class command_screen.CommandScreen(albow.screen.Screen)
CommandScreen
is an abstract base class for screens that respond to keyboard commands. It allows declaratively
describing a set of commands, with menu titles, keyboard equivalents
and associated actions. A menu of buttons may optionally be added to the screen to invoke the commands.
Each menu item is specified by a descriptor
(title, action_name, keys)
The title is a string to use as a button label.
The action_name is a string used to derive the names of two methods of the Shell object:
action_name + '_enable'
Method
returning a boolean indicating whether the command should be enabled.
If the method does not exist, the command is always enabled.
action_name + '_cmd'
Method to call when the command is invoked.
The keys
is a sequence of PyGame key codes specifying alternative keyboard
equivalents for the command. For non-function keys, the Control or
Command modifier is implicitly required along with the key. For function keys (K_F1 to K_F12) or the Escape key, no modifiers are required.
Class Attributes
title
String to use as a screen title, if a menu is being created.
title_class = MenuTitle
Widget class to use for the screen title, if a menu is being created. Should be a subclass of Label or something with a compatible constructor.
button_class = MenuButton
Widget class to use for the menu buttons, if a menu is being created. Should be a subclass of Button or something with a compatible constructor.
with_menu = False
Whether to create a title and menu.
menu_items
A sequence of menu item descriptors as defined above.
Constructor
CommandScreen(shell, with_menu = False)
Associates the screen with the given shell. If with_menu is true, a title and menu will be created and displayed.
Methods
create_button(title, action_name)
Creates a button with the given title that invokes the specified action. The button_class is used as the class of the button.
do_command(action_name)
If the command specified by action_name is enabled, calls the corresponding action method of the Shell.
You can customize the appearance of the title and menu at various levels by overriding the following methods.
create_title()
Creates and return a widget to use for the title of the menu. The default implementation calls the title_class passing it the title.
create_buttons()
Creates
and returns a widget implementing a menu for the screen. The default
implementation returns a column of buttons created by calling the button_class.
include_command(action_name)
Returns true if a button for the indicated action should be included in the menu.
add_title_and_buttons(title, buttons)
Given a title widget and a list of button widgets, adds them to the screen, appropriately arranged.
add_title_and_menu(title, menu)
Given a title widget and a menu widget, adds them to the screen, appropriately arranged.
Themable Classes
You can customize the default appearance of a CommandScreen menu by providing Albow themes
for the following classes defined in the main_commands module.