How to add one more CAGradientLayer to UIView?-CodePudding

I have a PopupView with a scrollable label (like Marquee type). Its scrolled inside a labelView, which is just a UIView.

I decided to add an effect of transparent gradient to the left and right sides of labelView using the following code:

    let gradientLayer = CAGradientLayer()
    
    gradientLayer.startPoint = CGPoint(x: 0, y: 0)
    gradientLayer.endPoint = CGPoint(x: 0.5, y: 0)
    gradientLayer.colors = [UIColor.clear.cgColor, UIColor.white.cgColor, UIColor.white.cgColor]
    gradientLayer.locations = [0, 0.2, 1]
    
    gradientLayer.frame = labelView.bounds
    labelView.layer.mask = gradientLayer

But the effect is visible only on the left side of the labelView. Right side is unchanged:

How can I apply the same gradient to the labelView right side?

CodePudding user response：

You should change your start/end points and your color locations

In a linear Gradient locations are relative points where [colors] are presented.

  0 0.2   0.8 1
  |--|-----|--|

so from 0 to 0.2 (20% of total length) we will have a gradient of clear to white, then from 0.2 (20%) to 0.8 (80%) a gradient from white to white (solid white) and from 0.8 (80%) to 1 (100%) a gradient from white to clear color.

From apple