I am trying to apply a CAGradientLayer using swift, and I would like it to fade from black to transparent.
I thought putting any color with an alpha: 0 would render the same "transparent" color. It is not the case. White with alpha: 0 is still a bit white, red with alpha: 0 is still a bit red...
I don't want any tint, just transparent. The black being less black to the point theres no color and you can fully see the view under it for example.
gradientLayer.colors = [UIColor(hex: 0x000000, alpha: 0.4).cgColor,
UIColor(hex: 0x6D6D6D, alpha: 0.3).cgColor,
UIColor.white.withAlphaComponent(0.0).cgColor]
gradientLayer.locations = [0.0, 0.3, 1.0]
If I apply the layer over a gray picture, it's easy to see that its not transparent but white:
EDIT 1:
gradientLayer.frame = self.gradientView.bounds
gradientLayer.masksToBounds = true
gradientLayer.colors = [UIColor.black.withAlphaComponent(1.0).cgColor, UIColor.black.withAlphaComponent(0.0).cgColor]
gradientLayer.locations = [0.0, 1.0]
gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.0)
gradientLayer.endPoint = CGPoint(x: 0.0, y: 1.0)
self.gradientView.layer.addSublayer(gradientLayer)
Output :
You can try this:
gradientLayer.colors = [UIColor.black.withAlphaComponent(1.0).cgColor,
UIColor.black.withAlphaComponent(0.0).cgColor]
//gradientLayer.locations = [0.0, 1.0]
gradientLayer.frame = myView.bound
gradientLayer.startPoint = CGPoint(x: 1.0, y: 0.0)
gradientLayer.endPoint = CGPoint(x: 1.0, y: 1.0)
myView.layer.insertSublayer(gradientLayer, at: 0)
It worked in my case.
Related
I'm trying to implement a underlined UITextField with a gradient. Therefore I created a extension with a function underlined().
To get a gradient, I created a CAGradientLayer and made these customizations:
func underlined(){
let color = UIColor(red: 11/255, green: 95/255, blue: 244/255, alpha: 1).cgColor
let sndColor = UIColor(red: 106/255, green: 178/255, blue: 255/255, alpha: 1).cgColor
let gradient: CAGradientLayer = CAGradientLayer()
gradient.colors = [color, sndColor]
gradient.locations = [0.0, 1.0]
gradient.startPoint = CGPoint(x: 0, y: 0)
gradient.endPoint = CGPoint(x: 1, y: 0)
let width = CGFloat(2.0)
gradient.frame = CGRect(x: 0, y: self.frame.size.height - width, width: self.frame.size.width, height: self.frame.size.height)
gradient.borderWidth = width
self.layer.insertSublayer(gradient, at: 0)
self.layer.masksToBounds = true
}
A underline is being displayed, but it solely solid black - I've tried to change the colors, but it remains black (Issue outdated - see edit).
Does anybody see the issue?
Edit:
Adding gradient.borderColor = UIColor.blue.cgColor let me change the color of the line - but how can I apply the gradient on the border color?
Remove the below line from your code:
gradient.borderWidth = width
Screenshot:
Your code was not working because, the borderWidth is covering whole of the gradient frame.Try setting the borderColor, then you'll see the difference.
gradient.borderColor = UIColor.red.cgColor
Let me know if you still face any issues.
I have a UIView that I would like to apply a fade / gradient too. I'd like this to appear only on the edges, the effect I am trying to create is
The grey line at the top of the image. Grey in the middle and both edges are faded to white.
I have tried something like this
func render(content: FeedItem) {
print(content.item.externalId)
// rowSeperatorView.backgroundColor = UIColor.usingHex("f2f2f2")
iconContainerView.backgroundColor = UIColor.usingHex("3bac58")
let gradientLayer: CAGradientLayer = CAGradientLayer()
gradientLayer.frame = rowSeperatorView.bounds
gradientLayer.colors = [
UIColor.white.cgColor,
UIColor.usingHex("f2f2f2").cgColor,
UIColor.white.cgColor,
]
gradientLayer.locations = [0,0.5,1]
rowSeperatorView.layer.addSublayer(gradientLayer)
iconContainerView.layer.cornerRadius = 5
iconContainerView.clipsToBounds = true
iconContainerView.layer.maskedCorners = [.layerMaxXMaxYCorner, .layerMaxXMinYCorner]
}
But cannot seem to achieve this result.
You are almost there, try adding a startPoint and endPoint and then play with the locations property.
let gradient = CAGradientLayer()
gradient.frame = rowSeperatorView.bounds
gradient.colors = [UIColor.white.cgColor, UIColor.usingHex("f2f2f2").cgColor, UIColor.white.cgColor]
gradient.locations = [0, 0.4, 0.6]
gradient.startPoint = CGPoint(x: 0.0, y: 0.0)
gradient.endPoint = CGPoint(x: 1.0, y: 0.0)
rowSeperatorView.layer.addSublayer(gradient)
I am trying to create a simple gradient for the background of a UIViewController. My code is:
let gradientLayer = CAGradientLayer()
gradientLayer.frame = view.bounds
let bottomColor = UIColor(hue: 208 / 360, saturation: 82 / 100, brightness: 0.9, alpha: 1)
let topColor = UIColor(hue: 208 / 360, saturation: 41 / 100, brightness: 0.9, alpha: 1)
gradientLayer.colors = [bottomColor, topColor]
gradientLayer.startPoint = CGPoint(x: 0.5, y: 0.1)
gradientLayer.endPoint = CGPoint(x: 0.5, y: 0.0)
view.layer.addSublayer(gradientLayer)
The gradient does not show. When I look in the view debugger, I do not see it. I check the frame of the view and it looks ok
x: 0, y:0, width: 375, height: 667
I've tried the view.layer.insert at method as well, but that did not work. If I do
view.layer.backgroundColor.orange
then I do see an orange background. Am I missing something?
Change
gradientLayer.colors = [bottomColor, topColor]
to
gradientLayer.colors = [bottomColor.cgColor, topColor.cgColor]
I'm trying to create an effect whereby a photo is blurry at the top, but not at the bottom, and the blurriness 'fades off' gradually. I achieved this with the code below, which worked fine in iOS9, but does not in iOS10.
I'm aware of a known bug, as described in this question, that prevents a layer having a mask and a blur on the same layer.
The difference between my question and the one linked, is I'm not interested in using a CAShapeLayer as my mask, but rather a CAGradientLayer. I've tried fiddling with adding views/masks/layers in different orders, but am not having much luck.
var visualEffectView = UIVisualEffectView(effect: UIBlurEffect(style: .light))
visualEffectView.frame = CGRect(x: 0.0, y:0.0, width: photo.bounds.width, height: photo.bounds.height)
photo.addSubview(visualEffectView)
let maskStartColour = UIColor(red: 0.0, green: 0.0, blue: 0.0, alpha: 1.0)
let maskEndColour = UIColor(red: 0.0, green: 0.0, blue: 0.0, alpha: 0.0)
let gradient = CAGradientLayer()
gradient.frame = CGRect(x: 0, y: 0, width: visualEffectView.bounds.width, height: visualEffectView.bounds.height)
let colors: [AnyObject] = [maskStartColour.cgColor, maskEndColour.cgColor]
gradient.colors = colors
gradient.startPoint = CGPoint(x: 0.0, y: 0.0)
gradient.endPoint = CGPoint(x: 0.0, y: 1.0)
visualEffectView.layer.mask = gradient
I'm trying to add opacity to my view. When I add a CAGradientlayer, I roughly get, what I planned, but have a few issues.
I can't change the color. No matter what values I use, I'll always get a white layer
Even though I wanted it to be distributed over the whole view, it seems like it has an offset to the left.
My code is as follows:
let maskLayer = CAGradientLayer()
maskLayer.anchorPoint = CGPoint(x: 0.0, y: 0.0)
maskLayer.startPoint = CGPoint(x: 0.0, y: 0.5)
maskLayer.endPoint = CGPoint(x: 1.0, y: 0.5)
maskLayer.colors = [UIColor(white: 0.0, alpha: 0.0).CGColor, UIColor(white: 1.0, alpha: 1.0).CGColor, UIColor(white: 0.0, alpha: 0.0).CGColor]
maskLayer.locations = [0.0, 0.5, 1.0]
maskLayer.bounds = CGRectMake(0, 0, self.frame.width, self.frame.height)
self.layer.mask = maskLayer
What am I doing wrong?
Thanks
About the white, this is because a layer mask does not contribute to color, only transparency. Essentially, only the alpha component has an effect, and the R,G,B components of the layer mask are ignored.
About the offset, could it be because your view is getting resized, and your layer isn't kept up to date? If so you could see the answer to this other question: CALayers didn't get resized on its UIView's bounds change. Why?