Is there a way to get directions(just routes) using google for mkmapview?

Question

I\'m using swift on iOS and using MKMapView. I\'ve been working on giving a user a from - to textfield and letting the user have a form of route between the from and to loca

Answer 1

Swift 3 version, slightly condensed, thanks to ztan.

If you want to use Googles geo polylines in iOS without Google SDK.

func polyLineWithEncodedString(encodedString: String) -> [CLLocationCoordinate2D] {
    var myRoutePoints=[CLLocationCoordinate2D]()
    let bytes = (encodedString as NSString).utf8String
    var idx: Int = 0
    var latitude: Double = 0
    var longitude: Double = 0
    while (idx < encodedString.lengthOfBytes(using: String.Encoding.utf8)) {
        var byte = 0
        var res = 0
        var shift = 0
        repeat {
            byte = bytes![idx] - 63
            idx += 1
            res |= (byte & 0x1F) << shift
            shift += 5
        } while (byte >= 0x20)
        let deltaLat = ((res & 1) != 0x0 ? ~(res >> 1) : (res >> 1))
        latitude += Double(deltaLat)

        shift = 0
        res = 0
        repeat {
            byte = bytes![idx] - 63
            idx += 1
            res |= (byte & 0x1F) << shift
            shift += 5
        } while (byte >= 0x20)
        let deltaLon = ((res & 1) != 0x0 ? ~(res >> 1) : (res >> 1))
        longitude += Double(deltaLon)

        myRoutePoints.append(CLLocation(latitude: Double(latitude * 1E-5), longitude: Double(longitude * 1E-5)).coordinate)
    }
    return myRoutePoints
}

Answer 2

I think this Stackoverflow answer can convert the encoded polyline to MKPolyline.

The answer is an Objective-C version, so I tried to convert it to Swift, sample code:

func polyLineWithEncodedString(encodedString: String) -> MKPolyline {
        let bytes = (encodedString as NSString).UTF8String
        let length = encodedString.lengthOfBytesUsingEncoding(NSUTF8StringEncoding)
        var idx: Int = 0

        var count = length / 4
        var coords = UnsafeMutablePointer<CLLocationCoordinate2D>.alloc(count)
        var coordIdx: Int = 0

        var latitude: Double = 0
        var longitude: Double = 0

        while (idx < length) {
            var byte = 0
            var res = 0
            var shift = 0

            do {
                byte = bytes[idx++] - 0x3F
                res |= (byte & 0x1F) << shift
                shift += 5
            } while (byte >= 0x20)

            let deltaLat = ((res & 1) != 0x0 ? ~(res >> 1) : (res >> 1))
            latitude += Double(deltaLat)

            shift = 0
            res = 0

            do {
                byte = bytes[idx++] - 0x3F
                res |= (byte & 0x1F) << shift
                shift += 5
            } while (byte >= 0x20)

            let deltaLon = ((res & 1) != 0x0 ? ~(res >> 1) : (res >> 1))
            longitude += Double(deltaLon)

            let finalLat: Double = latitude * 1E-5
            let finalLon: Double = longitude * 1E-5

            let coord = CLLocationCoordinate2DMake(finalLat, finalLon)
            coords[coordIdx++] = coord

            if coordIdx == count {
                let newCount = count + 10
                let temp = coords
                coords.dealloc(count)
                coords = UnsafeMutablePointer<CLLocationCoordinate2D>.alloc(newCount)
                for index in 0..<count {
                    coords[index] = temp[index]
                }
                temp.destroy()
                count = newCount
            }

        }

        let polyLine = MKPolyline(coordinates: coords, count: coordIdx)
        coords.destroy()

        return polyLine
    }

You can try the sample project from this GitHub link.

Below is the image of using Google Direction API web service to render a route on MKMapView from San Francisco to San Jose.

Answer 3

Using google api to find directions between origin and destination.


Required parameters:

• origin : lat + long current location or place ID 
.

• destination : lat + long destination location or place ID 
.

• Key: to create new google api key .

Optional parameters:

• mode (defaults to driving) driving give you more options, or set
  walking, bicycling, transit.
• alternatives : false give u just one route, option true give all directions between origin and destinations, then you can choose which route u want deponent on duration, or distance inside legs.

then convert points (inside overview_polyline) to list of CLLocationCoordinate2D using Polyline library https://github.com/raphaelmor/Polyline

Like this:

func convertPointToCoordinates() -> [CLLocationCoordinate2D]? {

let polyline = Polyline(encodedPolyline: overviewPolyline.points ?? "")

return polyline.coordinates

}

let coordinates = convertPointToCoordinates()

let polyLine = MKPolyline(coordinates: coordinates ?? [], count: (coordinates?.count ?? 0))

• to add polyline on map view:

  self.mapView.add(polyLine)

• to focus on polyline region:

  self.mapView.setVisibleMapRect(polyLine.boundingMapRect, edgePadding: UIEdgeInsets.init(top: 60, left: 60, bottom: 60, right: 60), animated: true)