Let Text widget self-layout its width and read the width in Rust?

[JanDiederich]

I need to implement an endless Text-Scroll in Slint.

Easy solution: Put the string twice in a Text widget and decrease the offset offset_x by a regular repeating timer. If it goes less than half the text width (-width / 2) add back half the width (+= width / 2). Not resetting just to 0, that should make it seamlessly animated (worked easily with GTK).

Here is the problem: As soon as the Text width is bound to a property, which I can access in code, Slint stops layouting the Text width, its Text may even be cut off, and it's impossible to know how wide it must be to contain its text. Therefore I don't know when to reset the scroll offset offset_x.

How can I force Slint to layout the Text width and still let me read the width in Rust code?

Slint-Code:

in-out property <length> offset_x: -10px;

// Also not working if I don't define `100px`, it's 0 then.
out property <length> out_width: 100px;

Text {
   x: offset_x;
   width: out_width;
}

[ogoffart]

Give a name to the text and use a binding from the out property rather than the other way.
eg:

in-out property <length> offset_x: -10px;
out property <length> out_width: text.width;  // or <=> text.width

text := Text {
   x: offset_x;
}

[JanDiederich]

Thanks. That works great.