 eaac730617
			
		
	
	
		eaac730617
		
	
	
	
	
		
			
			# Objective `Size::width` sets the `height` field to `Val::DEFAULT` which is `Val::Undefined`, but the default for `Size` `height` is `Val::Auto`. `Size::height` has the same problem, but with the `width` field. The UI examples specify numeric values in many places where they could either be elided or replaced by composition of the Flex enum properties. related: https://github.com/bevyengine/bevy/pull/7468 fixes: https://github.com/bevyengine/bevy/issues/6498 ## Solution Change `Size::width` so it sets `height` to `Val::AUTO` and change `Size::height` so it sets `width` to `Val::AUTO`. Added some tests so this doesn't happen again. ## Changelog Changed `Size::width` so it sets the `height` to `Val::AUTO`. Changed `Size::height` so it sets the `width` to `Val::AUTO`. Added tests to `geometry.rs` for `Size` and `UiRect` to ensure correct behaviour. Simplified the UI examples. Replaced numeric values with the Flex property enums or elided them where possible, and removed the remaining use of auto margins. ## Migration Guide The `Size::width` constructor function now sets the `height` to `Val::Auto` instead of `Val::Undefined`. The `Size::height` constructor function now sets the `width` to `Val::Auto` instead of `Val::Undefined`.
		
			
				
	
	
		
			318 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			318 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
| //! This example illustrates the various features of Bevy UI.
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| 
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| use bevy::{
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|     input::mouse::{MouseScrollUnit, MouseWheel},
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|     prelude::*,
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|     winit::WinitSettings,
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| };
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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_startup_system(setup)
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|         .add_system(mouse_scroll)
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|         .run();
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| }
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| 
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| fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
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|     // Camera
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|     commands.spawn(Camera2dBundle::default());
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| 
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|     // root node
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|     commands
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|         .spawn(NodeBundle {
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|             style: Style {
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|                 size: Size::width(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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|             ..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(NodeBundle {
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|                     style: Style {
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|                         size: Size::width(Val::Px(200.0)),
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|                         border: UiRect::all(Val::Px(2.0)),
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|                         ..default()
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|                     },
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|                     background_color: Color::rgb(0.65, 0.65, 0.65).into(),
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|                     ..default()
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|                 })
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|                 .with_children(|parent| {
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|                     // left vertical fill (content)
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|                     parent
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|                         .spawn(NodeBundle {
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|                             style: Style {
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|                                 size: Size::width(Val::Percent(100.0)),
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|                                 ..default()
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|                             },
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|                             background_color: Color::rgb(0.15, 0.15, 0.15).into(),
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|                             ..default()
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|                         })
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|                         .with_children(|parent| {
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|                             // text
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|                             parent.spawn(
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|                                 TextBundle::from_section(
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|                                     "Text Example",
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|                                     TextStyle {
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|                                         font: asset_server.load("fonts/FiraSans-Bold.ttf"),
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|                                         font_size: 30.0,
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|                                         color: Color::WHITE,
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|                                     },
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|                                 )
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|                                 .with_style(Style {
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|                                     margin: UiRect::all(Val::Px(5.0)),
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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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|             // right vertical fill
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|             parent
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|                 .spawn(NodeBundle {
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|                     style: Style {
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|                         flex_direction: FlexDirection::Column,
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|                         justify_content: JustifyContent::Center,
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|                         align_items: AlignItems::Center,
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|                         size: Size::width(Val::Px(200.0)),
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|                         ..default()
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|                     },
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|                     background_color: Color::rgb(0.15, 0.15, 0.15).into(),
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|                     ..default()
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|                 })
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|                 .with_children(|parent| {
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|                     // Title
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|                     parent.spawn(
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|                         TextBundle::from_section(
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|                             "Scrolling list",
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|                             TextStyle {
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|                                 font: asset_server.load("fonts/FiraSans-Bold.ttf"),
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|                                 font_size: 25.,
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|                                 color: Color::WHITE,
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|                             },
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|                         )
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|                         .with_style(Style {
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|                             size: Size::height(Val::Px(25.)),
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|                             ..default()
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|                         }),
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|                     );
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|                     // List with hidden overflow
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|                     parent
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|                         .spawn(NodeBundle {
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|                             style: Style {
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|                                 flex_direction: FlexDirection::Column,
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|                                 align_self: AlignSelf::Stretch,
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|                                 size: Size::height(Val::Percent(50.0)),
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|                                 overflow: Overflow::Hidden,
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|                                 ..default()
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|                             },
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|                             background_color: Color::rgb(0.10, 0.10, 0.10).into(),
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|                             ..default()
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|                         })
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|                         .with_children(|parent| {
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|                             // Moving panel
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|                             parent
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|                                 .spawn((
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|                                     NodeBundle {
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|                                         style: Style {
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|                                             flex_direction: FlexDirection::Column,
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|                                             flex_grow: 1.0,
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|                                             max_size: Size::UNDEFINED,
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|                                             align_items: AlignItems::Center,
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|                                             ..default()
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|                                         },
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|                                         ..default()
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|                                     },
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|                                     ScrollingList::default(),
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|                                 ))
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|                                 .with_children(|parent| {
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|                                     // List items
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|                                     for i in 0..30 {
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|                                         parent.spawn(
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|                                             TextBundle::from_section(
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|                                                 format!("Item {i}"),
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|                                                 TextStyle {
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|                                                     font: asset_server
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|                                                         .load("fonts/FiraSans-Bold.ttf"),
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|                                                     font_size: 20.,
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|                                                     color: Color::WHITE,
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|                                                 },
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|                                             )
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|                                             .with_style(Style {
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|                                                 flex_shrink: 0.,
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|                                                 size: Size::new(Val::Undefined, Val::Px(20.)),
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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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|                         });
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|                 });
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|             parent
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|                 .spawn(NodeBundle {
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|                     style: Style {
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|                         size: Size::new(Val::Px(200.0), Val::Px(200.0)),
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|                         position_type: PositionType::Absolute,
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|                         position: UiRect {
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|                             left: Val::Px(210.0),
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|                             bottom: Val::Px(10.0),
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|                             ..default()
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|                         },
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|                         border: UiRect::all(Val::Px(20.0)),
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|                         ..default()
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|                     },
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|                     background_color: Color::rgb(0.4, 0.4, 1.0).into(),
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|                     ..default()
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|                 })
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|                 .with_children(|parent| {
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|                     parent.spawn(NodeBundle {
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|                         style: Style {
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|                             size: Size::new(Val::Percent(100.0), Val::Percent(100.0)),
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|                             ..default()
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|                         },
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|                         background_color: Color::rgb(0.8, 0.8, 1.0).into(),
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|                         ..default()
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|                     });
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|                 });
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|             // render order test: reddest in the back, whitest in the front (flex center)
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|             parent
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|                 .spawn(NodeBundle {
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|                     style: Style {
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|                         size: Size::new(Val::Percent(100.0), Val::Percent(100.0)),
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|                         position_type: PositionType::Absolute,
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|                         align_items: AlignItems::Center,
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|                         justify_content: JustifyContent::Center,
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|                         ..default()
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|                     },
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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(NodeBundle {
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|                             style: Style {
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|                                 size: Size::new(Val::Px(100.0), Val::Px(100.0)),
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|                                 ..default()
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|                             },
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|                             background_color: Color::rgb(1.0, 0.0, 0.0).into(),
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|                             ..default()
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|                         })
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|                         .with_children(|parent| {
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|                             parent.spawn(NodeBundle {
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|                                 style: Style {
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|                                     // Take the size of the parent node.
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|                                     size: Size::all(Val::Percent(100.)),
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|                                     position_type: PositionType::Absolute,
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|                                     position: UiRect {
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|                                         left: Val::Px(20.0),
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|                                         bottom: Val::Px(20.0),
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|                                         ..default()
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|                                     },
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|                                     ..default()
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|                                 },
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|                                 background_color: Color::rgb(1.0, 0.3, 0.3).into(),
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|                                 ..default()
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|                             });
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|                             parent.spawn(NodeBundle {
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|                                 style: Style {
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|                                     size: Size::all(Val::Percent(100.)),
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|                                     position_type: PositionType::Absolute,
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|                                     position: UiRect {
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|                                         left: Val::Px(40.0),
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|                                         bottom: Val::Px(40.0),
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|                                         ..default()
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|                                     },
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|                                     ..default()
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|                                 },
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|                                 background_color: Color::rgb(1.0, 0.5, 0.5).into(),
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|                                 ..default()
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|                             });
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|                             parent.spawn(NodeBundle {
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|                                 style: Style {
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|                                     size: Size::all(Val::Percent(100.)),
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|                                     position_type: PositionType::Absolute,
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|                                     position: UiRect {
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|                                         left: Val::Px(60.0),
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|                                         bottom: Val::Px(60.0),
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|                                         ..default()
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|                                     },
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|                                     ..default()
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|                                 },
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|                                 background_color: Color::rgb(1.0, 0.7, 0.7).into(),
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|                                 ..default()
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|                             });
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|                             // alpha test
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|                             parent.spawn(NodeBundle {
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|                                 style: Style {
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|                                     size: Size::all(Val::Percent(100.)),
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|                                     position_type: PositionType::Absolute,
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|                                     position: UiRect {
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|                                         left: Val::Px(80.0),
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|                                         bottom: Val::Px(80.0),
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|                                         ..default()
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|                                     },
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|                                     ..default()
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|                                 },
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|                                 background_color: Color::rgba(1.0, 0.9, 0.9, 0.4).into(),
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|                                 ..default()
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|                             });
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|                         });
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|                 });
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|             // bevy logo (flex center)
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|             parent
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|                 .spawn(NodeBundle {
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|                     style: Style {
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|                         size: Size::width(Val::Percent(100.)),
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|                         position_type: PositionType::Absolute,
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|                         justify_content: JustifyContent::Center,
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|                         align_items: AlignItems::FlexStart,
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|                         ..default()
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|                     },
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|                     ..default()
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|                 })
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|                 .with_children(|parent| {
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|                     // bevy logo (image)
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|                     parent.spawn(ImageBundle {
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|                         style: Style {
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|                             size: Size::width(Val::Px(500.0)),
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|                             ..default()
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|                         },
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|                         image: asset_server.load("branding/bevy_logo_dark_big.png").into(),
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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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| 
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| #[derive(Component, Default)]
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| struct ScrollingList {
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|     position: f32,
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| }
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| 
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| fn mouse_scroll(
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|     mut mouse_wheel_events: EventReader<MouseWheel>,
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|     mut query_list: Query<(&mut ScrollingList, &mut Style, &Children, &Node)>,
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|     query_item: Query<&Node>,
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| ) {
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|     for mouse_wheel_event in mouse_wheel_events.iter() {
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|         for (mut scrolling_list, mut style, children, uinode) in &mut query_list {
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|             let items_height: f32 = children
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|                 .iter()
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|                 .map(|entity| query_item.get(*entity).unwrap().size().y)
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|                 .sum();
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|             let panel_height = uinode.size().y;
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|             let max_scroll = (items_height - panel_height).max(0.);
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|             let dy = match mouse_wheel_event.unit {
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|                 MouseScrollUnit::Line => mouse_wheel_event.y * 20.,
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|                 MouseScrollUnit::Pixel => mouse_wheel_event.y,
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|             };
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|             scrolling_list.position += dy;
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|             scrolling_list.position = scrolling_list.position.clamp(-max_scroll, 0.);
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|             style.position.top = Val::Px(scrolling_list.position);
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|         }
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|     }
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| }
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