SoPath Class Reference
Miscellaneous Classes

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

## Static Public Member Functions

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 SoType | getClassTypeId (void)
| This static method returns the SoType object associated with objects of this class.
static SoPath * | getByName (const SbName name)
static int | getByName (const SbName name, SoPathList &l)
Static Public Member Functions inherited from SoBase
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 SoType | getClassTypeId (void)
| This static method returns the SoType object associated with objects of this class.
static void | addName (SoBase *const base, const char *const name)
static void | removeName (SoBase *const base, const char *const name)
static void | incrementCurrentWriteCounter (void)
static void | decrementCurrentWriteCounter (void)
static SoBase * | getNamedBase (const SbName &name, SoType type)
static int | getNamedBases (const SbName &name, SoBaseList &baselist, SoType type)
static SbBool | read (SoInput *input, SoBase *&base, SoType expectedtype)
static void | setInstancePrefix (const SbString &c)
static void | setTraceRefs (SbBool trace)
static SbBool | getTraceRefs (void)
static SbBool | connectRoute (SoInput *input, const SbName &fromnodename, const SbName &fromfieldname, const SbName &tonodename, const SbName &tofieldname)
static SbBool | readRoute (SoInput *input)

## Protected Member Functions

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

## 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 |  | ) |

protected virtual

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

## Member Function Documentation

## operator=()

SoPath & SoPath::operator= | ( | const SoPath & | rhs | ) |

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

## 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
}
}
SoBase::getTypeId
virtual SoType getTypeId(void) const =0
Returns the type identification of an object derived from a class inheriting SoBase....
SoFile
The SoFile class is node container for another model file.
Definition SoFile.h:43
SoFile::getClassTypeId
static SoType getClassTypeId(void)
Definition SoFile.cpp:100
SoNode
The SoNode class is the base class for nodes used in scene graphs.
Definition SoNode.h:56

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.

## 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.

## getHead()

SoNode * SoPath::getHead | ( | void |  | ) | const

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

## 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 | ( | 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().

## append() [3/3]

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.

## push()

void SoPath::push | ( | const int | childindex | ) |

inline

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

## pop()

void SoPath::pop | ( | void |  | ) |

inline

This method pops the tail off the path.

## 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();
SoPath::getTail
SoNode * getTail(void) const
Definition SoPath.cpp:405

## 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.

## 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().

## 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).

## 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.

## 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

1. It is the caller's responsibility to ref() and unref() it according to use.

## 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.

## 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.

## 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.

## 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).

## 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);
SoAction::apply
virtual void apply(SoNode *root)
Definition SoAction.cpp:463
SoGroup::addChild
virtual void addChild(SoNode *node)
Definition SoGroup.cpp:453
SoSeparator
The SoSeparator class is a state-preserving group node.
Definition SoSeparator.h:44
SoWriteAction
The SoWriteAction class writes a scene graph to file.
Definition SoWriteAction.h:42

..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.

## auditPath()

void SoPath::auditPath | ( | const SbBool | flag | ) |

protected

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

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

- SoPath.h
- SoPath.cpp