The map responds to zoom gestures only when the switch is toggled on.

## 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](https://developers.google.com/maps/documentation/ios-sdk/examples.md.txt).

## View the code


### Swift

```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

```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
      
```

<br />

## Run the full sample app locally

The Maps SDK for iOS sample app is available as a
[download archive](https://github.com/googlemaps-samples/maps-sdk-for-ios-samples/archive/main.zip)
from [GitHub](https://github.com/googlemaps-samples/maps-sdk-for-ios-samples/tree/main/GoogleMaps).
Follow these steps to install and try the Maps SDK for iOS sample app.

> [!IMPORTANT]
> **Important:** You must remove any existing dependencies added using CocoaPods or manually. See [Step 2 of Set up an Xcode project](https://developers.google.com/maps/documentation/ios-sdk/config.md.txt#swift-package-manager) for instructions.

1. Run `git clone https://github.com/googlemaps-samples/maps-sdk-for-ios-samples.git` to clone the samples repository into a local directory.
2. 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
       open GoogleMapsSwiftXCFrameworkDemos.xcodeproj

   ### Objective-C

       cd maps-sdk-for-ios-samples-main/GoogleMaps
       open GoogleMapsDemos.xcodeproj

3. In the Xcode project, go to **File** \> **Add Package Dependencies** . Enter `https://github.com/googlemaps/ios-maps-sdk` as the URL, press **Enter** to pull in the package, and click **Add Package**.
4. In Xcode, press the compile button to [build the app](https://developer.apple.com/documentation/xcode/building-and-running-an-app) with the current scheme. The build produces an error, prompting you to enter your API key in the `SDKConstants.swift` file for Swift or`SDKDemoAPIKey.h` file for Objective-C.
5. [Get an API key](https://developers.google.com/maps/documentation/ios-sdk/get-api-key.md.txt) from your project with the [Maps SDK for iOS enabled](https://developers.google.com/maps/documentation/ios-sdk/cloud-setup#enabling-apis).
6. Edit the `SDKConstants.swift` file for Swift or`SDKDemoAPIKey.h` file for Objective-C and paste your API key into the definition of either the `apiKey` or `kAPIKey` constant. For example:

   ### Swift

   ```swift
   static let apiKey = "YOUR_API_KEY"
   ```

   ### Objective-C

   ```objective-c
   static NSString *const kAPIKey = @"YOUR_API_KEY";
   ```
7. In the `SDKConstants.swift` file (Swift) or`SDKDemoAPIKey.h` file (Objective-C), remove the following line, because it's used to register the user-defined issue:

   ### Swift

   ```swift
   #error (Register for API Key and insert here. Then delete this line.)
   ```

   ### Objective-C

   ```objective-c
   #error Register for API Key and insert here.
   ```
8. Build and run the project. The iOS simulator window appears, showing a list of **Maps SDK Demos**.
9. Choose one of the options displayed, to experiment with a feature of the Maps SDK for iOS.
10. If prompted to allow GoogleMapsDemos to access your location, choose **Allow**.