1ba7429371
# Objective Provide a starting point for #3951, or a partial solution. Providing a few comment blocks to discuss, and hopefully find better one in the process. ## Solution Since I am pretty new to pretty much anything in this context, I figured I'd just start with a draft for some file level doc blocks. For some of them I found more relevant details (or at least things I considered interessting), for some others there is less. ## Changelog - Moved some existing comments from main() functions in the 2d examples to the file header level - Wrote some more comment blocks for most other 2d examples TODO: - [x] 2d/sprite_sheet, wasnt able to come up with something good yet - [x] all other example groups... Also: Please let me know if the commit style is okay, or to verbose. I could certainly squash these things, or add more details if needed. I also hope its okay to raise this PR this early, with just a few files changed. Took me long enough and I dont wanted to let it go to waste because I lost motivation to do the whole thing. Additionally I am somewhat uncertain over the style and contents of the commets. So let me know what you thing please.
335 lines
15 KiB
Rust
335 lines
15 KiB
Rust
//! This example illustrates the various features of Bevy UI.
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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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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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fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
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// ui camera
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commands.spawn_bundle(UiCameraBundle::default());
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// root node
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commands
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.spawn_bundle(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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justify_content: JustifyContent::SpaceBetween,
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..default()
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},
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color: Color::NONE.into(),
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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_bundle(NodeBundle {
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style: Style {
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size: Size::new(Val::Px(200.0), 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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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_bundle(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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align_items: AlignItems::FlexEnd,
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..default()
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},
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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_bundle(TextBundle {
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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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text: Text::with_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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Default::default(),
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),
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..default()
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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_bundle(NodeBundle {
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style: Style {
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flex_direction: FlexDirection::ColumnReverse,
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justify_content: JustifyContent::Center,
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size: Size::new(Val::Px(200.0), Val::Percent(100.0)),
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..default()
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},
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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_bundle(TextBundle {
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style: Style {
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size: Size::new(Val::Undefined, Val::Px(25.)),
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margin: UiRect {
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left: Val::Auto,
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right: Val::Auto,
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..default()
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},
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..default()
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},
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text: Text::with_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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Default::default(),
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),
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..default()
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});
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// List with hidden overflow
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parent
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.spawn_bundle(NodeBundle {
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style: Style {
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flex_direction: FlexDirection::ColumnReverse,
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align_self: AlignSelf::Center,
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size: Size::new(Val::Percent(100.0), Val::Percent(50.0)),
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overflow: Overflow::Hidden,
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..default()
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},
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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_bundle(NodeBundle {
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style: Style {
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flex_direction: FlexDirection::ColumnReverse,
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flex_grow: 1.0,
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max_size: Size::new(Val::Undefined, Val::Undefined),
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..default()
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},
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color: Color::NONE.into(),
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..default()
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})
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.insert(ScrollingList::default())
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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_bundle(TextBundle {
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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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margin: UiRect {
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left: Val::Auto,
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right: Val::Auto,
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..default()
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},
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..default()
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},
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text: Text::with_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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Default::default(),
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),
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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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// absolute positioning
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parent
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.spawn_bundle(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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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_bundle(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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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_bundle(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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color: Color::NONE.into(),
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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_bundle(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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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_bundle(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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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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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_bundle(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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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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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_bundle(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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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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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_bundle(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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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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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_bundle(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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justify_content: JustifyContent::Center,
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align_items: AlignItems::FlexEnd,
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..default()
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},
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color: Color::NONE.into(),
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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_bundle(ImageBundle {
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style: Style {
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size: Size::new(Val::Px(500.0), Val::Auto),
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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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#[derive(Component, Default)]
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struct ScrollingList {
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position: f32,
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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 query_list.iter_mut() {
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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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