Trait Program

pub trait Program: Sized {
    type State;
    type Message: Send + Debug + 'static;
    type Theme: Default + DefaultStyle;
    type Renderer: Renderer;
    type Executor: Executor;

    // Required methods
    fn update(
        &self,
        state: &mut Self::State,
        message: Self::Message,
    ) -> Task<Self::Message>;
    fn view<'a>(
        &self,
        state: &'a Self::State,
        window: Id,
    ) -> Element<'a, Self::Message, Self::Theme, Self::Renderer>;

    // Provided methods
    fn title(&self, _state: &Self::State, _window: Id) -> String { ... }
    fn subscription(&self, _state: &Self::State) -> Subscription<Self::Message> { ... }
    fn theme(&self, _state: &Self::State, _window: Id) -> Self::Theme { ... }
    fn style(&self, _state: &Self::State, theme: &Self::Theme) -> Appearance { ... }
    fn scale_factor(&self, _state: &Self::State, _window: Id) -> f64 { ... }
    fn run(
        self,
        settings: Settings,
        window_settings: Option<Settings>,
    ) -> Result<(), Error>
       where Self: 'static,
             Self::State: Default { ... }
    fn run_with<I>(
        self,
        settings: Settings,
        window_settings: Option<Settings>,
        initialize: I,
    ) -> Result<(), Error>
       where Self: 'static,
             I: FnOnce() -> (Self::State, Task<Self::Message>) + 'static { ... }
}

The internal definition of a Program.

You should not need to implement this trait directly. Instead, use the methods available in the Program struct.

Required Associated Types

type State

The state of the program.

type Message: Send + Debug + 'static

The message of the program.

type Theme: Default + DefaultStyle

The theme of the program.

type Renderer: Renderer

The renderer of the program.

type Executor: Executor

The executor of the program.

Required Methods

fn update( &self, state: &mut Self::State, message: Self::Message, ) -> Task<Self::Message>

fn view<'a>( &self, state: &'a Self::State, window: Id, ) -> Element<'a, Self::Message, Self::Theme, Self::Renderer>

Provided Methods

fn title(&self, _state: &Self::State, _window: Id) -> String

fn subscription(&self, _state: &Self::State) -> Subscription<Self::Message>

fn theme(&self, _state: &Self::State, _window: Id) -> Self::Theme

fn style(&self, _state: &Self::State, theme: &Self::Theme) -> Appearance

fn scale_factor(&self, _state: &Self::State, _window: Id) -> f64

fn run( self, settings: Settings, window_settings: Option<Settings>, ) -> Result<(), Error>

where Self: 'static, Self::State: Default,

Runs the Program.

The state of the Program must implement Default. If your state does not implement Default, use run_with instead.

fn run_with<I>( self, settings: Settings, window_settings: Option<Settings>, initialize: I, ) -> Result<(), Error>

where Self: 'static, I: FnOnce() -> (Self::State, Task<Self::Message>) + 'static,

Runs the Program with the given settings, and a closure that creates the initial state.

Object Safety

This trait is not object safe.

Implementors