winit-sonoma-fix/examples/web.rs
Robert Bragg ae7497e18f
Remove RedrawEventsCleared + MainEventsCleared, and added AboutToWait
The idea that redraw events are dispatched with a specific ordering
that makes it possible to specifically report when we have finished
dispatching redraw events isn't portable and the way in which we
dispatched RedrawEventsCleared was inconsistent across backends.

More generally speaking, there is no inherent relationship between
redrawing and event loop iterations. An event loop may wake up at any
frequency depending on what sources of input events are being listened
to but redrawing is generally throttled and in some way synchronized
with the display frequency.

Similarly there's no inherent relationship between a single event loop
iteration and the dispatching of any specific kind of "main" event.

An event loop wakes up when there are events to read (e.g. input
events or responses from a display server / compositor) and goes back
to waiting when there's nothing else to read.

There isn't really a special kind of "main" event that is dispatched
in order with respect to other events.

What we can do more portably is emit an event when the event loop
is about to block and wait for new events.

In practice this is very similar to how MainEventsCleared was
implemented except it wasn't the very last event previously since
redraw events could be dispatched afterwards.

The main backend where we don't strictly know when we're going to
wait for events is Web (since the real event loop is internal to
the browser). For now we emulate AboutToWait on Web similar to how
MainEventsCleared was dispatched.

In practice most applications almost certainly shouldn't care about
AboutToWait because the frequency of event loop iterations is
essentially arbitrary and usually irrelevant.
2023-07-28 20:37:56 +04:00

143 lines
4.7 KiB
Rust

#![allow(clippy::disallowed_methods, clippy::single_match)]
use winit::{
event::{ElementState, Event, KeyEvent, WindowEvent},
event_loop::EventLoop,
keyboard::KeyCode,
window::{Fullscreen, WindowBuilder},
};
pub fn main() -> Result<(), impl std::error::Error> {
let event_loop = EventLoop::new();
let builder = WindowBuilder::new().with_title("A fantastic window!");
#[cfg(wasm_platform)]
let builder = {
use winit::platform::web::WindowBuilderExtWebSys;
builder.with_append(true)
};
let window = builder.build(&event_loop).unwrap();
#[cfg(wasm_platform)]
let log_list = wasm::insert_canvas_and_create_log_list(&window);
event_loop.run(move |event, _, control_flow| {
control_flow.set_wait();
#[cfg(wasm_platform)]
wasm::log_event(&log_list, &event);
match event {
Event::WindowEvent {
event: WindowEvent::CloseRequested,
window_id,
} if window_id == window.id() => control_flow.set_exit(),
Event::AboutToWait => {
window.request_redraw();
}
Event::WindowEvent {
window_id,
event:
WindowEvent::KeyboardInput {
event:
KeyEvent {
physical_key: KeyCode::KeyF,
state: ElementState::Released,
..
},
..
},
} if window_id == window.id() => {
if window.fullscreen().is_some() {
window.set_fullscreen(None);
} else {
window.set_fullscreen(Some(Fullscreen::Borderless(None)));
}
}
_ => (),
}
})
}
#[cfg(wasm_platform)]
mod wasm {
use std::num::NonZeroU32;
use softbuffer::{Surface, SurfaceExtWeb};
use wasm_bindgen::prelude::*;
use winit::{event::Event, window::Window};
#[wasm_bindgen(start)]
pub fn run() {
console_log::init_with_level(log::Level::Debug).expect("error initializing logger");
#[allow(clippy::main_recursion)]
let _ = super::main();
}
pub fn insert_canvas_and_create_log_list(window: &Window) -> web_sys::Element {
use winit::platform::web::WindowExtWebSys;
let canvas = window.canvas().unwrap();
let mut surface = Surface::from_canvas(canvas.clone()).unwrap();
surface
.resize(
NonZeroU32::new(canvas.width()).unwrap(),
NonZeroU32::new(canvas.height()).unwrap(),
)
.unwrap();
let mut buffer = surface.buffer_mut().unwrap();
buffer.fill(0xFFF0000);
buffer.present().unwrap();
let window = web_sys::window().unwrap();
let document = window.document().unwrap();
let body = document.body().unwrap();
let style = &canvas.style();
style.set_property("margin", "50px").unwrap();
// Use to test interactions with border and padding.
//style.set_property("border", "50px solid black").unwrap();
//style.set_property("padding", "50px").unwrap();
let log_header = document.create_element("h2").unwrap();
log_header.set_text_content(Some("Event Log"));
body.append_child(&log_header).unwrap();
let log_list = document.create_element("ul").unwrap();
body.append_child(&log_list).unwrap();
log_list
}
pub fn log_event(log_list: &web_sys::Element, event: &Event<()>) {
log::debug!("{:?}", event);
// Getting access to browser logs requires a lot of setup on mobile devices.
// So we implement this basic logging system into the page to give developers an easy alternative.
// As a bonus its also kind of handy on desktop.
let event = match event {
Event::WindowEvent { event, .. } => Some(format!("{event:?}")),
Event::Resumed | Event::Suspended => Some(format!("{event:?}")),
_ => None,
};
if let Some(event) = event {
let window = web_sys::window().unwrap();
let document = window.document().unwrap();
let log = document.create_element("li").unwrap();
let date = js_sys::Date::new_0();
log.set_text_content(Some(&format!(
"{:02}:{:02}:{:02}.{:03}: {event}",
date.get_hours(),
date.get_minutes(),
date.get_seconds(),
date.get_milliseconds(),
)));
log_list
.insert_before(&log, log_list.first_child().as_ref())
.unwrap();
}
}
}