Swift 3.1 Column Chart Animation using CABasicAnimation and CALayer

Created By: Debasis Das (22-May-2017)
In this post we will create a simple animation of Column Chart value changes.
We will be using CABasicAnimation and CALayers for creating this effect.

//  ViewController.swift
//  ColumnChart-RandomData-CoreAnimation
//  Created by Debasis Das on 5/15/17.
//  Copyright © 2017 Knowstack. All rights reserved.

import Cocoa

class ViewController: NSViewController {

    @IBOutlet weak var graphView:NSView!
    let noOfColumns = 30
    override func viewDidLoad() {
        super.viewDidLoad()
        let layer = CALayer()
        layer.frame = self.graphView.frame
        layer.backgroundColor = NSColor.black.cgColor
        self.graphView.layer = layer
        self.graphView.wantsLayer = true
        
       
        let offset = 10
        
        for i in 0...noOfColumns{
            let columnLayer = CALayer()
            columnLayer.backgroundColor = NSColor.blue.cgColor
            columnLayer.frame = CGRect(x: offset+(i*20), y: 10, width: 10, height: 1)
            layer.addSublayer(columnLayer)
        }
        redrawGraph(self)
    }

    @IBAction func redrawGraph(_ sender: Any) {
        CATransaction.setAnimationDuration(2.0)
        for i in 0...noOfColumns{
            let newHeight = CGFloat(arc4random()) / CGFloat(UInt32.max) * 200 + 40
            var layerBounds = self.graphView.layer?.sublayers?[i].frame
            layerBounds?.size.height = newHeight
            self.graphView.layer?.sublayers?[i].frame = layerBounds!
        }
    }
}

you can download the code hereColumnChart-RandomData-CoreAnimation