Module widgetry::app_state

A widgetry application splits its state into two pieces: global shared state that lasts for the entire lifetime of the application, and a stack of smaller states, only one of which is active at a time. For example, imagine an application to view a map. The shared state would include the map and pre-rendered geometry for it. The individual states might start with a splash screen or menu to choose a map, then a map viewer, then maybe a state to drill down into pieces of the map.

Structs

App
SimpleStateWrapper

Enums

DrawBaselayer	Before State::draw is called, draw something else.
Transition	When a state responds to an event, it can specify some way to manipulate the stack of states.

Traits

SharedAppState	Any data that should last the entire lifetime of the application should be stored in the struct implementing this trait.
SimpleState	Many states fit a pattern of managing a single panel, handling mouseover events, and other interactions on the map. Implementing this instead of State reduces some boilerplate.
State	A temporary state of an application. There's a stack of these, with the most recent being the active one.