run_on_demand/
run_on_demand.rs

1#![allow(clippy::single_match)]
2
3// Limit this example to only compatible platforms.
4#[cfg(any(windows_platform, macos_platform, x11_platform, wayland_platform,))]
5fn main() -> Result<(), Box<dyn std::error::Error>> {
6    use std::time::Duration;
7
8    use winit::application::ApplicationHandler;
9    use winit::event::WindowEvent;
10    use winit::event_loop::{ActiveEventLoop, EventLoop};
11    use winit::platform::run_on_demand::EventLoopExtRunOnDemand;
12    use winit::window::{Window, WindowId};
13
14    #[path = "util/fill.rs"]
15    mod fill;
16
17    #[derive(Default)]
18    struct App {
19        idx: usize,
20        window_id: Option<WindowId>,
21        window: Option<Window>,
22    }
23
24    impl ApplicationHandler for App {
25        fn about_to_wait(&mut self, _event_loop: &ActiveEventLoop) {
26            if let Some(window) = self.window.as_ref() {
27                window.request_redraw();
28            }
29        }
30
31        fn resumed(&mut self, event_loop: &ActiveEventLoop) {
32            let window_attributes = Window::default_attributes()
33                .with_title("Fantastic window number one!")
34                .with_inner_size(winit::dpi::LogicalSize::new(128.0, 128.0));
35            let window = event_loop.create_window(window_attributes).unwrap();
36            self.window_id = Some(window.id());
37            self.window = Some(window);
38        }
39
40        fn window_event(
41            &mut self,
42            event_loop: &ActiveEventLoop,
43            window_id: WindowId,
44            event: WindowEvent,
45        ) {
46            if event == WindowEvent::Destroyed && self.window_id == Some(window_id) {
47                println!(
48                    "--------------------------------------------------------- Window {} Destroyed",
49                    self.idx
50                );
51                self.window_id = None;
52                event_loop.exit();
53                return;
54            }
55
56            let window = match self.window.as_mut() {
57                Some(window) => window,
58                None => return,
59            };
60
61            match event {
62                WindowEvent::CloseRequested => {
63                    println!(
64                        "--------------------------------------------------------- Window {} \
65                         CloseRequested",
66                        self.idx
67                    );
68                    fill::cleanup_window(window);
69                    self.window = None;
70                },
71                WindowEvent::RedrawRequested => {
72                    fill::fill_window(window);
73                },
74                _ => (),
75            }
76        }
77    }
78
79    tracing_subscriber::fmt::init();
80
81    let mut event_loop = EventLoop::new().unwrap();
82
83    let mut app = App { idx: 1, ..Default::default() };
84    event_loop.run_app_on_demand(&mut app)?;
85
86    println!("--------------------------------------------------------- Finished first loop");
87    println!("--------------------------------------------------------- Waiting 5 seconds");
88    std::thread::sleep(Duration::from_secs(5));
89
90    app.idx += 1;
91    event_loop.run_app_on_demand(&mut app)?;
92    println!("--------------------------------------------------------- Finished second loop");
93    Ok(())
94}
95
96#[cfg(not(any(windows_platform, macos_platform, x11_platform, wayland_platform,)))]
97fn main() {
98    println!("This example is not supported on this platform");
99}
run_on_demand/run_on_demand.rs

run_on_demand/
run_on_demand.rs
