How could I get mouse click coordinates using Swift on MacOS? - swift

Question

I try to find out about getting mouse click coordinates to draw a line. I would like to make two clicks (first and second dots) and a line'll be create.
I analysed a lot of codes, but they are huge (for example, I'm fond of this way https://stackoverflow.com/a/47496766/9058168).
I hope drawing line in Swift isn't difficult. Could I type another variable which has mouse click coordinates instead of numeral coordinates (look at code below)? If your answer is true, how to code it? Help me, please, to make it simplier.
import Cocoa
class DrawLine: NSView {
override func draw(_ dirtyRect: NSRect) {
NSBezierPath.strokeLine(from: CGPoint(x: 20, y: 20), to: CGPoint(x: 0, y: 100))
}
}

Answer 1

Listen for the mouse down event and set start location and end location using it to draw the path.
import Cocoa
class DrawLine: NSView {
var startPoint:NSPoint?
var endPoint:NSPoint?
override func mouseDown(with event: NSEvent){
if startPoint == nil || self.endPoint != nil{
self.startPoint = event.locationInWindow
} else {
self.endPoint = event.locationInWindow
self.needsDisplay = true
}
}
override func draw(_ dirtyRect: NSRect) {
if let theStart = startPoint, let theEnd = endPoint{
NSBezierPath.strokeLine(from: theStart, to: theEnd)
}
}
}