**Ready for review. Examples migration progress: 100%.** # Objective - Implement https://github.com/bevyengine/bevy/discussions/15014 ## Solution This implements [cart's proposal](https://github.com/bevyengine/bevy/discussions/15014#discussioncomment-10574459) faithfully except for one change. I separated `TextSpan` from `TextSpan2d` because `TextSpan` needs to require the `GhostNode` component, which is a `bevy_ui` component only usable by UI. Extra changes: - Added `EntityCommands::commands_mut` that returns a mutable reference. This is a blocker for extension methods that return something other than `self`. Note that `sickle_ui`'s `UiBuilder::commands` returns a mutable reference for this reason. ## Testing - [x] Text examples all work. --- ## Showcase TODO: showcase-worthy ## Migration Guide TODO: very breaking ### Accessing text spans by index Text sections are now text sections on different entities in a hierarchy, Use the new `TextReader` and `TextWriter` system parameters to access spans by index. Before: ```rust fn refresh_text(mut query: Query<&mut Text, With<TimeText>>, time: Res<Time>) { let text = query.single_mut(); text.sections[1].value = format_time(time.elapsed()); } ``` After: ```rust fn refresh_text( query: Query<Entity, With<TimeText>>, mut writer: UiTextWriter, time: Res<Time> ) { let entity = query.single(); *writer.text(entity, 1) = format_time(time.elapsed()); } ``` ### Iterating text spans Text spans are now entities in a hierarchy, so the new `UiTextReader` and `UiTextWriter` system parameters provide ways to iterate that hierarchy. The `UiTextReader::iter` method will give you a normal iterator over spans, and `UiTextWriter::for_each` lets you visit each of the spans. --------- Co-authored-by: ickshonpe <david.curthoys@googlemail.com> Co-authored-by: Carter Anderson <mcanders1@gmail.com>
		
			
				
	
	
		
			97 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			97 lines
		
	
	
		
			3.3 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(NodeBundle {
 | 
						|
            style: Style {
 | 
						|
                width: Val::Percent(100.0),
 | 
						|
                height: Val::Percent(100.0),
 | 
						|
                align_items: AlignItems::Center,
 | 
						|
                justify_content: JustifyContent::Center,
 | 
						|
                ..default()
 | 
						|
            },
 | 
						|
            ..default()
 | 
						|
        })
 | 
						|
        .with_children(|parent| {
 | 
						|
            parent
 | 
						|
                .spawn(ButtonBundle {
 | 
						|
                    style: Style {
 | 
						|
                        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()
 | 
						|
                    },
 | 
						|
                    border_color: BorderColor(Color::BLACK),
 | 
						|
                    border_radius: BorderRadius::MAX,
 | 
						|
                    background_color: NORMAL_BUTTON.into(),
 | 
						|
                    ..default()
 | 
						|
                })
 | 
						|
                .with_child((
 | 
						|
                    Text::new("Button"),
 | 
						|
                    TextStyle {
 | 
						|
                        font: asset_server.load("fonts/FiraSans-Bold.ttf"),
 | 
						|
                        font_size: 33.0,
 | 
						|
                        color: Color::srgb(0.9, 0.9, 0.9),
 | 
						|
                        ..default()
 | 
						|
                    },
 | 
						|
                ));
 | 
						|
        });
 | 
						|
}
 |