IlvAccessorHolder Class Reference

Owns a list of objects of the class IlvAccessor class. More...

#include <ilviews/protos/accessor.h>

Inheritance diagram for IlvAccessorHolder:

List of all members.

Public Member Functions
virtual IlBoolean	changeValue (const IlvValue &val)
	Changes the object's value. Both the name and the new value are contained in val.
virtual IlBoolean	changeValues (const IlvValue *values, IlUShort count)
	Changes several values of an object in a single call. The default implementation calls changeValue for all values.
virtual IlUInt	compareValues (const IlvAccessible *ref, IlvValue *values, IlUShort count, IlvValueArray &diffs) const
	Compares two objects and returns the differing attributes.
virtual void	getAccessors (const IlSymbol *const **accessors, const IlvValueTypeClass *const **types, IlUInt &count) const
	Returns the names of all the accessors known by this object.
virtual IlBoolean	isOutputValue (const IlSymbol *valueName) const
	Indicates whether value designates an accessor that can generate notifying values.
virtual IlvAccessor *	nextAccessor (IlAny &link) const =0
	Iterator through the accessors.
virtual IlvValue &	queryValue (IlvValue &val) const
	Queries the value designated by value from the object. Both the value and the value type are stored in value.
virtual void	queryValues (IlvValue *values, IlUShort count) const
	Queries several values in a single call. The default implementation calls queryValue for each value.
Friends
class	IlvAccessor

---

Detailed Description

Owns a list of objects of the class IlvAccessor class.

Library: ilvproto

An IlvAccessorHolder owns a list of objects of the IlvAccessor class. Each of these IlvAccessor objects defines an accessor that is handled by the IlvAccessorHolder object. Therefore, the accessors in an IlvAccessorHolder can be defined dynamically by adding or removing IlvAccessor objects to and from the IlvAccessorHolder. The IlvAccessorHolder class overrides the changeValue[s], queryValue[s], getAccessors, and compareValues methods of the IlvAccessible class. Each of these methods looks at all the IlvAccessor objects owned by the IlvAccessorHolder, finds all the accessors that match the requested values, and calls the corresponding method of the matching IlvAccessors. IlvAccessorHolder is an abstract class that does not define the way an IlvAccessor is actually stored in the object. To do so, the nextAccessor method must be overridden.

Accessors are base 'bricks' of behavior that hold data (in which case they are called 'attributes') or perform side effects. Therefore, an attribute is a name that can be referenced to store data or perform side effects when a call to changeValue or queryValue is made. An attribute can consist of several accessors, each of them defining part of what the attribute is meant to do.

See also:

IlvAccessor, IlvGroup, IlvPrototype, IlvProtoInstance.

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Member Function Documentation

virtual IlBoolean IlvAccessorHolder::changeValue

(

const IlvValue &

v

)

[virtual]

Changes the object's value. Both the name and the new value are contained in val.

Parameters:

v

The value to be set (both name and value).

Returns:

Whether the object considered the operation successful or not.

Reimplemented from IlvAccessible.

Reimplemented in IlvGroup.

virtual IlBoolean IlvAccessorHolder::changeValues	(	const IlvValue *	v,
		IlUShort	c
	)			[virtual]

Changes several values of an object in a single call. The default implementation calls changeValue for all values.

Parameters:

	v	The changed values (both name and values).
	c	The number of values.

Returns:

Whether the object considered the operation successful or not.

Reimplemented from IlvAccessible.

Reimplemented in IlvGroup.

virtual IlUInt IlvAccessorHolder::compareValues	(	const IlvAccessible *	ref,
		IlvValue *	values,
		IlUShort	count,
		IlvValueArray &	diffs
	)			const [virtual]

Compares two objects and returns the differing attributes.

Compares the values of accessors known by this object with the corresponding values in the object ref. The values that differ are stored in diffs. The values stored are taken from the calling object (this), not from ref. The first method calls the getAccessors method to get the list of all known accessors, while the second only compares the provided values. Then, both methods call compareValues to actually compare the values.

Returns:

The number of differing attributes.

Parameters:

	ref	The object to compare to.
	any	Specifies whether to compare values of unknown types and pointer types.
	diffs	The differing attributes.
	values	The attributes to compare in both objects.
	count	The number of attributes to compare.

Reimplemented from IlvAccessible.

virtual void IlvAccessorHolder::getAccessors	(	const IlSymbol *const **	a,
		const IlvValueTypeClass *const **	t,
		IlUInt &	c
	)			const [virtual]

Returns the names of all the accessors known by this object.

Subclasses of IlvAccessible must override this method by calling the static method DeclareAccessor for each accessor handled by the subclass. The returned arrays are filled by the method and must not be freed.

Parameters:

	a	Pointer to an array filled on return with the names of the accessors defined for the object.
	t	Pointer to an array filled on return with the type of each accessor.
	c	Number of accessors, set by the method.

Implements IlvAccessible.

Reimplemented in IlvGroup.

virtual IlBoolean IlvAccessorHolder::isOutputValue

(

const IlSymbol *

value

)

const [virtual]

Indicates whether value designates an accessor that can generate notifying values.

Returns:

IlTrue if value designates an accessor that can generate notifying values, that is, a value for which pushValue calls may be issued. The default implementation returns IlFalse. Subclasses such as IlvAccessorHolder redefine this method.

Parameters:

value

Name of the accessor.

See also:

pushValue.

Reimplemented from IlvAccessible.

Reimplemented in IlvGroup.

virtual IlvAccessor* IlvAccessorHolder::nextAccessor

(

IlAny &

link

)

const [pure virtual]

Iterator through the accessors.

Returns the next accessor from a list of accessors owned by the IlvAccessorHolder object. If link is NULL, the first accessor is returned, and link is modified so that the next call to nextAccessor will return all the accessors successively. When all the accessors have been returned, the method returns 0.

Implemented in IlvGroup.

virtual IlvValue& IlvAccessorHolder::queryValue

(

IlvValue &

value

)

const [virtual]

Queries the value designated by value from the object. Both the value and the value type are stored in value.

Parameters:

value

The queried value name.

Returns:

The value passed in argument, set to the object value.

Reimplemented from IlvAccessible.

Reimplemented in IlvGroup.

virtual void IlvAccessorHolder::queryValues	(	IlvValue *	v,
		IlUShort	c
	)			const [virtual]

Queries several values in a single call. The default implementation calls queryValue for each value.

Parameters:

	v	The array of value names to be queried
	c	The number of values to be queried.

Reimplemented from IlvAccessible.

Reimplemented in IlvGroup.