Note

Menu subclasses must be registered before referencing them from Blender.

Note

Menus have their UILayout.operator_context initialized as ‘EXEC_REGION_WIN’ rather than ‘INVOKE_REGION_WIN’ (see Execution Context). If the operator context needs to initialize inputs from the Operator.invoke function, then this needs to be explicitly set. When a menu is added to UI elements such as a panel or header, the operator execution context will be inherited from them.

import bpy


class BasicMenu(bpy.types.Menu):
    bl_idname = "OBJECT_MT_select_test"
    bl_label = "Select"

    def draw(self, context):
        layout = self.layout

        layout.operator("object.select_all", text="Select/Deselect All").action = 'TOGGLE'
        layout.operator("object.select_all", text="Inverse").action = 'INVERT'
        layout.operator("object.select_random", text="Random")


bpy.utils.register_class(BasicMenu)

# Test call to display immediately.
bpy.ops.wm.call_menu(name="OBJECT_MT_select_test")

import bpy


class SubMenu(bpy.types.Menu):
    bl_idname = "OBJECT_MT_select_submenu"
    bl_label = "Select"

    def draw(self, context):
        layout = self.layout

        layout.operator("object.select_all", text="Select/Deselect All").action = 'TOGGLE'
        layout.operator("object.select_all", text="Inverse").action = 'INVERT'
        layout.operator("object.select_random", text="Random")

        # Access this operator as a sub-menu.
        layout.operator_menu_enum("object.select_by_type", "type", text="Select All by Type...")

        layout.separator()

        # Expand each operator option into this menu.
        layout.operator_enum("object.light_add", "type")

        layout.separator()

        # Use existing menu.
        layout.menu("VIEW3D_MT_transform")


bpy.utils.register_class(SubMenu)

# Test call to display immediately.
bpy.ops.wm.call_menu(name="OBJECT_MT_select_submenu")

import bpy


def menu_draw(self, context):
    self.layout.operator("wm.save_homefile")


bpy.types.TOPBAR_MT_file.append(menu_draw)

import bpy
from bpy.types import Operator, Menu
from bl_operators.presets import AddPresetBase


class OBJECT_MT_display_presets(Menu):
    bl_label = "Object Display Presets"
    preset_subdir = "object/display"
    preset_operator = "script.execute_preset"
    draw = Menu.draw_preset


class AddPresetObjectDisplay(AddPresetBase, Operator):
    '''Add a Object Display Preset'''
    bl_idname = "camera.object_display_preset_add"
    bl_label = "Add Object Display Preset"
    preset_menu = "OBJECT_MT_display_presets"

    # Variable used for all preset values.
    preset_defines = [
        "obj = bpy.context.object"
    ]

    # Properties to store in the preset.
    preset_values = [
        "obj.display_type",
        "obj.show_bounds",
        "obj.display_bounds_type",
        "obj.show_name",
        "obj.show_axis",
        "obj.show_wire",
    ]

    # Where to store the preset.
    preset_subdir = "object/display"


# Display into an existing panel.
def panel_func(self, context):
    layout = self.layout

    row = layout.row(align=True)
    row.menu(OBJECT_MT_display_presets.__name__, text=OBJECT_MT_display_presets.bl_label)
    row.operator(AddPresetObjectDisplay.bl_idname, text="", icon='ZOOM_IN')
    row.operator(AddPresetObjectDisplay.bl_idname, text="", icon='ZOOM_OUT').remove_active = True


classes = (
    OBJECT_MT_display_presets,
    AddPresetObjectDisplay,
)


def register():
    for cls in classes:
        bpy.utils.register_class(cls)
    bpy.types.OBJECT_PT_display.prepend(panel_func)


def unregister():
    for cls in classes:
        bpy.utils.unregister_class(cls)
    bpy.types.OBJECT_PT_display.remove(panel_func)


if __name__ == "__main__":
    register()

import bpy


def dump(obj, text):
    for attr in dir(obj):
        print("{!r}.{:s} = {:s}".format(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'}


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


def register():
    bpy.utils.register_class(WM_OT_button_context_test)
    bpy.types.UI_MT_button_context_menu.append(draw_menu)


def unregister():
    bpy.types.UI_MT_button_context_menu.remove(draw_menu)
    bpy.utils.unregister_class(WM_OT_button_context_test)


if __name__ == "__main__":
    register()