space_view3d_move_origin.py

'''
BEGIN GPL LICENSE BLOCK

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.    See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

END GPL LICENCE BLOCK
'''

bl_info = {
    'name': 'Move origin to selected',
    'author': '',
    'version': (0, 0, 1),
    'blender': (2, 6, 7),
    'location': '3d view > space bar > Origin Move to Selected',
    'description': 'in edit mode, sets object origin to the median of selected verts/edges/faces',
    'wiki_url': '',
    'tracker_url': '',
    'category': '3D View'}

import bpy

class MoveOrigin(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.origin_to_selected"
    bl_label = "Origin Move To Selected"
    bl_options = {'REGISTER', 'UNDO'}

    @classmethod
    def poll(cls, context):
        obj = context.active_object
        return obj is not None and obj.mode == 'EDIT'

    def execute(self, context):
        saved_location = bpy.context.scene.cursor_location.copy()
        bpy.ops.view3d.snap_cursor_to_selected()
                
        bpy.ops.object.mode_set(mode = 'OBJECT')
        bpy.ops.object.origin_set(type='ORIGIN_CURSOR')  
        bpy.context.scene.cursor_location = saved_location
        
        bpy.ops.object.mode_set(mode = 'EDIT')
        return {'FINISHED'}


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


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


if __name__ == "__main__":
    register()

Hi @zeffii, had tried to contact you via "blenderstackexchange" and in this page "https://blender.meta.stackexchange.com/questions/2434/how-do-i-send-a-message-to-a-specific-user/2435?noredirect=1#comment5367_2435" I had written this message:
/--------------------------------------------------
Hello zeffii, forgive me if I steal some attention from you. I'm a chess enthusiast, I modeled a chessboard (http://www.avelino.it/wa/scacchiera/) and (not knowing Python) I embarked on writing a program that reads a game from a PGN file and, controlled by a Tkinter interface via the Forward, Back buttons etc., should make moves on the chessboard. The program is only sketched out, and I found out only now that the moves are executed, but the 3D view updates only when the script ends. I have looked for solutions on the web and none seem to work.

I tried to implement the brilliant solution you proposed in the script of the page "blender.stackexchange.com/questions/28673/…; but given my poor python knowledge I could not get any results!

If I sent you the Blender file and the script, would you have the chance to give it a look?
Thank you and excuse me for the length of the message. Translated with www.DeepL.com/Translator
/------------------------------------------------
.... and thank you very much for this very useful addon.

Avelino De Sabbata

Thx alot, thought i will script this myself but then i found your script :-)