#include <jevois/Component/Parameter.H>

template<typename T>
class jevois::ParameterCore< T >

A changeable parameter for a Component, core class.

Parameters are used to expose user-configurable settings for a Component. They can be specified from the command line and will be set by the time Component::postInit() is called on the Component which owns the Parameter. A Parameter may have a callback function which is invoked each time an attempt is made to change the Parameter value.

Definition at line 189 of file Parameter.H.

Inheritance diagram for jevois::ParameterCore< T >:

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Collaboration diagram for jevois::ParameterCore< T >:

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Public Member Functions
	ParameterCore (ParameterDef< T > const &def)
	Constructor. More...

virtual	~ParameterCore ()
	Destructor. More...

virtual const std::string &	name () const override
	Get the parameter name. More...

virtual std::string	descriptor () const override
	Get the parameter fully-qualified name, aka descriptor. More...

T	get () const
	Get the value of this Parameter. More...

void	set (T const &newVal)
	Set the value of this Parameter. More...

virtual void	strset (std::string const &valstring) override
	Set the value from a string representation of it. More...

virtual const std::string	strget () const override
	Get the value as a string representation of it. More...

virtual const ParameterSummary	summary () const override
	Get summary info about this parameter. More...

virtual void	reset () override
	Reset this parameter to its default value. More...

const ParameterDef< T > &	def () const
	Access to our parameter def. More...

void	changeParameterDef (ParameterDef< T > const &def)
	Change the ParameterDef of this parameter. More...

void	setCallback (std::function< void(T const &)> cb)
	Set the parameter's callback. More...

Public Member Functions inherited from jevois::ParameterBase
	ParameterBase ()
	Constructor. More...

virtual	~ParameterBase ()
	Destructor, will remove the parameter from its owner component. More...

void	freeze ()
	Freeze this parameter, it becomes read-only and will not show up in the help message. More...

void	unFreeze ()
	Unfreeze this parameter, it becomes read-write and will show up in the help message. More...

void	freeze (bool doit)
	Alternate syntax that can be used instead of freeze()/unFreeze(), useful for programmatic freezing. More...

Protected Member Functions
virtual const Component *	owner () const =0
	Get the Component to which this Parameter is attached, or nullptr (individual parameters must override) More...

Additional Inherited Members
Protected Attributes inherited from jevois::ParameterBase
boost::shared_mutex	itsMutex
	Mutex to protect the parameter value. More...

volatile bool	itsFrozen
	When true, parameter is frozen (read-only, does not show up in help message) More...

bool	itsVirgin
	Param has not yet been explicitly set, need to call the callback (if any) at init time. More...

Constructor & Destructor Documentation

◆ ParameterCore()

template<typename T >

jevois::ParameterCore< T >::ParameterCore ( ParameterDef< T > const & def )

Constructor.

Parameters

def	A pointer to the definition for this parameter (given by a ParameterDef).

◆ ~ParameterCore()

template<typename T >

virtual jevois::ParameterCore< T >::~ParameterCore ( )

virtual

Destructor.

Member Function Documentation

◆ changeParameterDef()

template<typename T >

void jevois::ParameterCore< T >::changeParameterDef ( ParameterDef< T > const & def )

Change the ParameterDef of this parameter.

Use with caution, only people who know what they are doing should use this function. Its thread safety and possible side effects are dubious.

◆ def()

template<typename T >

const ParameterDef<T>& jevois::ParameterCore< T >::def ( ) const

Access to our parameter def.

◆ descriptor()

template<typename T >

virtual std::string jevois::ParameterCore< T >::descriptor ( ) const

overridevirtual

Get the parameter fully-qualified name, aka descriptor.

Implements jevois::ParameterBase.

◆ get()

template<typename T >

T jevois::ParameterCore< T >::get ( ) const

Get the value of this Parameter.

◆ name()

template<typename T >

virtual const std::string& jevois::ParameterCore< T >::name ( ) const

overridevirtual

Get the parameter name.

Implements jevois::ParameterBase.

◆ owner()

template<typename T >

virtual const Component* jevois::ParameterCore< T >::owner ( ) const

protectedpure virtual

Get the Component to which this Parameter is attached, or nullptr (individual parameters must override)

Implemented in jevois::DynamicParameter< T >.

◆ reset()

template<typename T >

virtual void jevois::ParameterCore< T >::reset ( )

overridevirtual

Reset this parameter to its default value.

Implements jevois::ParameterBase.

◆ set()

template<typename T >

void jevois::ParameterCore< T >::set ( T const & newVal )

Set the value of this Parameter.

Will throw jevois::exception::ParameterException if the new value is not accepted, in which case the old value will remain in the Parameter.

◆ setCallback()

template<typename T >

void jevois::ParameterCore< T >::setCallback ( std::function< void(T const &)> cb )

Set the parameter's callback.

The callback function is called each time one tries to change the value of the parameter. Try to avoid using setCallback() so you won't confuse users of your class. In most cases, just use the convenience JEVOIS_DECLARE_PARAMETER_WITH_CALLBACK() macro.

The callback should examine the candidate value newval and (1) if it does not like it, throw an std::range_error with a descriptive message of why the value is rejected, (2) otherwise, it is assumed that the value is accepted and the callback can then allocate resources or do other work with that value (the actual modification of the Parameter object is handled upstream and the callback does not need to worry about it: if it returns without throwing, the proposed value will become the new value of the Parameter). The Parameter is locked-up for writing as long as the callback is running, to avoid destruction of the parameter and/or concurrent parameter value changes by several different threads. Thus, callbacks should try to execute quickly, and should not call set(), etc on the parameter as this will always deadlock (get() is allowed if your callback needs to know the current value of the parameter).

◆ strget()

template<typename T >

virtual const std::string jevois::ParameterCore< T >::strget ( ) const

overridevirtual

Get the value as a string representation of it.

Implements jevois::ParameterBase.

◆ strset()

template<typename T >

virtual void jevois::ParameterCore< T >::strset ( std::string const & valstring )

overridevirtual

Set the value from a string representation of it.

Exceptions

std::range_error if the given string cannot be converted to a valid Parameter value.

Implements jevois::ParameterBase.

◆ summary()

template<typename T >

virtual const ParameterSummary jevois::ParameterCore< T >::summary ( ) const

overridevirtual

Get summary info about this parameter.

Implements jevois::ParameterBase.

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

include/jevois/Component/Parameter.H

template<typename T> class jevois::ParameterCore< T >

Public Member Functions

Protected Member Functions

Additional Inherited Members

Constructor & Destructor Documentation

◆ ParameterCore()

◆ ~ParameterCore()

Member Function Documentation

◆ changeParameterDef()

◆ def()

◆ descriptor()

◆ get()

◆ name()

◆ owner()

◆ reset()

◆ set()

◆ setCallback()

◆ strget()

◆ strset()

◆ summary()

template<typename T>
class jevois::ParameterCore< T >