Menu

An optional drop-down menu bar can be added to the main window by including a menu key in the YAML configuration file.

Basic structure

window:
  title: My Application
  width: 800
  height: 600
  module: callbacks
  variable_group: myapp

menu:
- text: File
  menu:
  - text: Open
    method: open_file
  - text: Save
    method: save_file
    separator: true
  - text: Exit
    method: exit

- text: Help
  menu:
  - text: About
    method: show_about

Menu keys

Key	Type	Default	Description
text	str		Menu item label
method	str		Callback function called when the item is clicked
module	str	inherited	Callback module override for this item (and its sub-items)
menu	list		Sub-menu items (creates a nested sub-menu)
separator	bool	false	Draw a separator line above this item
checkable	bool	false	Make the item a toggle (checkable menu item)

Nested sub-menus

Menu items can be nested to any depth by adding a menu key to a menu item:

menu:
- text: View
  menu:
  - text: Layers
    menu:
    - text: Show grid
      checkable: true
      method: toggle_grid
    - text: Show boundaries
      checkable: true
      method: toggle_boundaries

Per-menu callback modules

The callback module can be set globally in the window block, or overridden for individual top-level menus:

menu:
- text: File
  module: file_menu_callbacks
  menu:
  - text: Open
    method: open_file
- text: Edit
  module: edit_menu_callbacks
  menu:
  - text: Undo
    method: undo

Menu callbacks

Menu callbacks follow the same convention as element callbacks (see Callbacks):

# file_menu_callbacks.py
from app import app

def open_file(*args):
    path = app.gui.getvar("myapp", "last_directory")
    # ... open file dialog ...

Checkable menu items

A checkable menu item stores its checked state automatically. The callback receives True or False as its first argument:

def toggle_grid(checked, widget):
    app.gui.setvar("myapp", "show_grid", checked)
    # ... update map layer visibility ...