window_fallthrough/
window_fallthrough.rs

1//! This example illustrates how have a mouse's clicks/wheel/movement etc fall through the spawned transparent window to a window below.
2//! If you build this, and hit 'P' it should toggle on/off the mouse's passthrough.
3//! Note: this example will not work on following platforms: iOS / Android / Web / X11. Window fall through is not supported there.
4
5use bevy::{prelude::*, window::CursorOptions};
6
7fn main() {
8    App::new()
9        .insert_resource(ClearColor(Color::NONE)) // Use a transparent window, to make effects obvious.
10        .add_plugins(DefaultPlugins.set(WindowPlugin {
11            primary_window: Some(Window {
12                // Set the window's parameters, note we're setting the window to always be on top.
13                transparent: true,
14                decorations: true,
15                window_level: bevy::window::WindowLevel::AlwaysOnTop,
16                ..default()
17            }),
18            ..default()
19        }))
20        .add_systems(Startup, setup)
21        .add_systems(Update, toggle_mouse_passthrough) // This allows us to hit 'P' to toggle on/off the mouse's passthrough
22        .run();
23}
24
25fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
26    // UI camera
27    commands.spawn(Camera2d);
28    // Text with one span
29    commands.spawn((
30        // Accepts a `String` or any type that converts into a `String`, such as `&str`
31        Text::new("Hit 'P' then scroll/click around!"),
32        TextFont {
33            font: asset_server.load("fonts/FiraSans-Bold.ttf"),
34            font_size: 83.0, // Nice and big so you can see it!
35            ..default()
36        },
37        // Set the style of the TextBundle itself.
38        Node {
39            position_type: PositionType::Absolute,
40            bottom: px(5),
41            right: px(10),
42            ..default()
43        },
44    ));
45}
46// A simple system to handle some keyboard input and toggle on/off the hit test.
47fn toggle_mouse_passthrough(
48    keyboard_input: Res<ButtonInput<KeyCode>>,
49    mut cursor_options: Single<&mut CursorOptions>,
50) {
51    if keyboard_input.just_pressed(KeyCode::KeyP) {
52        cursor_options.hit_test = !cursor_options.hit_test;
53    }
54}
window_fallthrough/window_fallthrough.rs

window_fallthrough/
window_fallthrough.rs
