relative_cursor_position/
relative_cursor_position.rs

1//! Showcases the [`RelativeCursorPosition`] component, used to check the position of the cursor relative to a UI node.
2
3use bevy::{camera::Viewport, prelude::*, ui::RelativeCursorPosition};
4
5fn main() {
6    App::new()
7        .add_plugins(DefaultPlugins)
8        .add_systems(Startup, setup)
9        .add_systems(Update, relative_cursor_position_system)
10        .run();
11}
12
13fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
14    commands.spawn((
15        Camera2d,
16        Camera {
17            // Cursor position will take the viewport offset into account
18            viewport: Some(Viewport {
19                physical_position: [200, 100].into(),
20                physical_size: [600, 600].into(),
21                ..default()
22            }),
23            ..default()
24        },
25    ));
26
27    commands
28        .spawn(Node {
29            width: percent(100),
30            height: percent(100),
31            align_items: AlignItems::Center,
32            justify_content: JustifyContent::Center,
33            flex_direction: FlexDirection::Column,
34            ..default()
35        })
36        .with_children(|parent| {
37            parent
38                .spawn((
39                    Node {
40                        width: px(250),
41                        height: px(250),
42                        margin: UiRect::bottom(px(15)),
43                        ..default()
44                    },
45                    BackgroundColor(Color::srgb(0.92, 0.14, 0.05)),
46                ))
47                .insert(RelativeCursorPosition::default());
48
49            parent.spawn((
50                Text::new("(0.0, 0.0)"),
51                TextFont {
52                    font: asset_server.load("fonts/FiraSans-Bold.ttf"),
53                    font_size: 33.0,
54                    ..default()
55                },
56                TextColor(Color::srgb(0.9, 0.9, 0.9)),
57            ));
58        });
59}
60
61/// This systems polls the relative cursor position and displays its value in a text component.
62fn relative_cursor_position_system(
63    relative_cursor_position: Single<&RelativeCursorPosition>,
64    output_query: Single<(&mut Text, &mut TextColor)>,
65) {
66    let (mut output, mut text_color) = output_query.into_inner();
67
68    **output = if let Some(relative_cursor_position) = relative_cursor_position.normalized {
69        format!(
70            "({:.1}, {:.1})",
71            relative_cursor_position.x, relative_cursor_position.y
72        )
73    } else {
74        "unknown".to_string()
75    };
76
77    text_color.0 = if relative_cursor_position.cursor_over() {
78        Color::srgb(0.1, 0.9, 0.1)
79    } else {
80        Color::srgb(0.9, 0.1, 0.1)
81    };
82}
relative_cursor_position/relative_cursor_position.rs

relative_cursor_position/
relative_cursor_position.rs
