mirror of
https://github.com/bevyengine/bevy
synced 2024-11-25 14:10:19 +00:00
015f2c69ca
# 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(); } } ```
93 lines
3.1 KiB
Rust
93 lines
3.1 KiB
Rust
//! This example illustrates how to create a button that changes color and text based on its
|
|
//! interaction state.
|
|
|
|
use bevy::{color::palettes::basic::*, prelude::*, winit::WinitSettings};
|
|
|
|
fn main() {
|
|
App::new()
|
|
.add_plugins(DefaultPlugins)
|
|
// Only run the app when there is user input. This will significantly reduce CPU/GPU use.
|
|
.insert_resource(WinitSettings::desktop_app())
|
|
.add_systems(Startup, setup)
|
|
.add_systems(Update, button_system)
|
|
.run();
|
|
}
|
|
|
|
const NORMAL_BUTTON: Color = Color::srgb(0.15, 0.15, 0.15);
|
|
const HOVERED_BUTTON: Color = Color::srgb(0.25, 0.25, 0.25);
|
|
const PRESSED_BUTTON: Color = Color::srgb(0.35, 0.75, 0.35);
|
|
|
|
fn button_system(
|
|
mut interaction_query: Query<
|
|
(
|
|
&Interaction,
|
|
&mut BackgroundColor,
|
|
&mut BorderColor,
|
|
&Children,
|
|
),
|
|
(Changed<Interaction>, With<Button>),
|
|
>,
|
|
mut text_query: Query<&mut Text>,
|
|
) {
|
|
for (interaction, mut color, mut border_color, children) in &mut interaction_query {
|
|
let mut text = text_query.get_mut(children[0]).unwrap();
|
|
match *interaction {
|
|
Interaction::Pressed => {
|
|
**text = "Press".to_string();
|
|
*color = PRESSED_BUTTON.into();
|
|
border_color.0 = RED.into();
|
|
}
|
|
Interaction::Hovered => {
|
|
**text = "Hover".to_string();
|
|
*color = HOVERED_BUTTON.into();
|
|
border_color.0 = Color::WHITE;
|
|
}
|
|
Interaction::None => {
|
|
**text = "Button".to_string();
|
|
*color = NORMAL_BUTTON.into();
|
|
border_color.0 = Color::BLACK;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
|
|
// ui camera
|
|
commands.spawn(Camera2d);
|
|
commands
|
|
.spawn(Node {
|
|
width: Val::Percent(100.0),
|
|
height: Val::Percent(100.0),
|
|
align_items: AlignItems::Center,
|
|
justify_content: JustifyContent::Center,
|
|
..default()
|
|
})
|
|
.with_children(|parent| {
|
|
parent
|
|
.spawn((
|
|
Button,
|
|
Node {
|
|
width: Val::Px(150.0),
|
|
height: Val::Px(65.0),
|
|
border: UiRect::all(Val::Px(5.0)),
|
|
// horizontally center child text
|
|
justify_content: JustifyContent::Center,
|
|
// vertically center child text
|
|
align_items: AlignItems::Center,
|
|
..default()
|
|
},
|
|
BorderColor(Color::BLACK),
|
|
BorderRadius::MAX,
|
|
BackgroundColor(NORMAL_BUTTON),
|
|
))
|
|
.with_child((
|
|
Text::new("Button"),
|
|
TextFont {
|
|
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
|
|
font_size: 33.0,
|
|
..default()
|
|
},
|
|
TextColor(Color::srgb(0.9, 0.9, 0.9)),
|
|
));
|
|
});
|
|
}
|