node_Empty.py

import bpy
from node_s import *
from util import *
from bpy.props import FloatVectorProperty, StringProperty, BoolProperty


class svLinkedEmptyNode(Node, SverchCustomTreeNode):

    ''' Linked Empty to vector '''

    bl_idname = 'svLinkedEmptyNode'
    bl_label = 'Empty'
    bl_icon = 'OUTLINER_OB_EMPTY'

    n_id = StringProperty(default='', options={'SKIP_SAVE'})
    bpy.types.Object.identifier = StringProperty(default='')
    # bpy.types.Object.current_color = FloatVectorProperty(default=(.3, 0, 0), size=3)

    empty_location = FloatVectorProperty(
        default=(0, 0, 0), size=3)

    empty_matrix = FloatVectorProperty(
        default=(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1), size=16)

    empty_name = StringProperty(default='')
    # string prop for name
    is_copy = BoolProperty(default=False)

    def setup_new_empty(self):
        bpy.ops.object.add(type='EMPTY', location=self.empty_location)
        myob = bpy.context.active_object

        self.label = myob.name
        self.empty_name = myob.name

        myob.identifier = str(self.n_id)
        self.width = 140
        self.height = 50

    def add_outputs(self):
        self.outputs.new('VerticesSocket', "Vector", "Vector")
        self.outputs.new('MatrixSocket', "Matrix", "Matrix")

    def init(self, context):
        self.n_id = node_id(self)
        self.setup_new_empty()
        print('i am called', self.n_id, self.empty_name)

        if self.is_copy:
            # outputs already added
            return
        else:
            # needs outputs
            self.add_outputs()

    # def draw_buttons(self, context,layout):

    #     ao = bpy.context.active_object
    #     if not ao:
    #         return

    #     if ao.identifier == str(self.n_id):
    #         ao.current_color = (0.7, .4, 1)
    #     else:
    #         ao.current_color = (1, 1, 1)

    def find_empty(self):
        for obj in bpy.data.objects:
            if (obj.type == 'EMPTY') and (obj.identifier == str(self.n_id)):
                return obj

    def update(self):
        self.n_id = node_id(self)

        vector_out_socket = self.outputs.get('Matrix', None)
        if vector_out_socket:

            self.use_custom_color = True
            Empty = self.find_empty()
            if not Empty:
                # print empty seems to be removed, delete node or recreate from
                # .ext
                self.color = (1, 0.3, 0.3)
                return

            self.empty_location = Empty.location
            matrix = list(Empty.matrix_world)  # no need to flip this time.
            SvSetSocketAnyType(self, 'Vector', [Empty.location[:]])
            SvSetSocketAnyType(self, 'Matrix', [matrix])

            self.color = (1, 1, 1)
            return

        self.use_custom_color = False

    def update_socket(self, context):
        self.update()

    def copy(self, node):
        self.is_copy = True
        self.n_id = ''
        self.empty_location = node.empty_location
        self.init(bpy.context)

    def free(self):
        pass


def register():
    bpy.utils.register_class(svLinkedEmptyNode)


def unregister():
    bpy.utils.unregister_class(svLinkedEmptyNode)

if __name__ == "__main__":
    register()