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Route alerts

Display route alerts.
RouteAlertsViewController
/*
This code example is part of the Mapbox Navigation SDK for iOS demo app,
which you can build and run: https://github.com/mapbox/mapbox-navigation-ios-examples
To learn more about each example in this app, including descriptions and links
to documentation, see our docs: https://docs.mapbox.com/ios/navigation/examples/route-alerts
*/

import UIKit
import MapboxCoreNavigation
import MapboxNavigation
import MapboxDirections
import MapboxNavigationNative

class RouteAlertsViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()

let origin = CLLocationCoordinate2DMake(37.789811651648456, -122.47075850058)
let destination = CLLocationCoordinate2DMake(37.79727245401114, -122.46951395567203)
let options = NavigationRouteOptions(coordinates: [origin, destination])

Directions.shared.calculate(options) { [weak self] (_, result) in
switch result {
case .failure(let error):
print(error.localizedDescription)
case .success(let response):
guard let strongSelf = self else {
return
}

// For demonstration purposes, simulate locations if the Simulate Navigation option is on.

let indexedRouteResponse = IndexedRouteResponse(routeResponse: response, routeIndex: 0)
let navigationService = MapboxNavigationService(indexedRouteResponse: indexedRouteResponse,
customRoutingProvider: NavigationSettings.shared.directions,
credentials: NavigationSettings.shared.directions.credentials,
simulating: simulationIsEnabled ? .always : .onPoorGPS)

// Define a customized `topBanner` to display route alerts during turn-by-turn navigation, and pass it to `NavigationOptions`.
let topAlertsBannerViewController = TopAlertsBarViewController()
let navigationOptions = NavigationOptions(navigationService: navigationService,
topBanner: topAlertsBannerViewController)
let navigationViewController = NavigationViewController(for: indexedRouteResponse,
navigationOptions: navigationOptions)

let parentSafeArea = navigationViewController.view.safeAreaLayoutGuide
topAlertsBannerViewController.view.topAnchor.constraint(equalTo: parentSafeArea.topAnchor).isActive = true

navigationViewController.modalPresentationStyle = .fullScreen

strongSelf.present(navigationViewController, animated: true)
}
}
}
}

// MARK: - TopAlertsBarViewController
class TopAlertsBarViewController: ContainerViewController {

lazy var topAlertsBannerView: InstructionsBannerView = {
let banner = InstructionsBannerView()
banner.translatesAutoresizingMaskIntoConstraints = false
banner.layer.cornerRadius = 25
banner.layer.opacity = 0.8
return banner
}()

override func viewDidLoad() {
view.addSubview(topAlertsBannerView)
setupConstraints()
}

override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
setupConstraints()
}

private func setupConstraints() {

// To change top banner size and position change layout constraints directly.
let topAlertsBannerViewConstraints: [NSLayoutConstraint] = [
topAlertsBannerView.topAnchor.constraint(equalTo: view.topAnchor, constant: 10),
topAlertsBannerView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 60),
topAlertsBannerView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -60),
topAlertsBannerView.heightAnchor.constraint(equalToConstant: 100.0),
topAlertsBannerView.centerXAnchor.constraint(equalTo: view.centerXAnchor)
]
NSLayoutConstraint.activate(topAlertsBannerViewConstraints)
}

open override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
super.traitCollectionDidChange(previousTraitCollection)
setupConstraints()
}

public func updateAlerts(alerts: [String]) {

// Change the property of`primaryLabel: InstructionLabel`.
let text = alerts.joined(separator: "\n")
topAlertsBannerView.primaryLabel.text = text
topAlertsBannerView.primaryLabel.numberOfLines = 0
topAlertsBannerView.primaryLabel.lineBreakMode = NSLineBreakMode.byWordWrapping
}

// MARK: - NavigationServiceDelegate implementation

public func navigationService(_ service: NavigationService, didPassVisualInstructionPoint instruction: VisualInstructionBanner, routeProgress: RouteProgress) {
topAlertsBannerView.update(for: instruction)
}

public func navigationService(_ service: NavigationService, didRerouteAlong route: Route, at location: CLLocation?, proactive: Bool) {
topAlertsBannerView.updateDistance(for: service.routeProgress.currentLegProgress.currentStepProgress)
}

public func navigationService(_ service: NavigationService, didUpdate progress: RouteProgress, with location: CLLocation, rawLocation: CLLocation) {
topAlertsBannerView.updateDistance(for: service.routeProgress.currentLegProgress.currentStepProgress)
let allAlerts = progress.upcomingRouteAlerts.filter({ !$0.description.isEmpty }).map({ $0.description })
if !allAlerts.isEmpty {
updateAlerts(alerts: allAlerts)
} else {
// If there's no usable route alerts in the route progress, displaying `currentVisualInstruction` instead.
let instruction = progress.currentLegProgress.currentStepProgress.currentVisualInstruction
topAlertsBannerView.primaryLabel.lineBreakMode = NSLineBreakMode.byTruncatingTail
topAlertsBannerView.update(for: instruction)
}
}
}

// MARK: - MapboxCoreNavigation.RouteAlert to String implementation
extension MapboxDirections.Incident: CustomStringConvertible {

public var alertDescription: String {
guard let kind = self.kind else { return self.description }
if let impact = self.impact, let lanesBlocked = self.lanesBlocked {
return "A \(impact) \(kind) ahead blocking \(lanesBlocked)"
} else if let impact = self.impact {
return "A \(impact) \(kind) ahead"
} else {
return "A \(kind) ahead blocking \(self.lanesBlocked!)"
}
}
}

extension MapboxCoreNavigation.RouteAlert: CustomStringConvertible {

public var description: String {
let distance = Int64(self.distanceToStart)
guard distance > 0 && distance < 500 else { return "" }

switch roadObject.kind {
case .incident(let incident?):
return "\(incident.alertDescription) in \(distance)m."
case .tunnel(let alert?):
if let alertName = alert.name {
return "Tunnel \(alertName) in \(distance)m."
} else {
return "A tunnel in \(distance)m."
}
case .borderCrossing(let alert?):
return "Crossing border from \(alert.from) to \(alert.to) in \(distance)m."
case .serviceArea(let alert?):
switch alert.type {
case .restArea:
return "Rest area in \(distance)m."
case .serviceArea:
return "Service area in \(distance)m."
}
case .tollCollection(let alert?):
switch alert.type {
case .booth:
return "Toll booth in \(distance)m."
case .gantry:
return "Toll gantry in \(distance)m."
}
default:
return ""
}
}
}
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