Need help whenIntegrating complex UIView with SwiftUI failed - swift

Question

I tried to test a waving animated UIView that is runloop based on SwiftUI using ''UIViewRepresentable'' but it does not appear to be animating at all.
Using UIViewRepresentable Protocol to connect swiftui to UIView.
Swift UI Code:
import SwiftUI
struct WaveView: UIViewRepresentable {
func makeUIView(context: Context) -> WaveUIView {
WaveUIView(frame: .init(x: 0, y: 0, width: 300, height: 300))
}
func updateUIView(_ view: WaveUIView, context: Context) {
view.start()
}
}
struct WaveView_Previews: PreviewProvider {
static var previews: some View {
WaveView()
}
}
The "Waving" UIView that I tested working on UIViewController way of doing it.
import Foundation
import UIKit
class WaveUIView:UIView {
/// wave curvature (default: 1.5)
open var waveCurvature: CGFloat = 1.5
/// wave speed (default: 0.6)
open var waveSpeed: CGFloat = 0.6
/// wave height (default: 5)
open var waveHeight: CGFloat = 5
/// real wave color
open var realWaveColor: UIColor = UIColor.red {
didSet {
self.realWaveLayer.fillColor = self.realWaveColor.cgColor
}
}
/// mask wave color
open var maskWaveColor: UIColor = UIColor.red {
didSet {
self.maskWaveLayer.fillColor = self.maskWaveColor.cgColor
}
}
/// float over View
open var overView: UIView?
/// wave timmer
fileprivate var timer: CADisplayLink?
/// real aave
fileprivate var realWaveLayer :CAShapeLayer = CAShapeLayer()
/// mask wave
fileprivate var maskWaveLayer :CAShapeLayer = CAShapeLayer()
/// offset
fileprivate var offset :CGFloat = 0
fileprivate var _waveCurvature: CGFloat = 0
fileprivate var _waveSpeed: CGFloat = 0
fileprivate var _waveHeight: CGFloat = 0
fileprivate var _starting: Bool = false
fileprivate var _stoping: Bool = false
/**
Init view
- parameter frame: view frame
- returns: view
*/
override init(frame: CGRect) {
super.init(frame: frame)
var frame = self.bounds
frame.origin.y = frame.size.height
frame.size.height = 0
maskWaveLayer.frame = frame
realWaveLayer.frame = frame
// test
self.backgroundColor = UIColor.blue
}
/**
Init view with wave color
- parameter frame: view frame
- parameter color: real wave color
- returns: view
*/
public convenience init(frame: CGRect, color:UIColor) {
self.init(frame: frame)
self.realWaveColor = color
self.maskWaveColor = color.withAlphaComponent(0.4)
realWaveLayer.fillColor = self.realWaveColor.cgColor
maskWaveLayer.fillColor = self.maskWaveColor.cgColor
self.layer.addSublayer(self.realWaveLayer)
self.layer.addSublayer(self.maskWaveLayer)
}
required public init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
/**
Add over view
- parameter view: overview
*/
open func addOverView(_ view: UIView) {
overView = view
overView?.center = self.center
overView?.frame.origin.y = self.frame.height - (overView?.frame.height)!
self.addSubview(overView!)
}
/**
Start wave
*/
open func start() {
if !_starting {
_stop()
_starting = true
_stoping = false
_waveHeight = 0
_waveCurvature = 0
_waveSpeed = 0
timer = CADisplayLink(target: self, selector: #selector(wave))
timer?.add(to: RunLoop.current, forMode: RunLoop.Mode.common)
}
}
/**
Stop wave
*/
open func _stop(){
if (timer != nil) {
timer?.invalidate()
timer = nil
}
}
open func stop(){
if !_stoping {
_starting = false
_stoping = true
}
}
/**
Wave animation
*/
#objc func wave() {
// when view is not visible
// if overView?.window == nil {
// print("not playing cause not visible")
// return
// }
if _starting {
print("started")
if _waveHeight < waveHeight {
_waveHeight = _waveHeight + waveHeight/100.0
var frame = self.bounds
frame.origin.y = frame.size.height-_waveHeight
frame.size.height = _waveHeight
maskWaveLayer.frame = frame
realWaveLayer.frame = frame
_waveCurvature = _waveCurvature + waveCurvature / 100.0
_waveSpeed = _waveSpeed + waveSpeed / 100.0
} else {
_starting = false
}
}
if _stoping {
if _waveHeight > 0 {
_waveHeight = _waveHeight - waveHeight/50.0
var frame = self.bounds
frame.origin.y = frame.size.height
frame.size.height = _waveHeight
maskWaveLayer.frame = frame
realWaveLayer.frame = frame
_waveCurvature = _waveCurvature - waveCurvature / 50.0
_waveSpeed = _waveSpeed - waveSpeed / 50.0
} else {
_stoping = false
_stop()
}
}
offset += _waveSpeed
let width = frame.width
let height = CGFloat(_waveHeight)
let path = CGMutablePath()
path.move(to: CGPoint(x: 0, y: height))
var y: CGFloat = 0
let maskpath = CGMutablePath()
maskpath.move(to: CGPoint(x: 0, y: height))
let offset_f = Float(offset * 0.045)
let waveCurvature_f = Float(0.01 * _waveCurvature)
for x in 0...Int(width) {
y = height * CGFloat(sinf( waveCurvature_f * Float(x) + offset_f))
path.addLine(to: CGPoint(x: CGFloat(x), y: y))
maskpath.addLine(to: CGPoint(x: CGFloat(x), y: -y))
}
if (overView != nil) {
let centX = self.bounds.size.width/2
let centY = height * CGFloat(sinf(waveCurvature_f * Float(centX) + offset_f))
let center = CGPoint(x: centX , y: centY + self.bounds.size.height - overView!.bounds.size.height/2 - _waveHeight - 1 )
overView?.center = center
}
path.addLine(to: CGPoint(x: width, y: height))
path.addLine(to: CGPoint(x: 0, y: height))
path.closeSubpath()
self.realWaveLayer.path = path
maskpath.addLine(to: CGPoint(x: width, y: height))
maskpath.addLine(to: CGPoint(x: 0, y: height))
maskpath.closeSubpath()
self.maskWaveLayer.path = maskpath
}
}
I expect the SwiftUI to have the view animating and correctly have the frame/border changes according animation. But it is not animating at all right now.
Following is the animated view with UIViewController:
override func viewWillAppear(_ animated: Bool) {
cardView.start()
}
func viewdidload(){
let frame = CGRect(x: 0, y: 0, width: self.view.bounds.size.width * 0.8, height: view.bounds.height * 0.5)
cardView = HomeCardView(frame: frame, color: .gray)
cardView.addOverView(someUIView())
cardView.realWaveColor = UIColor.white.withAlphaComponent(0.7)
cardView.maskWaveColor = UIColor.white.withAlphaComponent(0.3)
cardView.waveSpeed = 1.2
cardView.waveHeight = 10
view.addSubview(cardView)
}

Answer 1

You forget to addOverview in update uimethod
func updateUIView(_ view: WaveUIView, context: Context) {
let overView: UIView = UIView(frame: CGRect.init(x: 0, y: 0, width: 300, height: 300))
overView.backgroundColor = UIColor.green
view.addOverView(overView)
view.start()
}