class MNodeMessage

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Inheritance:

MNodeMessage < MMessage

public members:

enum	AttributeMessage The type of attribute changed/addedOrRemoved messages that has occurred kConnectionMade a connection has been made to an attribute of this node kConnectionBroken a connection has been broken for an attribute of this node kAttributeEval an attribute of this node has been evaluated kAttributeSet an attribute value of this node has been set kAttributeLocked an attribute of this node has been locked kAttributeUnlocked an attribute of this node has been unlocked kAttributeAdded an attribute has been added to this node kAttributeRemoved an attribute has been removed from this node kAttributeRenamed an attribute of this node has been renamed kAttributeKeyable an attribute of this node has been marked keyable kAttributeUnkeyable an attribute of this node has been marked unkeyable kIncomingDirection the connection was coming into the node kAttributeArrayAdded an array attribute has been added to this node kAttributeArrayRemoved an array attribute has been removed from this node kOtherPlugSet the otherPlug data has been set kLast last value of the enum
enum	KeyableChangeMsg Allows you to prevent attributes from becoming (un)keyable. kKeyChangeInvalid kMakeKeyable kMakeUnkeyable kKeyChangeLast
static MCallbackId	addAttributeChangedCallback ( MObject & node, MNodeMessage::MAttr2PlugFunction func, void * clientData = NULL, MStatus * ReturnStatus = NULL )
static MCallbackId	addAttributeAddedOrRemovedCallback ( MObject & node, MNodeMessage::MAttrPlugFunction func, void * clientData = NULL, MStatus * ReturnStatus = NULL )
static MCallbackId	addNodeDirtyCallback ( MObject & node, MMessage::MNodeFunction func, void * clientData = NULL, MStatus * ReturnStatus = NULL )
static MCallbackId	addNodeDirtyPlugCallback ( MObject & node, MMessage::MNodePlugFunction func, void * clientData = NULL, MStatus * ReturnStatus = NULL )
static MCallbackId	addNameChangedCallback ( MObject & node, MMessage::MNodeStringFunction func, void * clientData = NULL, MStatus * ReturnStatus = NULL )
static MCallbackId	addNodeAboutToDeleteCallback ( MObject & node, MMessage::MNodeModifierFunction func, void * clientData = NULL, MStatus * ReturnStatus = NULL )
static MCallbackId	addNodePreRemovalCallback ( MObject & node, MMessage::MNodeFunction func, void * clientData = NULL, MStatus * ReturnStatus = NULL )
static MCallbackId	addNodeDestroyedCallback ( MObject & node, MMessage::MBasicFunction func, void * clientData = NULL, MStatus * ReturnStatus = NULL ) NodeDestroyed callback
static MCallbackId	addKeyableChangeOverride ( MPlug & plug, MNodeMessage::MKeyableFunction func, void *clientData = NULL, MStatus *status = NULL ) Attribute keyable state change override
static MCallbackId	addNodeDirtyCallback ( MObject & node, MMessage::MBasicFunction func, void * clientData = NULL, MStatus * ReturnStatus = NULL ) OBSOLETE and NO SCRIPT SUPPORT
static MCallbackId	addNodeDirtyCallback ( MObject & node, MMessage::MNodePlugFunction func, void * clientData = NULL, MStatus * ReturnStatus = NULL ) OBSOLETE and NO SCRIPT SUPPORT
static MCallbackId	addNameChangedCallback ( MObject & node, MMessage::MNodeFunction func, void * clientData = NULL, MStatus * ReturnStatus = NULL ) OBSOLETE and NO SCRIPT SUPPORT
static MCallbackId	addNodeAboutToDeleteCallback ( MObject & node, MMessage::MModifierFunction func, void * clientData = NULL, MStatus * ReturnStatus = NULL ) OBSOLETE and NO SCRIPT SUPPORT

Inherited from MMessage:

public members:

static MStatus	removeCallback ( MCallbackId id )
static MStatus	removeCallbacks ( MCallbackIdArray &ids )
static MCallbackId	currentCallbackId ( MStatus * ReturnStatus = NULL )
static MStatus	nodeCallbacks ( MObject & node, MCallbackIdArray & ids )
static void	setRegisteringCallableScript ()
static bool	registeringCallableScript ()
static MStatus	removeCallbacks ( MIntArray &ids )
static MStatus	nodeCallbacks ( MObject & node, MIntArray & ids )

Documentation

Description

This class is used to register callbacks for dependency node messages of specific dependency nodes.

There are 4 add callback methods which will add callbacks for the following messages

• Attribute Changed
• Attribute Added or Removed
• Node Dirty
• Name Changed

The first parameter passed to each of the add callback methods is the depenency node that will trigger the callback.

Callbacks that are registered for attribute changed/addedOrRemoved messages will be passed an AttributeMessage value as a parameter. This value indicates the type of attribute message that has occurred. See the AttributeMessage enum for all available messages.

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.

Functions

MCallbackId MNodeMessage:: addAttributeChangedCallback ( MObject & node, MNodeMessage::MAttr2PlugFunction func, void * clientData, MStatus * ReturnStatus )

Description

This method registers a callback for attribute changed messages. See the AttributeChanged enum for a list of all possible messages that will trigger the callback.

Note: Attribute Changed messages will not be generated while Maya is either in playback or scrubbing modes. If you need to do something during playback or scrubbing you will have to register a callback for the timeChanged message which is the only message message that is sent during those modes.

The callback function will be passed the type of attribute message that has occurred, the plug(s) for the attributes, and any client data that the user wishes to pass in.

Example callback ( prints out a message when a connection is made or broken ) :

    void userCB( MNodeMessage::AttributeMessage msg, MPlug & plug,
                 MPlug & otherPlug, void* )
    {
        if ( msg & MNodeMessage::kConnectionMade ) {
            cout << "Connection made ";
        } else if ( msg & MNodeMessage::kConnectionBroken ) {
            cout << "Connection broken ";
        } else {
            return;
        }
        cout << plug.info();
        if  ( msg & MNodeMessage::kOtherPlugSet ) {
            if ( msg & MNodeMessage::kIncomingDirection ) {
                cout << "  <--  " << otherPlug.info();
            } else {
                cout << "  -->  " << otherPlug.info();
            }
        }
        cout << endl;
    }
	

Arguments

• node the node to register the callback for
• func the callback function
  • msg the kind of attribute change triggering the callback
  • plug the node's plug where the connection changed
  • otherPlug the plug opposite the node's plug where the connection changed
  • clientData User defined data passed to the callback function
• clientData User defined data that will be passed to the callback function
• ReturnStatus status code

Return Value

• identifier used for removing the callback.

Status Codes

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

MCallbackId MNodeMessage:: addAttributeAddedOrRemovedCallback ( MObject & node, MNodeMessage::MAttrPlugFunction func, void * clientData, MStatus * ReturnStatus )

Description

Registers callbacks for attribute add/removed messages. This is a more specific version of addAttributeChanged as only attribute added and attribute removed messages will trigger the callback.

Arguments

• node the node to register the callback for
• func the callback function
  • msg the kind of attribute change triggering the callback
  • plug the node's plug where the connection changed
  • clientData User defined data passed to the callback function
• clientData User defined data that will be passed to the callback function
• ReturnStatus status code

Return Value

• identifier used for removing the callback.

Status Codes

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

MCallbackId MNodeMessage:: addNodeDirtyCallback ( MObject & node, MMessage::MBasicFunction func, void * clientData, MStatus * ReturnStatus )

Description

OBSOLETE. Use the version of addNodeDirtyCallback that has an MObject as the first argument. This callback will not let you know which node is dirty.

Arguments

• node the node to register the callback for
• func the callback function
  • clientData User defined data passed to the callback function
• clientData User defined data that will be passed to the callback function
• ReturnStatus status code

Return Value

• identifier used for removing the callback.

Status Codes

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

MCallbackId MNodeMessage:: addNodeDirtyCallback ( MObject & node, MMessage::MNodeFunction func, void * clientData, MStatus * ReturnStatus )

Description

Registers a callback for node dirty messages.

Arguments

• node the node to register the callback for
• func the callback function
  • node The node that has become dirty
  • clientData User defined data passed to the callback function
• clientData User defined data that will be passed to the callback function
• ReturnStatus status code

Return Value

• identifier used for removing the callback.

Status Codes

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

MCallbackId MNodeMessage:: addNodeDirtyPlugCallback ( MObject & node, MMessage::MNodePlugFunction func, void * clientData, MStatus * ReturnStatus )

Description

Registers a callback for node dirty messages. This callback provides the plug on the node that was dirtied. Only provides dirty information on input plugs.

Arguments

• node the node to register the callback for
• func the callback function
  • node The node that has become dirty
  • plug The plug on the node that has become dirty
  • clientData User defined data passed to the callback function
• clientData User defined data that will be passed to the callback function
• ReturnStatus status code

Return Value

• identifier used for removing the callback.

Status Codes

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

MCallbackId MNodeMessage:: addNodeDirtyCallback ( MObject & node, MMessage::MNodePlugFunction func, void * clientData, MStatus * ReturnStatus )

Description

THIS IS AN OBSOLETE METHOD AND HAS BEEN REPLACED BY addNodeDirtyPlugCallback.

MCallbackId MNodeMessage:: addNameChangedCallback ( MObject & node, MMessage::MNodeFunction func, void * clientData, MStatus * ReturnStatus )

Description

OBSOLETE. Use the version of addNameChangedCallback that has an MMessage::MNodeStringFunction as its callback type. This callback will not let you know the previous name of the node.

Registers a callback for name changed messages.

Arguments

• node the node. If this is a NULL MObject then the callback applies to all node name changes.
• func the callback function
  • node the node
  • clientData User defined data passed to the callback function
• clientData User defined data that will be passed to the callback function
• ReturnStatus status code

Return Value

• identifier used for removing the callback.

Status Codes

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

MCallbackId MNodeMessage:: addNameChangedCallback ( MObject & node, MMessage::MNodeStringFunction func, void * clientData, MStatus * ReturnStatus )

Description

Registers a callback for name changed messages.

Arguments

• node the node. If this is a NULL MObject then the callback applies to all node name changes.
• func the callback function
  • node the node
  • prevName the previous name of the node
  • clientData User defined data passed to the callback function
• clientData User defined data that will be passed to the callback function
• ReturnStatus status code

Return Value

• identifier used for removing the callback.

Status Codes

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

MCallbackId MNodeMessage:: addNodeAboutToDeleteCallback ( MObject & node, MMessage::MModifierFunction func, void * clientData, MStatus * ReturnStatus )

Description

OBSOLETE. Use the version of addNodeAboutToDeleteCallback that has an MObject as the first argument. This callback will not let you know which node is about to be deleted.

Arguments

• node the node to register the callback for
• func the callback function
  • modifier DG modifier used to delete the node
  • clientData User defined data passed to the callback function
• clientData User defined data that will be passed to the callback function
• ReturnStatus status code

Return Value

• identifier used for removing the callback.

Status Codes

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

MCallbackId MNodeMessage:: addNodeAboutToDeleteCallback ( MObject & node, MMessage::MNodeModifierFunction func, void * clientData, MStatus * ReturnStatus )

Description

Registers a callback which will get called when a node is about to be deleted.

The user callback will be passed the MDGModifer that will be used to delete the node. This modifier can be used to do any DG modifications, such as disconnections, before the node is deleted. These operations are also stored and performed when the deletion operation is undone or redone. Note that MDGModifier::doIt() will get called automatically and does not need to be called in the callback.

The callback registered with this method will only get called when the deletion operation is first performed. If you also wish to receive notification of deletion events when they are redone, you should register an additional callback using addNodePreRemovalCallback().

Arguments

• node the node to register the callback for
• func the callback function
  • node the node that will be deleted
  • modifier DG modifier used to delete the node
  • clientData User defined data passed to the callback function
• clientData User defined data that will be passed to the callback function
• ReturnStatus status code

Return Value

• identifier used for removing the callback.

Status Codes

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

MCallbackId MNodeMessage:: addNodePreRemovalCallback ( MObject & node, MMessage::MNodeFunction func, void * clientData, MStatus * ReturnStatus )

Description

Registers a callback which will get called before a node is deleted. This callback is called before connections on the node are removed. Unlike the aboutToDelete callback, this callback will be invoked whenever the node is deleted, even during a redo.

Pre-removal and aboutToDelete callbacks serve different purposes. If DG changes need to be made when a node is deleted, the aboutToDelete callback should be used to add undoable operations to an MDGModifier to perform these changes. When the desired actions cannot be accomplished using the MDGModifier passed to the aboutToDelete callback, this callback can be used to receive notification of the deletion event, even during redo.

Note that this callback method should not perform any DG operations.

Arguments

• node the node to register the callback for
• func the callback function
  • node the node that is being deleted
  • clientData User defined data passed to the callback function
• clientData User defined data that will be passed to the callback function
• ReturnStatus status code

Return Value

• identifier used for removing the callback.

Status Codes

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

MCallbackId MNodeMessage:: addNodeDestroyedCallback ( MObject & node, MMessage::MBasicFunction func, void * clientData , MStatus * ReturnStatus )

Description

Registers a callback which will get called when a node's destructor is called.

Arguments

• node the node to register the callback for
• func the callback function
  • clientData User defined data passed to the callback function
• clientData User defined data that will be passed to the callback function
• ReturnStatus status code

Return Value

• identifier used for removing the callback.

Status Codes

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

MCallbackId MNodeMessage:: addKeyableChangeOverride ( MPlug & plug, MNodeMessage::MKeyableFunction func, void *clientData, MStatus *ReturnStatus )

Description

This method registers a callback that is invoked by any class that changes the keyable state of an attribute. When the callback is invoked, the API programmer can make a decision on how to handle the given keyable change event. The programmer can either accept the the keyable state change by returning a decision == 'true' or reject it by returning decision == 'false'.

Note: you can only attach one callback keyable change override callback per attribute. It is an error to attach more than one callback to the same attribute.

Arguments

• plug - The plug to attach the callback.
  • plug - The plug that triggered the callback.
  • clientData - User defined data passed to the callback function.
  • eventType - Description of the event.
  • decision - Decision to accept the keyable state change, decision == 'true', or regect it, decision == 'false'.
• clientData - User defined data passed back to the user.
• status - status code
  • MS::kFailure - Error registering callback. This can occur when a global watcher is already attached to the node.
  • MS::kInsufficientMemory - Not enough memory to register the callback.
  • MS::kInvalidParameter - The given node is not a valid node to register the callback on.
  • MS::kSuccess - Callback successfully added.

This class has no child classes.