How can we do modal window in egui?

[jackyzsn]

How can we do modal window in egui? I checked the popup is close but not what I want. Demo app doesn't have something similar. Thanks.

[jackyzsn]

End up using native-dialog in my app for showing modal dialog

[coderedart]

there's Rusty File Dialog which is popular

[Barugon]

I use a flag to disable the main UI when I show a window that I want to be modal. When the window is no longer shown then the UI is enabled again.

[mrkaragoz]

I use a flag to disable the main UI when I show a window that I want to me modal. When the window is no longer shown then the UI is enabled again.

How did you do that? Can you post a simple example?

[Barugon]

How did you do that? Can you post a simple example?

Something like this:

use eframe::egui;

#[derive(Default)]
struct App {
    window_open: bool,
}

impl eframe::App for App {
    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
        if self.window_open {
            egui::Window::new("Modal Window")
                .open(&mut self.window_open)
                .show(ctx, |ui| {
                    ui.label("contents");
                });
        }

        egui::CentralPanel::default().show(ctx, |ui| {
            ui.set_enabled(!self.window_open);
            if ui.button("Open the window").clicked() {
                self.window_open = true;
            }
        });
    }
}

fn main() {
    eframe::run_native(
        "Modal window",
        eframe::NativeOptions::default(),
        Box::new(|_cc| Box::new(App::default())),
    );
}

[jackyzsn]

I'm using another dependency.

[dependencies]
native-dialog = "0.6.3"

                        MessageDialog::new()
                            .set_type(MessageType::Info)
                            .set_title("Success")
                            .set_text("Connected ..")
                            .show_alert()
                            .unwrap();

[Barugon]

Unfortunately, native-dialog (and rfg) manifest bad behavior on Gnome. The dialogs are not truly modal, so they can be behind your app window. Also, you have to put them in a separate thread (which may be problematic for Mac) or the system will think your app is not responding.

[John-Nagle]

The dialogs are not truly modal, so they can be behind your app window.

Yes. This is a problem with file pickers. Today, you have to use the system's file picker, because file pickers are privileged. In various sandbox modes, they grant the program access to the file. How this works varies with the platform. But you can't just code a file picker in egui.

    let task = rfd::AsyncFileDialog::new()
        .set_title(t!("title.open_replay", state.get_lang()))
        .add_filter("json", &["json"])
        .set_parent(window)
        .pick_file();

The set_parent, given the parent window's &winit::window::Window, tells the file dialog that its parent is the main window. This does exactly the right thing on Windows - the file dialog is always in front, and clicking on the main window will not change that. It just gets you a beep.

Linux, (X/Gnome, at least), totally ignores that parenting. I brought this up for the rfd crate, and it's being worked on upstream. If you click on the main window, the main window gains focus, the file dialog goes behind it, and, in full screen mode, the user is very frustrated, since they have no easy way to get the file dialog on top again.

Anyone tried Mac?

If you want to try this, see my ui-mock, which is the GUI for a game minus the game. You can run it and try egui menus, which aren't connected to anything. I'd appreciate someone building this in Mac and reporting back. Clicking on the big "Open replay file" will get you a file picker. It wants a .json file, but doesn't actually read it.

I wrote that thing to wring out all the common UI cases for a game (full screen, file picker, Rend3 running 3D, etc.). So try it and see if it breaks. You'll have to build it, with "cargo build --examples --release".

Except for file pickers, I'd stay within egui. Don't bring up a system dialog. You can make an egui dialog that acts modal, with the background window disabled, as others have pointed out.

[Barugon]

Today, you have to use the system's file picker, because file pickers are privileged. In various sandbox modes, they grant the program access to the file. How this works varies with the platform. But you can't just code a file picker in egui.

https://github.com/Barugon/egui_file

I can't tell you if it will work on WASM but it should work for any other platform.

[jackyzsn]

I tested native-dialog in Mac. Mac behaviour is same as windows. If you click main window, it beeps but the dialog still shows in the front.

[John-Nagle]

I tested native-dialog in Mac. Mac behaviour is same as windows. If you click main window, it beeps but the dialog still shows in the front.

Excellent.

On Linux, the rfd people are struggling with this. There's an upstream problem. See PolyMeilex/rfd#46