mirror of
https://github.com/bevyengine/bevy
synced 2024-11-21 20:23:28 +00:00
015f2c69ca
# Objective Continue improving the user experience of our UI Node API in the direction specified by [Bevy's Next Generation Scene / UI System](https://github.com/bevyengine/bevy/discussions/14437) ## Solution As specified in the document above, merge `Style` fields into `Node`, and move "computed Node fields" into `ComputedNode` (I chose this name over something like `ComputedNodeLayout` because it currently contains more than just layout info. If we want to break this up / rename these concepts, lets do that in a separate PR). `Style` has been removed. This accomplishes a number of goals: ## Ergonomics wins Specifying both `Node` and `Style` is now no longer required for non-default styles Before: ```rust commands.spawn(( Node::default(), Style { width: Val::Px(100.), ..default() }, )); ``` After: ```rust commands.spawn(Node { width: Val::Px(100.), ..default() }); ``` ## Conceptual clarity `Style` was never a comprehensive "style sheet". It only defined "core" style properties that all `Nodes` shared. Any "styled property" that couldn't fit that mold had to be in a separate component. A "real" style system would style properties _across_ components (`Node`, `Button`, etc). We have plans to build a true style system (see the doc linked above). By moving the `Style` fields to `Node`, we fully embrace `Node` as the driving concept and remove the "style system" confusion. ## Next Steps * Consider identifying and splitting out "style properties that aren't core to Node". This should not happen for Bevy 0.15. --- ## Migration Guide Move any fields set on `Style` into `Node` and replace all `Style` component usage with `Node`. Before: ```rust commands.spawn(( Node::default(), Style { width: Val::Px(100.), ..default() }, )); ``` After: ```rust commands.spawn(Node { width: Val::Px(100.), ..default() }); ``` For any usage of the "computed node properties" that used to live on `Node`, use `ComputedNode` instead: Before: ```rust fn system(nodes: Query<&Node>) { for node in &nodes { let computed_size = node.size(); } } ``` After: ```rust fn system(computed_nodes: Query<&ComputedNode>) { for computed_node in &computed_nodes { let computed_size = computed_node.size(); } } ```
86 lines
2.8 KiB
Rust
86 lines
2.8 KiB
Rust
//! Showcases the [`RelativeCursorPosition`] component, used to check the position of the cursor relative to a UI node.
|
|
|
|
use bevy::{
|
|
prelude::*, render::camera::Viewport, ui::RelativeCursorPosition, winit::WinitSettings,
|
|
};
|
|
|
|
fn main() {
|
|
App::new()
|
|
.add_plugins(DefaultPlugins)
|
|
// Only run the app when there is user input. This will significantly reduce CPU/GPU use.
|
|
.insert_resource(WinitSettings::desktop_app())
|
|
.add_systems(Startup, setup)
|
|
.add_systems(Update, relative_cursor_position_system)
|
|
.run();
|
|
}
|
|
|
|
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
|
|
commands.spawn((
|
|
Camera2d,
|
|
Camera {
|
|
// Cursor position will take the viewport offset into account
|
|
viewport: Some(Viewport {
|
|
physical_position: [200, 100].into(),
|
|
physical_size: [600, 600].into(),
|
|
..default()
|
|
}),
|
|
..default()
|
|
},
|
|
));
|
|
|
|
commands
|
|
.spawn(Node {
|
|
width: Val::Percent(100.),
|
|
height: Val::Percent(100.0),
|
|
align_items: AlignItems::Center,
|
|
justify_content: JustifyContent::Center,
|
|
flex_direction: FlexDirection::Column,
|
|
..default()
|
|
})
|
|
.with_children(|parent| {
|
|
parent
|
|
.spawn((
|
|
Node {
|
|
width: Val::Px(250.),
|
|
height: Val::Px(250.),
|
|
margin: UiRect::bottom(Val::Px(15.)),
|
|
..default()
|
|
},
|
|
BackgroundColor(Color::srgb(235., 35., 12.)),
|
|
))
|
|
.insert(RelativeCursorPosition::default());
|
|
|
|
parent.spawn((
|
|
Text::new("(0.0, 0.0)"),
|
|
TextFont {
|
|
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
|
|
font_size: 33.0,
|
|
..default()
|
|
},
|
|
TextColor(Color::srgb(0.9, 0.9, 0.9)),
|
|
));
|
|
});
|
|
}
|
|
|
|
/// This systems polls the relative cursor position and displays its value in a text component.
|
|
fn relative_cursor_position_system(
|
|
relative_cursor_position: Single<&RelativeCursorPosition>,
|
|
output_query: Single<(&mut Text, &mut TextColor)>,
|
|
) {
|
|
let (mut output, mut text_color) = output_query.into_inner();
|
|
|
|
**output = if let Some(relative_cursor_position) = relative_cursor_position.normalized {
|
|
format!(
|
|
"({:.1}, {:.1})",
|
|
relative_cursor_position.x, relative_cursor_position.y
|
|
)
|
|
} else {
|
|
"unknown".to_string()
|
|
};
|
|
|
|
text_color.0 = if relative_cursor_position.mouse_over() {
|
|
Color::srgb(0.1, 0.9, 0.1)
|
|
} else {
|
|
Color::srgb(0.9, 0.1, 0.1)
|
|
};
|
|
}
|