Inconsistent behavour for keypress Alt+Key

[xiyuzhai]

In a web text edit, when one press Alt+"o", nothing happens. But for text edit in egui with eframe, "o" is entered into the content. Same for other keys.

Is this intentional or to be fixed?

[xiyuzhai]

fn install_keydown(runner_ref: &WebRunner, target: &EventTarget) -> Result<(), JsValue> {
    runner_ref.add_event_listener(
        target,
        "keydown",
        |event: web_sys::KeyboardEvent, runner| {
            if !runner.input.raw.focused {
                return;
            }

            let modifiers = modifiers_from_kb_event(&event);
            if !modifiers.ctrl
                && !modifiers.command
                // When text agent is focused, it is responsible for handling input events
                && !runner.text_agent.has_focus()
            {
                if let Some(text) = text_from_keyboard_event(&event) {
                    runner.input.raw.events.push(egui::Event::Text(text));
                    runner.needs_repaint.repaint_asap();

                    // If this is indeed text, then prevent any other action.
                    event.prevent_default();

                    // Assume egui uses all key events, and don't let them propagate to parent elements.
                    event.stop_propagation();
                }
            }

            on_keydown(event, runner);
        },
    )
}

I found the above code in crates/eframe/src/web/events.rs might be related to this behavior. I wonder why !modifiers.alt isn't in the condition for emitting Event::Text

[emilk]

That's because alt is used to modify characters, e.g. Alt+2 is ™ on my keyboard, so if we ignored modifiers.alt we would not be able to type ™ and other characters.

[xiyuzhai]

I see.

[xiyuzhai]

Is there any way to customize the behavior?

[xiyuzhai]

In crates/egui-winit/src/lib.rs, we have the following:

let is_cmd = self.egui_input.modifiers.ctrl
                    || self.egui_input.modifiers.command
                    || self.egui_input.modifiers.mac_cmd;
                if pressed && !is_cmd {
                    self.egui_input
                        .events
                        .push(egui::Event::Text(text.to_string()));
                }
                ```

[xiyuzhai]

After adding modifiers.alt, on my forked egui, I do get the behavior I wanted, no text input when Alt is pressed.

[xiyuzhai]

https://github.com/xiyuzhai-husky-lang/egui