"""
Extending the Button Context Menu
+++++++++++++++++++++++++++++++++

This example enables you to insert your own menu entry into the common
right click menu that you get while hovering over a value field,
color, string, etc.

To make the example work, you have to first select an object
then right click on an user interface element (maybe a color in the
material properties) and choose *Execute Custom Action*.

Executing the operator will then print all values.
"""

import bpy
from bpy.types import Menu


def dump(obj, text):
    for attr in dir(obj):
        print("%r.%s = %s" % (obj, attr, getattr(obj, attr)))


class WM_OT_button_context_test(bpy.types.Operator):
    """Right click entry test"""
    bl_idname = "wm.button_context_test"
    bl_label = "Run Context Test"

    @classmethod
    def poll(cls, context):
        return context.active_object is not None

    def execute(self, context):
        value = getattr(context, "button_pointer", None)
        if value is not None:
            dump(value, "button_pointer")

        value = getattr(context, "button_prop", None)
        if value is not None:
            dump(value, "button_prop")

        value = getattr(context, "button_operator", None)
        if value is not None:
            dump(value, "button_operator")

        return {'FINISHED'}


# This class has to be exactly named like that to insert an entry in the right click menu
class WM_MT_button_context(Menu):
    bl_label = "Unused"

    def draw(self, context):
        pass


def menu_func(self, context):
    layout = self.layout
    layout.separator()
    layout.operator(WM_OT_button_context_test.bl_idname)


classes = (
    WM_OT_button_context_test,
    WM_MT_button_context,
)


def register():
    for cls in classes:
        bpy.utils.register_class(cls)
    bpy.types.WM_MT_button_context.append(menu_func)


def unregister():
    for cls in classes:
        bpy.utils.unregister_class(cls)
    bpy.types.WM_MT_button_context.remove(menu_func)


if __name__ == "__main__":
    register()