scripted/multiPlugInfoCmd.py

#-
# ==========================================================================
# Copyright 2010 Autodesk, Inc. All rights reserved.
#
# Use of this software is subject to the terms of the Autodesk
# license agreement provided at the time of installation or download,
# or which otherwise accompanies this software in either electronic
# or hard copy form.
# ==========================================================================
#+

#
# This plugin prints out the child plug information for a multiPlug.
# If the -index flag is used, the logical index values used by the plug
# will be returned.  Otherwise, the plug values will be returned.
#
# import maya.cmds as cmds
# cmds.loadPlugin("multiPlugInfoCmd.py")
# cmds.multiPlugInfo("myObj.myMultiAttr", index=True)
#

import maya.OpenMaya as OpenMaya
import maya.OpenMayaMPx as OpenMayaMPx
import sys
kPluginCmdName  = "multiPlugInfo"
kIndexFlag      = "-i"
kIndexFlagLong  = "-index"

# Wrapper to handle exception when MArrayDataHandle hits the end of the array.
def advance(arrayHdl):
    try:
        arrayHdl.next()
    except:
        return False

    return True


# command
class multiPlugInfo(OpenMayaMPx.MPxCommand):
    def __init__(self):
        OpenMayaMPx.MPxCommand.__init__(self)
        # setup private data members
        self.__isIndex = False

    def doIt(self, args):
        """
        This method is called from script when this command is called.
        It should set up any class data necessary for redo/undo,
        parse any given arguments, and then call redoIt.
        """
        argData = OpenMaya.MArgDatabase(self.syntax(), args)

        if argData.isFlagSet(kIndexFlag):
            self.__isIndex = True

        # Get the plug specified on the command line.
        slist = OpenMaya.MSelectionList()
        argData.getObjects(slist)
        if slist.length() == 0:
            print "Must specify an array plug in the form <nodeName>.<multiPlugName>."
            return

        plug = OpenMaya.MPlug()
        slist.getPlug(0, plug)
        if plug.isNull():
            print "Must specify an array plug in the form <nodeName>.<multiPlugName>."
            return

        # Construct a data handle containing the data stored in the plug.
        dh = plug.asMDataHandle()
        adh = None
        try:
            adh = OpenMaya.MArrayDataHandle(dh)
        except:
            print "Could not create the array data handle."
            plug.destructHandle(dh)
            return

        # Iterate over the values in the multiPlug.  If the index flag has been used, just return
        # the logical indices of the child plugs.  Otherwise, return the plug values.
        for i in range(adh.elementCount()):
            try:
                indx = adh.elementIndex()
            except:
                advance(adh)
                continue

            if self.__isIndex:
                self.appendToResult(indx)
            else:
                h = adh.outputValue()
                if h.isNumeric():
                    if h.numericType() == OpenMaya.MFnNumericData.kBoolean:
                        self.appendToResult(h.asBool())
                    elif h.numericType() == OpenMaya.MFnNumericData.kShort:
                        self.appendToResult(h.asShort())
                    elif h.numericType() == OpenMaya.MFnNumericData.kInt:
                        self.appendToResult(h.asInt())
                    elif h.numericType() == OpenMaya.MFnNumericData.kFloat:
                        self.appendToResult(h.asFloat())
                    elif h.numericType() == OpenMaya.MFnNumericData.kDouble:
                        self.appendToResult(h.asDouble())
                    else:
                        print "This sample command only supports boolean, integer, and floating point values."
            advance(adh)

        plug.destructHandle(dh)

# Creator
def cmdCreator():
    return OpenMayaMPx.asMPxPtr(multiPlugInfo())


# Syntax creator
def syntaxCreator():
    syntax = OpenMaya.MSyntax()
    syntax.addFlag(kIndexFlag, kIndexFlagLong, OpenMaya.MSyntax.kNoArg)
    syntax.setObjectType(OpenMaya.MSyntax.kSelectionList, 1, 1)
    return syntax


def initializePlugin(mobject):
    mplugin = OpenMayaMPx.MFnPlugin(mobject, "Autodesk", "1.0", "Any")
    try:
        mplugin.registerCommand(kPluginCmdName, cmdCreator, syntaxCreator)
    except:
        sys.stderr.write( "Failed to register command: %s\n" % kPluginCmdName)
        raise

def uninitializePlugin(mobject):
    mplugin = OpenMayaMPx.MFnPlugin(mobject)
    try:
        mplugin.deregisterCommand(kPluginCmdName)
    except:
        sys.stderr.write("Failed to unregister command: %s\n" % kPluginCmdName)
        raise