The Mystery of the Missing KeyCodes

[pop]

Hey all. I'm working on an app which needs a simple text-box with user input. Not a complex text editor -- just accept keystrokes into a text file and save it/load it later.

I have looked into tools like egui, which I believe can do the job -- but I am curious if vanilla Bevy can work. I am trying to avoid adding dependencies where possible.

The road-block I am hitting is some keys do not have a KeyCode, so I cannot detect that key being pressed. For example !, # and $ are handled by EventReader<KeyboardInput> as None KeyCodes whereas @ and all letters/numbers are handled fine.

Example

Below is a simplified example demonstrating the problem:

use bevy::input::keyboard::KeyboardInput;
use bevy::input::ButtonState;
use bevy::prelude::*;

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_systems(Startup, init)
        .add_systems(Update, update)
        .run();
}

fn init(mut commands: Commands) {
    // UI Camera
    commands.spawn((
        Camera2dBundle { ..default() },
        UiCameraConfig { show_ui: true },
    ));

    // Text Box
    commands.spawn(TextBundle::from_section(
        "Start typing! (Escape to clear)\n",
        TextStyle {
            color: Color::WHITE,
            ..default()
        },
    ));
}

fn update(mut query: Query<&mut Text>, mut events: EventReader<KeyboardInput>) {
    for KeyboardInput {
        key_code,
        scan_code,
        state,
        ..
    } in events.iter()
    {
        if *state == ButtonState::Pressed {
            let mut text = query.single_mut();
            if *key_code == Some(KeyCode::Escape) {
                text.sections.drain(1..);
            } else {
                let style = TextStyle {
                    color: Color::WHITE,
                    ..default()
                };
                let added = format!(
                    "Pressed: KeyCode: {:?} / ScanCode {:?}\n",
                    key_code, scan_code
                );
                text.sections.push(TextSection::new(added, style));
            }
        }
    }
}

Demo

In the screenshot I typed ASDF then 1234 then Shift + 1234.

I have the ScanCode but I can't determine any way to programmatically correlate that with a keyboard character, Shift-ed or otherwise.

Prior art

I'm sure as work on UI and a Bevy Editor picks up this will be resolved.

It also seems like winit had some recent work on keyboard input event so this issue may be moot once those changes land in Bevy.

Request

Does anybody have a workaround in the meantime? winit and bevy may update to include all of the changes mentioned above, but has anybody seen a way of handling textbox input?

Workaround

For anybody curious my workarounds are:

• Accept a subset of keys and communicate that to the user, probably just letters and numbers for simplicity.
• For my game editor I plan to edit files in an external editor and import the files as assets. The assets should auto-update if the user edits files while the editor is running somewhat reducing development friction.
• Once the upstream winit changes land in Bevy I will update this thread with a new status and updated example(s).

[Vrixyz]

YES! Thanks for asking!

In my experience, altgr was incorrectly handled by winit, it was fixed in winit, come help me #8745.