Google Maps Directions API - polyline drawer helper

this is couroutines implementation, for RX see https://github.com/rozkminiacz/DirectionsSDK

What is it?

It's small library written in Kotlin to utilize Google Directions API calls and convert response to PolylineOptions, ready to add to GoogleMap.

Why should I use it?

Well, you don't have to. But if you already reading this - consider using it if you don't want to parse nested jsons by yourself.

How do I use it?

Add dependency

That's simple. First - add dependency to your build.gradle:

allprojects {
	repositories {
		...
		maven { url 'https://jitpack.io' }
	}
}

implementation : "com.github.rozkminiacz:GoogleMapsPolyline:1.0"	

You must also provide google maps core dependency:

implementation : "com.google.android.gms:play-services-maps:11.8.0"

Create instance of DirectionsApiClient:

class AnotherBoringMapActivity : Activity(){
    fun createClient() {
        directionsApiClient = DirectionsApiClient(
                    apiKey = getString(R.string.google_directions_key))
    }
}

Request route between points

class AnotherBoringMapActivity : Activity(){
    fun requestRoute(from : LatLng, to: LatLng){
       directionsApiClient.getRoutePolylines(origin = from, dest = to) {
            //do something with list of PolylineOptions
            //remember, that you are not on main thread here
       }
    }
}

Customize request!

You can add some customization to Directions API request, just look at TransitOptions class. You can specify transit mode, and what to avoid during route planning.

Write your own parser!

Yeah! That's possible! Just implement Converter<GeocodedResponse?, List> and you are ready to go!

class AnotherBoringMapActivity : Activity(){
    fun configure(){
        val myConverter = object : Converter<GeocodedResponse?, List<PolylineOptions>> {
                override fun convert(from: GeocodedResponse?): List<PolylineOptions> {
                    //
                }
            }
            
        val directionsApiClient = DirectionsApiClient(
            apiKey = getString(R.string.google_directions_key),
            polylineConverter = myConverter)
    }
}

I still don't know hot to use it

Look at example in this repo, in app directory.

I want to improve this library!

Sure! Pull requests are welcome! Any reasonable extension will be added.

Tools used:

• Google Maps API
• Kotlin Coroutines
• OkHttp
• Retrofit
• Retrofit coroutines extensions