requesting default focus

[lunixbochs]

I'm playing with dialog prompts in egui. It would be nice to be able to request that a widget receives "default focus" upon appearing, so the user can just press enter to activate the default button without pressing tab first. (e.g. when a window first appears, focus the "ok" button)

I tried this pattern, which works ok, though there's weirdness (see the end of this comment).

let button = ui.button("OK");
{
    let mut memory = ui.memory();
    if memory.focus() == None {
        memory.request_focus(button.id);
    }                      
}

A method like ui.memory().default_focus(widget.id) that sets focus only if it's not already set, may work well as a starting point for this.

I think one alternative is tracking a "first open" flag somewhere in my own code for each UI container that cares about default focus, however that may not handle something like a multi-page wizard where the contents change without creating a new container.

Weirdness with my memory approach:

1. Clicking in a background section will flash the widget's focus for a frame. (I think I'd prefer in this case that clicking on the UI background doesn't affect tab focus, but it's probably more nuanced than that, e.g. input boxes?)
2. Clicking any other button unsets the focus afterwards, which re-focuses the default button and flashes both buttons for a frame.

[fundon]

In this case, need a flag to set the input is focused.

#[derive(Clone, Default, PartialEq, Eq, Deserialize, Serialize)]
pub struct AddWindow {
    name: String,
    autofocus: bool,
}

impl Window for AddWindow {
    fn show(
        &mut self,
        data: Option<Message>,
    ) {
        // first rendered
        if let Some(Message::Normal) = data {
            self.autofocus = true;
        }
        egui::Window::new("the window")
            .resizable(false)
            .default_width(280.0)
            .open(true)
            .show(ctx, |ui| self.ui(ui));
    }
}

impl View for AddWindow {
    fn ui(&mut self, ui: &mut egui::Ui) {
        ui.horizontal(|ui| {
            ui.add_sized((50., 24.), egui::Label::new("Name:"));
            let resp =
                ui.add(egui::TextEdit::singleline(&mut self.name).hint_text("Write folder name"));
            // turn off `autofocus`
            if self.autofocus {
                self.autofocus = false;
                ui.memory().request_focus(resp.id);
            }
        });
    }
}

[tedsteen]

Any updates here, is this something you do manually or is there an egui way now?

[mackler]

Any updates here, is this something you do manually or is there an egui way now?

I, too, am interested in this.