Weird behavior when adding a certain number of rects on click

[Rewrite4828]

Hello,

Let me start of by saying that I am a huge fan of slint. I am currently in the process of learning/experimenting and would like to apologize if this question (or a similar one) has been answered before. My code is:

slint::slint! {

    struct StackElement {
        id: int,
    }

    component Button inherits Rectangle {
        callback clicked <=> touch.clicked;
        background: grey;
        animate background {
            duration: 100ms;
        }
        Text {
            text: "Hello, world!";
        }
        touch := TouchArea { }
    }

    export component App inherits Window {
        in-out property <[StackElement]> stack;
        callback add_stack_element;

        VerticalLayout {
            alignment: start;

            button := Button {
                width: root.width;
                height: root.height / 5;
                clicked => {
                    root.add_stack_element();
                    // self.background = green;
                }
            }

            for element[i] in root.stack: Rectangle {
                width: root.width;
                height: root.height / 5;
                background: green;

                Text {
                    text: "Hello!";
                }
            }
        }
    }
}

fn main() {
    let app = App::new().unwrap();

    let app_weak = app.as_weak();

    let mut stack: Vec<StackElement> = Vec::new();
    let mut stack_model = std::rc::Rc::new(slint::VecModel::from(stack));

    app.on_add_stack_element(move || {
        stack_model.push(StackElement { id: 0,});
        let app = app_weak.unwrap();
        app.set_stack(stack_model.clone().into());
    });

    app.run().unwrap()
}

This allows me to add rectangles up until the window is full. If I try to add more, something weird happens (the window becomes elongated and can't be closed anymore). I must be doing something very wrong.

Could someone please explain?

Regards

[ogoffart]

I think you are seeing something like what's described in this bug: #2902
What happens is that the layout size depends on the window size, and the windows size depends on the layout size. That makes a loop which is unfortunately not detected by the compiler at this time. And the size of the window just grows.