use eframe::egui::{
    self,
    CentralPanel,
    TextEdit,
};

fn main() -> Result<(), eframe::Error,> {
    let options = eframe::NativeOptions {
        ..Default::default()
    };

    eframe::run_native(
        "editor big file test",
        options,
        Box::new(|_cc| Box::<MyApp,>::new(MyApp::new(),),),
    )
}

struct MyApp {
    text: String,
}

impl MyApp {
    fn new() -> Self {
        let bytes = include_bytes!("../10mb.png"); // a 10mb png file
        let encoding = detect_encoding(bytes,);
        let (str, _, _,) = encoding.decode(bytes,);
        let string: String = str.into();
        MyApp {
            text: string,
        }
    }
}

pub fn detect_encoding(text: &[u8],) -> &'static encoding_rs::Encoding {
    let len = text.len();
    let to = std::cmp::min(1000, len,);
    let mut encoding_detector = chardetng::EncodingDetector::new();
    encoding_detector.feed(&text[0..to], to == len,);
    encoding_detector.guess(None, true,)
}

impl eframe::App for MyApp {
    fn update(
        &mut self,
        ctx: &egui::Context,
        _frame: &mut eframe::Frame,
    ) {
        CentralPanel::default().show(ctx, |ui| {
            let code_editor = TextEdit::multiline(&mut self.text,)
                .code_editor()
                .frame(true,)
                .lock_focus(true,)
                .desired_width(f32::INFINITY,)
                .desired_rows(40,);
            let _output = code_editor.show(ui,);
        },);
    }
}