azul_winit/platform/
run_return.rs

1#![cfg(any(
2    target_os = "windows",
3    target_os = "macos",
4    target_os = "android",
5    target_os = "linux",
6    target_os = "dragonfly",
7    target_os = "freebsd",
8    target_os = "netbsd",
9    target_os = "openbsd"
10))]
11
12use crate::{
13    event::Event,
14    event_loop::{ControlFlow, EventLoop, EventLoopWindowTarget},
15};
16
17/// Additional methods on `EventLoop` to return control flow to the caller.
18pub trait EventLoopExtRunReturn {
19    /// A type provided by the user that can be passed through `Event::UserEvent`.
20    type UserEvent;
21
22    /// Initializes the `winit` event loop.
23    ///
24    /// Unlike `run`, this function accepts non-`'static` (i.e. non-`move`) closures and returns
25    /// control flow to the caller when `control_flow` is set to `ControlFlow::Exit`.
26    ///
27    /// # Caveats
28    /// Despite its appearance at first glance, this is *not* a perfect replacement for
29    /// `poll_events`. For example, this function will not return on Windows or macOS while a
30    /// window is getting resized, resulting in all application logic outside of the
31    /// `event_handler` closure not running until the resize operation ends. Other OS operations
32    /// may also result in such freezes. This behavior is caused by fundamental limitations in the
33    /// underlying OS APIs, which cannot be hidden by `winit` without severe stability repercussions.
34    ///
35    /// You are strongly encouraged to use `run`, unless the use of this is absolutely necessary.
36    fn run_return<F>(&mut self, event_handler: F)
37    where
38        F: FnMut(
39            Event<'_, Self::UserEvent>,
40            &EventLoopWindowTarget<Self::UserEvent>,
41            &mut ControlFlow,
42        );
43}
44
45impl<T> EventLoopExtRunReturn for EventLoop<T> {
46    type UserEvent = T;
47
48    fn run_return<F>(&mut self, event_handler: F)
49    where
50        F: FnMut(
51            Event<'_, Self::UserEvent>,
52            &EventLoopWindowTarget<Self::UserEvent>,
53            &mut ControlFlow,
54        ),
55    {
56        self.event_loop.run_return(event_handler)
57    }
58}
azul_winit/platform/run_return.rs

azul_winit/platform/
run_return.rs
