PropCategory Class Reference

Category properties define a tree-relationship between all properties in a property map. More...

Inheritance diagram for PropCategory:

Public Member Functions
std::vector< Property >	features (Error &err=Error::Default()) const
	Retrieves the list of properties in a property category.
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

Category properties define a tree-relationship between all properties in a property map.

The root of the tree is always the category property with the name Root.

To find which properties are linked from a category, use PropCategory::features().

Categories can contain other categories recursively. A very simple category tree might look like this:

• Root (category)
  • AcquisitionControl (category)
    • AcquisitionStart (command)
    • AcquisitionStop (command)
    • AcquisitionFrameRate (float)
  • ImageFormatControl (category)
    • Width (integer)
    • Height (integer)

PropCategory instances are created in two ways:

• By converting a property known to be a category property using Property::asCategory()
• By directly querying a typed known property using PropertyMap::findCategory().

Member Function Documentation

features()

std::vector< Property > features ( Error &  err = Error::Default() ) const

inline

Retrieves the list of properties in a property category.

Parameters

[out]

err

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

Returns

A std::vector containing the properties in this category.
If an error occurred, the function returns an empty vector. Check the err output parameter for details.