bevy_app/
terminal_ctrl_c_handler.rs

1use core::sync::atomic::{AtomicBool, Ordering};
2
3use bevy_ecs::event::EventWriter;
4
5use crate::{App, AppExit, Plugin, Update};
6
7pub use ctrlc;
8
9/// Indicates that all [`App`]'s should exit.
10static SHOULD_EXIT: AtomicBool = AtomicBool::new(false);
11
12/// Gracefully handles `Ctrl+C` by emitting a [`AppExit`] event. This plugin is part of the `DefaultPlugins`.
13///
14/// ```no_run
15/// # use bevy_app::{App, NoopPluginGroup as MinimalPlugins, PluginGroup, TerminalCtrlCHandlerPlugin};
16/// fn main() {
17///     App::new()
18///         .add_plugins(MinimalPlugins)
19///         .add_plugins(TerminalCtrlCHandlerPlugin)
20///         .run();
21/// }
22/// ```
23///
24/// If you want to setup your own `Ctrl+C` handler, you should call the
25/// [`TerminalCtrlCHandlerPlugin::gracefully_exit`] function in your handler if you want bevy to gracefully exit.
26/// ```no_run
27/// # use bevy_app::{App, NoopPluginGroup as DefaultPlugins, PluginGroup, TerminalCtrlCHandlerPlugin, ctrlc};
28/// fn main() {
29///     // Your own `Ctrl+C` handler
30///     ctrlc::set_handler(move || {
31///         // Other clean up code ...
32///
33///         TerminalCtrlCHandlerPlugin::gracefully_exit();
34///     });
35///
36///     App::new()
37///         .add_plugins(DefaultPlugins)
38///         .run();
39/// }
40/// ```
41#[derive(Default)]
42pub struct TerminalCtrlCHandlerPlugin;
43
44impl TerminalCtrlCHandlerPlugin {
45    /// Sends the [`AppExit`] event to all apps using this plugin to make them gracefully exit.
46    pub fn gracefully_exit() {
47        SHOULD_EXIT.store(true, Ordering::Relaxed);
48    }
49
50    /// Sends a [`AppExit`] event when the user presses `Ctrl+C` on the terminal.
51    pub fn exit_on_flag(mut events: EventWriter<AppExit>) {
52        if SHOULD_EXIT.load(Ordering::Relaxed) {
53            events.send(AppExit::from_code(130));
54        }
55    }
56}
57
58impl Plugin for TerminalCtrlCHandlerPlugin {
59    fn build(&self, app: &mut App) {
60        let result = ctrlc::try_set_handler(move || {
61            Self::gracefully_exit();
62        });
63        match result {
64            Ok(()) => {}
65            Err(ctrlc::Error::MultipleHandlers) => {
66                bevy_utils::tracing::info!("Skipping installing `Ctrl+C` handler as one was already installed. Please call `TerminalCtrlCHandlerPlugin::gracefully_exit` in your own `Ctrl+C` handler if you want Bevy to gracefully exit on `Ctrl+C`.");
67            }
68            Err(err) => bevy_utils::tracing::warn!("Failed to set `Ctrl+C` handler: {err}"),
69        }
70
71        app.add_systems(Update, TerminalCtrlCHandlerPlugin::exit_on_flag);
72    }
73}
bevy_app/terminal_ctrl_c_handler.rs

bevy_app/
terminal_ctrl_c_handler.rs
