SoPath Class Reference

The SoPath class is a container class for traversal path descriptions. More...

#include <Inventor/SoPath.h>

Inheritance diagram for SoPath:

Public Member Functions
	SoPath (const int approxlength=4)
	SoPath (const SoPath &rhs)
	SoPath (SoNode *const head)
void	append (const int childindex)
void	append (const SoPath *const frompath)
void	append (SoNode *const node)
SbBool	containsNode (const SoNode *const node) const
SbBool	containsPath (const SoPath *const path) const
SoPath *	copy (const int startfromnodeindex=0, int numnodes=0) const
int	findFork (const SoPath *const path) const
int	findNode (const SoNode *const node) const
SoNode *	getHead (void) const
int	getIndex (const int index) const
int	getIndexFromTail (const int index) const
int	getLength (void) const
SoNode *	getNode (const int index) const
SoNode *	getNodeFromTail (const int index) const
SoNode *	getTail (void) const
virtual SoType	getTypeId (void) const
	Returns the type identification of an object derived from a class inheriting SoBase. This is used for runtime type checking and "downward" casting.
void	insertIndex (SoNode *const parent, const int newindex)
SbBool	isRelevantNotification (SoNotList *const l) const
SoPath &	operator= (const SoPath &rhs)
void	pop (void)
void	push (const int childindex)
void	removeIndex (SoNode *const parent, const int oldindex)
void	replaceIndex (SoNode *const parent, const int index, SoNode *const newchild)
void	setHead (SoNode *const head)
void	truncate (const int length)
virtual void	write (SoWriteAction *action)
Public Member Functions inherited from SoBase
void	addAuditor (void *const auditor, const SoNotRec::Type type)
virtual void	addWriteReference (SoOutput *out, SbBool isfromfield=FALSE)
void	assertAlive (void) const
const SoAuditorList &	getAuditors (void) const
virtual SbName	getName (void) const
int32_t	getRefCount (void) const
SbBool	isOfType (SoType type) const
	Returns TRUE if the type of this object is either of the same type or inherited from type.
virtual void	notify (SoNotList *l)
void	ref (void) const
void	removeAuditor (void *const auditor, const SoNotRec::Type type)
virtual void	setName (const SbName &newname)
SbBool	shouldWrite (void)
virtual void	startNotify (void)
void	touch (void)
void	unref (void) const
void	unrefNoDelete (void) const

Static Public Member Functions
static SoPath *	getByName (const SbName name)
static int	getByName (const SbName name, SoPathList &l)
static SoType	getClassTypeId (void)
	This static method returns the SoType object associated with objects of this class.
static void	initClass (void)
	Sets up initialization for data common to all instances of this class, like submitting necessary information to the Coin type system.
Static Public Member Functions inherited from SoBase
static void	addName (SoBase *const base, const char *const name)
static SbBool	connectRoute (SoInput *input, const SbName &fromnodename, const SbName &fromfieldname, const SbName &tonodename, const SbName &tofieldname)
static void	decrementCurrentWriteCounter (void)
static SoType	getClassTypeId (void)
	This static method returns the SoType object associated with objects of this class.
static SoBase *	getNamedBase (const SbName &name, SoType type)
static int	getNamedBases (const SbName &name, SoBaseList &baselist, SoType type)
static SbBool	getTraceRefs (void)
static void	incrementCurrentWriteCounter (void)
static void	initClass (void)
	Sets up initialization for data common to all instances of this class, like submitting necessary information to the Coin type system.
static SbBool	read (SoInput *input, SoBase *&base, SoType expectedtype)
static SbBool	readRoute (SoInput *input)
static void	removeName (SoBase *const base, const char *const name)
static void	setInstancePrefix (const SbString &c)
static void	setTraceRefs (SbBool trace)

Protected Member Functions
virtual	~SoPath ()
void	auditPath (const SbBool flag)
Protected Member Functions inherited from SoBase
	SoBase (void)
virtual	~SoBase ()
virtual SoNotRec	createNotRec (void)
virtual void	destroy (void)
virtual const char *	getFileFormatName (void) const
SbBool	hasMultipleWriteRefs (void) const
void	writeFooter (SoOutput *out) const
SbBool	writeHeader (SoOutput *out, SbBool isgroup, SbBool isengine) const

Additional Inherited Members
Protected Types inherited from SoBase
enum	BaseFlags { IS_ENGINE = 0x01 , IS_GROUP = 0x02 }
Static Protected Member Functions inherited from SoBase
static uint32_t	getCurrentWriteCounter (void)
static void	staticDataLock (void)
static void	staticDataUnlock (void)

Detailed Description

The SoPath class is a container class for traversal path descriptions.

SoPath objects contain a list of SoNode pointers and a list of child indices. Indices are necessary to disambiguate situations where a node uses the same node as a child multiple times.

Paths can be export and imported to/from file, like other SoBase derived objects. Read the documentation on the write() method to see how the file format is.

It's important to know the difference between this class and SoFullPath when working with paths. SoPath::getTail() will return the first node in the path that doesn't inherit SoGroup, and getLength() returns the number of nodes down to this node.

If you need the actual path length, or the actual tail node, you need to cast the path to SoFullPath.

Constructor & Destructor Documentation

SoPath() [1/3]

SoPath::SoPath

(

const int

approxlength = 4

)

The default constructor. approxlength is used to indicate in advance the length of the path to minimize the number of reallocations.

SoPath() [2/3]

SoPath::SoPath

(

SoNode *const

head

)

A constructor. The argument is set as the head (and only) node of the path.

SoPath() [3/3]

SoPath::SoPath

(

const SoPath &

rhs

)

Copy constructor. Not part of the original Open Inventor API.

~SoPath()

SoPath::~SoPath ( void )

protectedvirtual

The destructor is protected as destruction of SoPath instances happens through unref() (as for all objects derived from classes inheriting SoBase).

Member Function Documentation

append() [1/3]

void SoPath::append

(

const int

childindex

)

This function appends the childindex child of the path's tail to the end of the path. It can only be used after the head is set.

append() [2/3]

void SoPath::append

(

const SoPath *const

frompath

)

This method appends the path to the end of the path if the head of frompath is either the tail of the path or a child of the path's tail. If the head of frompath is used multiple times as a child of the path tail, the lowest child index is used.

append() [3/3]

void SoPath::append

(

SoNode *const

node

)

This function adds node to the end if it is a child of the current tail. If path is empty, this is equivalent to calling setHead().

auditPath()

void SoPath::auditPath ( const SbBool flag )

protected

Set whether or not to audit the nodes in the path to detect changes.

containsNode()

SbBool SoPath::containsNode

(

const SoNode *const

node

)

const

This method returns TRUE is node is contained somewhere in the full path (possibly also in the normally hidden parts), and FALSE otherwise.

containsPath()

SbBool SoPath::containsPath

(

const SoPath *const

path

)

const

This method returns TRUE if path is contained in the path, and FALSE otherwise.

copy()

SoPath * SoPath::copy	(	const int	startfromnodeindex = 0,
		int	numnodes = 0 ) const

This method returns a copy of the path starting at startfromnodeindex with length numnodes. If numnodes is 0 (default) the path will be copied to the end.

The returned SoPath instance will have an initial reference count of 0. It is the caller's responsibility to ref() and unref() it according to use.

findFork()

int SoPath::findFork

(

const SoPath *const

path

)

const

This method returns the index of the last node that is the same for both paths, or -1 if the paths don't even start on the same node.

findNode()

int SoPath::findNode

(

const SoNode *const

node

)

const

Returns the index of node if found in the full path (possibly also in the normally hidden parts), or -1 otherwise.

Note that this method is not part of the original Open Inventor API.

getByName() [1/2]

SoPath * SoPath::getByName ( const SbName name )

static

This static method is for retrieving an SoPath by its name. The last registered SoPath with the given name is returned, or NULL if no SoPath by name exists.

getByName() [2/2]

int SoPath::getByName ( const SbName name, SoPathList & l )

static

This static method is for finding all the paths with a given name and append them to the l list. The number of SoPath instances with name found is returned.

getHead()

SoNode * SoPath::getHead

(

void

)

const

This method returns the head of the path, or NULL if the path is empty.

getIndex()

int SoPath::getIndex

(

const int

index

)

const

This method returns the child index of the node at index in the path.

getIndexFromTail()

int SoPath::getIndexFromTail

(

const int

index

)

const

This method returns the child index of the node at index in the path, counting from the tail. The index argument should be zero or positive.

getLength()

int SoPath::getLength

(

void

)

const

This method returns the number of nodes in the path. Only the "visible" nodes are counted, i.e. hidden nodes of e.g. nodekits are not included.

If you need the actual path length, you need to cast your path to SoFullPath and use SoFullPath::getLength().

getNode()

SoNode * SoPath::getNode

(

const int

index

)

const

This method returns the node at index in the path, counted from 0 at the head.

getNodeFromTail()

SoNode * SoPath::getNodeFromTail

(

const int

index

)

const

This method returns the node at index in the path, counting from the tail. The index argument should be zero or positive.

getTail()

SoNode * SoPath::getTail

(

void

)

const

This method returns the tail node of the path. Please note that this method only considers group nodes without hidden children (nodes inheriting SoGroup) when finding the tail.

If you want to find the real tail node (also below node kits and VRML nodes with hidden children), you have to use SoFullPath::getTail(). You don't have to create an SoFullPath instance to do this, just cast the SoPath instance to SoFullPath before getting the tail node:

SoNode * tail = static_cast<SoFullPath*>(path)->getTail();

getTypeId()

SoType SoPath::getTypeId ( void ) const

virtual

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

Usage example:

void foo(SoNode * node)
{
  if (node->getTypeId() == SoFile::getClassTypeId()) {
    SoFile * filenode = (SoFile *)node;  // safe downward cast, knows the type
  }
}

For application programmers wanting to extend the library with new nodes, engines, nodekits, draggers or others: 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 for instance Inventor/nodes/SoSubNode.h (SO_NODE_INIT_CLASS and SO_NODE_CONSTRUCTOR for node classes), Inventor/engines/SoSubEngine.h (for engine classes) and so on.

For more information on writing Coin extensions, see the class documentation of the top level superclasses for the various class groups.

Implements SoBase.

insertIndex()

void SoPath::insertIndex	(	SoNode *const	parent,
		const int	newindex )

This method is called when a node in the path chain has a child added, to update the index of its child.

newindex is the index of the child which was inserted. If newindex is lower than the index value of the child node stored in the path, the path is updated accordingly.

isRelevantNotification()

SbBool SoPath::isRelevantNotification

(

SoNotList *const

l

)

const

Return TRUE if the notification chain l will affect the path. l will affect the path either if the notification is in the path (the notification started on a field in a node in the path), or off the path (the notification started in a non-separator node that is left of the path's node).

operator=()

SoPath & SoPath::operator=

(

const SoPath &

rhs

)

Assignment operator, copies the rhs path into this. Not part of the original Open Inventor API.

pop()

void SoPath::pop ( void )

inline

This method pops the tail off the path.

push()

void SoPath::push ( const int childindex )

inline

This method pushes the child at childindex on the tail on the path.

removeIndex()

void SoPath::removeIndex	(	SoNode *const	parent,
		const int	oldindex )

This method is called when a node in the path chain has a child removed, to update the index of its child.

oldindex was the index of the removed child. If oldindex is lower than or equal to the index value of the child node stored in the path, the path is updated accordingly.

replaceIndex()

void SoPath::replaceIndex	(	SoNode *const	parent,
		const int	index,
		SoNode *const	newchild )

This method is called when a node newchild replaces a node in the path. index is the position of the child which has been replaced.

setHead()

void SoPath::setHead

(

SoNode *const

node

)

This method sets the head of the path to node. If the object already has a path set, it will be truncated.

truncate()

void SoPath::truncate

(

const int

length

)

This method truncates the path to the given length (i.e. all nodes in the path list from index length and onwards will be removed from the path list).

write()

void SoPath::write ( SoWriteAction * action )

virtual

This method is used to write the contents of an SoPath.

A path is written as:

Path {
  HEAD-NODE-OF-SUBGRAPH
  NUMBER-OF-INDICES
  INDEX0
  INDEX1
  ...
}

[The rest of the documentation for this method only explains the reason behind a mismatch in behavior between the original Open Inventor and Coin. Don't read it if you're not taking a particular interest. (Short version: we do SoPath export in a somewhat more inefficient way to avoid the potential for bugs).]

Note that unlike Open Inventor, we write the complete subgraph below the head node. Only writing the parts of the subgraph affecting the state for nodes within the path is error prone if a subgraph is written out as part of path before it is written out "properly". Consider writing a scene graph which looks like this (in memory):

DEF top_sep Separator {
  Cone { }
  DEF a_sphere Sphere { }
  Cube { }
}
 
DEF path_switch PathSwitch {
  path Path {
    ...path from "top_sep" to "a_sphere"...
  }
}

..if we now do:

SoSeparator * root = new SoSeparator;
root->addChild([ptr to path_switch]);
root->addChild([ptr to top_sep]);
SoWriteAction wa;
wa.apply(root);

..we would get the scene graph exported like this:

Separator {
  DEF path_switch PathSwitch {
    path Path {
      DEF top_sep Separator {
        DEF a_sphere Sphere {
        }
      }
      1
      0
    }
  }
  USE top_sep
}

..and as you can see, both the Cone and the Cube nodes have vanished, as they were not important for the part per se, and not written as part of it.

This is why we do full subgraph export for head nodes in paths.

---

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

• SoPath.h
• SoPath.cpp