bevy/examples/ui/window_fallthrough.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

57 lines
2.2 KiB
Rust

//! This example illustrates how have a mouse's clicks/wheel/movement etc fall through the spawned transparent window to a window below.
//! If you build this, and hit 'P' it should toggle on/off the mouse's passthrough.
use bevy::prelude::*;
fn main() {
App::new()
.insert_resource(ClearColor(Color::NONE)) // Use a transparent window, to make effects obvious.
.add_plugins(DefaultPlugins.set(WindowPlugin {
primary_window: Some(Window {
// Set the window's parameters, note we're setting the window to always be on top.
transparent: true,
decorations: true,
always_on_top: true,
..default()
}),
..default()
}))
.add_startup_system(setup)
.add_system(toggle_mouse_passthrough) // This allows us to hit 'P' to toggle on/off the mouse's passthrough
.run();
}
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
// UI camera
commands.spawn(Camera2dBundle::default());
// Text with one section
commands.spawn((
// Create a TextBundle that has a Text with a single section.
TextBundle::from_section(
// Accepts a `String` or any type that converts into a `String`, such as `&str`
"Hit 'P' then scroll/click around!",
TextStyle {
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
font_size: 100.0, // Nice and big so you can see it!
color: Color::WHITE,
},
)
// Set the style of the TextBundle itself.
.with_style(Style {
position_type: PositionType::Absolute,
position: UiRect {
bottom: Val::Px(5.),
right: Val::Px(10.),
..default()
},
..default()
}),
));
}
// A simple system to handle some keyboard input and toggle on/off the hittest.
fn toggle_mouse_passthrough(keyboard_input: Res<Input<KeyCode>>, mut windows: Query<&mut Window>) {
if keyboard_input.just_pressed(KeyCode::P) {
let mut window = windows.single_mut();
window.cursor.hit_test = !window.cursor.hit_test;
}
}