MapScaleView_iOS_API

an iOS swift Map ScaleView UI View component

Development Target: iOS 14

Provide a scale view with iOS MKMapView:

Installation

Cocoapods

MapScaleView can be added to your project using CocoaPods 0.36 or later by adding the following line to your Podfile:

pod 'MapScaleView'

Swift Package Manager

To add MapScaleView to a Swift Package Manager based project, add:

.package(url: "https://github.com/xattacker/MapScaleView_iOS_API.git", .upToNextMajor(from: "1.2.3")),

to your Package.swift files dependencies array.

How to use:

import MapScaleView

let scale_view: UIMapScaleView

scale_view.scaleCalculator = mapView // setup with MKMapView
scale_view.outlineColor = UIColor.white
scale_view.bodyColor = UIColor.black
scale_view.direction = .leftToRight // set the bar start direction in leftToRight / rightToRight, default is leftToRight
scale_view.unit = .metric // you could set distance unit in metric / imperial, default is metric mode


// implement from MKMapViewDelegate
func mapView(_ mapView: MKMapView, regionDidChangeAnimated animated: Bool)
{
   // udpate with mapView
   scaleView.setNeedsLayout()
}

How to support Google Map API:

import MapScaleView
import GoogleMaps

let scale_view: UIMapScaleView

scale_view.mapScaleCalculator = mapView // setup with GMSMapView

// implement from GMSMapViewDelegate
func mapView(_ mapView: GMSMapView, didChange position: GMSCameraPosition)
{
   // update with mapView
   scaleView.setNeedsLayout()
}

// let GMSMapView implement protocol MapScaleCalculator that make it could support ScaleView
extension GMSMapView: MapScaleCalculator
{
    public var metersPerPixel: CGFloat
    {
        let topLeft = self.projection.visibleRegion().farLeft
        let bottomLeft = self.projection.visibleRegion().nearLeft
        let lat = CGFloat(abs(Float(topLeft.latitude - bottomLeft.latitude)))
        let metersPerPixel = CGFloat((cos(lat * .pi / 180) * 2 * .pi) * 6378137 / CGFloat((256 * pow(2, self.camera.zoom))))
        return metersPerPixel
    }
}