction, SoBoxHighlightRenderAction, SoLineHighlightRenderAction, SoGetBoundingBoxAction, SoGetPrimitiveCountAction, SoWriteAction, SoHandleEventAction, SoPickAction, and SoRayPickAction.

void SoAction::initClasses (  void )  [static]

Initialize all the SoAction subclasses. Automatically called from SoAction::initClass().

SoType SoAction::getClassTypeId (  void )  [static]

Returns the run-time type object associated with instances of this class.

SoType SoAction::getTypeId (  void )  const [pure virtual]

Returns the type identification of an action derived from a class inheriting SoAction. This is used for run-time 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 renderaction } For application programmers wanting to extend the library with new actions: this method needs to be overloaded 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 pre-defined 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.

SbBool SoAction::isOfType (  SoType type )  const [virtual]

Returns TRUE if the type of this object is either of the same type or a subclass of type.

void SoAction::apply (  SoNode * node )  [virtual]

Applies the action to the scene graph rooted at root. Note that you should not apply an action to a node with a zero reference count. The behavior in that case is undefined. Reimplemented in SoBoxHighlightRenderAction, and SoLineHighlightRenderAction.

void SoAction::apply (  SoPath * path )  [virtual]

Applies the action to the parts of the graph defined by path. Reimplemented in SoBoxHighlightRenderAction, and SoLineHighlightRenderAction.

void SoAction::apply (  const SoPathList & pathlist, SbBool obeysrules = FALSE )  [virtual]

Applies action to the graphs defined by pathlist. If obeysrules is set to TRUE, pathlist must obey the following four conditions (which is the case for path lists returned from search actions for non-group nodes and path lists returned from picking actions): All paths must start at the same head node. All paths must be sorted in traversal order. The paths must be unique. No path can continue through the end point of another path. Reimplemented in SoBoxHighlightRenderAction, and SoLineHighlightRenderAction.

void SoAction::invalidateState (  void )  [virtual]

Invalidates the state, forcing it to be recreated at the next apply() invocation. Reimplemented in SoGLRenderAction.

void SoAction::nullAction (  SoAction * action, SoNode * node )  [static]

This method is used for filling up the lookup tables with void methods.

SoAction::AppliedCode SoAction::getWhatAppliedTo (  void )  const

Returns a code indicating what (node, path, or pathlist) the action instance is being applied to.

SoNode * SoAction::getNodeAppliedTo (  void )  const

Returns a pointer to the node the action is being applied to. If action is not being applied to a node (but a path or a pathlist), the method returns NULL.

SoPath * SoAction::getPathAppliedTo (  void )  const

Returns the pointer to the path the action is being applied to. The path is managed by the action instance and should not be destroyed or modified by the caller. If action is not being applied to a path (but a node or a pathlist), the method returns NULL.

const SoPathList * SoAction::getPathListAppliedTo (  void )  const

Returns the pointer to the path list the action is currently being applied to. The path list is managed by the action instance and should not be destroyed or modified by the caller. If action is not being applied to a path list (but a node or a path), the method returns NULL. The returned pathlist pointer need not be equal to the list apply() was called with, as the action may have reorganized the path list for efficiency reasons. See also: void SoAction::apply(const SoPathList &, SbBool)

const SoPathList * SoAction::getOriginalPathListAppliedTo (  void )  const

Returns a pointer to the original path list the action is being applied to. If the action is not being applied to a path list (but a node or a path), the method returns NULL.

SbBool SoAction::isLastPathListAppliedTo (  void )  const

This method is not supported in Coin. It should probably have been private in OIV.

SoAction::PathCode SoAction::getPathCode (  int & numindices, const int *& indices )

Returns a code that indicates where the current node lies with respect to the path(s) the action is being applied to. The arguments indices and numindices are only set if the method returns IN_PATH.

void SoAction::traverse (  SoNode *const node )

Traverses a scene graph rooted at node, invoking the action methods of the nodes in the graph.

SbBool SoAction::hasTerminated (  void )  const

Returns TRUE if the action was prematurely terminated. Note that the termination flag will be FALSE if the action simply completed its run over the scene graph in the "ordinary" fashion, i.e. was not explicitly aborted from any of the nodes in the graph. See also: setTerminated()

const SoPath * SoAction::getCurPath (  void )

Returns a pointer to the path generated during traversal, from the root of the traversed graph to the current node.

SoState * SoAction::getState (  void )  const

Returns a pointer to the state of the action instance. The state contains the current set of elements used during traversal.

SoAction::PathCode SoAction::getCurPathCode (  void )  const [inline]

Returns the current traversal path code.

SoNode * SoAction::getCurPathTail (  void )  [virtual]

For internal use only. Reimplemented in SoCallbackAction.

void SoAction::usePathCode (  int & numindices, const int *& indices )

For internal use only.

void SoAction::pushCurPath (  const int childindex, SoNode * node = NULL )

Get ready to traverse the childindex'th child. Use this method if the path code might change as a result of this. This method is very internal. Do not use unless you know what you're doing.

void SoAction::popCurPath (  const PathCode prevpathcode )  [inline]

Pops the current path, and sets the path code to prevpathcode. This method is very internal. Do not use unless you know what you're doing.

void SoAction::pushCurPath (  void )

Pushes a NULL node onto the current path. Use this before traversing all children when you know that the path code will not change while traversing children. This method is very internal. Do not use unless you know what you're doing.

void SoAction::popPushCurPath (  const int childindex, SoNode * node = NULL )

Get ready to traverse the childindex'th child. Use this method if you know the path code will not change as a result of this. This method is very internal. Do not use unless you know what you're doing.

void SoAction::popCurPath (  void )

Pops of the last child in the current path. Use this if you know the path code hasn't changed since the current path was pushed. This method is very internal. Do not use unless you know what you're doing.

void SoAction::switchToPathTraversal (  SoPath * path )

Store our state, traverse the given path, restore our state and continue traversal.

void SoAction::switchToNodeTraversal (  SoNode * node )

Store our state, traverse the subgraph rooted at the given node, restore our state and continue traversal.

void SoAction::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 in SoGetMatrixAction, SoSearchAction, SoGLRenderAction, SoCallbackAction, SoGetBoundingBoxAction, SoGetPrimitiveCountAction, SoWriteAction, SoHandleEventAction, SoPickAction, and SoRayPickAction.

void SoAction::endTraversal (  SoNode * node )  [protected, virtual]

This virtual method can be overloaded to execute code after the scene graph traversal. Default method does nothing. Reimplemented in SoGLRenderAction.

void SoAction::setTerminated (  const SbBool flag )  [protected]

Set the termination flag. Typically set to TRUE from nodes upon special conditions being met during scene graph traversal -- like the correct node being found when doing SoSearchAction traversal or when grabbing the event from an SoHandleEventAction. See also: hasTerminated()

const SoEnabledElementsList & SoAction::getEnabledElements (  void )  const [protected, virtual]

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

SbBool SoAction::shouldCompactPathList (  void )  const [protected, virtual]

For internal use only.

SoEnabledElementsList * SoAction::getClassEnabledElements (  void )  [static, protected]

For internal use only.

SoActionMethodList * SoAction::getClassActionMethods (  void )  [static, protected]

For internal use only.

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Member Data Documentation

SoAction::state [protected]

Pointer to the traversal state instance of the action.

SoAction::traversalMethods [protected]

Stores the list of "nodetype to actionmethod" mappings for the particular action instance.

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

• SoAction.cpp
• SoAction.h

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