Trait Objects

trait_objects.rs

trait Draw {
    fn draw(&self);
}
struct Screen {
    components: Vec<Box<dyn Draw>>,
}
impl Screen {
    fn run(&self) {
        for component in self.components.iter() {
            component.draw();
        }
    }
}

struct Screen2<T: Draw> {
    components: Vec<T>,
}
impl<T> Screen2<T>
where
    T: Draw,
{
    fn run(&self) {
        for component in self.components.iter() {
            component.draw();
        }
    }
}

struct Button {
    width: u32,
    height: u32,
    label: String,
}
impl Draw for Button {
    fn draw(&self) {
        println!("Draw for Button called!");
    }
}

struct SelectBox {
    width: u32,
    height: u32,
    options: Vec<String>,
}
impl Draw for SelectBox {
    fn draw(&self) {
        println!("Draw for SelectBox called!");
    }
}

fn main() {
    let button = Box::new(Button {
        width: 10,
        height: 5,
        label: String::from("Button"),
    });
    let select = Box::new(SelectBox {
        width: 10,
        height: 5,
        options: vec![String::from("SelectBox")],
    });
    // let components = Vec
    let screen = Screen {
        components: vec![button, select],
    };
    screen.run();
}