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openvrml::exposedfield< FieldValue > Class Template Reference

Inheritance diagram for openvrml::exposedfield< FieldValue >:

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List of all members.

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Detailed Description

template<typename FieldValue>
class openvrml::exposedfield< FieldValue >

Class template to simplify implementation of exposedFields.

exposedfield conveniently implements an event_listener and an event_emitter. Trivial exposedFields can be implemented simply by instantiating this template with a FieldValue. For the purposes of OpenVRML, a trivial exposedField is one that has no side-effects. That is, it simply receives an event, updates an internal value, and fires an eventOut. Nontrivial exposedFields (i.e., those with side-effects) can generally be implemented by inheriting an instance of this class template and overriding exposedfield<FieldValue>::event_side_effect.

Public Member Functions
	exposedfield (openvrml::node &node, const typename FieldValue::value_type &value=typename FieldValue::value_type())
	Construct.
virtual	~exposedfield () throw ()
	Destroy.
Private Member Functions
virtual void	do_process_event (const FieldValue &value, double timestamp) throw (std::bad_alloc)
	Process an event.
virtual void	event_side_effect (const FieldValue &value, double timestamp) throw (std::bad_alloc)
	Called by exposedfield<FieldValue>::do_process_event.

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Constructor & Destructor Documentation

template<typename FieldValue>

openvrml::exposedfield< FieldValue >::exposedfield	(	openvrml::node &	node,
		const typename FieldValue::value_type &	value = typename FieldValue::value_type()
	)			[inline]

Construct.

Parameters:

	node	a reference to the node to which the exposedField belongs.
	value	default value.

template<typename FieldValue>

openvrml::exposedfield< FieldValue >::~exposedfield

(

)

throw () [inline, virtual]

Destroy.

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Member Function Documentation

template<typename FieldValue>

void openvrml::exposedfield< FieldValue >::do_process_event	(	const FieldValue &	value,
		double	timestamp
	)			throw (std::bad_alloc) [inline, private, virtual]

Process an event.

This function performs the following steps:

1. set the exposedField value.
2. call exposedfield<FieldValue>::event_side_effect.
3. set the modified flag.
4. emit the event.

Warning:

This function should not be overridden by subclasses. Subclasses should override exposedfield<FieldValue>::event_side_effect instead.

Parameters:

	value	new value.
	timestamp	the current time.

Exceptions:

std::bad_alloc

if memory allocation fails.

Implements openvrml::field_value_listener< FieldValue >.

template<typename FieldValue>

void openvrml::exposedfield< FieldValue >::event_side_effect	(	const FieldValue &	value,
		double	timestamp
	)			throw (std::bad_alloc) [inline, private, virtual]

Called by exposedfield<FieldValue>::do_process_event.

Subclasses should override this method to implement event handling functionality specific to a particular exposedField. The default implementation of this function does nothing.

Parameters:

	value	new value.
	timestamp	the current time.

Exceptions:

std::bad_alloc

if memory allocation fails.