PropFloat Class Reference

Float properties represent a feature whose value is a floating-point number. More...

Inheritance diagram for PropFloat:

Public Member Functions
PropFloatRepresentation	representation (Error &err=Error::Default()) const
	Returns the suggested representation for this float property.
std::string	unit (Error &err=Error::Default()) const
	Returns the unit of this float property.
PropDisplayNotation	displayNotation (Error &err=Error::Default()) const
	Returns a suggested display notation to use when displaying the float property's value.
int64_t	displayPrecision (Error &err=Error::Default()) const
	Returns a suggested number of significant digits to use when displaying the float property's value.
bool	setValue (double value, Error &err=Error::Default())
	Changes the value of this property.
double	getValue (Error &err=Error::Default()) const
	Reads the current value of this property.
double	minimum (Error &err=Error::Default()) const
	Returns the minimum value accepted by this property.
double	maximum (Error &err=Error::Default()) const
	Returns the maximum value accepted by this property.
PropIncrementMode	incrementMode (Error &err=Error::Default()) const
	Returns how this float property restricts which values are valid between its minimum and maximum value.
double	increment (Error &err=Error::Default()) const
	Returns the step size for valid values accepted by this float property.
std::vector< double >	validValueSet (Error &err=Error::Default()) const
	Returns the valid value set for this property.
Public Member Functions inherited from Property
	Property ()=default
	Creates an invalid object.
bool	is_valid () const noexcept
	Checks whether this property is a valid object.
bool	operator== (const Property &other) const noexcept
	Checks whether a property object refers to the same property as another property object.
bool	operator!= (const Property &other) const noexcept
	Checks whether a property object refers to a different property as another property object.
bool	operator< (const Property &other) const noexcept
	Provides an ordering of property objects.
PropType	type (Error &err=Error::Default()) const
	Returns the type of the property.
std::string	name (Error &err=Error::Default()) const
	Returns the name of the property.
bool	isAvailable (Error &err=Error::Default()) const
	Checks whether a property is currently available.
bool	isLocked (Error &err=Error::Default()) const
	Checks whether a property is currently locked.
bool	isLikelyLockedByStream (Error &err=Error::Default()) const
	Tries to determine whether a property is locked because a data stream is active.
bool	isReadOnly (Error &err=Error::Default()) const
	Checks whether a property is read-only.
PropVisibility	visibility (Error &err=Error::Default()) const
	Returns a visibility hint for the property.
std::string	displayName (Error &err=Error::Default()) const
	Returns the display name of the property.
std::string	tooltip (Error &err=Error::Default()) const
	Returns a tooltip for the property.
std::string	description (Error &err=Error::Default()) const
	Returns a description for the property.
PropCommand	asCommand (Error &err=Error::Default()) const
	Converts this property into a PropCommand.
PropInteger	asInteger (Error &err=Error::Default()) const
	Converts this property into a PropInteger.
PropBoolean	asBoolean (Error &err=Error::Default()) const
	Converts this property into a PropBoolean.
PropFloat	asFloat (Error &err=Error::Default()) const
	Converts this property into a PropFloat.
PropString	asString (Error &err=Error::Default()) const
	Converts this property into a PropString.
PropEnumeration	asEnumeration (Error &err=Error::Default()) const
	Converts this property into a PropEnumeration.
PropEnumEntry	asEnumEntry (Error &err=Error::Default()) const
	Converts this property into a PropEnumEntry.
PropRegister	asRegister (Error &err=Error::Default()) const
	Converts this property into a PropRegister.
PropCategory	asCategory (Error &=Error::Default()) const
	Converts this property into a PropCategory.
NotificationToken	eventAddNotification (NotificationHandler cb, Error &err=Error::Default())
	Registers a new property notification event handler.
bool	eventRemoveNotification (NotificationToken token, Error &err=Error::Default())
	Unregisters a previously registered property notification event handler.
bool	isSelector (Error &err=Error::Default()) const
	Indicates whether this property's value changes the meaning and/or value of other properties.
std::vector< Property >	selectedProperties (Error &err=Error::Default()) const
	Returns the list of properties whose values' meaning depend on this property.

Additional Inherited Members
Public Types inherited from Property
using	NotificationHandler = std::function< void(Property &prop)>
	Function prototype for property notification event handlers.
using	NotificationToken = void *
	Represents a registered callback.

Detailed Description

Float properties represent a feature whose value is a floating-point number.

Common examples for a float properties are AcquisitionFrameRate, ExposureTime or Gain.

A float property can limit the range of valid values. The range of possible values can be queried by calling PropFloat::minimum() and PropFloat::maximum().

The possible values can be further restricted by an increment value or a set of value values. Check PropFloat::incrementMode(), PropFloat::increment() and PropFloat::validValueSet() for details.

A float property supplies hints that can be useful when creating a user interface:

• A representation (PropFloat::representation())
• A unit (PropFloat::unit())
• Display notation and precision (PropFloat::displayNotation(), PropFloat::displayPrecision())

PropFloat instances are created in two ways:

• By converting a Property known to be a command property using Property::asFloat()
• By directly querying a typed known property using PropertyMap::findFloat().

Member Function Documentation

displayNotation()

PropDisplayNotation displayNotation ( Error &  err = Error::Default() ) const

inline

Returns a suggested display notation to use when displaying the float property's value.

Parameters

[out]

err

Reference to an error handler. See Error Handling for details.

Returns

The suggested display notation for this property.
If an error occurred, this function returns a default representation. Check the err output parameter for details.

displayPrecision()

int64_t displayPrecision ( Error &  err = Error::Default() ) const

inline

Returns a suggested number of significant digits to use when displaying the float property's value.

Parameters

[out]

err

Reference to an error handler. See Error Handling for details.

Returns

The suggested display notation for this property.
If an error occurred, this function returns a default precision. Check the err output parameter for details.

getValue()

double getValue ( Error &  err = Error::Default() ) const

inline

Reads the current value of this property.

Parameters

[out]

err

Reference to an error handler. See Error Handling for details.

Returns

The current value.
If an error occurs, the function returns 0. Check the err output parameter for details.

See also

PropFloat::setValue()

increment()

double increment ( Error &  err = Error::Default() ) const

inline

Returns the step size for valid values accepted by this float property.

The increment restricts the set of valid values for a float property. For example, if the property's minimum value is 0, the maximum is 10, and the increment is 0.5, 0.25 is not a valid value for the property and will be rejected when trying to write it.

This function will fail if PropFloat::incrementMode() does not return PropIncrementMode::Increment.

Parameters

[out]

err

Reference to an error handler. See Error Handling for details.

Returns

The step size.
If an error occurs, the function returns 0. Check the err output parameter for details.

See also

PropInteger::incrementMode()

incrementMode()

PropIncrementMode incrementMode ( Error &  err = Error::Default() ) const

inline

Returns how this float property restricts which values are valid between its minimum and maximum value.

Parameters

[out]

err

Reference to an error handler. See Error Handling for details.

Returns

PropIncrementMode::Increment, if the property has a fixed step size between valid values.
PropIncrementMode::ValueSet if the property has a set of valid values.
PropIncrementMode::None if the property has no restrictions.
If an error occurs, the function returns PropIncrementMode::None. Check the err output parameter for details.

See also

PropFloat::increment()

PropFloat::validValueSet()

maximum()

double maximum ( Error &  err = Error::Default() ) const

inline

Returns the maximum value accepted by this property.

Parameters

[out]

err

Reference to an error handler. See Error Handling for details.

Returns

The maximum value.
If an error occurs, the function returns 0. Check the err output parameter for details.

See also

PropFloat::minimum()

minimum()

double minimum ( Error &  err = Error::Default() ) const

inline

Returns the minimum value accepted by this property.

Parameters

[out]

err

Reference to an error handler. See Error Handling for details.

Returns

The minimum value.
If an error occurs, the function returns 0. Check the err output parameter for details.

See also

PropFloat::maximum()

representation()

PropFloatRepresentation representation ( Error &  err = Error::Default() ) const

inline

Returns the suggested representation for this float property.

The representation can be used as a hint when creating user interfaces.

Parameters

[out]

err

Reference to an error handler. See Error Handling for details.

Returns

The suggested representation of this property.
If an error occurred, this function returns a default representation. Check the err output parameter for details.

setValue()

bool setValue ( double  value, Error &  err = Error::Default()  )

inline

Changes the value of this property.

Parameters

[in]	value	The new value to set
[out]	err	Reference to an error handler. See Error Handling for details.

Returns

true on success, otherwise false.
Check the err output parameter for details.

See also

PropFloat::getValue()

unit()

std::string unit ( Error &  err = Error::Default() ) const

inline

Returns the unit of this float property.

Parameters

[out]

err

Reference to an error handler. See Error Handling for details.

Returns

The unit of this property. The unit can be an empty string, if there is no unit for the property.
If an error occurred, this function returns an empty string. Check the err output parameter for details.

validValueSet()

std::vector< double > validValueSet ( Error &  err = Error::Default() ) const

inline

Returns the valid value set for this property.

This function will fail if PropFloat::incrementMode() does not return PropIncrementMode::ValueSet.

Parameters

[out]

err

Reference to an error handler. See Error Handling for details.

Returns

A vector containing the set of valid values.
If an error occurs, the function returns an empty vector. Check the err output parameter for details.

See also

PropFloat::incrementMode()