585dac0582
# Objective Fixes #6498. ## Solution Adding a parent node with properties AlignItems::Center and JustifyContent::Center to centered child nodes and removing their auto-margin properties.
135 lines
5.7 KiB
Rust
135 lines
5.7 KiB
Rust
//! Demonstrates how to use the z-index component on UI nodes to control their relative depth
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//!
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//! It uses colored boxes with different z-index values to demonstrate how it can affect the order of
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//! depth of nodes compared to their siblings, but also compared to the entire UI.
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use bevy::prelude::*;
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fn main() {
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App::new()
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.insert_resource(ClearColor(Color::BLACK))
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.add_plugins(DefaultPlugins)
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.add_startup_system(setup)
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.run();
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}
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fn setup(mut commands: Commands) {
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commands.spawn(Camera2dBundle::default());
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// spawn the container with default z-index.
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// the default z-index value is `ZIndex::Local(0)`.
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// because this is a root UI node, using local or global values will do the same thing.
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commands
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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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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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background_color: Color::GRAY.into(),
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style: Style {
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size: Size::new(Val::Px(180.0), Val::Px(100.0)),
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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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// spawn a node with default z-index.
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parent.spawn(NodeBundle {
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background_color: Color::RED.into(),
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style: Style {
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position_type: PositionType::Absolute,
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position: UiRect {
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left: Val::Px(10.0),
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bottom: Val::Px(40.0),
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..default()
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},
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size: Size::new(Val::Px(100.0), Val::Px(50.0)),
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..default()
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},
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..default()
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});
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// spawn a node with a positive local z-index of 2.
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// it will show above other nodes in the grey container.
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parent.spawn(NodeBundle {
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z_index: ZIndex::Local(2),
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background_color: Color::BLUE.into(),
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style: Style {
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position_type: PositionType::Absolute,
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position: UiRect {
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left: Val::Px(45.0),
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bottom: Val::Px(30.0),
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..default()
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},
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size: Size::new(Val::Px(100.0), Val::Px(50.0)),
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..default()
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},
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..default()
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});
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// spawn a node with a negative local z-index.
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// it will show under other nodes in the grey container.
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parent.spawn(NodeBundle {
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z_index: ZIndex::Local(-1),
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background_color: Color::GREEN.into(),
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style: Style {
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position_type: PositionType::Absolute,
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position: UiRect {
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left: Val::Px(70.0),
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bottom: Val::Px(20.0),
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..default()
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},
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size: Size::new(Val::Px(100.0), Val::Px(75.0)),
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..default()
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},
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..default()
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});
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// spawn a node with a positive global z-index of 1.
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// it will show above all other nodes, because it's the highest global z-index in this example.
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// by default, boxes all share the global z-index of 0 that the grey container is added to.
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parent.spawn(NodeBundle {
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z_index: ZIndex::Global(1),
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background_color: Color::PURPLE.into(),
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style: Style {
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position_type: PositionType::Absolute,
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position: UiRect {
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left: Val::Px(15.0),
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bottom: Val::Px(10.0),
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..default()
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},
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size: Size::new(Val::Px(100.0), 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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// spawn a node with a negative global z-index of -1.
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// this will show under all other nodes including its parent, because it's the lowest global z-index
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// in this example.
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parent.spawn(NodeBundle {
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z_index: ZIndex::Global(-1),
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background_color: Color::YELLOW.into(),
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style: Style {
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position_type: PositionType::Absolute,
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position: UiRect {
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left: Val::Px(-15.0),
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bottom: Val::Px(-15.0),
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..default()
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},
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size: Size::new(Val::Px(100.0), Val::Px(125.0)),
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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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});
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}
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