bevy/examples/window/scale_factor_override.rs
Aceeri ddfafab971 Windows as Entities (#5589)
# Objective

Fix https://github.com/bevyengine/bevy/issues/4530

- Make it easier to open/close/modify windows by setting them up as `Entity`s with a `Window` component.
- Make multiple windows very simple to set up. (just add a `Window` component to an entity and it should open)

## Solution

- Move all properties of window descriptor to ~components~ a component.
- Replace `WindowId` with `Entity`.
- ~Use change detection for components to update backend rather than events/commands. (The `CursorMoved`/`WindowResized`/... events are kept for user convenience.~
  Check each field individually to see what we need to update, events are still kept for user convenience.

---

## Changelog

- `WindowDescriptor` renamed to `Window`.
    - Width/height consolidated into a `WindowResolution` component.
    - Requesting maximization/minimization is done on the [`Window::state`] field.
- `WindowId` is now `Entity`.

## Migration Guide

- Replace `WindowDescriptor` with `Window`.
    - Change `width` and `height` fields in a `WindowResolution`, either by doing
      ```rust
      WindowResolution::new(width, height) // Explicitly
      // or using From<_> for tuples for convenience
      (1920., 1080.).into()
      ```
- Replace any `WindowCommand` code to just modify the `Window`'s fields directly  and creating/closing windows is now by spawning/despawning an entity with a `Window` component like so:
  ```rust
  let window = commands.spawn(Window { ... }).id(); // open window
  commands.entity(window).despawn(); // close window
  ```

## Unresolved
- ~How do we tell when a window is minimized by a user?~
  ~Currently using the `Resize(0, 0)` as an indicator of minimization.~
  No longer attempting to tell given how finnicky this was across platforms, now the user can only request that a window be maximized/minimized.
  
 ## Future work
 - Move `exit_on_close` functionality out from windowing and into app(?)
 - https://github.com/bevyengine/bevy/issues/5621
 - https://github.com/bevyengine/bevy/issues/7099
 - https://github.com/bevyengine/bevy/issues/7098


Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2023-01-19 00:38:28 +00:00

101 lines
3.5 KiB
Rust

//! This example illustrates how to override the window scale factor imposed by the
//! operating system.
use bevy::{prelude::*, window::WindowResolution};
fn main() {
App::new()
.add_plugins(DefaultPlugins.set(WindowPlugin {
primary_window: Some(Window {
resolution: WindowResolution::new(500., 300.).with_scale_factor_override(1.0),
..default()
}),
..default()
}))
.add_startup_system(setup)
.add_system(display_override)
.add_system(toggle_override)
.add_system(change_scale_factor)
.run();
}
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
// camera
commands.spawn(Camera2dBundle::default());
// root node
commands
.spawn(NodeBundle {
style: Style {
size: Size::new(Val::Percent(100.0), Val::Percent(100.0)),
justify_content: JustifyContent::SpaceBetween,
..default()
},
..default()
})
.with_children(|parent| {
// left vertical fill (border)
parent
.spawn(NodeBundle {
style: Style {
size: Size::new(Val::Px(200.0), Val::Percent(100.0)),
border: UiRect::all(Val::Px(2.0)),
..default()
},
background_color: Color::rgb(0.65, 0.65, 0.65).into(),
..default()
})
.with_children(|parent| {
parent.spawn(
TextBundle::from_section(
"Example text",
TextStyle {
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
font_size: 30.0,
color: Color::WHITE,
},
)
.with_style(Style {
align_self: AlignSelf::FlexEnd,
..default()
}),
);
});
});
}
/// Set the title of the window to the current override
fn display_override(mut windows: Query<&mut Window>) {
let mut window = windows.single_mut();
window.title = format!(
"Scale override: {:?}",
window.resolution.scale_factor_override()
);
}
/// This system toggles scale factor overrides when enter is pressed
fn toggle_override(input: Res<Input<KeyCode>>, mut windows: Query<&mut Window>) {
let mut window = windows.single_mut();
if input.just_pressed(KeyCode::Return) {
let scale_factor_override = window.resolution.scale_factor_override();
window
.resolution
.set_scale_factor_override(scale_factor_override.xor(Some(1.0)));
}
}
/// This system changes the scale factor override when up or down is pressed
fn change_scale_factor(input: Res<Input<KeyCode>>, mut windows: Query<&mut Window>) {
let mut window = windows.single_mut();
let scale_factor_override = window.resolution.scale_factor_override();
if input.just_pressed(KeyCode::Up) {
window
.resolution
.set_scale_factor_override(scale_factor_override.map(|n| n + 1.0));
} else if input.just_pressed(KeyCode::Down) {
window
.resolution
.set_scale_factor_override(scale_factor_override.map(|n| (n - 1.0).max(1.0)));
}
}