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Traverse the children of each node
in a node
hierarchy only once.
More...
#include <openvrml/node.h>
Inherits noncopyable.
Public Member Functions | |
node_traverser () throw ( std::bad_alloc ) | |
Construct. More... | |
virtual | ~node_traverser ()=0 throw () |
Destroy. More... | |
void | traverse (node &n) |
Traverse a node . More... | |
void | traverse (const boost::intrusive_ptr< node > &node) |
Traverse a node . More... | |
void | traverse (const std::vector< boost::intrusive_ptr< node > > &nodes) |
Traverse a std::vector of nodes . More... | |
Protected Member Functions | |
void | halt_traversal () throw () |
Halt the traversal. More... | |
bool | halted () const throw () |
Indicate whether the traversal has been halted. More... | |
bool | traversed (node &n) const throw () |
Check whether a node has been traversed. More... | |
Private Member Functions | |
virtual void | on_entering (node &n) |
Called for each node in the traversal before traversing the its descendants. More... | |
virtual void | on_leaving (node &n) |
Called for each node in the traversal after traversing the its descendants. More... | |
Traverse the children of each node
in a node
hierarchy only once.
The node_traverser
provides a generalized traversal mechanism that avoids redundantly traversing branches of the node
hierarchy. If a node
occurs multiple places in a branch, the children of that node
will be visited in the traversal only once.
For each node
encountered in the traversal, node_traverser
does the following:
on_entering
.on_leaving
.Concrete subclasses of node_traverser
implement the on_entering
and/or on_leaving
member functions in order to perform some operation(s) on each node. The traversal can be ended prematurely by calling halt_traversal
.
openvrml::node_traverser::node_traverser | ( | ) | ||
throw | ( | std::bad_alloc | ||
) |
Construct.
std::bad_alloc | if memory allocation fails. |
|
pure virtual |
Destroy.
void openvrml::node_traverser::traverse | ( | node & | n) |
Traverse a node
.
No guarantee is made about the state of the node_traverser
instance in the event that this method throws.
In addition to std::bad_alloc
, this function throws any exception thrown from on_entering
or on_leaving
.
[in,out] | n | the root node of the branch to traverse. |
std::bad_alloc | if memory allocation fails. |
void openvrml::node_traverser::traverse | ( | const boost::intrusive_ptr< node > & | node) |
Traverse a node
.
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
[in,out] | node | the root node of the branch to traverse. |
std::bad_alloc | if memory allocation fails. |
void openvrml::node_traverser::traverse | ( | const std::vector< boost::intrusive_ptr< node > > & | nodes) |
Traverse a std::vector
of nodes
.
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
[in,out] | nodes | the root nodes of the branch to traverse. |
|
protected |
Halt the traversal.
If this method is called during a traversal, no more descendant nodes
will be traversed. Note that if halt_traversal
is called in the implementation of on_entering
, on_leaving
will still be called for the current node and any parent nodes (that is, any node for which on_entering
has been called). Implementations of on_leaving
can call halted
to check whether the traversal has been halted.
|
protected |
Indicate whether the traversal has been halted.
This function is useful in implementations of on_leaving
that need to check whether the traversal has been halted.
true
if the traversal has been halted; false
otherwise.
|
protected |
Check whether a node
has been traversed.
[in] | n | the node to check. |
true
if n
has been traversed; false
otherwise.
|
privatevirtual |
Called for each node
in the traversal before traversing the its descendants.
[in,out] | n | the node currently being traversed. |
|
privatevirtual |
Called for each node
in the traversal after traversing the its descendants.
[in,out] | n | the node currently being traversed. |