public WindowCtlModel()
{
WindowVisible = WindowState
.Select(state => state != Minimized)
.ToReadOnlyReactivePropertySlim();
var a = WindowViewed.Where(r => ValidTrigger(r, true, true));
var b = WindowResized.Where(r => ValidTrigger(r, false, false));
var c = TimerTick.Where(r => ValidTrigger(r, false, true));
NonOverlapLocation = Observable
.Merge(a, b, c)
.Select(MoveToNonOverlapPosition)
.Where(p => p.HasValue)
.Select(p => p.Value)
.ToReadOnlyReactivePropertySlim(mode: DistinctUntilChanged | IgnoreException);
}
