Remove hover effect in checkboxes

[martenbjork]

When hovered, the checkboxes grow in size. They shouldn't. The scale of the element should remain the same. Only the color should change on hover.

[abey79]

Here is the current situation, which applies to all controls:

{
    // Expand hovered and active button frames:
    egui_style.visuals.widgets.hovered.expansion = 2.0;
    egui_style.visuals.widgets.active.expansion = 2.0;
    egui_style.visuals.widgets.open.expansion = 2.0;
}

Setting hovered.expansion to 0 removes the scaling on hover.

Questions:

• Should the scaling be removed on click as well (active.expension = 0.0? I would say this is not necessary as there is already some click feedback with thickening of the white check mark.
• How about open.expension? It refers buttons dropdown menu, see 2nd video.
• Since this is a rather global setting, do we expect undesirable side-effects (e.g. other types of widgets would should scale on hover and/or activation)?

This is with both hovered and active set to 0.0:

Export-1690193981179.mp4

Effect of open.expansion = 2.0 (current situation):

Export-1690194564613.mp4

[martenbjork]

I think scaling is a disorienting pattern. I think we should remove it across the app. Colors + hover cursor should be enough to signify interactivity. So, I think we should remove scaling from any interactive elements for now.

If we remove it, we will spot where states are missing and then we can fix that upstream in the design system 🙂

[abey79]

#2796 reverted by #2824