CODEWITHSUNDEEP
iosswiftgoogle-maps
Mohammed Fazil
Mohammed Fazil

Reputation: 31

How To Set a Restricted Region or Limited Region in Google Map,Swift

I have list of markers on my Googlemap,fixed all the markers.Now I need to get Limited Region only possible to scroll inside the limited Region.How its possible.anyone Please help me to fix it.

Here is My Center Location

 let center = CLLocationCoordinate2DMake(11.250220, 75.781573)


 let camera: GMSCameraPosition = GMSCameraPosition.camera(withLatitude: center.latitude, longitude: center.longitude, zoom: 18.0)

Upvotes: 0

Views: 686

Answers (1)

Aleem
Aleem

Reputation: 3291

Start by defining two locations which specify the bounds of the region you want to display. These could be opposite corners of the bounding box, or just two locations, for example:

CLLocationCoordinate2D location1 = 
CLLocationCoordinate2DMake(-33.8683, 151.2086); // Sydney
CLLocationCoordinate2D location2 = 
    CLLocationCoordinate2DMake(-31.9554, 115.8585); // Perth

If you have more than two points that you want to include, you could calculate the bounds of them yourself. This can also be done using GMSCoordinateBounds, for example:

GMSCoordinateBounds* bounds =
[[GMSCoordinateBounds alloc]
initWithCoordinate: CLLocationCoordinate2DMake(-33.8683, 151.2086) // Sydney
andCoordinate: CLLocationCoordinate2DMake(-31.9554, 115.8585)]; // Perth
bounds = [bounds including: 
    CLLocationCoordinate2DMake(-12.4667, 130.8333)]; // Darwin
CLLocationCoordinate2D location1 = bounds.southWest;
CLLocationCoordinate2D location2 = bounds.northEast;

Next, you need to get the size of the map view in points. You could use this:

float mapViewWidth = _mapView.frame.size.width;
float mapViewHeight = _mapView.frame.size.height;

Now you have the info necessary to calculate the camera position:

MKMapPoint point1 = MKMapPointForCoordinate(location1);
MKMapPoint point2 = MKMapPointForCoordinate(location2);
MKMapPoint centrePoint = MKMapPointMake(
    (point1.x + point2.x) / 2,
    (point1.y + point2.y) / 2);
CLLocationCoordinate2D centreLocation = MKCoordinateForMapPoint(centrePoint);

double mapScaleWidth = mapViewWidth / fabs(point2.x - point1.x);
double mapScaleHeight = mapViewHeight / fabs(point2.y - point1.y);
double mapScale = MIN(mapScaleWidth, mapScaleHeight);

double zoomLevel = 20 + log2(mapScale);

GMSCameraPosition *camera = [GMSCameraPosition
    cameraWithLatitude: centreLocation.latitude
    longitude: centreLocation.longitude
    zoom: zoomLevel];

You can then initialize the map view with this camera, or set the map view to this camera.

For this code to compile, you will need to add the MapKit framework to your project, and then also import it:

#import <MapKit/MapKit.h>

Note that this code doesn't handle wrap-around if your coordinates span across the date line. For example if you tried using this code with Tokyo and Hawaii, instead of displaying an area of the Pacific, it will try to display almost the entire world. In portrait mode it's not possible to zoom out far enough to see Hawaii on the left and Tokyo on the right, and so the map ends up centred on Africa with neither location visible. You could modify the above code to handle the wrap-around at the date line if you wanted to.

Upvotes: 1

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