AI-generated Key Takeaways
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          This webpage provides code samples demonstrating how to control zoom gestures on a Google Map using a switch. 
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          When the switch is toggled on, users can zoom in and out of the map using gestures. 
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          To run the sample code, you need to configure your development environment and obtain a Google Maps API key. 
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          The webpage provides step-by-step instructions on how to set up and run the sample app locally. 
Get started
Before you can try the sample code, you must configure your development environment. For more information, see Maps SDK for iOS code samples.
View the code
Swift
import GoogleMaps import UIKit class GestureControlViewController: UIViewController { private let holderHeight: CGFloat = 60 private let zoomLabelInset: CGFloat = 16 private lazy var mapView: GMSMapView = { let camera = GMSCameraPosition(latitude: -25.5605, longitude: 133.605097, zoom: 3) return GMSMapView(frame: .zero, camera: camera) }() private lazy var zoomSwitch: UISwitch = UISwitch(frame: .zero) override func viewDidLoad() { super.viewDidLoad() view.addSubview(mapView) let holder = UIView(frame: .zero) holder.backgroundColor = UIColor(white: 1, alpha: 0.8) view.addSubview(holder) let zoomLabel = UILabel(frame: .zero) zoomLabel.text = "Zoom gestures" zoomLabel.font = .boldSystemFont(ofSize: 18) holder.addSubview(zoomLabel) // Control zooming. holder.addSubview(zoomSwitch) zoomSwitch.addTarget(self, action: #selector(toggleZoom), for: .valueChanged) zoomSwitch.isOn = true [mapView, holder, zoomLabel, zoomSwitch].forEach({ $0.translatesAutoresizingMaskIntoConstraints = false }) NSLayoutConstraint.activate([ mapView.leftAnchor.constraint(equalTo: view.leftAnchor), mapView.rightAnchor.constraint(equalTo: view.rightAnchor), mapView.topAnchor.constraint(equalTo: view.topAnchor), mapView.bottomAnchor.constraint(equalTo: view.bottomAnchor), holder.heightAnchor.constraint(equalToConstant: holderHeight), holder.centerXAnchor.constraint(equalTo: view.centerXAnchor), holder.widthAnchor.constraint(equalTo: view.widthAnchor), zoomLabel.leftAnchor.constraint(equalTo: holder.leftAnchor, constant: zoomLabelInset), zoomLabel.centerYAnchor.constraint(equalTo: holder.centerYAnchor), zoomSwitch.rightAnchor.constraint(equalTo: holder.rightAnchor, constant: -zoomLabelInset), zoomSwitch.centerYAnchor.constraint( equalTo: holder.centerYAnchor), ]) NSLayoutConstraint.activate([ holder.topAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.topAnchor) ]) } @objc func toggleZoom() { mapView.settings.zoomGestures = zoomSwitch.isOn } }
Objective-C
#import "GoogleMapsDemos/Samples/GestureControlViewController.h" #import <GoogleMaps/GoogleMaps.h> @implementation GestureControlViewController { GMSMapView *_mapView; UISwitch *_zoomSwitch; } - (void)viewDidLoad { [super viewDidLoad]; GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:-25.5605 longitude:133.605097 zoom:3]; _mapView = [GMSMapView mapWithFrame:CGRectZero camera:camera]; _mapView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight; _mapView.accessibilityIdentifier = @"gestureControlDemoMapView"; self.view = [[UIView alloc] initWithFrame:CGRectZero]; [self.view addSubview:_mapView]; UIView *holder = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, 59)]; holder.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleBottomMargin; holder.backgroundColor = [UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.8f]; [self.view addSubview:holder]; // Zoom label. UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(16, 16, 200, 29)]; label.text = @"Zooming?"; label.font = [UIFont boldSystemFontOfSize:18.0f]; label.textAlignment = NSTextAlignmentLeft; label.backgroundColor = [UIColor clearColor]; label.layer.shadowColor = [[UIColor whiteColor] CGColor]; label.layer.shadowOffset = CGSizeMake(0.0f, 1.0f); label.layer.shadowOpacity = 1.0f; label.layer.shadowRadius = 0.0f; [holder addSubview:label]; // Control zooming. _zoomSwitch = [[UISwitch alloc] initWithFrame:CGRectMake(-90, 16, 0, 0)]; _zoomSwitch.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin; [_zoomSwitch addTarget:self action:@selector(didChangeZoomSwitch) forControlEvents:UIControlEventValueChanged]; _zoomSwitch.on = YES; [holder addSubview:_zoomSwitch]; } - (void)didChangeZoomSwitch { _mapView.settings.zoomGestures = _zoomSwitch.isOn; } @end
Run the full sample app locally
The Maps SDK for iOS sample app is available as a download archive from GitHub. Follow these steps to install and try the Maps SDK for iOS sample app.
- Run git clone https://github.com/googlemaps-samples/maps-sdk-for-ios-samples.gitto clone the samples repository into a local directory.
- Open a terminal window, navigate to the directory where you cloned the sample files, and drill down into the GoogleMaps directory: - Swift- cd maps-sdk-for-ios-samples/GoogleMaps-Swift - pod install- open GoogleMapsSwiftXCFrameworkDemos.xcworkspace- Objective-C- cd maps-sdk-for-ios-samples-main/GoogleMaps - pod install- open GoogleMapsDemos.xcworkspace
- In Xcode, press the compile button to
    build the app
    with the current scheme. The build produces an error, prompting you to enter your API key
    in the SDKConstants.swiftfile for Swift orSDKDemoAPIKey.hfile for Objective-C.
- Get an API key from your project with the Maps SDK for iOS enabled.
- Edit the SDKConstants.swiftfile for Swift orSDKDemoAPIKey.hfile for Objective-C and paste your API key into the definition of either theapiKeyorkAPIKeyconstant. For example:Swiftstatic let apiKey = "YOUR_API_KEY"Objective-Cstatic NSString *const kAPIKey = @"YOUR_API_KEY"; 
- In the SDKConstants.swiftfile (Swift) orSDKDemoAPIKey.hfile (Objective-C), remove the following line, because it's used to register the user-defined issue:Swift#error (Register for API Key and insert here. Then delete this line.) Objective-C#error Register for API Key and insert here. 
- Build and run the project. The iOS simulator window appears, showing a list of Maps SDK Demos.
- Choose one of the options displayed, to experiment with a feature of the Maps SDK for iOS.
- If prompted to allow GoogleMapsDemos to access your location, choose Allow.