winit-sonoma-fix/examples/control_flow.rs
Philippe Renon 505f312d5f
Add new example that demonstrates the different control flow schemes (#1460)
User can switch between Wait, WaitUntil and Poll modes with key '1', '2' and '3' respectivly.
User can toggle request_redraw calls with the 'R' key.

Helpful for testing all control flow modes and use of request_redraw.
2020-02-13 15:20:32 -07:00

114 lines
3.9 KiB
Rust

use std::{thread, time};
use winit::{
event::{Event, KeyboardInput, WindowEvent},
event_loop::{ControlFlow, EventLoop},
window::WindowBuilder,
};
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum Mode {
Wait,
WaitUntil,
Poll,
}
const WAIT_TIME: time::Duration = time::Duration::from_millis(100);
const POLL_SLEEP_TIME: time::Duration = time::Duration::from_millis(100);
fn main() {
simple_logger::init().unwrap();
println!("Press '1' to switch to Wait mode.");
println!("Press '2' to switch to WaitUntil mode.");
println!("Press '3' to switch to Poll mode.");
println!("Press 'R' to toggle request_redraw() calls.");
println!("Press 'Esc' to close the window.");
let event_loop = EventLoop::new();
let window = WindowBuilder::new()
.with_title("Press 1, 2, 3 to change control flow mode. Press R to toggle redraw requests.")
.build(&event_loop)
.unwrap();
let mut mode = Mode::Wait;
let mut request_redraw = false;
let mut wait_cancelled = false;
let mut close_requested = false;
event_loop.run(move |event, _, control_flow| {
use winit::event::{ElementState, StartCause, VirtualKeyCode};
println!("{:?}", event);
match event {
Event::NewEvents(start_cause) => {
wait_cancelled = mode == Mode::WaitUntil;
match start_cause {
StartCause::ResumeTimeReached {
start: _,
requested_resume: _,
} => {
wait_cancelled = false;
}
_ => (),
}
}
Event::WindowEvent { event, .. } => match event {
WindowEvent::CloseRequested => {
close_requested = true;
}
WindowEvent::KeyboardInput {
input:
KeyboardInput {
virtual_keycode: Some(virtual_code),
state: ElementState::Pressed,
..
},
..
} => match virtual_code {
VirtualKeyCode::Key1 => {
mode = Mode::Wait;
println!("\nmode: {:?}\n", mode);
}
VirtualKeyCode::Key2 => {
mode = Mode::WaitUntil;
println!("\nmode: {:?}\n", mode);
}
VirtualKeyCode::Key3 => {
mode = Mode::Poll;
println!("\nmode: {:?}\n", mode);
}
VirtualKeyCode::R => {
request_redraw = !request_redraw;
println!("\nrequest_redraw: {}\n", request_redraw);
}
VirtualKeyCode::Escape => {
close_requested = true;
}
_ => (),
},
_ => (),
},
Event::MainEventsCleared => {
if request_redraw && !wait_cancelled && !close_requested {
window.request_redraw();
}
if close_requested {
*control_flow = ControlFlow::Exit;
}
}
Event::RedrawRequested(_window_id) => {}
Event::RedrawEventsCleared => {
*control_flow = match mode {
Mode::Wait => ControlFlow::Wait,
Mode::WaitUntil => ControlFlow::WaitUntil(time::Instant::now() + WAIT_TIME),
Mode::Poll => {
thread::sleep(POLL_SLEEP_TIME);
ControlFlow::Poll
}
};
}
_ => (),
}
});
}