bevy/examples/window/window_resizing.rs
UkoeHB c2c19e5ae4
Text rework (#15591)
**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>
2024-10-09 18:35:36 +00:00

89 lines
2.5 KiB
Rust

//! This example illustrates how to resize windows, and how to respond to a window being resized.
use bevy::{prelude::*, window::WindowResized};
fn main() {
App::new()
.insert_resource(ResolutionSettings {
large: Vec2::new(1920.0, 1080.0),
medium: Vec2::new(800.0, 600.0),
small: Vec2::new(640.0, 360.0),
})
.add_plugins(DefaultPlugins)
.add_systems(Startup, (setup_camera, setup_ui))
.add_systems(Update, (on_resize_system, toggle_resolution))
.run();
}
/// Marker component for the text that displays the current resolution.
#[derive(Component)]
struct ResolutionText;
/// Stores the various window-resolutions we can select between.
#[derive(Resource)]
struct ResolutionSettings {
large: Vec2,
medium: Vec2,
small: Vec2,
}
// Spawns the camera that draws UI
fn setup_camera(mut commands: Commands) {
commands.spawn(Camera2d);
}
// Spawns the UI
fn setup_ui(mut commands: Commands) {
// Node that fills entire background
commands
.spawn(NodeBundle {
style: Style {
width: Val::Percent(100.),
..default()
},
..default()
})
// Text where we display current resolution
.with_child((
Text::new("Resolution"),
TextStyle {
font_size: 42.0,
..default()
},
ResolutionText,
));
}
/// This system shows how to request the window to a new resolution
fn toggle_resolution(
keys: Res<ButtonInput<KeyCode>>,
mut windows: Query<&mut Window>,
resolution: Res<ResolutionSettings>,
) {
let mut window = windows.single_mut();
if keys.just_pressed(KeyCode::Digit1) {
let res = resolution.small;
window.resolution.set(res.x, res.y);
}
if keys.just_pressed(KeyCode::Digit2) {
let res = resolution.medium;
window.resolution.set(res.x, res.y);
}
if keys.just_pressed(KeyCode::Digit3) {
let res = resolution.large;
window.resolution.set(res.x, res.y);
}
}
/// This system shows how to respond to a window being resized.
/// Whenever the window is resized, the text will update with the new resolution.
fn on_resize_system(
mut q: Query<&mut Text, With<ResolutionText>>,
mut resize_reader: EventReader<WindowResized>,
) {
let mut text = q.single_mut();
for e in resize_reader.read() {
// When resolution is being changed
**text = format!("{:.1} x {:.1}", e.width, e.height);
}
}