bevy/crates/bevy_window/src/system.rs
Daniel McNab b731ebad1b Allow closing windows at runtime (#3575)
# Objective

Fixes #3180, builds from https://github.com/bevyengine/bevy/pull/2898

## Solution

Support requesting a window to be closed and closing a window in `bevy_window`, and handle this in `bevy_winit`.

This is a stopgap until we move to windows as entites, which I'm sure I'll get around to eventually.

## Changelog

### Added

- `Window::close` to allow closing windows.
- `WindowClosed` to allow reacting to windows being closed.

### Changed

Replaced `bevy::system::exit_on_esc_system` with `bevy:🪟:close_on_esc`.

## Fixed

The app no longer exits when any window is closed. This difference is only observable when there are multiple windows. 

## Migration Guide

`bevy::input::system::exit_on_esc_system` has been removed. Use `bevy:🪟:close_on_esc` instead.
`CloseWindow` has been removed. Use `Window::close` instead.
The `Close` variant has been added to `WindowCommand`. Handle this by closing the relevant window.
2022-05-05 13:35:43 +00:00

57 lines
2 KiB
Rust

use crate::{Window, WindowCloseRequested, WindowFocused, WindowId, Windows};
use bevy_app::AppExit;
use bevy_ecs::prelude::*;
use bevy_input::{keyboard::KeyCode, Input};
/// Exit the application when there are no open windows.
///
/// This system is added by the [`WindowPlugin`] in the default configuration.
/// To disable this behaviour, set `close_when_requested` (on the [`WindowPlugin`]) to `false`.
/// Ensure that you read the caveats documented on that field if doing so.
///
/// [`WindowPlugin`]: crate::WindowPlugin
pub fn exit_on_all_closed(mut app_exit_events: EventWriter<AppExit>, windows: Res<Windows>) {
if windows.iter().count() == 0 {
app_exit_events.send(AppExit);
}
}
/// Close windows in response to [`WindowCloseRequested`] (e.g. when the close button is pressed).
///
/// This system is added by the [`WindowPlugin`] in the default configuration.
/// To disable this behaviour, set `close_when_requested` (on the [`WindowPlugin`]) to `false`.
/// Ensure that you read the caveats documented on that field if doing so.
///
/// [`WindowPlugin`]: crate::WindowPlugin
pub fn close_when_requested(
mut windows: ResMut<Windows>,
mut closed: EventReader<WindowCloseRequested>,
) {
for event in closed.iter() {
windows.get_mut(event.id).map(Window::close);
}
}
/// Close the focused window whenever the escape key (<kbd>Esc</kbd>) is pressed
///
/// This is useful for examples or prototyping.
pub fn close_on_esc(
mut focused: Local<Option<WindowId>>,
mut focused_events: EventReader<WindowFocused>,
mut windows: ResMut<Windows>,
input: Res<Input<KeyCode>>,
) {
// TODO: Track this in e.g. a resource to ensure consistent behaviour across similar systems
for event in focused_events.iter() {
*focused = event.focused.then(|| event.id);
}
if let Some(focused) = &*focused {
if input.just_pressed(KeyCode::Escape) {
if let Some(window) = windows.get_mut(*focused) {
window.close();
}
}
}
}