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Composite< V > Class Template Reference

A visitable node class that can have multiple children and parents. More...

#include <Composite.h>

Inheritance diagram for Composite< V >:

List of all members.

Public Types
typedef Composite	Node
typedef Ref< Node >	NodeRef
typedef Ref< V >	VisitorRef
typedef std::vector< NodeRef >	ChildList
	A list of child node references.
typedef std::vector< Node * >	ParentList
	A list of parent node pointers (which avoids circular references).
Public Methods
virtual VisitorRef	accept (VisitorRef v)=0
	Accept a visitor.
virtual bool	addChild (Node *node)
	Add a child to this node.
virtual bool	removeChild (Node *node)
	Remove a child from this node.
virtual bool	removeChild (unsigned int pos, unsigned int count=1)
	Remove one or more children.
unsigned int	getNumChildren () const
	Get the number of immediate children of this node.
virtual bool	setChild (unsigned int i, Node *node)
	Replace an existing child node with a new one.
Node *	getChild (unsigned int i)
	Get a child by index number.
const Node *	getChild (unsigned int i) const
	Get a child by index number.
ChildList const &	getChildren () const
	Get a list of immediate children of this node.
bool	containsNode (Node const *node) const
	Test if this node contains a given node.
unsigned int	getChildIndex (Node const *node) const
	Get the index of a child node.
const ParentList &	getParents () const
	Get a list of immediate parents of this node.
Node *	getParent (unsigned int i)
	Get a parent by index number.
const Node *	getParent (unsigned int i) const
	Get a parent by index number.
unsigned int	getNumParents () const
	Get the number of immediate parents of this node.
virtual bool	isContainer () const
virtual bool	canBeAdded () const
virtual Ref< V >	accept (Ref< V > v)=0
Protected Methods
ParentList	getParents ()
	Get a copy of this node's parent list.
void	descend (VisitorBase *visitor)
	Propagate a visitor through all immediate children.
void	ascend (VisitorBase *visitor)
	Propagate a visitor through all immediate parents.

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Detailed Description

template<class V>
class Composite< V >

A visitable node class that can have multiple children and parents.

Composite should be used as a base class for nodes in a Composite/Visitor design pattern. First declare a context specific visitor class (see Visitor), then create use Composite<> as a base class for the primary node type. Starting from a context specific visitor (see Visitor for details) named MyNodeVisitor, one would declare MyNode as:

class MyNode: public Composite<MyNodeVisitor> { public: SIMDATA_VISITABLE(MyNodeVisitor); // the rest of MyNode's declaration... };

MyNode and each of its subclasses must define an accept() method, which is just a couple lines of boilerplate code handled by the SIMDATA_VISITABLE macro (feel free to write it out by hand if you despise macros). Defining accept() in each subclass allows the overloaded apply() method in MyNodeVisitor to be correctly selected based on the type of each node.

Notes:

Although Composite supports multiple parents, this capability can easily be disabled within a given context by overriding the addChild() method of the primary node class and testing that getNumOfParents() equals zero for each child to be added.

The current implementation does not support non- composite leaf nodes. Any node can contain other nodes, although again this feature can be disabled for specific node classes simply by overriding addChild().

Parameters:

V	is a context specific visitor class.

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Member Typedef Documentation

template<class V> typedef std::vector< NodeRef > Composite< V >::ChildList

A list of child node references.

template<class V> typedef Composite Composite< V >::Node

template<class V> typedef Ref<Node> Composite< V >::NodeRef

template<class V> typedef std::vector< Node* > Composite< V >::ParentList

A list of parent node pointers (which avoids circular references).

template<class V> typedef Ref<V> Composite< V >::VisitorRef

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Member Function Documentation

template<class V> virtual Ref<V> Visitable< V >::accept (  Ref< V >    v )  [pure virtual, inherited]

template<class V> virtual VisitorRef Composite< V >::accept (  VisitorRef    v )  [pure virtual]

Accept a visitor. This method must be implemented in each subclasses to ensure proper dispatch of the visitor's apply methods. See the Composite class documentation for details.

template<class V> virtual bool Composite< V >::addChild (  Node *    node )  [inline, virtual]

Add a child to this node. Extend this method to inforce constraints on the graph structure, such as preventing nodes from having multiple parents. Returns: True if the child was added, false if it already exists.

template<class V> void Composite< V >::ascend (  VisitorBase *    visitor )  [inline, protected, virtual]

Propagate a visitor through all immediate parents. Implements CompositeBase< Visitable< V > >.

template<class V> virtual bool Composite< V >::canBeAdded (    )  const [inline, virtual]

template<class V> bool Composite< V >::containsNode (  Node const *    node )  const [inline]

Test if this node contains a given node. Returns: True if the node is an immediate child, false otherwise.

template<class V> void Composite< V >::descend (  VisitorBase *    visitor )  [inline, protected, virtual]

Propagate a visitor through all immediate children. Implements CompositeBase< Visitable< V > >.

template<class V> const Node* Composite< V >::getChild (  unsigned int    i )  const [inline]

Get a child by index number. Returns: 0 if the index is out of range.

template<class V> Node* Composite< V >::getChild (  unsigned int    i )  [inline]

Get a child by index number. Returns: 0 if the index is out of range.

template<class V> unsigned int Composite< V >::getChildIndex (  Node const *    node )  const [inline]

Get the index of a child node. Returns: The index if found, otherwise the number of children.

template<class V> ChildList const& Composite< V >::getChildren (    )  const [inline]

Get a list of immediate children of this node.

template<class V> unsigned int Composite< V >::getNumChildren (    )  const [inline]

Get the number of immediate children of this node.

template<class V> unsigned int Composite< V >::getNumParents (    )  const [inline]

Get the number of immediate parents of this node.

template<class V> const Node* Composite< V >::getParent (  unsigned int    i )  const [inline]

Get a parent by index number. Returns: 0 if the index is out of range.

template<class V> Node* Composite< V >::getParent (  unsigned int    i )  [inline]

Get a parent by index number. Returns: 0 if the index is out of range.

template<class V> ParentList Composite< V >::getParents (    )  [inline, protected]

Get a copy of this node's parent list.

template<class V> const ParentList& Composite< V >::getParents (    )  const [inline]

Get a list of immediate parents of this node.

template<class V> virtual bool Composite< V >::isContainer (    )  const [inline, virtual]

template<class V> virtual bool Composite< V >::removeChild (  unsigned int    pos, unsigned int    count = 1 )  [inline, virtual]

Remove one or more children. Parameters: pos  The index of the first child to remove. count  The number of children to remove (default 1). Returns: True if one or more children were removed, false otherwise.

template<class V> virtual bool Composite< V >::removeChild (  Node *    node )  [inline, virtual]

Remove a child from this node. Returns: True if the child was removed, false if it was not found.

template<class V> virtual bool Composite< V >::setChild (  unsigned int    i, Node *    node )  [inline, virtual]

Replace an existing child node with a new one. The original node will be destroyed if it is not already referenced elsewhere. Returns: True if the child was replaced, false otherwise.

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

• Composite.h

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SimData version pre-0.4.0. For more information on SimData, visit the SimData Homepage. Generated on Tue Oct 14 12:06:40 2003, using Doxygen 1.2.18.