Detailed Description

Dependency graph modifier.

An MDGModifier is used to change the structure of the dependency graph. This includes adding nodes, making new connections, and removing existing connections. To perform operations using an MDGModifier, register all of the changes that are to be made and then call the doIt method to make the changes. Undo is provided through the undoIt method.

Under some situations, a doIt() call may be required to separate some of the operations. The specific case of interest involves performing a disconnect() and a deleteNode() on the same node within the stack of operations.

Assuming that the Maya model has a connected node that was going to be deleted, do the following:

    MStatus cmd::redoIt()
    {
        MStatus result = dgModifier.disconnect(plugA, plugB);
        if (!result)
            ...
        result = dgModifier.doIt();
        if (!result)
            ...

        result = dgModifier.deleteNode(plugBNode);
        if (!result)
            ...

        result = dgModifier.doIt();
        if (!result)
            ...

        return result;
    }

Then undoIt() can be implemented as:

    MStatus cmd::undoIt()
    {
        MStatus result = dgModifier.undoIt();
        if (!result)
            ...
        return result;
    }

Examples:: cgfxAttrDef.cpp, cgfxAttrDef.h, cgfxShaderCmd.cpp, cgfxShaderCmd.h, cgfxShaderNode.cpp, closestPointOnCurveCmd.cpp, createClipCmd.cpp, D3DResourceManager.cpp, deletedMsgCmd.cpp, geometrySurfaceConstraint.cpp, geometrySurfaceConstraint.h, GLSLShaderNode.cpp, GLSLShaderNode.h, latticeNoiseCmd.cpp, narrowPolyViewer.h, pointOnMeshCmd.cpp, polyModifierCmd.cpp, polyModifierCmd.h, and polyPrimitiveCmd.cpp.

#include <MDGModifier.h>

Inheritance diagram for MDGModifier:

[legend]

List of all members.

Public Member Functions
	MDGModifier ()
	The class constructor.
virtual	~MDGModifier ()
	The class destructor.
MObject	createNode (const MTypeId &typeId, MStatus *ReturnStatus=NULL)
	This method adds an operation to this dependency graph modifier that will add a new dependency graph node of the given type to the dependency graph.
MObject	createNode (const MString &type, MStatus *ReturnStatus=NULL)
	This method adds an operation to this dependency graph modifier that will add a new dependency graph node of the given type to the dependency graph.
MStatus	deleteNode (const MObject &node)
	This method adds an operation to this dependency graph modifier that will delete a dependency graph node from the dependency graph.
MStatus	renameNode (const MObject &node, const MString &newName)
	This method adds an operation to this dependency graph modifier that will rename a dependency graph node.
MStatus	setNodeLockState (const MObject &node, bool newState)
	This method adds an operation to this dependency graph modifier that will set the lock state of the node.
MStatus	connect (const MObject &sourceNode, const MObject &sourceAttr, const MObject &destNode, const MObject &destAttr)
	Adds an operation to this dependency graph modifier that connects two attributes of two nodes in the dependency graph.
MStatus	disconnect (const MObject &sourceNode, const MObject &sourceAttr, const MObject &destNode, const MObject &destAttr)
	Adds an operation to this dependency graph modifier that disconnects two attributes of two nodes in the dependency graph.
MStatus	connect (const MPlug &source, const MPlug &dest)
	Adds an operation to this dependency graph modifier that connects two plugs in the dependency graph.
MStatus	disconnect (const MPlug &source, const MPlug &dest)
	Adds an operation to this dependency graph modifier that disconnects two plugs in the dependency graph.
MStatus	addAttribute (const MObject &node, const MObject &attribute)
	Add a new dynamic attribute to the given dependency node.
MStatus	removeAttribute (const MObject &node, const MObject &attribute)
	Removes a dynamic attribute from the given dependency node.
MStatus	addExtensionAttribute (const MNodeClass &nodeClass, const MObject &attribute)
	Add a new extension attribute to the given dependency node class.
MStatus	removeExtensionAttribute (const MNodeClass &nodeClass, const MObject &attribute)
	Removes an extension attribute from the given dependency node type.
MStatus	removeExtensionAttributeIfUnset (const MNodeClass &nodeClass, const MObject &attribute)
	Removes an extension attribute from the given dependency node type but only if there are no nodes in the graph with non-default values for this attribute.
MStatus	linkExtensionAttributeToPlugin (const MObject &plugin, const MObject &attribute)
	The plugin calls this to indicate that the extension attribute defines part of the plugin, regardless of the node type to which it attaches itself.
MStatus	unlinkExtensionAttributeFromPlugin (const MObject &mPlugin, const MObject &mAttribute)
	Tells a plugin that it no longer requires an extension attribute for operation.
MStatus	commandToExecute (const MString &command)
	Adds an operation to this dependency graph modifier that executes a MEL command.
MStatus	newPlugValue (const MPlug &plug, MObject &plugValue)
	Adds an operation to this dependency graph modifier that sets a plug value.
MStatus	newPlugValueBool (const MPlug &plug, bool plugValue)
	Adds an operation to this dependency graph modifier that sets a plug to a boolean value.
MStatus	newPlugValueChar (const MPlug &plug, char plugValue)
	Adds an operation to this dependency graph modifier that sets a plug to a char value.
MStatus	newPlugValueDouble (const MPlug &plug, double plugValue)
	Adds an operation to this dependency graph modifier that sets a plug to a double value.
MStatus	newPlugValueFloat (const MPlug &plug, float plugValue)
	Adds an operation to this dependency graph modifier that sets a plug to a float value.
MStatus	newPlugValueInt (const MPlug &plug, int plugValue)
	Adds an operation to this dependency graph modifier that sets a plug to an int value.
MStatus	newPlugValueMAngle (const MPlug &plug, const MAngle &plugValue)
	Adds an operation to this dependency graph modifier that sets a plug to an MAngle value.
MStatus	newPlugValueMDistance (const MPlug &plug, const MDistance &plugValue)
	Adds an operation to this dependency graph modifier that sets a plug to an MDistance value.
MStatus	newPlugValueMTime (const MPlug &plug, const MTime &plugValue)
	Adds an operation to this dependency graph modifier that sets a plug to an MTime value.
MStatus	newPlugValueShort (const MPlug &plug, short plugValue)
	Adds an operation to this dependency graph modifier that sets a plug to a short value.
MStatus	newPlugValueString (const MPlug &plug, const MString &plugValue)
	Adds an operation to this dependency graph modifier that sets a plug to a string value.
MStatus	doIt ()
	Executes all of the operations that have been given to this modifier.
MStatus	undoIt ()
	Undoes all of the operations that have been given to this modifier.
MStatus	addAttribute (const MObject &node, const MObject &attribute, MFnDependencyNode::MAttrClass type)
MStatus	removeAttribute (const MObject &node, const MObject &attribute, MFnDependencyNode::MAttrClass type)
Static Public Member Functions
static const char *	className ()
	Returns the name of this class.

Member Function Documentation

MObject createNode	(	const MTypeId &	typeId,
		MStatus *	ReturnStatus = `NULL`
	)

[in]	typeId	type of the node to create
[out]	ReturnStatus	return status

MObject createNode	(	const MString &	type,
		MStatus *	ReturnStatus = `NULL`
	)

[in]	type	type name of the node to create
[out]	ReturnStatus	return status

MStatus renameNode	(	const MObject &	node,
		const MString &	newName
	)

MStatus setNodeLockState	(	const MObject &	node,
		bool	newState
	)

MStatus connect	(	const MObject &	sourceNode,
		const MObject &	sourceAttr,
		const MObject &	destNode,
		const MObject &	destAttr
	)

[in]	sourceNode	the source node in the connection
[in]	sourceAttr	the attribute of the source node that is to be connected
[in]	destNode	the destination node in the connection
[in]	destAttr	the attribute of the destination node that is to be connected

MStatus disconnect	(	const MObject &	sourceNode,
		const MObject &	sourceAttr,
		const MObject &	destNode,
		const MObject &	destAttr
	)

[in]	source	the source plug in the connection
[in]	dest	the destination plug in the connection

MStatus disconnect	(	const MPlug &	source,
		const MPlug &	dest
	)

MStatus addAttribute	(	const MObject &	node,
		const MObject &	attribute
	)

[in]	node	node to which to add the attribute
[in]	attribute	attribute to add

MStatus removeAttribute	(	const MObject &	node,
		const MObject &	attribute
	)

[in]	node	node to add an attribute to
[in]	attribute	attribute to add

MStatus addExtensionAttribute	(	const MNodeClass &	nodeClass,
		const MObject &	attribute
	)

[in]	nodeClass	class of node to which to add the attribute
[in]	attribute	attribute to add

MStatus removeExtensionAttribute	(	const MNodeClass &	nodeClass,
		const MObject &	attribute
	)

[in]	nodeClass	class of node from which to remove the attribute
[in]	attribute	attribute to remove

MStatus removeExtensionAttributeIfUnset	(	const MNodeClass &	nodeClass,
		const MObject &	attribute
	)

MStatus linkExtensionAttributeToPlugin	(	const MObject &	mPlugin,
		const MObject &	mAttribute
	)

MDGModifier Class Reference

OpenMaya - API module for common classes

Detailed Description

Public Member Functions

Static Public Member Functions

Member Function Documentation

[in]	mPlugin	plugin to which the attribute is to be tied
[in]	mAttribute	attribute to associate with the plugin, must not have a parent

MStatus unlinkExtensionAttributeFromPlugin	(	const MObject &	mPlugin,
		const MObject &	mAttribute
	)

[in]	mPlugin	plugin from which the attribute is to be released
[in]	mAttribute	attribute to disassociate with the plugin, must not have a parent

MStatus newPlugValue	(	const MPlug &	plug,
		MObject &	plugValue
	)

MStatus newPlugValueBool	(	const MPlug &	plug,
		bool	plugValue
	)

MStatus newPlugValueChar	(	const MPlug &	plug,
		char	plugValue
	)

MStatus newPlugValueDouble	(	const MPlug &	plug,
		double	plugValue
	)

MStatus newPlugValueFloat	(	const MPlug &	plug,
		float	plugValue
	)

MStatus newPlugValueMAngle	(	const MPlug &	plug,
		const MAngle &	plugValue
	)

MStatus newPlugValueMDistance	(	const MPlug &	plug,
		const MDistance &	plugValue
	)