How to get animated polyline route in GMSMapView, so that it move along with map when map is moved?

Question

I have created animated polyline like CAShapeLayer by following code, I have added CAShapeLayer as sublayer to GMSMapiew but, if I move the map the layer won't moves. where to add the layer, so that it move along with map?

   func layer(from path: GMSPath) -> CAShapeLayer {
        let breizerPath = UIBezierPath()
        let firstCoordinate: CLLocationCoordinate2D = path.coordinate(at: 0)
        breizerPath.move(to: self.mapView.projection.point(for: firstCoordinate))
        for i in 1 ..< Int((path.count())){
            print(path.coordinate(at: UInt(i)))
            let coordinate: CLLocationCoordinate2D = path.coordinate(at: UInt(i))
            breizerPath.addLine(to: self.mapView.projection.point(for: coordinate))
        }

        let shapeLayer = CAShapeLayer()
        shapeLayer.path = breizerPath.reversing().cgPath
        shapeLayer.strokeColor = UIColor.green.cgColor
        shapeLayer.lineWidth = 4.0
        shapeLayer.fillColor = UIColor.clear.cgColor
        shapeLayer.lineJoin = kCALineJoinRound
        shapeLayer.lineCap = kCALineCapRound
        shapeLayer.cornerRadius = 5
        return shapeLayer
    }

    func animatePath(_ layer: CAShapeLayer) {
        let pathAnimation = CABasicAnimation(keyPath: "strokeEnd")
        pathAnimation.duration = 6
        //pathAnimation.delegate = self
        pathAnimation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseOut)
        pathAnimation.fromValue = Int(0.0)
        pathAnimation.toValue = Int(1.0)
        pathAnimation.repeatCount = 100
        layer.add(pathAnimation, forKey: "strokeEnd")
    }

Added to GoogleMapView by

    let shapelayer: CAShapeLayer = self.layer(from: path!)
    self.animatePath(shapelayer)
    self.mapView.layer.addSublayer(shapelayer)

Answer 1

You can create a variable for shapeLayer and use the GMSMapViewDelegate methods mapView(_ mapView: GMSMapView, willMove gesture: Bool) and mapView(_ mapView: GMSMapView, idleAt position: GMSCameraPosition) to add and remove the layer from the map. There are two downsides to this approach, first is that the layer doesn't animate when the map is being dragged(moved) and second downside is that the layer always sits on top of all other map elements like markers, road names, POIs etc. I couldn't find a way to add this layer as a sublayer directly to the ground overlay. You can find the full code below:

var polyLineShapeLayer:CAShapeLayer?

 var layerAdded = false

 var path = GMSPath()

 var polyLine:GMSPolyline!



// Add regular polyline to the map 

func addPolyLineWithEncodedStringInMap(_ encodedString:String) {
        self.polyLine = GMSPolyline(path: self.path)
        polyLine.strokeWidth = 3.8
        self.polyLine.strokeColor = .black
        polyLine.map = googleMapView

        DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 2) {
            self.addPolyLineShapeLayerToMapView()
            self.layerAdded = true
        }

    }


// Add CAshapeLayer to map 

  func layer(from path: GMSPath) -> CAShapeLayer {
        let breizerPath = UIBezierPath()
        let firstCoordinate: CLLocationCoordinate2D = path.coordinate(at: 0)
        breizerPath.move(to: self.googleMapView.projection.point(for: firstCoordinate))
        for i in 1 ..< Int((path.count())){
            print(path.coordinate(at: UInt(i)))
            let coordinate: CLLocationCoordinate2D = path.coordinate(at: UInt(i))
            breizerPath.addLine(to: self.googleMapView.projection.point(for: coordinate))
        }

        let shapeLayer = CAShapeLayer()
        shapeLayer.path = breizerPath.cgPath
        shapeLayer.strokeColor = UIColor.lightGray.withAlphaComponent(0.8).cgColor
        shapeLayer.lineWidth = 4.0
        shapeLayer.fillColor = UIColor.clear.cgColor
        shapeLayer.lineJoin = kCALineJoinRound
        shapeLayer.lineCap = kCALineCapRound
        shapeLayer.cornerRadius = 5
        return shapeLayer
    }

    func animatePath(_ layer: CAShapeLayer) {
        let pathAnimation = CABasicAnimation(keyPath: "strokeEnd")
        pathAnimation.duration = 2
        pathAnimation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
        pathAnimation.fromValue = Int(0.0)
        pathAnimation.toValue = Int(1.0)
        pathAnimation.repeatCount = 200
        layer.add(pathAnimation, forKey: "strokeEnd")
    }

    func addPolyLineShapeLayerToMapView(){

        polyLineShapeLayer = self.layer(from: self.path)

        if let polyLineShapeLayer = polyLineShapeLayer{
            self.animatePath(polyLineShapeLayer)
            self.googleMapView.layer.addSublayer(polyLineShapeLayer)
            polyLineShapeLayer.zPosition = 0

        }

    }


// Delegate methods to control the polyline 


// whenever map is about to move, if layer is already added, remove the layer from superLayer 

    func mapView(_ mapView: GMSMapView, willMove gesture: Bool) {
        if layerAdded{
            DispatchQueue.main.async {
                self.polyLineShapeLayer?.removeFromSuperlayer()
                self.polyLineShapeLayer = nil
            }
        }
    }

// when map is idle again(var layerAdded:bool ensures that additional layer is not added initially when the delegate method is fired) add new instance of polylineShapeLayer to the map with current projected coordinates. 

    func mapView(_ mapView: GMSMapView, idleAt position: GMSCameraPosition) {
        if self.layerAdded{
            self.addPolyLineShapeLayerToMapView()
        }

    }

Answer 2

This is an adaptation of the code from Elangovan

The changes that I did was to remove the var from the class to be just in the function and also removed the #selector that is no longer need in iOS >= 10.

var timerAnimation: Timer!
var mapView:GMSMapView?



    func drawRoute(encodedString: String, animated: Bool) {

        if let path = GMSMutablePath(fromEncodedPath: encodedString) {

            let polyline = GMSPolyline(path: path)
            polyline.strokeWidth = 3.0
            polyline.strokeColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.5)
            polyline.map = Singleton.shared.getMapView()

            if(animated){
                self.animatePolylinePath(path: path)
            }
        }
    }

    func animatePolylinePath(path: GMSMutablePath) {

        var pos: UInt = 0
        var animationPath = GMSMutablePath()
        let animationPolyline = GMSPolyline()
        self.timerAnimation = Timer.scheduledTimer(withTimeInterval: 0.003, repeats: true) { timer in

            pos += 1
            if(pos >= path.count()){
                pos = 0
                animationPath = GMSMutablePath()
                animationPolyline.map = nil
            }
            animationPath.add(path.coordinate(at: pos))
            animationPolyline.path = animationPath
            animationPolyline.strokeColor = UIColor.yellow
            animationPolyline.strokeWidth = 3
            animationPolyline.map = self.mapView
        }
    }


    func stopAnimatePolylinePath() {

        self.timerAnimation.invalidate()
    }

Answer 3

SWIFT

Declartion

var polyline = GMSPolyline()
var animationPolyline = GMSPolyline()
var path = GMSPath()
var animationPath = GMSMutablePath()
var i: UInt = 0
var timer: Timer!

To Darw Route

func drawRoute(routeDict: Dictionary<String, Any>) {

        let routesArray = routeDict ["routes"] as! NSArray

        if (routesArray.count > 0)
        {
            let routeDict = routesArray[0] as! Dictionary<String, Any>
            let routeOverviewPolyline = routeDict["overview_polyline"] as! Dictionary<String, Any>
            let points = routeOverviewPolyline["points"]
            self.path = GMSPath.init(fromEncodedPath: points as! String)!

            self.polyline.path = path
            self.polyline.strokeColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.5)
            self.polyline.strokeWidth = 3.0
            self.polyline.map = self.mapView

            self.timer = Timer.scheduledTimer(timeInterval: 0.003, target: self, selector: #selector(animatePolylinePath), userInfo: nil, repeats: true)
        }
    }

To Animate Path

func animatePolylinePath() {
        if (self.i < self.path.count()) {
            self.animationPath.add(self.path.coordinate(at: self.i))
            self.animationPolyline.path = self.animationPath
            self.animationPolyline.strokeColor = UIColor.black
            self.animationPolyline.strokeWidth = 3
            self.animationPolyline.map = self.mapView
            self.i += 1
        }
        else {
            self.i = 0
            self.animationPath = GMSMutablePath()
            self.animationPolyline.map = nil
        }
    }

Don't forgot to stop timer in viewWillDisappear

self.timer.invalidate()

Output

Answer 4

I am create GMSPath animation with path coordinate

Objective C

interface

@interface MapWithTracking () 

@property (weak, nonatomic) IBOutlet GMSMapView *mapView;

@property (nonatomic,strong) GMSMutablePath *path2;

@property (nonatomic,strong)NSMutableArray *arrayPolylineGreen;

@property (nonatomic,strong) GMSPolyline *polylineBlue;

@property (nonatomic,strong) GMSPolyline *polylineGreen;

@end

implementation

-(void)viewDidLoad {
    _arrayPolylineGreen = [[NSMutableArray alloc] init];
    _path2 = [[GMSMutablePath alloc]init];
}

Get a GMSPath and create a blue polyline.

-(void)createBluePolyline(GMSPath *path) {

       // Here create a blue poly line
      _polylineBlue = [GMSPolyline polylineWithPath:path];
      _polylineBlue.strokeColor = [UIColor blueColor];
      _polylineBlue.strokeWidth = 3;
      _polylineBlue.map = _mapView;

       // animate green path with timer
       [NSTimer scheduledTimerWithTimeInterval:0.003 repeats:true block:^(NSTimer * _Nonnull timer) {
             [self animate:path];
       }];

}

Animate a Green Polyline

Adding coordinate to path 2 and assign to map

-(void)animate:(GMSPath *)path {

    dispatch_async(dispatch_get_main_queue(), ^{
        if (i < path.count) {
            [_path2 addCoordinate:[path coordinateAtIndex:i]];
            _polylineGreen = [GMSPolyline polylineWithPath:_path2];
            _polylineGreen.strokeColor = [UIColor greenColor];
            _polylineGreen.strokeWidth = 3;
            _polylineGreen.map = _mapView;
            [arrayPolylineGreen addObject:_polylineGreen];
            i++;
        }
        else {
            i = 0;
            _path2 = [[GMSMutablePath alloc] init];

            for (GMSPolyline *line in arrayPolylineGreen) {
                line.map = nil;
            }

        }
    });
}

Answer 5

You need to use GMSPolyline for this. Create a GMSPolyline instance, set your GMSMapView instance to be it's parent map.

GMSPolyline* routeOverlay = // config
routeOverlay.map = // my GMSMapView instance

That's all. You don't need to do anything extra to make it move with the map camera movement. It does that automatically.

Answer 6

Move the layer whenever the map moves by implementing the delegate mapView:didChangeCameraPosition:.