Drawable Example

drawable.rs

use crate::draw::Draw;
use std::cell::Cell;
use std::cell::RefCell;
use std::rc::Rc;

pub trait Drawable {
    fn add_line(&mut self) -> &mut dyn Drawable;
    fn shift(&mut self, x: f32, y: f32) -> &mut dyn Drawable;
}
#[derive(Debug, Clone, Copy)]
pub struct Point {
    x: f32,
    y: f32,
}
impl Point {
    pub fn new() -> Self {
        Point { x: 0., y: 0. }
    }
}
#[derive(Debug)]
pub struct Line {
    points: Vec<Point>,
}
impl Line {
    pub fn new() -> Self {
        let points = Vec::new();
        Line { points }
    }
    pub fn add(&mut self, point: Point) {
        // self.points.borrow_mut().push(point);
        self.points.push(point);
    }
}

#[derive(Debug)]
pub struct Rect {
    lines: Vec<Line>,
}
impl Rect {
    pub fn new() -> Self {
        let lines = Vec::new();
        Rect { lines }
    }
    pub fn add(&mut self, line: Line) {
        self.lines.push(line);
    }
}

impl Drawable for Rect {
    fn add_line(&mut self) -> &mut dyn Drawable {
        println!("Drawing Rect!");
        self.lines.push(Line {
            points: vec![Point { x: 50., y: 50. }, Point { x: 70., y: 70. }],
        });
        self
    }
    fn shift(&mut self, x: f32, y: f32) -> &mut dyn Drawable {
        println!("Shifting Rect!");
        for line in &mut self.lines {
            for pt in &mut line.points {
                pt.x += x;
                pt.y += y;
            }
        }
        self
    }
}

fn main() {
    let point = Point { x: 3., y: 2. };
    let mut line = Line::new();
    let mut rect = Rect::new();
    line.add(point);
    line.add(Point { x: 10., y: 15. });
    println!("point = {:?}", point);
    println!("line = {:?}", line);
    rect.add(line);

    rect.add_line().shift(100., 100.);
    println!("rect = {:?}", rect);

    let a = Rc::new(RefCell::new(vec![1, 2, 3]));
    let b = Rc::clone(&a);
    let c = Rc::clone(&a);
    a.borrow_mut().push(4);
    // *a.borrow_mut() += 10; //This doesn't work
    println!("a = {:?}", a);
    println!("b = {:?}", b);
    println!("c = {:?}", c);
}