Addressing array of items

[Tsuiban]

I'm trying to address an array of items that are created like this:

for i in [0, 1, 2, 3, 4] : SingleCharInputField { ... }

At some point later in my code I want to do two things: fetch the contents of the text property and clear it to "". I can't seem to figure out how to address those SingleChar components to get at their text fields.

[MostroW1502]

you could set it up like this.

assuming the following situation:

export struct SingleCharInputField {
    value: string
}

and then inside your component.

in property <[SingleCharInputField]> char-fields;

for field in char-fields : Text {
    text: field.value;
}

when (any) of the char-fields are altered from the code side, the field(s) will be rerendered accordingly.

[Tsuiban]

That's about 90% of what I wanted. Now I just want to be able to send the text field back out again. I guess I can just copy the text to the field in the accepted(text) => routine.

Thanks!

[MostroW1502]

if you'd make the property in-out you could access the array from the programming side or possibly use a custom callback routine from within your component itself?

[Tsuiban]

Hmm. Would something like this work:

export struct SingleCharInputField {
    value: string
}

component SingleCharInputLineEdit {
    in-out property <SingleCharInputField> char-field;
    LineEdit {
        text: parent.char-field.value;
        accepted(text) => { parent.char-field.value = text; }
    }
}

for field in char-fields : SingleCharInputLineEdit {
    char-field <=> field;
}

Basically I'm a little unclear whether SingleCharInputLineEdit.char-field would get a copy or a reference to the original field.

[MostroW1502]

according to the documentation of Slint, it's a callback called when the user presses enter.

depending on what your need is on the ui side.

if the user needs to press enter before the text value is accepted you'd set the text field in the LineEdit to an empty string i guess.
if the value needs to be updated whilst typing then the accepted callback won't be needed for that purpose.

in both instances you'd take the value out on the programming side and do something with it.

[MostroW1502]

single-char-field.slint

export struct SingleCharInputField {
    id: int,
    value: string
}

app-window.slint

import { SingleCharInputField } from "single-char-field.slint";

export component AppWindow inherits Window {
    width: 640px;
    height: 480px;

    in-out property <[SingleCharInputField]> char-fields: [
        { id: 0, value: "A" }, { id: 1, value: "B" }, { id: 2, value: "C" },
        { id: 3, value: "D" }, { id: 4, value: "E" }, { id: 5, value: "F" },
        { id: 6, value: "G" }, { id: 7, value: "H" }, { id: 8, value: "I" }
    ];

    callback send-key-to-rust(id: int, value: string);

    VerticalLayout {
        padding: 10px;
        spacing: 10px;

        for field in char-fields : LineEdit {
            text: field.value;
            key-pressed(event) => {
                let nav_key = event.text == Key.Backspace ||
                              event.text == Key.LeftArrow ||
                              event.text == Key.RightArrow ||
                              event.text == Key.Home ||
                              event.text == Key.End ||
                              event.text == Key.Delete;

                if self.text.character-count > 0 && !nav-key { return accept; }

                field.value = event.text;
                send-key-to-rust(field.id, field.value);
                return reject;
            }
        }
    }
}

main.rs

#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]

use std::error::Error;
use slint::include_modules;

include_modules!();

fn main() -> Result<(), Box<dyn Error>> {
    let ui = AppWindow::new()?;

    ui.on_send_key_to_rust(|id, value| {
        println!("id: {} - value: {}", id, value);
    });

    ui.run()?;

    Ok(())
}

now depending on what you want to do with the field(s), if you're using rust, then there's the ui.get_char_fields and ui.set_char_fields functions that you can use to read / write these properties.

i've also thrown in the use of the key-pressed callback exposed by the line edit control, i've coupled this with a callback that basically sends the key over to the rust side.
using the callback method you could potentially remove the in-out parameter from the SingleCharInputField array property.
but at this point i am not 100% sure and what your need is and what you're trying to achieve.

i'm also quite new at the slint / rust thing, so this is the best i can do with my current knowledge, there could be people out there having better advice on to handle things than what i'm showing at the moment.