Create a custom set origin menu

set_origin.py

# made in response to https://blender.stackexchange.com/q/92105/935

bl_info = {
    "name": "Test setting origin",
    "author": "sambler",
    "version": (1, 0),
    "blender": (2, 75, 0),
    "location": "blender",
    "description": "test setting origin menu",
    "warning": "Only testing",
    "category": "Test",
    }

import bpy

def my_custom_centring():
    print('Setting origin my way')

class My_Operator(bpy.types.Operator):
    bl_idname = 'object.my_set_origin'
    bl_label = 'Custom set origin'

    centre = bpy.props.StringProperty(default='')

    def execute(self, context):
        if self.centre == 'ORIGIN_TO_0Z':
            my_custom_centring()
        else:
            return bpy.ops.object.origin_set(type=self.centre)
        return {'FINISHED'}

class My_menu(bpy.types.Menu):
    bl_label = "My Custom Menu"
    bl_idname = "OBJECT_MT_my_custom_menu"

    def draw(self, context):
        layout = self.layout
        layout.operator(My_Operator.bl_idname, text='Geom to orig').centre = 'GEOMETRY_ORIGIN'
        layout.operator(My_Operator.bl_idname, text='orig to geom').centre = 'ORIGIN_GEOMETRY'
        layout.operator(My_Operator.bl_idname, text='orig to cursor').centre = 'ORIGIN_CURSOR'
        layout.operator(My_Operator.bl_idname, text='orig to mass').centre = 'ORIGIN_CENTER_OF_MASS'
        layout.operator(My_Operator.bl_idname, text='orig to vol').centre = 'ORIGIN_CENTER_OF_VOLUME'
        layout.operator(My_Operator.bl_idname, text='orig to zeroZ').centre = 'ORIGIN_TO_0Z'

def register():
    bpy.utils.register_class(My_Operator)
    bpy.utils.register_class(My_menu)

    wm = bpy.context.window_manager
    win_keymaps = wm.keyconfigs.user.keymaps.get('Object Non-modal')
    if win_keymaps:
        # disable standard set origin keymap
        for kmi in win_keymaps.keymap_items:
            if kmi.idname == 'object.origin_set':
                kmi.active = False

        # add a keymap for our set origin operator
        kmi = win_keymaps.keymap_items.new('wm.call_menu', 'C',
                    'PRESS', ctrl=True, alt=True, shift=True)
        setattr(kmi.properties, 'name', My_menu.bl_idname)

def unregister():
    bpy.utils.unregister_class(My_menu)
    bpy.utils.unregister_class(My_Operator)

    wm = bpy.context.window_manager
    win_keymaps = wm.keyconfigs.user.keymaps.get('Object Non-modal')
    if win_keymaps:
        for kmi in win_keymaps.keymap_items:
            # re-enable standard set origin
            if kmi.idname == 'object.origin_set':
                kmi.active = True
            # remove our custom set origin
            if kmi.idname == 'wm.call_menu' and getattr(kmi.properties, 'name') == My_menu.bl_idname:
                win_keymaps.keymap_items.remove(kmi)

if __name__ == "__main__":
    register()

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