I created a custom UIView class where I override the draw(_ rect: CGRect) function. In it, I added a gradient (CAGradientLayer) sublayer (which works without much problem) and then add another sublayer above it, a custom 'CloseLayer' class that inherits from CALayer.
That second sublayer I add gets correctly added in front with the right dimensions, however the line drawing I implemented in the draw(in ctx: CGContext) function of the custom CALayer class doesn't seem to be doing anything. I have been looking at several resources and googling for the past few days and am started to get a bit discouraged. Below is my code for the UIView class (that contains the two sublayers) and the custom layer class I want drawing to occur in. Any help is much appreciated!
class GraphAView: UIView {
// trading 9:00AM EST to 6:00PM EST
// Normal: 9:30AM EST to 4:00PM EST
// 9 hours total, 5 min intervals (12 intervals per hour, 108 total)
let HonchoGreyComponents : [CGFloat] = [0.2,0.2,0.2,1.0]
let graphBackGreyComponents: [CGFloat] = [0.8,0.8,0.8,1.0]
override func draw(_ rect: CGRect) {
setUpBack()
}
func setUpBack(){
let RGBSpace = CGColorSpaceCreateDeviceRGB()
let HonchoGrey = CGColor(colorSpace: RGBSpace, components: HonchoGreyComponents)
let graphBackGrey = CGColor(colorSpace: RGBSpace, components: graphBackGreyComponents)
let Gradlayer = CAGradientLayer()
Gradlayer.frame = self.bounds
Gradlayer.colors = [HonchoGrey!,graphBackGrey!,graphBackGrey!,HonchoGrey!]
//layer.locations = [NSNumber(value: PreMarketEnd),NSNumber(value: RegMarketEnd)]
Gradlayer.locations = [0,0.055555, 0.7777777]
Gradlayer.startPoint = CGPoint(x: 0, y: 0)
Gradlayer.endPoint = CGPoint(x: 1, y: 0)
self.layer.insertSublayer(Gradlayer, at: 0)
let closingLay = CloseLayer()
closingLay.frame = self.bounds
let yer = UIColor(red: 0.3, green: 0.6, blue: 0.8, alpha: 1.0)
//closingLay.backgroundColor = UIColor.blue.cgColor
//closingLay.backgroundColor = UIColor(white: 0.4, alpha: 0.0).cgColor
closingLay.backgroundColor = yer.cgColor
self.layer.insertSublayer(closingLay, above: Gradlayer)
closingLay.setNeedsDisplay()
self.layer.setNeedsDisplay()
}
}
class CloseLayer: CALayer {
let ClosinglineWidth: CGFloat = 4.0
let dashPattern: [CGFloat] = [2,2]
override func draw(in ctx: CGContext) {
let CloseContext = UIGraphicsGetCurrentContext()
let middleY = self.frame.height / 2
// let width = self.frame.width
// let context = UIGraphicsGetCurrentContext()
CloseContext?.setLineWidth(ClosinglineWidth)
CloseContext?.setLineDash(phase: 1, lengths: dashPattern)
CloseContext?.move(to: CGPoint(x: 0, y: middleY))
CloseContext?.addLine(to: CGPoint(x: self.frame.width, y: middleY)) // 358 width
let closingLineColor = UIColor.red.cgColor
CloseContext?.setStrokeColor(closingLineColor)
CloseContext?.strokePath()
}
func drawLine(start: CGPoint, end: CGPoint){
}
}
The problem is this line:
let CloseContext = UIGraphicsGetCurrentContext()
There is no current context. Your job is to draw into ctx, the context you were handed.
Long story short, change that line to:
let CloseContext : CGContext? = ctx
...and bingo, you will see your line. (But that is just for instant gratification. In the end, you should get rid of CloseContext everywhere and subsitute ctx.)