tk::action to simplify access to a gui action

in a typical graphical application, menu entries are often also available in toolbars or other widgets. and sometimes, you want to enable or disable a given action, and this means having to update all those entries and widgets everywhere this action is allowed / forbidden.

this is not fun.

therefore, i wrote tk::action, a module to help managing actions in a tk gui: just create a new object, associate some widgets and bindings with add_widget() / add_binding() and then de/activate the whole action at once with enable() or disable().

simple and efficient, as you can see on this synopsis: