AppContext

The AppContext gives access to application wide services.

There are some builtins:

• add_timer(): Define a timer that will send TimeOut events.

• spawn(): Spawn long running tasks in the thread-pool. You can work with some shared memory model to get the results, but the preferred method is to return a Control::Message from the thread.

• spawn_async(): Spawn async tasks in the tokio runtime. The result of the async task can be returned as a Control::Message too.

• spawn_async_ext(): Gives you an extra channel to return multiple results from the async task.

• queue(): Add results to the event-handling queue if a single return value from event-handling is not enough.

• focus(): An instance of Focus can be stored here. Setting up the focus is the job of the application.

• count: Gives you the frame-counter of the last render.

All application wide stuff goes into g which is an instance of your Global state.

RenderContext

Rendercontext is limited compared to AppContext.

It gives you g as your Global state.

And it lets you set the screen-cursor position.