Trait Program

pub trait Program<Message> {
    type State: Default + 'static;
    type Primitive: Primitive + 'static;

    // Required method
    fn draw(
        &self,
        state: &Self::State,
        cursor: Cursor,
        bounds: Rectangle,
    ) -> Self::Primitive;

    // Provided methods
    fn update(
        &self,
        _state: &mut Self::State,
        _event: &Event,
        _bounds: Rectangle,
        _cursor: Cursor,
    ) -> Option<Action<Message>> { ... }
    fn mouse_interaction(
        &self,
        _state: &Self::State,
        _bounds: Rectangle,
        _cursor: Cursor,
    ) -> Interaction { ... }
}

The state and logic of a Shader widget.

A Program can mutate the internal state of a Shader widget and produce messages for an application.

Required Associated Types

type State: Default + 'static

The internal state of the Program.

type Primitive: Primitive + 'static

The type of primitive this Program can draw.

Required Methods

fn draw( &self, state: &Self::State, cursor: Cursor, bounds: Rectangle, ) -> Self::Primitive

Draws the Primitive.

Provided Methods

fn update( &self, _state: &mut Self::State, _event: &Event, _bounds: Rectangle, _cursor: Cursor, ) -> Option<Action<Message>>

Update the internal State of the Program. This can be used to reflect state changes based on mouse & other events. You can return an Action to publish a message, request a redraw, or capture the event.

By default, this method returns None.

fn mouse_interaction( &self, _state: &Self::State, _bounds: Rectangle, _cursor: Cursor, ) -> Interaction

Returns the current mouse interaction of the Program.

The interaction returned will be in effect even if the cursor position is out of bounds of the Shader’s program.

Implementations on Foreign Types

impl<Message, T> Program<Message> for &T

where T: Program<Message>,

type State = <T as Program<Message>>::State

type Primitive = <T as Program<Message>>::Primitive

fn update( &self, state: &mut <&T as Program<Message>>::State, event: &Event, bounds: Rectangle, cursor: Cursor, ) -> Option<Action<Message>>

fn draw( &self, state: &<&T as Program<Message>>::State, cursor: Cursor, bounds: Rectangle, ) -> <&T as Program<Message>>::Primitive

fn mouse_interaction( &self, state: &<&T as Program<Message>>::State, bounds: Rectangle, cursor: Cursor, ) -> Interaction

Implementors