Layout Nodes

import hou


def main(sortDirection, r):
    # first we make sure we are in an approved category by checking
    # against one of the selected nodes
    approvedCategories = ["Sop", "Driver", "Cop2", "Chop", "Vop", "Object",
                          "Shop", "CopNet", "Dop"]
    if hou.selectedNodes():
        node = hou.selectedNodes()[0]
    else:
        return
    curCategory = node.type().category().name()
    if curCategory in approvedCategories:
        # if we are in vops we need to reverse sort and sort from
        # the x pos not the y pos
        if curCategory == "Vop":
            sortDirection = 0
            r = False

        # loop through the selected nodes and then sort by pos
        xPositions = []
        yPositions = []
        positions = []
        for aNode in hou.selectedNodes():
            xPositions.append(aNode.position()[0])
            yPositions.append(aNode.position()[1])
            positions.append([aNode.position()[sortDirection], aNode])
        positions = sorted(positions, reverse=r)

        # if we are in vops we want to iterate the x pos not the y pos
        # xPos = sum(xPositions)/float(len(xPositions))
        if sortDirection == 1:
            xPos = max(set(xPositions), key=xPositions.count)
        else:
            xPos = min(xPositions)
        yPos = max(yPositions)
        for i in xrange(len(positions)):
            aNode = positions[i][1]
            pos = hou.Vector2(xPos, yPos)
            aNode.setPosition(pos)
            if sortDirection == 0:
                xPos += 2
                if curCategory != "Vop":
                    yPos -= 0.5
            else:
                yPos -= 1

        # bottomNode = positions[len(positions)-1][1]
        # if curCategory == "Sop":
        #    bottomNode.setDisplayFlag(True)
        #    bottomNode.setRenderFlag(True)

        # bottomNode.setCurrent(True, clear_all_selected=True)


def upDown():
    main(1, True)


def leftRight():
    main(0,  False)