fltk_scroll_group.rs

use fltk::*;

fn main() {
    let app = app::App::default();
    let mut win = window::Window::new(100, 100, 400, 300, "");
    let mut scroll = group::Group::default().size_of(&win);
    let mut pack = group::Pack::default()
        .with_size(200, 100)
        .center_of(&scroll);
    let mut frame = frame::Frame::default().with_size(0, 160);
    let mut but = button::Button::default()
        .with_size(0, 40)
        .with_label("Click");
    pack.end();
    scroll.end();
    win.end();
    win.show();
    but.set_callback(move || frame.set_label("Clicked!"));
    scroll.handle2({let mut win = win.clone(); move |s, ev| match ev {
        Event::MouseWheel => {
            let dy = app::event_dy();
            if dy > 0 {
                pack.set_pos(pack.x(), pack.y() - 10);
                s.set_damage_type(Damage::Scroll);
                win.set_damage_type(Damage::Scroll);
            } else {
                pack.set_pos(pack.x(), pack.y() + 10);
                s.set_damage_type(Damage::Scroll);
                win.set_damage_type(Damage::Scroll);
            }
            true
        }
        _ => false,
    }});
    win.handle2(|w, _| {
        let mut damage = w.damage_type();
        damage &= Damage::Scroll;
        if damage == Damage::Scroll {
            println!("Window received a Scroll damage and was redrawn");
        }
        true
    });
    app.run().unwrap();
}