pub fn move_sel(
selection: usize,
len: usize,
d: i32, cycle: bool,
) -> usize {
if len == 0 {
return 0;
}
let ns = (selection as i32) + d;
if ns < 0 {
if cycle {
len - 1
} else {
0
}
} else if ns >= len as i32 {
if cycle {
0
} else {
len - 1
}
} else {
ns as usize
}
}