bevy_link_window_to_monitor

bevy_link_window_to_monitor is a bevy micro-crate designed to provide a small API around linking windows with monitors, since that API is currently missing within Bevy itself.

To use this crate you just need to insert the LinkWindowToMonitorPlugin, after which the plugin will attempt to determine and add a relationship onto the Window specifying which Monitor the Window is on. After which you can use the OnMonitor and HasWindows Relationship Components to determine which window it's on.

You may also use determine_monitor() which will return the Monitor we determine the window to be on, if we can determine it, if you wish to handle the linking yourself.

Bevy Version Compatibility

Example

Here's a brief example of a very basic Bevy App that, alongside this crate, will create a window and print out the monitor it is on.

use bevy::prelude::*;
use bevy::window::{Monitor, PrimaryWindow};
use bevy_link_window_to_monitor::LinkWindowToMonitorPlugin;

fn main() {
  App::new()
          .add_plugins((DefaultPlugins, LinkWindowToMonitorPlugin))
          .add_systems(Update, print_monitor)
          .run();
}

fn print_monitor(primary_window: Single<&OnMontior, With<PrimaryWindow>>, monitors: Query<(Entity, &Monitor)>) {
  println!("{:?}", monitors.iter().find(|(e, ..)| *e == primary_window.0).unwrap().1.name)
}

Known Edge Cases

If you want to use determine_monitor(), you may encounter some edge-cases where the function is unable to determine the Monitor the Window is on, or otherwise experience a delay, such as:

• If you set window.position to WindowPosition::Automatic then detecting the Monitor may take up to one frame.
• If you set window.position to WindowPosition::Centered with MonitorSelection::Curent or MonitorSelection::Index then monitor detection may take up to one frame.
• Detection can completely fail if you continuously set window.position or do it immediately before the linking system runs or immediately after the changed_windows system provided by Bevy.

The plugin manages to get access to the underlying Winit Windows and is able to get the monitor the window is on that way.