MFnCompoundAttribute Class Reference
[OpenMaya - API module for common classes, FunctionSet classes]

#include <MFnCompoundAttribute.h>

Inheritance diagram for MFnCompoundAttribute:

[legend]

Collaboration diagram for MFnCompoundAttribute:

[legend]

List of all members.

---

Detailed Description

Compound attribute function set.

MFnCompoundAttribute is the function set for compound dependency node attributes.

Compound attributes allow the grouping of related attributes into a larger unit. It is possible to connect to a compound attribute as a whole, or to any of the individual children.

For example, the three attributes RED, GREEN, and BLUE could be grouped into a compound attribute of type COLOR. It is then possible to connect two COLOR attributes together. This removes the need to connect each child explicitly.

A second use for compound attributes is when there are multi attributes that relate to each other on an element-by-element basis. An example of this is the weighted matrix node that has a multi attribute with matrices that must be matched with the multi attribute that provides the weights for each matrix.

Examples:

cgfxAttrDef.cpp, clearcoat.cpp, geometrySurfaceConstraint.cpp, maTranslator.cpp, and weightListNode.cpp.

Public Member Functions
virtual MFn::Type	type () const
	Function set type.
virtual	~MFnCompoundAttribute ()
	Destructor.
	MFnCompoundAttribute ()
	Default constructor.
	MFnCompoundAttribute (MObject &object, MStatus *ReturnStatus=NULL)
	Constructor.
MObject	create (const MString &full, const MString &brief, MStatus *ReturnStatus=NULL)
MStatus	addChild (const MObject &child)
MStatus	removeChild (const MObject &child)
unsigned int	numChildren (MStatus *ReturnStatus=NULL) const
MObject	child (unsigned int index, MStatus *ReturnStatus=NULL) const
MStatus	getAddAttrCmds (MStringArray &cmds, bool useLongNames=false) const
	MFnCompoundAttribute (const MObject &object, MStatus *ReturnStatus=NULL)
	NO SCRIPT SUPPORT.
Protected Member Functions
virtual const char *	className () const
	Class name.

---

Constructor & Destructor Documentation

MFnCompoundAttribute::MFnCompoundAttribute	(	MObject &	object,
		MStatus *	ReturnStatus = NULL
	)

Constructor.

Class constructor that initializes the function set to the given MObject.

Parameters:

[in]	object	The MObject to attach the function set to
[out]	ReturnStatus	the return status

Status Codes:

• MS::kSuccess if the function set is successfully attached
• MS::kInvalidParameter if the MObject does not represent a valid Maya object or if the function set is not allowed to attach to this MObject

MFnCompoundAttribute::MFnCompoundAttribute	(	const MObject &	object,
		MStatus *	ReturnStatus = NULL
	)

NO SCRIPT SUPPORT.

Constructor

Class constructor that initializes the function set to the given MObject.

Parameters:

[in]	object	The MObject to attach the function set to
[out]	ReturnStatus	the return status

Status Codes:

• MS::kSuccess if the function set is successfully attached
• MS::kInvalidParameter if the MObject does not represent a valid Maya object or if the function set is not allowed to attach to this MObject

---

Member Function Documentation

MFn::Type MFnCompoundAttribute::type

(

)

const [virtual]

Function set type.

Return the class type : MFn::kCompoundAttribute

Reimplemented from MFnAttribute.

const char * MFnCompoundAttribute::className

(

)

const [protected, virtual]

Class name.

Return the class name : "MFnCompoundAttribute"

Reimplemented from MFnAttribute.

MObject MFnCompoundAttribute::create	(	const MString &	full,
		const MString &	brief,
		MStatus *	ReturnStatus = NULL
	)

Creates a new compound attribute.

The create method needs to be called on a per node basis. That means if you want to create and add the same attribute to multiple nodes, you need to call the create method for each node to get a unique MObject back. If you call create just once and add the attribute to multiple nodes, Maya will encounter a fatal error.

Parameters:

[in]	full	long name of the attribute
[in]	brief	short name of the attribute

Returns:

Return status

Status Codes:

• MS::kSuccess operation successful
• MS::kInsufficientMemory out of memory

Examples:

geometrySurfaceConstraint.cpp, and weightListNode.cpp.

MStatus MFnCompoundAttribute::addChild

(

const MObject &

child

)

Add a child attribute under this compound attribute.

Parameters:

[in]

child

new child attribute

Returns:

Return status

Status Codes:

• MS::kSuccess operation successful
• MS::kInvalidParameter argument is not a valid attribute, or has a larger alignment requirement than the first child in this compound attribute.
• MS::kFailure adding child failed

Examples:

geometrySurfaceConstraint.cpp, and weightListNode.cpp.

MStatus MFnCompoundAttribute::removeChild

(

const MObject &

child

)

Remove a child attribute from this compound attribute.

Parameters:

[in]

child

child attribute to remove

Returns:

Return status

Status Codes:

• MS::kSuccess operation successful
• MS::kInvalidParameter argument is not a valid attribute
• MS::kFailure removing child failed

unsigned int MFnCompoundAttribute::numChildren

(

MStatus *

ReturnStatus = NULL

)

const

Returns the number of child attributes that this compound attribute has.

Parameters:

[out]

ReturnStatus

return status

Returns:

The number of children

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure function set does not have a valid object

Examples:

cgfxAttrDef.cpp.

MObject MFnCompoundAttribute::child	(	unsigned int	index,
		MStatus *	ReturnStatus = NULL
	)			const

Get a child of this compound attribute.

Parameters:

[in]	index	index of child
[out]	ReturnStatus	return status

Returns:

The child attribute

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure function set does not have a valid object

Examples:

cgfxAttrDef.cpp.

MStatus MFnCompoundAttribute::getAddAttrCmds	(	MStringArray &	cmds,
		bool	useLongNames = false
	)			const

Returns a string array containing the addAttr commands which would be required to recreate the attribute and all of its descendents on a node.

The attributes are returned in depth-first order, meaning that element 0 of the array will contain this attribute's addAttr command, element 1 will contain the command for its first child, element 2 will contain the command for its first child's child, if one exists, and so on.

Each command is returned with the terminating semicolon and is formatted as if for use with a selected node, meaning that no node name is supplied.

Parameters:

[out]	cmds	string array to receive the adAttr commands
[in]	useLongNames	if true, long attribute names are used rather than short

Returns:

Return status

Status Codes:

• MS::kSuccess operation successful
• MS::kFailure operation failed
• MS::kInvalidParameter function set is not bound to an attribute