MDagMessage Class Reference

#include <MDagMessage.h>

Class Description

DAG messages.

This class is used to register callbacks for DAG messages.

There are 6 types of add callback methods which will add callbacks for the following messages

• Parent Added
• Parent Removed
• Child Added
• Child Removed
• Child Reordered
• Instance Added
• Instance Removed

Methods exist to register callbacks for every time any DAG node is affected as well as methods that work on specific nodes. Each method returns an id which is used to remove the callback.

To remove a callback use MMessage::removeCallback. All callbacks that are registered by a plug-in must be removed by that plug-in when it is unloaded. Failure to do so will result in a fatal error.

NOTE: It is possible to get Parent Added and Child Added messages before the node name has been set. This can happen if the node is newly created. Additionally, the MDagPath string path names passed to the callback may not be set as yet if the node has not been added to the model. Accessing objects that are newly created or calling commands that access such objects from a callback may produce unknown results.

Inheritance diagram for MDagMessage:

Public Types
enum	DagMessage {   kInvalidMsg = -1, kParentAdded, kParentRemoved, kChildAdded,   kChildRemoved, kChildReordered, kInstanceAdded, kInstanceRemoved,   kLast }
	The type of DAG changed messages that have occurred. More...
typedef void(*	MMessageParentChildFunction) (MDagMessage::DagMessage msgType, MDagPath &child, MDagPath &parent, void *clientData)
	Pointer to a callback function which takes an MDagMessage, two MDagPaths and a clientData pointer. More...
typedef void(*	MWorldMatrixModifiedFunction) (MObject &transformNode, MDagMessage::MatrixModifiedFlags &modified, void *clientData)
	Pointer to world matrix modified callback function. More...
Public Types inherited from MMessage
enum	Action { kDefaultAction, kDoNotDoAction, kDoAction }
	Callback result action codes. More...
typedef void(*	MBasicFunction) (void *clientData)
	Pointer to a basic callback function. More...
typedef void(*	MElapsedTimeFunction) (float elapsedTime, float lastTime, void *clientData)
	Pointer to an elapsed time callback function. More...
typedef void(*	MCheckFunction) (bool *retCode, void *clientData)
	Pointer to callback function which returns a true/false result. More...
typedef void(*	MCheckFileFunction) (bool *retCode, MFileObject &file, void *clientData)
	Pointer to a callback function which takes a file object and returns a result. More...
typedef void(*	MCheckPlugFunction) (bool *retCode, MPlug &plug, void *clientData)
	Pointer to a callback function which takes a plug and returns a result. More...
typedef void(*	MComponentFunction) (MUintArray componentIds[], unsigned int count, void *clientData)
	Pointer to a callback function which takes an array of component ids. More...
typedef void(*	MNodeFunction) (MObject &node, void *clientData)
	Pointer to a callback function which takes a dependency node. More...
typedef void(*	MStringFunction) (const MString &str, void *clientData)
	Pointer to callback function which takes a string. More...
typedef void(*	MTwoStringFunction) (const MString &str1, const MString &str2, void *clientData)
	Pointer to a callback function which takes two strings. More...
typedef void(*	MThreeStringFunction) (const MString &str1, const MString &str2, const MString &str3, void *clientData)
	Pointer to a callback function which takes three strings. More...
typedef void(*	MStringIntBoolIntFunction) (const MString &str, unsigned int index, bool flag, unsigned int type, void *clientData)
	Pointer to callback function which takes a string, an index, a flag and a type. More...
typedef void(*	MStringIndexFunction) (const MString &, unsigned int index, void *clientData)
	Pointer to callback function which takes a string and index. More...
typedef void(*	MNodeStringBoolFunction) (MObject &node, const MString &, bool, void *clientData)
	Pointer to a callback function which takes a node, a string and a boolean. More...
typedef void(*	MStateFunction) (bool state, void *clientData)
	Pointer to a callback function which takes a boolean state. More...
typedef void(*	MTimeFunction) (MTime &time, void *clientData)
	Pointer to callback function which takes a time. More...
typedef void(*	MPlugFunction) (MPlug &srcPlug, MPlug &destPlug, bool made, void *clientData)
	Pointer to plug connection callback function. More...
typedef void(*	MNodePlugFunction) (MObject &node, MPlug &plug, void *clientData)
	Pointer to a callback function which takes a dependency node and a plug. More...
typedef void(*	MNodeStringFunction) (MObject &node, const MString &str, void *clientData)
	Pointer to a callback function which takes a dependency node and a string. More...
typedef void(*	MParentChildFunction) (MDagPath &child, MDagPath &parent, void *clientData)
	Pointer to to a callback function which takes two DAG nodes in a parent/child relationship. More...
typedef void(*	MModifierFunction) (MDGModifier &modifier, void *clientData)
	Pointer to a callback function which takes a DG modifier. More...
typedef void(*	MStringArrayFunction) (const MStringArray &strs, void *clientData)
	Pointer to a callback function which takes a string array. More...
typedef void(*	MNodeModifierFunction) (MObject &node, MDGModifier &modifier, void *clientData)
	Pointer to a callback function which takes a dependency node and a DG modifier. More...
typedef void(*	MObjArray) (MObjectArray &objects, void *clientData)
	Pointer to a callback function which takes an array of objects. More...
typedef void(*	MNodeObjArray) (MObject &node, MObjectArray &objects, void *clientData)
	Pointer to a callback function which takes a dependency node and an array of objects. More...
typedef void(*	MStringNode) (const MString &str, MObject &node, void *clientData)
	Pointer to a callback function which takes a string and a dependency node. More...
typedef void(*	MCameraLayerFunction) (MObject &cameraSetNode, unsigned int multiIndex, bool added, void *clientData)
	Pointer to a callback function which takes a dependency node, an unsigned integer, and a boolean value. More...
typedef void(*	MCameraLayerCameraFunction) (MObject &cameraSetNode, unsigned int multiIndex, MObject &oldCamera, MObject &newCamera, void *clientData)
	Pointer to a callback function which takes a dependency node, an unsigned integer, and two camera transform nodes. More...
typedef void(*	MConnFailFunction) (MPlug &srcPlug, MPlug &destPlug, const MString &srcPlugName, const MString &dstPlugName, void *clientData)
	Pointer to connection-failed callback function. More...
typedef void(*	MPlugsDGModFunction) (MPlugArray &plugs, MDGModifier &modifier, void *clientData)
	Pointer to a callback function which takes an array of MPlugs and an MDGModifier. More...
typedef void(*	MNodeUuidFunction) (MObject &node, const MUuid &uuid, void *clientData)
	Pointer to a callback function which takes a dependency node and a UUID. More...
typedef Action(*	MCheckNodeUuidFunction) (bool doAction, MObject &node, MUuid &uuid, void *clientData)
	Pointer to a callback function which takes a dependency node and a UUID, and returns a result. More...
typedef void(*	MObjectFileFunction) (const MObject &object, const MFileObject &file, void *clientData)
	Pointer to a callback function which takes an object and a file object. More...
typedef void(*	MCheckObjectFileFunction) (bool *retCode, const MObject &referenceNode, MFileObject &file, void *clientData)
	Pointer to a callback function which takes an object and a file object and returns a result. More...
typedef void(*	MRenderTileFunction) (int originX, int originY, int tileMaxX, int tileMaxY, const void *tileData)
	Pointer to a callback function which receives origin, size and image data. More...

Static Public Member Functions
static MCallbackId	addParentAddedCallback (MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever a parent is added in the DAG. More...
static MCallbackId	addParentAddedDagPathCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever a parent is added to the specified DAG node. More...
static MCallbackId	addParentRemovedCallback (MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever a parent is removed in the DAG. More...
static MCallbackId	addParentRemovedDagPathCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever a parent is removed from the specified DAG node. More...
static MCallbackId	addChildAddedCallback (MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever a child is added in the DAG. More...
static MCallbackId	addChildAddedDagPathCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever a child is added to the specified DAG node. More...
static MCallbackId	addChildRemovedCallback (MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever a child is removed in the DAG. More...
static MCallbackId	addChildRemovedDagPathCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever a child is removed from the specified DAG node. More...
static MCallbackId	addChildReorderedCallback (MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever a child is reordered in the DAG. More...
static MCallbackId	addChildReorderedDagPathCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever a child of the specified DAG node is reordered. More...
static MCallbackId	addDagCallback (DagMessage msgType, MDagMessage::MMessageParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called for specified DAG changes on all nodes. More...
static MCallbackId	addDagDagPathCallback (MDagPath &node, DagMessage msgType, MDagMessage::MMessageParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called for specified a DAG change is made to the specified DAG path. More...
static MCallbackId	addAllDagChangesCallback (MDagMessage::MMessageParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever any DAG change is made to any DAG node. More...
static MCallbackId	addAllDagChangesDagPathCallback (MDagPath &node, MDagMessage::MMessageParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever a DAG change is made to the specified DAG path. More...
static MCallbackId	addInstanceAddedCallback (MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever any node in the DAG is instanced. More...
static MCallbackId	addInstanceAddedDagPathCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever the specified node is instanced. More...
static MCallbackId	addInstanceRemovedCallback (MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever an instance of any DAG node is removed or deleted. More...
static MCallbackId	addInstanceRemovedDagPathCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called whenever an instance of the specified node is removed. More...
static MCallbackId	addWorldMatrixModifiedCallback (MDagPath &node, MDagMessage::MWorldMatrixModifiedFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	This method registers a callback that is called when a DAG node's worldMatrix changes. More...
static const char *	className ()
	Returns the name of this class. More...
static MCallbackId	addParentAddedCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	Obsolete and no script support. More...
static MCallbackId	addParentRemovedCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	Obsolete and no script support. More...
static MCallbackId	addChildAddedCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	obsolete and no script support More...
static MCallbackId	addChildRemovedCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	Obsolete and no script support. More...
static MCallbackId	addChildReorderedCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	Obsolete and no script support. More...
static MCallbackId	addInstanceAddedCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	Obsolete and no script support. More...
static MCallbackId	addInstanceRemovedCallback (MDagPath &node, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	Obsolete and no script support. More...
static MCallbackId	addDagCallback (DagMessage msgType, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	Obsolete and no script support. More...
static MCallbackId	addDagCallback (MDagPath &node, DagMessage msgType, MMessage::MParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	Obsolete and no script support. More...
static MCallbackId	addDagCallback (MDagPath &node, DagMessage msgType, MDagMessage::MMessageParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	obsolete and no script support More...
static MCallbackId	addAllDagChangesCallback (MDagPath &node, MDagMessage::MMessageParentChildFunction func, void *clientData=NULL, MStatus *ReturnStatus=NULL)
	Obsolete and no script support. More...
Static Public Member Functions inherited from MMessage
static MStatus	removeCallback (MCallbackId id)
	Remove the specified callback from maya. More...
static MStatus	removeCallbacks (MCallbackIdArray &ids)
	Remove all of the specified callbacks from maya. More...
static MCallbackId	currentCallbackId (MStatus *ReturnStatus=NULL)
	Return the callback ID of the currently executing callback. More...
static MStatus	nodeCallbacks (MObject &node, MCallbackIdArray &ids)
	Returns a list of callback IDs associated registered to a given node. More...
static void	setRegisteringCallableScript ()
	Mark this MMessage object as one that will be passed callbacks defined in script.
static bool	registeringCallableScript ()
	Return true if this MMessage object has its callbacks defined in script.
static const char *	className ()
	Returns the name of this class. More...
static MStatus	removeCallbacks (MIntArray &ids)
	This method is obsolete. This method is not available in Python. More...
static MStatus	nodeCallbacks (MObject &node, MIntArray &ids)
	This method is obsolete. More...

Member Typedef Documentation

typedef void(* MMessageParentChildFunction) (MDagMessage::DagMessage msgType, MDagPath &child, MDagPath &parent, void *clientData)

Pointer to a callback function which takes an MDagMessage, two MDagPaths and a clientData pointer.

Parameters

[in]	msgType	Type of message which caused the function to be called.
[in,out]	child	First DAG path, usually used to pass the child of a parent/child pair.
[in,out]	parent	Second DAG path, usually use to pass the parent of a parent/child pair.
[in,out]	clientData	User-defined data which was supplied when the callback was added.

typedef void(* MWorldMatrixModifiedFunction) (MObject &transformNode, MDagMessage::MatrixModifiedFlags &modified, void *clientData)

Pointer to world matrix modified callback function.

Parameters

[in]	transformNode	The node whose transformation has changed.
[in]	modified	The flag which shows what has changed.
[in]	clientData	Pointer to user-defined data supplied when the callback was registered.

Member Enumeration Documentation

enum DagMessage

The type of DAG changed messages that have occurred.

Enumerator
kInvalidMsg	an invalid message was used.
kParentAdded	a dummy enum used for looping through the message types
kParentRemoved	a parent was removed from a DAG node
kChildAdded	a child was added to a DAG node
kChildRemoved	a child was removed from a DAG node
kChildReordered	a child of a DAG node was reordered
kInstanceAdded	a DAG node was instanced
kInstanceRemoved	a DAG node instance was removed
kLast	last value of the enum

Member Function Documentation

MCallbackId addParentAddedCallback ( MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever a parent is added in the DAG.

Please see the note in the Description section about this callback.

Parameters

[in]

func

the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

MCallbackId addParentAddedDagPathCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever a parent is added to the specified DAG node.

Please see the note in the Description section about this callback.

Parameters

[in]	node	The DAG node to register the callback for
[in]	func	the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

Examples:

MCallbackId addParentRemovedCallback ( MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever a parent is removed in the DAG.

Parameters

[in]

func

the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

MCallbackId addParentRemovedDagPathCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever a parent is removed from the specified DAG node.

Parameters

[in]	node	The DAG node to register the callback for
[in]	func	the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

Examples:

MCallbackId addChildAddedCallback ( MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever a child is added in the DAG.

Please see the note in the Description section about this callback.

Parameters

[in]

func

the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

MCallbackId addChildAddedDagPathCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever a child is added to the specified DAG node.

Please see the note in the Description section about this callback.

Parameters

[in]	node	The DAG node to register the callback for
[in]	func	the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

MCallbackId addChildRemovedCallback ( MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever a child is removed in the DAG.

Parameters

[in]

func

the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

MCallbackId addChildRemovedDagPathCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever a child is removed from the specified DAG node.

Parameters

[in]	node	The DAG node to register the callback for
[in]	func	the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

MCallbackId addChildReorderedCallback ( MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever a child is reordered in the DAG.

Parameters

[in]

func

the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

MCallbackId addChildReorderedDagPathCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever a child of the specified DAG node is reordered.

Parameters

[in]	node	The DAG node to register the callback for
[in]	func	the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

MCallbackId addDagCallback ( DagMessage  msgType, MDagMessage::MMessageParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called for specified DAG changes on all nodes.

The callback will also receive the DagMessage.

Please see the note in the Description section about this callback if Parent Added or Child Added messages are being used.

Parameters

[in]	msgType	The type of DAG change to trigger the callback
[in]	func	the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

Examples:

MCallbackId addDagDagPathCallback ( MDagPath &  node, DagMessage  msgType, MDagMessage::MMessageParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called for specified a DAG change is made to the specified DAG path.

The callback receives the DagMessage as well.

Please see the note in the Description section about this callback if Parent Added or Child Added messages are being used.

Parameters

[in]	node	The DAG node to register the callback for.
[in]	msgType	The type of DAG change to trigger the callback.
[in]	func	The callback function.

• child The child involved in the change.
• parent The parent involved in the change.
• clientData User defined data passed to the callback function.

Parameters

[in]	clientData	User defined data passed to the callback function.
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded.
• MS::kInsufficientMemory No memory available.
• MS::kFailure Error adding callback.

MCallbackId addAllDagChangesCallback ( MDagMessage::MMessageParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever any DAG change is made to any DAG node.

Please see the note in the Description section about this callback if Parent Added or Child Added messages are being used.

Parameters

[in]

func

the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

Examples:

MCallbackId addAllDagChangesDagPathCallback ( MDagPath &  node, MDagMessage::MMessageParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever a DAG change is made to the specified DAG path.

Parameters

[in]	node	The DAG node to register the callback for.
[in]	func	The callback function.

• child The child involved in the change.
• parent The parent involved in the change.
• clientData User defined data passed to the callback function.

Parameters

[in]	clientData	User defined data passed to the callback function.
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded.
• MS::kInsufficientMemory No memory available.
• MS::kFailure Error adding callback.

MCallbackId addInstanceAddedCallback ( MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever any node in the DAG is instanced.

Parameters

[in]

func

the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

Examples:

MCallbackId addInstanceAddedDagPathCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever the specified node is instanced.

Parameters

[in]	node	The DAG node to register the callback for.
[in]	func	The callback function.

• child The child involved in the change.
• parent The parent involved in the change.
• clientData User defined data passed to the callback function.

Parameters

[in]	clientData	User defined data passed to the callback function.
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded.
• MS::kInsufficientMemory No memory available.
• MS::kFailure Error adding callback.

Examples:

MCallbackId addInstanceRemovedCallback ( MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever an instance of any DAG node is removed or deleted.

Parameters

[in]

func

the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

Examples:

MCallbackId addInstanceRemovedDagPathCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called whenever an instance of the specified node is removed.

Parameters

[in]	node	The DAG node to register the callback for.
[in]	func	The callback function.

• child The child involved in the change
• parent The parent involved in the change.
• clientData User defined data passed to the callback function.

Parameters

[in]	clientData	User defined data passed to the callback function.
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded.
• MS::kInsufficientMemory No memory available.
• MS::kFailure Error adding callback.

Examples:

MCallbackId addWorldMatrixModifiedCallback ( MDagPath &  affectedNode, MDagMessage::MWorldMatrixModifiedFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

This method registers a callback that is called when a DAG node's worldMatrix changes.

Since a node's worldMatrix is affected by the transforms of its ancestors in the DAG, it's possible for there to be two different nodes involved: the "trigger" node, whose transform has changed, and the "affected" node, whose worldMatrix is affected by the change to the trigger.

The trigger node may be the same as the affected node, or it may be one of its ancestors.

The callback is placed on the affected node, but it is the trigger node which is passed to the callback.

If the trigger node's transformation is already dirty (i.e. it has not been evaluated since it was last changed) then the callback will not be triggered. So if the trigger node's transformation is modified multiple times between evaluations, only the first one will result in the callback being called.

Parameters

[in]	affectedNode	The DAG node to register the callback for.
[in]	func	The callback function. triggerNode The node whose transformation changed flag How the trigger node's transformation changed clientData User defined data passed to the callback function.
[in]	clientData	User defined data passed to the callback function.
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded.
• MS::kInsufficientMemory No memory available.
• MS::kFailure Error adding callback.

Examples:

const char * className ( )

static

Returns the name of this class.

Returns

The name of this class.

MCallbackId addParentAddedCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

Obsolete and no script support.

This method is obsolete. This method is not available in Python.

Deprecated:

Use MDagMessage::addParentAddedDagPathCallback instead.

This method registers a callback that is called whenever a parent is added to the specified DAG node.

Parameters

[in]	node	The DAG node to register the callback for.
[in]	func	The callback function.

• child The child involved in the change.
• parent The parent involved in the change.
• clientData User defined data passed to the callback function.

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

MCallbackId addParentRemovedCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

Obsolete and no script support.

This method is obsolete. This method is not available in Python.

Deprecated:

Use MDagMessage::addParentRemovedDagPathCallback instead.

This method registers a callback that is called whenever a parent is removed from the specified DAG node.

Parameters

[in]	node	The DAG node to register the callback for.
[in]	func	The callback function.

• child The child involved in the change.
• parent The parent involved in the change.
• clientData User defined data passed to the callback function.

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

MCallbackId addChildAddedCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

obsolete and no script support

This method is obsolete. This method is not available in Python.

Deprecated:

Use MDagMessage::addChildAddedDagPathCallback instead.

This method registers a callback that is called whenever a child is added to the specified DAG node.

Please see the note in the Description section about this callback.

Parameters

[in]	node	The DAG node to register the callback for.
[in]	func	The callback function.

• child The child involved in the change.
• parent The parent involved in the change.
• clientData User defined data passed to the callback function.

Parameters

[in]	clientData	User defined data passed to the callback function.
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded.
• MS::kInsufficientMemory No memory available.
• MS::kFailure Error adding callback.

MCallbackId addChildRemovedCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

Obsolete and no script support.

This method is obsolete. This method is not available in Python.

Deprecated:

Use MDagMessage::addChildRemovedDagPathCallback instead.

This method registers a callback that is called whenever a child is removed from the specified DAG node.

Parameters

[in]	node	The DAG node to register the callback for.
[in]	func	The callback function.

• child The child involved in the change.
• parent The parent involved in the change.
• clientData User defined data passed to the callback function.

Parameters

[in]	clientData	User defined data passed to the callback function.
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded.
• MS::kInsufficientMemory No memory available.
• MS::kFailure Error adding callback.

MCallbackId addChildReorderedCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

Obsolete and no script support.

This method is obsolete. This method is not available in Python.

Deprecated:

Use MDagMessage::addChildReorderedDagPathCallback instead.

This method registers a callback that is called whenever a child of the specified DAG node is reordered.

Parameters

[in]	node	The DAG node to register the callback for.
[in]	func	The callback function.

• child The child involved in the change.
• parent The parent involved in the change.
• clientData User defined data passed to the callback function.

Parameters

[in]	clientData	User defined data passed to the callback function.
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded.
• MS::kInsufficientMemory No memory available.
• MS::kFailure Error adding callback.

MCallbackId addInstanceAddedCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

Obsolete and no script support.

This method is obsolete. This method is not available in Python.

Deprecated:

Use MDagMessage::addDagCallback instead.

This method registers a callback that is called whenever the specified node is instanced

Parameters

[in]	node	The DAG node to register the callback for.
[in]	func	The callback function.

• child The child involved in the change.
• parent The parent involved in the change.
• clientData User defined data passed to the callback function.

Parameters

[in]	clientData	User defined data passed to the callback function.
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded.
• MS::kInsufficientMemory No memory available.
• MS::kFailure Error adding callback.

MCallbackId addInstanceRemovedCallback ( MDagPath &  node, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

Obsolete and no script support.

This method is obsolete. This method is not available in Python.

Deprecated:

Use MDagMessage::addDagCallback instead.

This method registers a callback that is called whenever an instance of the specified node is removed.

Parameters

[in]	node	The DAG node to register the callback for.
[in]	func	The callback function.

• child The child involved in the change.
• parent The parent involved in the change.
• clientData User defined data passed to the callback function.

Parameters

[in]	clientData	User defined data passed to the callback function.
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded.
• MS::kInsufficientMemory No memory available.
• MS::kFailure Error adding callback.

MCallbackId addDagCallback ( DagMessage  msgType, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

Obsolete and no script support.

This method is obsolete. This method is not available in Python.

This method registers a callback that is called whenever a DAG change is made.

Please see the note in the Description section about this callback if Parent Added or Child Added messages are being used.

Parameters

[in]	msgType	The type of DAG change to trigger the callback
[in]	func	the callback function

• child The child involved in the change
• parent The parent involved in the change
• clientData User defined data passed to the callback function

Parameters

[in]	clientData	User defined data passed to the callback function
[out]	ReturnStatus	status code

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded
• MS::kInsufficientMemory No memory available
• MS::kFailure Error adding callback

MCallbackId addDagCallback ( MDagPath &  node, DagMessage  msgType, MMessage::MParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

Obsolete and no script support.

This method is obsolete. This method is not available in Python.

This method registers a callback that is called whenever a DAG change is made to a specified node.

Please see the note in the Description section about this callback if Parent Added or Child Added messages are being used.

Parameters

[in]	node	The DAG node to register the callback for.
[in]	msgType	The type of DAG change to trigger the callback.
[in]	func	The callback function.

• child The child involved in the change.
• parent The parent involved in the change.
• clientData User defined data passed to the callback function.

Parameters

[in]	clientData	User defined data passed to the callback function.
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded.
• MS::kInsufficientMemory No memory available.
• MS::kFailure Error adding callback.

MCallbackId addDagCallback ( MDagPath &  node, DagMessage  msgType, MDagMessage::MMessageParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

obsolete and no script support

This method is obsolete. This method is not available in Python.

Deprecated:

Use MDagMessage::addDagDagPathCallback instead.

MCallbackId addAllDagChangesCallback ( MDagPath &  node, MDagMessage::MMessageParentChildFunction  func, void *  clientData = NULL, MStatus *  ReturnStatus = NULL  )

static

Obsolete and no script support.

This method is obsolete. This method is not available in Python.

Deprecated:

Use MDagMessage::addAllDagChangesDagPathCallback instead.

This method registers a callback that is called whenever a DAG change is made to the specified DAG path.

Parameters

[in]	node	The DAG node to register the callback for.
[in]	func	the callback function.

• child The child involved in the change.
• parent The parent involved in the change.
• clientData User defined data passed to the callback function.

Parameters

[in]	clientData	User defined data passed to the callback function.
[out]	ReturnStatus	Status code.

Returns

Identifier used for removing the callback.

Status Codes:

• MS::kSuccess Operation succeeded.
• MS::kInsufficientMemory No memory available.
• MS::kFailure Error adding callback.

---

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

• MDagMessage.h
• MDagMessage.cpp