如何实现rust druid在textbox中输入的回调(不是镜头，而是一个方法调用)？

[dependencies]
druid = "0.7"

use druid::widget::{TextBox, Widget};
use druid::{AppLauncher, Data, Env, Event, EventCtx, Lens, WidgetExt, WindowDesc};

#[derive(Clone, Data, Lens)]
struct AppState {
    input_text: String,
}

fn main() {
    let main_window = WindowDesc::new(build_ui)
        .title("Rust Druid Textbox Callback")
        .window_size((400.0, 200.0));

    let initial_state = AppState {
        input_text: String::new(),
    };

    AppLauncher::with_window(main_window)
        .launch(initial_state)
        .expect("Failed to launch application");
}

fn build_ui() -> impl Widget<AppState> {
    TextBox::new()
        .with_placeholder("Enter text here")
        .fix_width(200.0)
        .lens(AppState::input_text)
        .on_event(|ctx, event, data: &mut String, _env| {
            if let Event::KeyDown(key_event) = event {
                if key_event.key == druid::keyboard_types::Key::Enter {
                    // 在这里执行你的回调操作，可以调用其他方法或处理输入的文本
                    println!("Input text: {}", data);
                }
            }
            // 返回false表示事件未被处理，继续传递给其他部件
            false
        })
}