How to get aggregated scaling factor for QML items?

Asperamanca

The effect of "scaling" a QML item aggregates, i.e. if an item's parent is scaled to 200 %, the item will also appear at 200 % scale.
Is there an easy way to get the aggregated scaling factor for an item?

Use case: My item opens a popup. The popup should use the same scaling as the item. Since the popup does not belong into the same item tree, it does not "inherit" the scaling automatically.

GrecKo

Can you assume only the direct parent will have its scale set and bind the popup's scale to it?
If you instead need to support a recursive item tree you could do it like that:

property real aggregatedScale: {
    let parent = popup.parent;
    let scale = 1;
    while (parent) {
        scale *= parent.scale;
        parent = parent.parent;
   }
   return scale;
}

Asperamanca

Thanks for your reply. I should have been more specific in my question: I know how to write it myself, I was looking for an existing function that already gives the that, akin to QGraphicsItem::sceneTransform.

Because how would you expose such a function to QML, so you have it available globally, for all items? I guess that would mean something like a singleton object.