It's under menu [NGUI] => [Attach] => [Collider].
Or you can use the hotkey by pressing [Alt]+[Shift]+[C]
I know about this feature, but i need to do it
automaticaly, meaning when widget size changes collider
automatically changes its size to cover it.
About the bug:
I found that during update Widget.HasTransformChanged() is being called
inside there is the following code
if (cachedTransform.hasChanged)
{
mTrans.hasChanged = false;
return true;
}
it won't work in case of multiple widget on one gameobject, because in that case two widget share the same cached transform(at least it seems that way), and what widget is the first to render sets cachedTransform.hasChanged to false. Preventing update of all the other widgets.