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.

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