# Keyboard Navigation

Most platforms allow you to use the Tab key to move from one text field to another within a window. Some (e.g. Gtk, Windows) also allow you to tab into non-text controls such as buttons and check boxes. Some (e.g. MacOSX) do not do this by default, but provide a user preference setting for enabling it.
By default, PyGUI follows the platform conventions concerning the behaviour of the Tab key, but allows the user to change it.
On Gtk and Windows, setting the PYGUI_KEYBOARD_NAVIGATION environment variable to a true value ("True" or "1") enables tabbing into all controls, and setting it to a false value ("False" or "0") disables this.
On MacOSX, this environment variable is not used, and the System Preferences settings under Keyboard Shortcuts for tab key behaviour are always followed.