//! Scrolling moves content and stops at its ends.

use iris::harness::{Harness, assert_corners};
use iris::prelude::*;

#[test]
fn a_wheel_scrolls_the_content_and_stops_at_its_end() {
    let mut h = Harness::new((400, 200));
    // Twice the window's height, so there is 200 to scroll.
    let top = rect(Color::RED).height(200).add(&mut h.rsc);
    let bottom = rect(Color::BLUE).height(200).add(&mut h.rsc);
    h.set_root((top, bottom).span(Dir::DOWN).scrollable());
    h.move_to((200, 100));

    // `Scroll` starts snapped to the end.
    assert_corners!(h, top, (0, -200), (400, 0));

    // The handler scales a wheel line by 50.
    h.scroll((0, 1));
    h.frame();
    assert_corners!(h, top, (0, -150), (400, 50));

    h.scroll((0, 10));
    h.frame();
    assert_corners!(h, top, (0, 0), (400, 200));
}