bevy/examples/window/transparent_window.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

36 lines
1.2 KiB
Rust

//! Shows how to display a window in transparent mode.
//!
//! This feature works as expected depending on the platform. Please check the
//! [documentation](https://docs.rs/bevy/latest/bevy/prelude/struct.WindowDescriptor.html#structfield.transparent)
//! for more details.
use bevy::{
prelude::*,
window::{Window, WindowPlugin},
};
fn main() {
App::new()
// ClearColor must have 0 alpha, otherwise some color will bleed through
.insert_resource(ClearColor(Color::NONE))
.add_startup_system(setup)
.add_plugins(DefaultPlugins.set(WindowPlugin {
primary_window: Some(Window {
// Setting `transparent` allows the `ClearColor`'s alpha value to take effect
transparent: true,
// Disabling window decorations to make it feel more like a widget than a window
decorations: false,
..default()
}),
..default()
}))
.run();
}
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
commands.spawn(Camera2dBundle::default());
commands.spawn(SpriteBundle {
texture: asset_server.load("branding/icon.png"),
..default()
});
}