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(); } } ```
87 lines
2.8 KiB
Rust
87 lines
2.8 KiB
Rust
//! Showcases the [`RelativeCursorPosition`] component, used to check the position of the cursor relative to a UI node.
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use bevy::{
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prelude::*, render::camera::Viewport, ui::RelativeCursorPosition, winit::WinitSettings,
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};
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fn main() {
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App::new()
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.add_plugins(DefaultPlugins)
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// Only run the app when there is user input. This will significantly reduce CPU/GPU use.
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.insert_resource(WinitSettings::desktop_app())
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.add_systems(Startup, setup)
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.add_systems(Update, relative_cursor_position_system)
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.run();
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}
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fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
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commands.spawn((
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Camera2d,
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Camera {
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// Cursor position will take the viewport offset into account
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viewport: Some(Viewport {
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physical_position: [200, 100].into(),
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physical_size: [600, 600].into(),
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..default()
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}),
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..default()
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},
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));
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commands
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.spawn(Node {
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width: Val::Percent(100.),
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height: Val::Percent(100.0),
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align_items: AlignItems::Center,
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justify_content: JustifyContent::Center,
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flex_direction: FlexDirection::Column,
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..default()
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})
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.with_children(|parent| {
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parent
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.spawn((
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Node {
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width: Val::Px(250.),
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height: Val::Px(250.),
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margin: UiRect::bottom(Val::Px(15.)),
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..default()
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},
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BackgroundColor(Color::srgb(235., 35., 12.)),
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))
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.insert(RelativeCursorPosition::default());
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parent.spawn((
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Text::new("(0.0, 0.0)"),
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TextFont {
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font: asset_server.load("fonts/FiraSans-Bold.ttf"),
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font_size: 33.0,
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..default()
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},
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TextColor(Color::srgb(0.9, 0.9, 0.9)),
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));
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});
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}
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/// This systems polls the relative cursor position and displays its value in a text component.
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fn relative_cursor_position_system(
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relative_cursor_position: Single<&RelativeCursorPosition>,
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output_query: Single<(&mut Text, &mut TextColor)>,
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) {
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let (mut output, mut text_color) = output_query.into_inner();
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**output = if let Some(relative_cursor_position) = relative_cursor_position.normalized {
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format!(
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"({:.1}, {:.1})",
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relative_cursor_position.x, relative_cursor_position.y
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)
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} else {
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"unknown".to_string()
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};
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text_color.0 = if relative_cursor_position.mouse_over() {
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Color::srgb(0.1, 0.9, 0.1)
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} else {
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Color::srgb(0.9, 0.1, 0.1)
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};
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}
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