NSLabel Autoshrink with top constraints - ios

Question

I try to figure out autoshrink option in UILabel with regarding top constraint.
I have UIView and three labels. One of them has autoshrink option on. It has constraint to be centered, and has Trailing and Top constraint which should shrink label when changing size of UIView. If I make UIVIew thinner, font size is decreased, but if I change height of UIView font is not changed.
Constraints on UILabels :
Align Center X to Superview
Align Center Y to Superview
Trailing Space to Superview >= 50
Top Space to Superview >= 40
Align Center X to label2
Top Space to label1 equals :15
Bottom space to label2 equals :3
Label 1 constraints :
Align Center x to superview
Trailing Space to superview >=10
Leading Space to superview >=10
Bottom Space to Shrink Label equal 15
Label 2 constraint :
Align Center X to Shrink label
Top Space to Shrink label equals 3
How to change this?
What I want is, on last image that label will be nice autoshrink. So if I change width or height of the UIView label should shrink.

Answer 1

plz select your Shrink label set
Number of lines is 0
Line Breaks: Clip
Autoshrink: Minimum Font Scale 0.25

Answer 2

I hope below code will help you in some way,
extension Double {
/// Returns propotional width according to device width
var propotional: CGFloat {
if UIDevice.current.userInterfaceIdiom == .pad {
return CGFloat(414.0) / CGFloat(375.0) * CGFloat(self)
}
return CGFloat(Screen.width) / CGFloat(375.0) * CGFloat(self)
}
}
extension UILabel {
/// This property is change font-size of Label's text propotionaly, if assigned `On` from Interface builder
#IBInspectable
var isPropotional: Bool{
get {
return true
}
set {
if newValue == true {
let fontSize = Double((self.font!.pointSize))
self.font = UIFont(name: self.font!.fontName, size: fontSize.propotional)
}
}
}
}
In extension of Double, propotional value is calculated by considering current device set in storyboard as iPhone 6 size.
After adding this code set on from interface builder for Label where you can see isPropotional attribute in attribute inspector tab. Please refer image.