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@mnbayan
Created February 23, 2015 02:33
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MKMapView extension to center map to coordinates with defined zoom level using Swift language
//
// MKMapViewExtension.swift
// AutocompleteTextfieldSwift
//
// Created by Mylene Bayan on 2/22/15.
// Copyright (c) 2015 MaiLin. All rights reserved.
//
import Foundation
import MapKit
let MERCATOR_OFFSET = 268435456.0
let MERCATOR_RADIUS = 85445659.44705395
let DEGREES = 180.0
extension MKMapView{
//MARK: Map Conversion Methods
private func longitudeToPixelSpaceX(longitude:Double)->Double{
return round(MERCATOR_OFFSET + MERCATOR_RADIUS * longitude * M_PI / DEGREES)
}
private func latitudeToPixelSpaceY(latitude:Double)->Double{
return round(MERCATOR_OFFSET - MERCATOR_RADIUS * log((1 + sin(latitude * M_PI / DEGREES)) / (1 - sin(latitude * M_PI / DEGREES))) / 2.0)
}
private func pixelSpaceXToLongitude(pixelX:Double)->Double{
return ((round(pixelX) - MERCATOR_OFFSET) / MERCATOR_RADIUS) * DEGREES / M_PI
}
private func pixelSpaceYToLatitude(pixelY:Double)->Double{
return (M_PI / 2.0 - 2.0 * atan(exp((round(pixelY) - MERCATOR_OFFSET) / MERCATOR_RADIUS))) * DEGREES / M_PI
}
private func coordinateSpanWithCenterCoordinate(centerCoordinate:CLLocationCoordinate2D, zoomLevel:Double)->MKCoordinateSpan{
// convert center coordiate to pixel space
let centerPixelX = longitudeToPixelSpaceX(centerCoordinate.longitude)
let centerPixelY = latitudeToPixelSpaceY(centerCoordinate.latitude)
// determine the scale value from the zoom level
let zoomExponent:Double = 20.0 - zoomLevel
let zoomScale:Double = pow(2.0, zoomExponent)
// scale the map’s size in pixel space
let mapSizeInPixels = self.bounds.size
let scaledMapWidth = Double(mapSizeInPixels.width) * zoomScale
let scaledMapHeight = Double(mapSizeInPixels.height) * zoomScale
// figure out the position of the top-left pixel
let topLeftPixelX = centerPixelX - (scaledMapWidth / 2.0)
let topLeftPixelY = centerPixelY - (scaledMapHeight / 2.0)
// find delta between left and right longitudes
let minLng = pixelSpaceXToLongitude(topLeftPixelX)
let maxLng = pixelSpaceXToLongitude(topLeftPixelX + scaledMapWidth)
let longitudeDelta = maxLng - minLng
let minLat = pixelSpaceYToLatitude(topLeftPixelY)
let maxLat = pixelSpaceYToLatitude(topLeftPixelY + scaledMapHeight)
let latitudeDelta = -1.0 * (maxLat - minLat)
return MKCoordinateSpan(latitudeDelta: latitudeDelta, longitudeDelta: longitudeDelta)
}
func setCenterCoordinate(centerCoordinate:CLLocationCoordinate2D, var zoomLevel:Double, animated:Bool){
// clamp large numbers to 28
zoomLevel = min(zoomLevel, 28)
// use the zoom level to compute the region
let span = self.coordinateSpanWithCenterCoordinate(centerCoordinate, zoomLevel: zoomLevel)
let region = MKCoordinateRegionMake(centerCoordinate, span)
if region.center.longitude == -180.00000000{
println("Invalid Region")
}
else{
self.setRegion(region, animated: animated)
}
}
}
@vatsal1992
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easy to use thanks...

@ihorodnikoff
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nice job thanks!

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