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223use bevy::prelude::*;
use bevy_ui_navigation::{
prelude::{
DefaultNavigationPlugins, FocusState, Focusable, MenuBuilder, MenuSetting, NavEvent,
NavRequest, NavRequestSystem,
},
systems::InputMapping,
};
/// This example demonstrates a more complex menu system where you navigate
/// through menus and go to submenus using the `Action` and `Cancel`
/// (`ENTER` and `BACKSPACE` on keyboard) requests.
///
/// This introduces the concept of "active" and "dormant" focusable elements.
///
/// The focus goes back to active elements from the parent menu if you request
/// `Cancel` in a given submenu.
///
/// The focus goes back to the child menu's dormant element if you request
/// `Action` while the parent menu's corresponding `Focusable` is focused.
///
/// To navigate to the right column, move focus to the button with the right arrow
/// and press `ENTER`, to navigate to the left, press `BACKSPACE`. Notice how
/// going back to an already explored menu sets the focused element to the last
/// focused one.
///
/// This example also demonstrates the `NavRequest::FocusOn` request. When
/// `ENTER` is pressed when a green circle button is focused, it sends the
/// `FocusOn` request with a first row button as target.
fn main() {
App::new()
.add_plugins((DefaultPlugins, DefaultNavigationPlugins))
.init_resource::<Materials>()
.insert_resource(Gameui::new())
.add_systems(Startup, setup)
.add_systems(
Update,
(button_system, handle_nav_events).after(NavRequestSystem),
)
.run();
}
#[derive(Resource)]
struct Gameui {
from: Vec<Entity>,
to: Entity,
}
impl Gameui {
pub fn new() -> Self {
Self {
from: Vec::new(),
to: Entity::from_raw(1),
}
}
}
#[derive(Resource)]
struct Materials {
background: Color,
rarrow: UiImage,
circle: UiImage,
}
impl FromWorld for Materials {
fn from_world(world: &mut World) -> Self {
let assets = world.get_resource::<AssetServer>().unwrap();
Materials {
background: Color::BLACK,
rarrow: assets.load("rarrow.png").into(),
circle: assets.load("green_circle.png").into(),
}
}
}
fn button_system(
mut interaction_query: Query<(&Focusable, &mut BackgroundColor), Changed<Focusable>>,
) {
for (focus, mut material) in interaction_query.iter_mut() {
let color = match focus.state() {
FocusState::Focused => Color::ORANGE_RED,
FocusState::Active => Color::GOLD,
FocusState::Prioritized => Color::GRAY,
FocusState::Inert => Color::DARK_GRAY,
FocusState::Blocked => Color::ANTIQUE_WHITE,
};
*material = color.into();
}
}
fn handle_nav_events(
mut events: EventReader<NavEvent>,
mut requests: EventWriter<NavRequest>,
game: Res<Gameui>,
) {
use NavRequest::Action;
for event in events.read() {
if let NavEvent::FocusChanged { from, to } = &event {
println!("----------\nfrom: {:?}\n to: {:?}", from, to);
}
match event {
NavEvent::NoChanges {
from,
request: Action,
} if game.from.contains(from.first()) => requests.send(NavRequest::FocusOn(game.to)),
_ => {}
}
}
}
fn menu(materials: &Materials) -> NodeBundle {
let style = Style {
width: Val::Percent(20.0),
height: Val::Percent(95.0),
flex_direction: FlexDirection::Column,
flex_wrap: FlexWrap::Wrap,
justify_content: JustifyContent::Center,
align_content: AlignContent::Stretch,
..Default::default()
};
NodeBundle {
style,
background_color: materials.background.into(),
..Default::default()
}
}
fn setup(
mut commands: Commands,
materials: Res<Materials>,
mut game: ResMut<Gameui>,
mut input_mapping: ResMut<InputMapping>,
) {
input_mapping.keyboard_navigation = true;
// ui camera
commands.spawn(Camera2dBundle::default());
let pct = Val::Percent;
let style = Style {
position_type: PositionType::Absolute,
flex_direction: FlexDirection::Row,
width: pct(100.),
height: pct(100.),
..Default::default()
};
let bundle = NodeBundle {
style,
..Default::default()
};
let image_style = Style {
width: pct(100.),
height: pct(100.),
..Default::default()
};
let rarrow = || ImageBundle {
style: image_style.clone(),
image: materials.rarrow.clone(),
..Default::default()
};
let circle = || ImageBundle {
style: image_style.clone(),
image: materials.circle.clone(),
..Default::default()
};
commands.spawn(bundle).with_children(|commands| {
let mut next_menu_button: Option<Entity> = None;
for j in 0..5 {
commands
.spawn((
menu(&materials),
// Note: when next_menu_button is None,
// `with_parent(next_menu_button)` represents the root menu
MenuSetting::new().wrapping(),
MenuBuilder::from(next_menu_button),
))
.with_children(|commands| {
for i in 0..4 {
let mut button = commands.spawn(button());
button.insert(Focusable::default());
if j == 0 && i == 3 {
game.to = button.id();
}
if j == i {
button.with_children(|commands| {
commands.spawn(rarrow());
});
next_menu_button = Some(button.id());
}
if j == 3 && i == 1 {
button.insert(Focusable::cancel()).with_children(|cmds| {
cmds.spawn(circle());
});
}
if j == 2 && i == 1 {
button.insert(Focusable::new().blocked());
}
if j == 4 {
let to_add = button
.with_children(|commands| {
commands.spawn(circle());
})
.id();
game.from.push(to_add);
}
}
});
}
});
}
fn button() -> ButtonBundle {
let pct = Val::Percent;
let style = Style {
width: pct(95.),
height: pct(12.),
margin: UiRect::all(Val::Percent(3.0)),
..Default::default()
};
ButtonBundle {
style,
..Default::default()
}
}