# 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(); } } ```
		
			
				
	
	
		
			106 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			106 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
//! This example illustrates how to override the window scale factor imposed by the
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//! operating system.
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use bevy::{prelude::*, window::WindowResolution};
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#[derive(Component)]
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struct CustomText;
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fn main() {
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    App::new()
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        .add_plugins(DefaultPlugins.set(WindowPlugin {
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            primary_window: Some(Window {
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                resolution: WindowResolution::new(500., 300.).with_scale_factor_override(1.0),
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                ..default()
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            }),
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            ..default()
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        }))
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        .add_systems(Startup, setup)
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        .add_systems(
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            Update,
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            (display_override, toggle_override, change_scale_factor),
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        )
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        .run();
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}
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fn setup(mut commands: Commands) {
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    // camera
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    commands.spawn(Camera2d);
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    // root node
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    commands
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        .spawn(Node {
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            width: Val::Percent(100.0),
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            height: Val::Percent(100.0),
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            justify_content: JustifyContent::SpaceBetween,
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            ..default()
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        })
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        .with_children(|parent| {
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            // left vertical fill (border)
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            parent
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                .spawn((
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                    Node {
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                        width: Val::Px(300.0),
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                        height: Val::Percent(100.0),
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                        border: UiRect::all(Val::Px(2.0)),
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                        ..default()
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                    },
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                    BackgroundColor(Color::srgb(0.65, 0.65, 0.65)),
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                ))
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                .with_child((
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                    CustomText,
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                    Text::new("Example text"),
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                    TextFont {
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                        font_size: 25.0,
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                        ..default()
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                    },
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                    Node {
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                        align_self: AlignSelf::FlexEnd,
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                        ..default()
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                    },
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                ));
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        });
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}
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/// Set the title of the window to the current override
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fn display_override(
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    mut window: Single<&mut Window>,
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    mut custom_text: Single<&mut Text, With<CustomText>>,
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) {
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    let text = format!(
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        "Scale factor: {:.1} {}",
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        window.scale_factor(),
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        if window.resolution.scale_factor_override().is_some() {
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            "(overridden)"
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        } else {
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            "(default)"
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        }
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    );
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    window.title.clone_from(&text);
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    custom_text.0 = text;
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}
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/// This system toggles scale factor overrides when enter is pressed
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fn toggle_override(input: Res<ButtonInput<KeyCode>>, mut window: Single<&mut Window>) {
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    if input.just_pressed(KeyCode::Enter) {
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        let scale_factor_override = window.resolution.scale_factor_override();
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        window
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            .resolution
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            .set_scale_factor_override(scale_factor_override.xor(Some(1.0)));
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    }
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}
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/// This system changes the scale factor override when up or down is pressed
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fn change_scale_factor(input: Res<ButtonInput<KeyCode>>, mut window: Single<&mut Window>) {
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    let scale_factor_override = window.resolution.scale_factor_override();
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    if input.just_pressed(KeyCode::ArrowUp) {
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        window
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            .resolution
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            .set_scale_factor_override(scale_factor_override.map(|n| n + 1.0));
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    } else if input.just_pressed(KeyCode::ArrowDown) {
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        window
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            .resolution
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            .set_scale_factor_override(scale_factor_override.map(|n| (n - 1.0).max(1.0)));
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    }
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}
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