How to change frame of gradient layer at runtime? - ios

When I run the app the gradient layer frame doesn't match with UIView frame. I tried with below code:
let color1 = UIColor(red: 20.0/255, green: 43.0/255, blue: 81.0/255, alpha: 1.0).cgColor
let color2 = UIColor(red: 149.0/255, green: 45.0/255, blue: 122.0/255, alpha: 1.0).cgColor
let gradientLayer = CAGradientLayer()
gradientLayer.frame = self.backBarcodeSrch.bounds
gradientLayer.colors = [color1,color2 ]
gradientLayer.locations = [0.0, 1.0]
gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.6)
gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.6)
self.backBarcodeSrch.layer.addSublayer(gradientLayer)

Update the frame of gradientLayer in viewDidLayoutSubviews() in your ViewController.
class VC: UIViewController {
var gradientLayer = CAGradientLayer()
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
gradientLayer.frame = self.backBarcodeSrch.bounds
}
override func viewDidLoad() {
super.viewDidLoad()
self.addGradient()
}
func addGradient() {
let color1 = UIColor(red: 20.0/255, green: 43.0/255, blue: 81.0/255, alpha: 1.0).cgColor
let color2 = UIColor(red: 149.0/255, green: 45.0/255, blue: 122.0/255, alpha: 1.0).cgColor
gradientLayer.frame = self.backBarcodeSrch.bounds
gradientLayer.colors = [color1,color2 ]
gradientLayer.locations = [0.0, 1.0]
gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.6)
gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.6)
self.backBarcodeSrch.layer.addSublayer(gradientLayer)
}
}

try this :
func addGradientLayer() {
let color1 = UIColor(red: 20.0/255, green: 43.0/255, blue: 81.0/255, alpha:1.0).cgColor
let color2 = UIColor(red: 149.0/255, green: 45.0/255, blue: 122.0/255, alpha: 1.0).cgColor
let gradientLayer = CAGradientLayer()
gradientLayer.frame = self.backBarcodeSrch.bounds
gradientLayer.colors = [color1,color2 ]
gradientLayer.locations = [0.0, 1.0]
gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.6)
gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.6)
self.backBarcodeSrch.layer.addSublayer(gradientLayer)
}
override func viewDidLayoutSubviews() {
addGradientLayer()
}

Related

How to set gradient color in UIbutton?

How we can set gradient colour in UIButton using swift?
I have tried this:
func addGradient(btn : UIButton){
let color1 = UIColor(red: 221.0/255, green: 96.0/255, blue: 129.0/255, alpha: 1.0).cgColor
let color2 = UIColor(red: 171.0/255, green: 74.0/255, blue: 141.0/255, alpha: 1.0).cgColor
let gradientLayer = CAGradientLayer()
gradientLayer.colors = [color2,color1 ]
gradientLayer.locations = [0.0, 1.0]
gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.6)
gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.6)
btn.layer.insertSublayer(gradientLayer, at: 0)
}
it's not working properly.
Try below code hope it will fix your issue:
Uses:
override func viewDidAppear(_ animated: Bool) {
yesBtn.clipsToBounds = true
yesBtn.addGradient(btn: yesBtn)
}
Extension:
func addGradient(btn : UIButton){
let color1 = UIColor(red: 221.0/255, green: 96.0/255, blue: 129.0/255, alpha: 1.0).cgColor
let color2 = UIColor(red: 171.0/255, green: 74.0/255, blue: 141.0/255, alpha: 1.0).cgColor
let gradientLayer = CAGradientLayer()
gradientLayer.frame = btn.bounds
gradientLayer.colors = [color2,color1 ]
gradientLayer.locations = [0.0, 1.0]
gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.6)
gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.6)
btn.layer.insertSublayer(gradientLayer, at: 0)
}

NavBar title hidden behind CAGradientLayer

I would like to add gradient layer to my navbar, but after I add it, layer hides my title, like its behind that new sublayer.
override func viewDidLoad() {
super.viewDidLoad()
self.title = "My Trips"
self.navigationController?.navigationBar.titleTextAttributes = [NSAttributedString.Key.foregroundColor:UIColor.white]
//self.navigationController?.navigationBar.layer.addSublayer(gradientLayer)
self.navigationController?.navigationBar.layer.insertSublayer(gradientLayer, at: 1)
setupGradient()
}
let gradientLayer = CAGradientLayer()
func setupGradient() {
gradientLayer.colors = [
UIColor(red: 0.259, green: 0.188, blue: 0.475, alpha: 1).cgColor,
UIColor(red: 0.11, green: 0.024, blue: 0.369, alpha: 1).cgColor
]
gradientLayer.locations = [0, 1]
gradientLayer.startPoint = CGPoint(x: 0.25, y: 0.5)
gradientLayer.endPoint = CGPoint(x: 0.75, y: 0.5)
gradientLayer.transform = CATransform3DMakeAffineTransform(CGAffineTransform(a: 0, b: 0.58, c: -0.58, d: 0, tx: 0.5, ty: 0))
gradientLayer.bounds = (self.navigationController?.navigationBar.bounds.insetBy(dx: -0.01*view.bounds.size.width, dy: -1*view.bounds.size.height))!
}
Use this line for inserting layer.
self.navigationController?.navigationBar.subviews.first?.layer.insertSublayer(gradientLayer, at: 0)

How to set gradient colour to UIButton in background?

Am trying to set CAGradientLayer for UIButton.
But it is not getting exactly. am I doing any wrong ?
am getting output like
You can see there is some horizontal line
Here is the code which I tried
let topColor = UIColor(red: 0.62, green: 0.38, blue: 1, alpha: 1).cgColor
let bottomColor = UIColor(red: 0.87, green: 0.51, blue: 0.93, alpha: 1).cgColor
let gradientLayer = CAGradientLayer()
gradientLayer.frame = myButton.bounds
gradientLayer.colors = [topColor, bottomColor]
gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.5)
gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.5)
myButton.layer.insertSublayer(myButton, at: 0)
Create a Designable custom class like this
import Foundation
import UIKit
#IBDesignable class CustomButton:UIButton {
#IBInspectable var firstColor:UIColor = UIColor.clear {
didSet {
updateUI()
}
}
#IBInspectable var secondColor:UIColor = UIColor.clear {
didSet{
updateUI()
}
}
override class var layerClass: AnyClass {
get {
return CAGradientLayer.self
}
}
func updateUI(){
let gradient: CAGradientLayer = self.layer as! CAGradientLayer
gradient.frame = self.bounds
gradient.colors = [firstColor,secondColor].map { $0.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)
}
}
from your Identity inspector set your UIbutton class to CustomButtom like this
from your Attribute inspector change your gradient color to whatever you want to set
and finally your button will be like this
if you want to change the starting and endpoint to those colors
just play around with these two values
gradient.startPoint = CGPoint(x: 0.0, y: 1.0)
gradient.endPoint = CGPoint(x: 1.0, y: 1.0)
You have to update the gradient's frame when the view is laid out:
override func viewDidLayoutSubviews() {
myButton.layer.sublayers?.first?.frame = myButton.bounds
}

How do I center and aspect fit an image in Swift 3?

I have a project in Swift 3 that I am using a gradient on the view. I placed a image on the view, but it is under the gradient layer so I was going to draw the image programmatically instead of with the storyboard. I can't seem to figure out how to get the image to be centered and to aspect fit inside the bounds of the view.
What I have...
//Gradient Background
let gradientLayer = CAGradientLayer()
gradientLayer.frame = self.view.frame
gradientLayer.colors = [UIColor(red: 0/255, green: 147/255, blue: 255/255, alpha: 1.0).cgColor, UIColor(red: 162/255, green: 134/255, blue: 255/255, alpha: 1.0).cgColor]
gradientLayer.locations = [0.0, 1.0]
gradientLayer.startPoint = CGPoint(x: 0.0, y: 1.0)
gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.0)
self.view.layer.addSublayer(gradientLayer)
//Image
let mainImage = UIImage(named:"WhiteLogoFront")
var mainImageView = UIImageView(image:mainImage)
self.view.addSubview(mainImageView)
You can try it
let mainImage = UIImage(named:"WhiteLogoFront")
var mainImageView = UIImageView(image:mainImage)
mainImageView.contentMode = .ScaleAspectFit
let gradientLayer = CAGradientLayer()
gradientLayer.frame = self.view.frame
gradientLayer.colors = [UIColor(red: 0/255, green: 147/255, blue: 255/255, alpha: 1.0).cgColor, UIColor(red: 162/255, green: 134/255, blue: 255/255, alpha: 1.0).cgColor]
gradientLayer.locations = [0.0, 1.0]
gradientLayer.startPoint = CGPoint(x: 0.0, y: 1.0)
gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.0)
self.view.layer.addSublayer(gradientLayer)
//Image
let mainImage = UIImage(named:"WhiteLogoFront")
var mainImageView = UIImageView(image:mainImage)
mainImageView.center = self.view.cente
mainImageView.contentMode = .ScaleAspectFit
self.view.addSubview(mainImageView)
Try this one

Gradiant in playground different from simulator

I tried to make a gradiant using playground then make it into a subclass of uiview to use it in my codebase.
The playground code is like this:
let view = UIView(frame: CGRect(x: 0, y: 0, width: 640, height: 41
))
let gradient: CAGradientLayer = CAGradientLayer(layer: view.layer)
gradient.frame = view.frame
let lightColor = UIColor(red: 157/256, green: 157/256, blue: 154/256, alpha: 1)
let darkColor = UIColor(red: 108/256, green: 104/256, blue: 104/256, alpha: 1)
gradient.colors = [lightColor.CGColor, darkColor.CGColor]
gradient.locations = [0.6 , 0.4]
gradient.startPoint = CGPoint(x: 1, y: 0.55)
gradient.endPoint = CGPoint(x: 0, y: 0.45)
view.layer.insertSublayer(gradient, atIndex: 0)
view //displayed
And display like this:
I tried to make it into my codebase with:
class GradiantView : UIView {
override var frame: CGRect {
didSet {
let gradient: CAGradientLayer = CAGradientLayer(layer: layer)
gradient.frame = bounds
let lightColor = UIColor(red: 157/256, green: 157/256, blue: 154/256, alpha: 1)
let darkColor = UIColor(red: 108/256, green: 104/256, blue: 104/256, alpha: 1)
gradient.colors = [lightColor.CGColor, darkColor.CGColor]
gradient.locations = [0.6 , 0.4]
gradient.startPoint = CGPoint(x: 1, y: 0.55)
gradient.endPoint = CGPoint(x: 0, y: 0.45)
layer.insertSublayer(gradient, atIndex: 0)
}
}
}
However, the result is like this: (no gradiant applied)
What happened and how to fix it ?
I inverted the locations and it seems to work.
I welcome any explanation on the difference between simulator and playground.
gradientLayer.locations = [0.4 , 0.6]

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