move more view model logic into the files view model

pkg/utils/utils.go

@@ -59,6 +59,15 @@ func Max(x, y int) int {
 	return y
 }
 
+func Clamp(x int, min int, max int) int {
+	if x < min {
+		return min
+	} else if x > max {
+		return max
+	}
+	return x
+}
+
 func AsJson(i interface{}) string {
 	bytes, _ := json.MarshalIndent(i, "", "    ")
 	return string(bytes)