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)
Related
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?
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 https://developer.apple.com/documentation/quartzcore/cagradientlayer/1462410-locations
Discussion
The gradient stops are specified as values between 0 and 1. The values must be monotonically increasing. If nil, the stops are spread uniformly across the range. Defaults to nil.
When rendered, the colors are mapped to the output color space before being interpolated.
let gradientLayer = CAGradientLayer()
gradientLayer.startPoint = CGPoint(x: 0, y: 0.5)
gradientLayer.endPoint = CGPoint(x: 1, y: 0.5)
gradientLayer.colors = [UIColor.clear.cgColor, UIColor.white.cgColor, UIColor.white.cgColor, UIColor.clear.cgColor]
gradientLayer.locations = [0, 0.2, 0.8, 1]
gradientLayer.frame = labelView.bounds
labelView.layer.mask = gradientLayer
After Updated answer
I have to follow through my designer's gradient layer as shown below and I'm running into a wall trying to replicate her design (below).
I have the following code to try to replicate the same shadow but it is too solid compared to her gradient. How do I reduce my layer to have a gradient look and feel?
backgroundView.layer.shadowColor = UIColor.Custom.darkBlue.cgColor
backgroundView.layer.shadowOpacity = 1.0
backgroundView.layer.shadowRadius = 10
EDIT:
I implemented what I needed using #Frankenstein's solution below.
backgroundView.backgroundColor = UIColor.Custom.darkBlue
let gradient: CAGradientLayer = CAGradientLayer()
gradient.colors = [UIColor.black.cgColor, UIColor.Custom.darkBlue.cgColor]
gradient.frame = CGRect(x: backgroundView.frame.origin.x, y: backgroundView.frame.origin.y - 39, width: view.bounds.width, height: 40)
view.layer.addSublayer(gradient)
With the expected result below. Thank you!
You need to add a new CAGradientLayer and not set the shadow, here is an example:
let gradient: CAGradientLayer = CAGradientLayer()
gradient.colors = [UIColor.black.cgColor, UIColor.Custom.darkBlue.cgColor]
gradient.locations = [0.0 , 1.0]
gradient.startPoint = CGPoint(x: 0.0, y: 1.0)
gradient.endPoint = CGPoint(x: 1.0, y: 1.0)
gradient.frame = view.bounds
view.layer.addSublayer(gradient)
Here is how you can achieve that
let gradient: CAGradientLayer = CAGradientLayer()
gradient.colors = [UIColor.black.cgColor, UIColor.blue.cgColor]
gradient.locations = [0.0 , 1.0]
gradient.startPoint = CGPoint(x : 0.0, y : 0)
gradient.endPoint = CGPoint(x :0.0, y: 0.15) // you need to play with 0.15 to adjust gradient vertically
gradient.frame = view.bounds
view.layer.addSublayer(gradient)
With 0.15 to 0.5 you get
Here is what I am trying to do:
The screenshot is taken from Iphone:
This is my code:
#IBOutlet weak var viewBottomBorder: UIView!
let gradient = CAGradientLayer()
gradient.startPoint = CGPoint(x: 0.5, y: 0.0)
gradient.endPoint = CGPoint(x: 0.5, y: 1.0)
let whiteColor = UIColor.black
gradient.colors = [whiteColor.withAlphaComponent(0.0).cgColor, whiteColor.withAlphaComponent(1.0), whiteColor.withAlphaComponent(1.0).cgColor]
gradient.locations = [NSNumber(value: 0.0),NSNumber(value: 0.2),NSNumber(value: 1.0)]
gradient.frame = viewBottomBorder.bounds
viewBottomBorder.layer.mask = gradient
Question: How to show same text in white color with gradient?
Can someone please explain to me how to solve this , i've tried to solve this issue but no results yet.
Any help would be greatly appreciated.
Thanks in advance.
You need to start your gradient at the top, because it's darker at the top. So x should be have max alpha. Then as y increases reduce the alpha.
Try this:
let gradient = CAGradientLayer()
gradient.startPoint = CGPoint(x: 1.0, y: 0.0)
gradient.endPoint = CGPoint(x: 0.0, y: 1.0)
let whiteColor = UIColor.black
gradient.colors = [whiteColor.withAlphaComponent(1.0).cgColor, whiteColor.withAlphaComponent(1.0), whiteColor.withAlphaComponent(0.0).cgColor]
gradient.locations = [NSNumber(value: 1.0),NSNumber(value: 0.7),NSNumber(value: 0.0)]
gradient.frame = viewBottomBorder.bounds
viewBottomBorder.layer.mask = gradient
A little alternative:
func setupGradient(on view: UIView, withHeight height: CGFloat) {
// this is view that holds gradient
let gradientHolderView = UIView()
gradientHolderView.backgroundColor = .clear
gradientHolderView.translatesAutoresizingMaskIntoConstraints = false
// here you set layout programmatically (you can create this view in storyoard as well and attach gradient to it)
// make sure to position this view under your text
view.addSubview(gradientHolderView) // alternative: view.insertSubview(gradientHolderView, belowSubview: YourTextLaber)
gradientHolderView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
gradientHolderView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor).isActive = true
gradientHolderView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
gradientHolderView.heightAnchor.constraint(equalToConstant: height).isActive = true
// this is needed to kinda refresh layout a little so later we can get bounds from view. I'm not sure exactly why but without this if you create view programmatically it is needed
gradientHolderView.setNeedsLayout()
gradientHolderView.layoutIfNeeded()
// here you create gradient as layer and add it as a sublayer on your view (modify colors as you like)
let gradientLayer = CAGradientLayer()
gradientLayer.frame = gradientHolderView.bounds
gradientLayer.colors = [UIColor.clear.cgColor, UIColor(white: 0, alpha: 0.6).cgColor]
gradientHolderView.layer.addSublayer(gradientLayer)
}
Use above code to apply Gradient to your view
var gradientBackground : CAGradientLayer?
func applyGradientToBackground() {
if self.gradientBackground != nil {
self.gradientBackground?.removeFromSuperlayer()
}
self.gradientBackground = CAGradientLayer()
self.gradientBackground?.frame = self.your_view_name.bounds
let cor1 = UIColor.black.withAlphaComponent(1).cgColor
let cor2 = UIColor.white.cgColor
let arrayColors = [cor1, cor2]
self.gradientBackground?.colors = arrayColors
self.your_view_name.layer.insertSublayer(self.gradientBackground!, at: 0)
}
I want to make a UIView have an effect of transparent gradient from the middle to the left and right. Like in this example:
The word 籍 has the desired effect. This view is achieved by the class MarqueeLabel. I examined the source code, it is likely implemented by class CALayer.
In Swift 4: for top to bottom transparent gradient.
let gradient = CAGradientLayer()
gradient.startPoint = CGPoint(x: 0.5, y: 0.0)
gradient.endPoint = CGPoint(x: 0.5, y: 0.6)
let whiteColor = UIColor.white
gradient.colors = [whiteColor.withAlphaComponent(0.0).cgColor, whiteColor.withAlphaComponent(1.0).cgColor, whiteColor.withAlphaComponent(1.0).cgColor]
gradient.locations = [NSNumber(value: 0.0),NSNumber(value: 0.2),NSNumber(value: 1.0)]
gradient.frame = gradientView.bounds
gradientView.layer.mask = gradient
Screenshot
Swift code
let mask = CAGradientLayer()
mask.startPoint = CGPointMake(0.0, 0.5)
mask.endPoint = CGPointMake(1.0, 0.5)
let whiteColor = UIColor.whiteColor()
mask.colors = [whiteColor.colorWithAlphaComponent(0.0).CGColor,whiteColor.colorWithAlphaComponent(1.0),whiteColor.colorWithAlphaComponent(1.0).CGColor]
mask.locations = [NSNumber(double: 0.0),NSNumber(double: 0.2),NSNumber(double: 1.0)]
mask.frame = label.bounds
label.layer.mask = mask
You can use CAGradientLayer as following.
gradientLayer = [CAGradientLayer layer];
gradientLayer.frame = baseView.bounds;
gradientLayer.startPoint = CGPointMake(0.5,0.0);
gradientLayer.endPoint = CGPointMake(0.5,1.0);
gradientLayer.locations = #[#(0.0), #(0.2), #(1.0)];
gradientLayer.colors = #[(id)[UIColor colorWithWhite:1.0 alpha:0.9].CGColor,
(id)[UIColor colorWithWhite:1.0 alpha:0.3].CGColor,
(id)[UIColor colorWithWhite:1.0 alpha:0.0].CGColor];
[baseView.layer addSublayer:gradientLayer];
CAGradientLayer supports several properties to make natural gradient, such as setting gradient direction by startPoint and endPoint, changing color curve by locations and colors.
You also make a transparent effect by using alpha channel of color.
Swift 3:
let mask = CAGradientLayer()
mask.startPoint = CGPoint(x: 0, y: 0.5)
mask.endPoint = CGPoint(x:1.0, y:0.5)
let whiteColor = UIColor.white
mask.colors = [whiteColor.withAlphaComponent(0.0).cgColor,whiteColor.withAlphaComponent(1.0),whiteColor.withAlphaComponent(1.0).cgColor]
mask.locations = [NSNumber(value: 0.0),NSNumber(value: 0.2),NSNumber(value: 1.0)]
mask.frame = view.bounds
view.layer.mask = mask
Use clear color instead of set the alpha value.
let gradientLayer = CAGradientLayer()
gradientLayer.startPoint = CGPoint(x: 0, y: 0.5)
gradientLayer.endPoint = CGPoint(x: 1, y: 0.5)
gradientLayer.colors = [UIColor.clear.cgColor, UIColor.white.cgColor, UIColor.white.cgColor]
gradientLayer.locations = [0, 0.2, 1]
gradientLayer.frame = gradientView.bounds
gradientView.layer.mask = gradientLayer
I have created CAGradientLayer having three colors, i need to give each color different locations.
Example:
Red = 0 to 50 %
Yellow = 51 to 80 %
Green = 81 to 100 %
I have tried with giving startPoint and endPoint but it did not work.
If you put the following code into a Playground you will get the exact desired output:
let view = UIView(frame: CGRectMake(0,0,200,100))
let layer = CAGradientLayer()
layer.frame = view.frame
layer.colors = [UIColor.greenColor().CGColor, UIColor.yellowColor().CGColor, UIColor.redColor().CGColor]
layer.locations = [0.0, 0.8, 1.0]
view.layer.addSublayer(layer)
XCPShowView("ident", view: view)
Outputting:
You simply define the colors as an array of CGColors, and an array of the same size of NSNumbers each between 0.0 and 1.0.
Dont use startPoint and endPoint for that - they are for defining from where to where the gradient is shown in the layer - it does not have anything to do with the percents and the colors etc.
More recent Swift3 version of the code:
let view = UIView(frame: CGRect(x: 0, y: 0, width: 200, height: 100))
let layer = CAGradientLayer()
layer.frame = view.frame
layer.colors = [UIColor.green.cgColor, UIColor.yellow.cgColor, UIColor.red.cgColor]
layer.locations = [0.0, 0.8, 1.0]
view.layer.addSublayer(layer)
PlaygroundPage.current.liveView = view