Question

There is a resize DOM event, even for generic elements but I can’t find a event that is fired when the position of an element changed. I’d like to have an event that is fired whenever the geometry of an element is changed. It can be Mozilla specific, because I write a Firefox Add-On.

Edit: Or is there a way to pin an element to another one that always works, no matter what crazy stylesheets might be used (so one is always on top of the other)?

Answer 1

Edit: Or is there a way to pin an
element to another one that always
works, no matter what crazy
stylesheets might be used (so one is
always on top of the other)?

you can set a bunch of !important rules, which take priority (unless someone else uses !important, which is rare):

.pinned {
    position : absolute !important;
    top      : 0px      !important;
    right    : 0px      !important;
    bottom   : 0px      !important;
    left     : 0px      !important;
}