docs/bevy/examples/ui/text/text_wrap_debug.rs 4 K · 127 lines · raw · history

1 //! This example demonstrates text wrapping and use of the `LineBreakOn` property.
2
3 use argh::FromArgs;
4 use bevy::{prelude::*, text::LineBreak, window::WindowResolution};
5
6 #[derive(FromArgs, Resource)]
7 /// `text_wrap_debug` demonstrates text wrapping and use of the `LineBreakOn` property
8 struct Args {
9 #[argh(option)]
10 /// window scale factor
11 scale_factor: Option<f32>,
12
13 #[argh(option, default = "1.")]
14 /// ui scale factor
15 ui_scale: f32,
16 }
17
18 fn main() {
19 // `from_env` panics on the web
20 #[cfg(not(target_arch = "wasm32"))]
21 let args: Args = argh::from_env();
22 #[cfg(target_arch = "wasm32")]
23 let args = Args::from_args(&[], &[]).unwrap();
24
25 let window = if let Some(scale_factor) = args.scale_factor {
26 Window {
27 resolution: WindowResolution::default().with_scale_factor_override(scale_factor),
28 ..Default::default()
29 }
30 } else {
31 Window::default()
32 };
33
34 App::new()
35 .add_plugins(DefaultPlugins.set(WindowPlugin {
36 primary_window: Some(window),
37 ..Default::default()
38 }))
39 .insert_resource(UiScale(args.ui_scale))
40 .add_systems(Startup, spawn)
41 .run();
42 }
43
44 fn spawn(mut commands: Commands, asset_server: Res<AssetServer>) {
45 commands.spawn(Camera2d);
46
47 let text_font = TextFont {
48 font: asset_server.load("fonts/FiraSans-Bold.ttf").into(),
49 font_size: FontSize::Px(12.0),
50 ..default()
51 };
52
53 let root = commands
54 .spawn((
55 Node {
56 width: percent(100),
57 height: percent(100),
58 flex_direction: FlexDirection::Column,
59 ..default()
60 },
61 BackgroundColor(Color::BLACK),
62 ))
63 .id();
64
65 for linebreak in [
66 LineBreak::AnyCharacter,
67 LineBreak::WordBoundary,
68 LineBreak::WordOrCharacter,
69 LineBreak::NoWrap,
70 ] {
71 let row_id = commands
72 .spawn(Node {
73 flex_direction: FlexDirection::Row,
74 justify_content: JustifyContent::SpaceAround,
75 align_items: AlignItems::Center,
76 width: percent(100),
77 height: percent(50),
78 ..default()
79 })
80 .id();
81
82 let justifications = vec![
83 JustifyContent::Center,
84 JustifyContent::FlexStart,
85 JustifyContent::FlexEnd,
86 JustifyContent::SpaceAround,
87 JustifyContent::SpaceBetween,
88 JustifyContent::SpaceEvenly,
89 ];
90
91 for (i, justification) in justifications.into_iter().enumerate() {
92 let c = 0.3 + i as f32 * 0.1;
93 let column_id = commands
94 .spawn((
95 Node {
96 justify_content: justification,
97 flex_direction: FlexDirection::Column,
98 width: percent(16),
99 height: percent(95),
100 overflow: Overflow::clip_x(),
101 ..default()
102 },
103 BackgroundColor(Color::srgb(0.5, c, 1.0 - c)),
104 ))
105 .id();
106
107 let messages = [
108 format!("JustifyContent::{justification:?}"),
109 format!("LineBreakOn::{linebreak:?}"),
110 "Line 1\nLine 2".to_string(),
111 "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas auctor, nunc ac faucibus fringilla.".to_string(),
112 "pneumonoultramicroscopicsilicovolcanoconiosis".to_string()
113 ];
114
115 for (j, message) in messages.into_iter().enumerate() {
116 commands.entity(column_id).with_child((
117 Text(message.clone()),
118 text_font.clone(),
119 TextLayout::new(Justify::Left, linebreak),
120 BackgroundColor(Color::srgb(0.8 - j as f32 * 0.2, 0., 0.)),
121 ));
122 }
123 commands.entity(row_id).add_child(column_id);
124 }
125 commands.entity(root).add_child(row_id);
126 }
127 }