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SoPath Class Reference

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

#include <Inventor/SoPath.h>

Inheritance diagram for SoPath::

SoBase SoFullPath SoNodeKitPath List of all members.

Public Methods

 SoPath (const int approxlength=4)
 SoPath (SoNode *const head)
 SoPath (const SoPath &rhs)
SoPath & operator= (const SoPath &rhs)
virtual SoType getTypeId (void) const
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)

Static Public Methods

void initClass (void)
SoType getClassTypeId (void)
SoPath * getByName (const SbName name)
int getByName (const SbName name, SoPathList &l)

Protected Methods

virtual ~SoPath ()
void auditPath (const SbBool flag)

Friends

COIN_DLL_API SbBool operator== (const SoPath &lhs, const SoPath &rhs)
COIN_DLL_API SbBool operator!= (const SoPath &lhs, const SoPath &rhs)

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.

Constructor & Destructor Documentation

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::SoPath (  SoNode *const head ) 
 

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

SoPath::SoPath (  const SoPath & rhs ) 
 

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

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

void SoPath::initClass (  void )  [static]
 

Sets up initialization for data common to all instances of this class, like submitting necessary information to the Coin type system.

Reimplemented from SoBase.

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

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

SoType SoPath::getClassTypeId (  void )  [static]
 

This static method returns the SoType object associated with objects of this class.

Reimplemented from SoBase.

SoType SoPath::getTypeId (  void )  const [virtual]
 

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

Usage example: 

  void foo(SoNode * node)
  {
    if (node->getTypeId() == SoFile::getClassTypeId()) {
    }
    else if (node->getTypeId().isOfType(SoGroup::getClassTypeId())) {
      SoGroup * group = (SoGroup *)node;  // safe downward cast, know the type
      // then something else
    }
  }

For application programmers wanting to extend the library with new nodes, engines, nodekits, draggers or others: 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 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 toplevel superclasses for the various class groups.

Reimplemented from SoBase.

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.

SoNode * SoPath::getHead (  void )  const
 

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

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.

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().

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.

void SoPath::push (  const int childIndex )  [inline]
 

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

void SoPath::pop (  void )  [inline]
 

This method pops the tail off the path.

Reimplemented in SoFullPath, and SoNodeKitPath.

SoNode * SoPath::getTail (  void )  const
 

This method returns the tail node of the path.

Reimplemented in SoFullPath, and SoNodeKitPath.

SoNode * SoPath::getNode (  const int idx )  const
 

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

Reimplemented in SoNodeKitPath.

SoNode * SoPath::getNodeFromTail (  const int idx )  const
 

This method returns the node at index in the path, counting from the tail.

Reimplemented in SoFullPath, and SoNodeKitPath.

int SoPath::getIndex (  const int i )  const
 

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

int SoPath::getIndexFromTail (  const int i )  const
 

This method returns the child index of the node at index in the path, counting from the tail.

Reimplemented in SoFullPath.

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.

Reimplemented in SoFullPath, and SoNodeKitPath.

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).

Reimplemented in SoNodeKitPath.

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.

int SoPath::findNode (  const SoNode *const node )  const
 

Returns the index of node if found in path, -1 otherwise.

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

SbBool SoPath::containsNode (  const SoNode *const node )  const
 

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

SbBool SoPath::containsPath (  const SoPath *const path )  const
 

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

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.

SoPath * SoPath::getByName (  const SbName name )  [static]
 

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

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.

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 it's 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.

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 it's 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.

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.

SbBool SoPath::isRelevantNotification (  SoNotList *const l )  const
 

Not implemented yet.

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 has vanished, as they was 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.

void SoPath::auditPath (  const SbBool flag )  [protected]
 

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

Friends And Related Function Documentation

COIN_DLL_API SbBool operator== (  const SoPath & lhs,
const SoPath & rhs
)  [friend]
 

Compares contents of path lhs and path rhs, and returns TRUE if they are equal.

COIN_DLL_API SbBool operator!= (  const SoPath & lhs,
const SoPath & rhs
)  [friend]
 

Returns TRUE if paths lhs and rhs does not contain the same nodes in the same order.

The documentation for this class was generated from the following files:
Generated at Tue Mar 5 03:31:28 2002 for Coin by doxygen1.2.9 written by Dimitri van Heesch, © 1997-2001