I’m a beginner – I can't create a second window in Slint, please help 🙏

[Bodden007]

Hi everyone 👋

I’m new to Rust and Slint, and I’ve been trying to open a second window in my application — but I just can’t get it to work. I've tried using SecondWindow::new() and calling .run() or .window().show(), but nothing seems to work.

main
`use slint::ComponentHandle;

slint::include_modules!();

fn main() -> Result<(), Box> {

let ui = AppWindow::new()?; 

let  second_win = SecondWindow::new()?;
let handle = ui.as_weak()?;

let _ = slint::invoke_from_event_loop(move || {
    if let Some(ui) = handle.upgrade() {
        ui.window().set_maximized(true);
    }
});

ui.run()?; 

Ok(()) 

}
`

I also tried adding a callback like this in my .slint file:

`export component AppWindow inherits Window
{

callback open_second_window(); `

also

build.rs

`fn main() {
println!("cargo:rerun-if-changed=ui/app-window.slint");
println!("cargo:rerun-if-changed=ui/second_window.slint");
println!("cargo:rerun-if-changed=ui/main_ui.slint");

slint_build::compile("ui/main_ui.slint").expect("Slint build failed");

}`

fault
[{ "resource": "/c:/Rust_DEV/slint_Rel/src/main.rs", "owner": "rustc", "code": { "value": "Click for full compiler diagnostic", "target": { "$mid": 1, "path": "/diagnostic message [0]", "scheme": "rust-analyzer-diagnostics-view", "query": "0", "fragment": "file:///c%3A/Rust_DEV/slint_Rel/src/main.rs" } }, "severity": 8, "message": "failed to resolve: use of undeclared type SecondWindow\nuse of undeclared type SecondWindow", "source": "rustc", "startLineNumber": 9, "startColumn": 22, "endLineNumber": 9, "endColumn": 34, "origin": "extHost1" },{ "resource": "/c:/Rust_DEV/slint_Rel/src/main.rs", "owner": "rustc", "code": { "value": "Click for full compiler diagnostic", "target": { "$mid": 1, "path": "/diagnostic message [1]", "scheme": "rust-analyzer-diagnostics-view", "query": "1", "fragment": "file:///c%3A/Rust_DEV/slint_Rel/src/main.rs" } }, "severity": 8, "message": "no method named on_open_second_windowfound for structAppWindowin the current scope\nmethod not found inAppWindow", "source": "rustc", "startLineNumber": 19, "startColumn": 21, "endLineNumber": 19, "endColumn": 42, "relatedInformation": [ { "startLineNumber": 19, "startColumn": 9, "endLineNumber": 19, "endColumn": 21, "message": " ", "resource": "/c:/Rust_DEV/slint_Rel/src/main.rs" }, { "startLineNumber": 1069, "startColumn": 6, "endLineNumber": 1069, "endColumn": 28, "message": "method on_open_second_window not found for this struct", "resource": "/c:/Rust_DEV/slint_Rel/target/debug/build/slint-rust-template-98bb09f5ce4edaaf/out/app-window.rs" } ], "origin": "extHost1" }]

My questions:

How do I properly include multiple .slint files so Rust can see them?

How do I fix the 'SecondWindow' not found and 'on_open_second_window' not found errors?

Is there a simple working example of two windows in Slint?

I'm totally stuck and would really appreciate any help 🙏

Thank you in advance!

[uAtomicBoolean]

If your second window is in its own slint file, then you need to export it from your main slint file to be able to use it from Rust.

main.slint

export { SecondWindow } from "second-window.slint";

export component AppWindow inherits Window {
    // your code
}

second-window.slint

export component SecondWindow inherits Window {
    // Your code
}

Hope this helps

[Bodden007]

Do you have a piece of code on how to open and close windows?

[uAtomicBoolean]

You can use this code in a callback handler.

let second_window = SecondWindow::new()?;
second_window.show()?; 

I attached a small working example.

[Bodden007]

If I create 3 or more windows, should I initialize them all as well?

[uAtomicBoolean]

Yes. I attached the example this time with two windows opening.

multi-window.zip

[Bodden007]

Thanks a lot! I'm new to Rust and Slint, and your help really made a difference.