objects_place_empty_in_edit_mode.py

import bpy
import bmesh
from mathutils import Vector

bl_info = {
    'name': 'Add Empties',
    'author': 'Dealga McArdle (zeffii)',
    'version': (1, 1, 2),
    'blender': (2, 7, 3),
    'location': 'Add > Empties',
    'description': 'adds new Empty while in edit mode',
    'wiki_url': '',
    'tracker_url': '',
    'category': 'Mesh'}


def add_to_selected(context, kind):
    D = bpy.data
    scn = context.scene
    obj = context.edit_object
    obj_name = obj.name
    mesh = obj.data

    bm = bmesh.from_edit_mesh(mesh)

    def add_empty(coordinate, kind='PLAIN_AXIS'):
        empty = D.objects.new('MT_' + obj_name, None)
        empty.location = coordinate
        empty.empty_draw_size = 0.45
        empty.empty_draw_type = kind
        scn.objects.link(empty)
        scn.update()

    coordinates = [v.co[:] for v in bm.verts if v.select]

    # must be in object mode to add objects to the scene.
    myob = D.objects[obj_name]
    bpy.ops.object.mode_set(mode='OBJECT')

    if not coordinates:
        coordinate = context.scene.cursor_location
        add_empty(coordinate, kind)
    else:
        for co in coordinates:
            vert_coordinate = myob.matrix_world * Vector(co)
            add_empty(vert_coordinate, kind)

    # set original object to active, selects it, place back into editmode
    scn.objects.active = myob
    myob.select = True
    bpy.ops.object.mode_set(mode='EDIT')
    return


class AddEmpties(bpy.types.Operator):
    """Add a vertex to 3d cursor location"""
    bl_idname = "object.empties_add"
    bl_label = "Add Empties"
    bl_options = {'REGISTER', 'UNDO'}

    kind = bpy.props.StringProperty(default='PLAIN_AXES')

    def execute(self, context):
        add_to_selected(context, self.kind)
        return {'FINISHED'}


class EDITMODE_MT_PlaceEmpties(bpy.types.Menu):
    bl_label = "Adding Empties.."

    def draw(self, context):
        options = [
            'PLAIN_AXES', 'ARROWS', 'SINGLE_ARROW',
            'CIRCLE', 'CUBE', 'SPHERE', 'CONE', 'IMAGE']

        layout = self.layout
        for opt in options:
            layout.operator("object.empties_add", text=opt).kind = opt


def menu_func(self, context):
    self.layout.menu("EDITMODE_MT_PlaceEmpties", icon='EMPTY_DATA')


def register():
    bpy.utils.register_module(__name__)
    bpy.types.INFO_MT_mesh_add.prepend(menu_func)


def unregister():
    bpy.utils.unregister_module(__name__)
    bpy.types.INFO_MT_mesh_add.remove(menu_func)

if __name__ == "__main__":
    register()