Placing @children in PopupWindow doesn't work

[floers]

Platform: Linux, WASM Language: Slint (Rust)

When using @children inside a PopupWindow the children aren't placed inside the popup window. This worked in 1.5 but doesn't work in 1.6 anymore.

Here is a slintpad with an code example: example

And here is just the code example:

component Dropdown inherits Rectangle {

    in-out property <string> text;

    height: 2rem;
    width: 10rem;
    border-color: black;
    border-width: 1px;

    popup := PopupWindow {
        x: 0px;
        y: 2.1rem;
        width: 10rem;
        Rectangle {
            border-color: black;
            border-width: 1px;
            VerticalLayout {
                padding: 0.5rem;
                @children
            }
        }
    }

    Text {
        text: text;
    }

    t := TouchArea {
        clicked => {
            popup.show()
        }
    }
}

export component Demo {
    width: 400px;
    height: 300px;

    VerticalLayout {
        alignment: start;

        Dropdown {
            text: "foo";
            Text {
                text: "Option 1";
            }
            Text {
                text: "Another Option";
            }
        }
    }
}

The 1.6.0 release notes mention some work on placing @children in https://github.com/slint-ui/slint/issues/4935. Maybe this is related.

[Vadoola]

I might have encountered this bug as well. I had some rough code for adding tooltips in my program. It used @children inside of a popup window.

When I upgraded to 1.6 this seemed to partially break. However the code wasn't fully functional to begin with, so I just commented it out and went to work on other things without digging too deep.

[ogoffart]

Thanks both for reporting the issue.

I bisected the change and this is caused by commit 12d904a71ca31f947bfe983e7dbfe745b2439b74

Indeed, the change does change the order between PopupWindow "extraction" and children inlining. So the @children is now in the wrong place.

This could be fixed. However it is still a bit akward to put children in a PopupWindow. It sould be borbidden for the same reason that it should be forbidden to put them in if or for as you get the error from bug https://github.com/slint-ui/slint/issues/4438 when trying to access properties of that element.

[floers]

I feared that you would consider this as "forbidden". I could create a Dropdown like above either with a fixed data model or (if it's sufficient) by just adding a vec of strings for entries (which seems more "the slint way" atm?). But it is very nice to have composability like before. A dropdown is much more generic that way as each consumer can define how options look like. Similar to what TailwindCSS's Headless UI does. For me these patterns are a huge productivity booster.

So if it's out of scope today I can relate but being able to do smth like would elevate slint soo much above other frameworks for me.