Android Google Maps get Boundary Co-ordinates

Question

I am using Google Maps v2 in my application. When the user pans or zooms on the screen I would like to get the area of the map based on which I want to fetch the POI only in the screen view part.
I went through the documentation but could not find any help.

Solution 1

You need to use Projection and VisibleRegion classes in order to get visible LatLng region.
So your code would look something like:

LatLngBounds curScreen = googleMap.getProjection()
    .getVisibleRegion().latLngBounds;

Solution 2

In Android(Kotlin) you can find LatLng this way, in every time zoom or. gesture detect

private var mMap: GoogleMap? = null
..........



    mMap?.setOnCameraMoveStartedListener { reasonCode ->
        if (reasonCode == GoogleMap.OnCameraMoveStartedListener.REASON_GESTURE) {
            val curScreen: LatLngBounds =  mMap!!.getProjection().getVisibleRegion().latLngBounds
            var northeast=curScreen.northeast
            var southwest=curScreen.southwest
            var center=curScreen.center
            Log.v("northeast LatLng","-:"+northeast)
            Log.v("southwest LatLng","-:"+southwest)
            Log.v("center LatLng","-:"+center)
        }
    }

Comments

[Harsha M V]

i tried this i am getting only northwest and southwest value. any idea how to get the other two values ?

[Pavel Dudka]

northeast and southwest you mean? If so - that's how the bounding box is represented (top-right and bottom-left corners of the viewport). Given these two points it is pretty straight forward to calculate other 2 points. Right? The simplest way to check whether certain POI(LatLng) is within the box - is to call LatLngBounds.contains(LatLng point) interface. However, displaying big amount of Markers on a map is a separate story

[Harsha M V]

how can i get get the other two points, am sorry am confused. Ant about showin a lot of markers is there any optimized way of doing that ?

[Pavel Dudka]

well, top-left corner would have [curScreen.southwest.longitude;curScreen.northeast.latitude] coordinates and bottom-right corner would have [curScreen.northeast.longitude;curScreen.southwest.latitude] coordinates. You can treat latitude as Y axis and longitude as X axis

[Pavel Dudka]

as far as I know, there is no native way to clusterize markers on a map. There is a good article though about this topic: developers.google.com/maps/articles/toomanymarkers

[stackunderflow]

@HarshaMV your question seem doesn't signifies your reputations

[Harsha M V]

@Dagon see the date it was asked ;-)

[stackunderflow]

@HarshaMV i see. that was toooo long ago. is that the day when you're still at primary school? actually i refer to your question comment. anyway thank you for your post and also for the answer. it solved my today's problem

[kgandroid]

It is returning 0.0 both latitude and longitude,any idea??

[Pavel Dudka]

@kgandroid usually it means that current location is not known at the moment

[kgandroid]

Plase have a look: stackoverflow.com/questions/31446401/latlng-bound-returns-0-‌​0