Trait Program 

pub trait Program: Sized {
    type Message: Send + 'static;

    // Required method
    fn view(&self) -> String;

    // Provided methods
    fn init(
        &mut self,
        _mailbox: Mailbox<Self::Message>,
    ) -> Command<Self::Message> { ... }
    fn exit(self) { ... }
    fn on_event(_ev: TermEvent) -> Command<Self::Message> { ... }
    fn update(&mut self, _message: Self::Message) -> Command<Self::Message> { ... }
    fn run(self, config: &mut Config) -> Result<()> { ... }
}

A program describes a terminal application capable of generating and responding to messages, as well as rendering its UI to a string.

A douglas program consists of 3 main ingredients:

1. init initialize your state model
2. update update your state model in response to messages
3. view render your program’s UI

At minimum, you must implement view.

Required Associated Types

type Message: Send + 'static

Required Methods

fn view(&self) -> String

Render your program’s UI.

Provided Methods

fn init(&mut self, _mailbox: Mailbox<Self::Message>) -> Command<Self::Message>

Initialize your program’s state.

fn exit(self)

Perform any cleanup before your application exits.

fn on_event(_ev: TermEvent) -> Command<Self::Message>

Respond to any terminal events (mouse, keyboard) by generating messages.

fn update(&mut self, _message: Self::Message) -> Command<Self::Message>

Update your program’s state in response to messages.

fn run(self, config: &mut Config) -> Result<()>

Run your application.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors