Handle marker events

This example displays a map with two markers. When a marker is tapped, the camera zooms and rotates to focus on the selected marker.

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

final class MarkerEventsViewController: UIViewController {

  private lazy var mapView: GMSMapView = {
    let camera = GMSCameraPosition(latitude: -37.81969, longitude: 144.966085, zoom: 4)
    return GMSMapView(frame: .zero, camera: camera)
  }()

  private var melbourneMarker = GMSMarker(
    position: CLLocationCoordinate2D(latitude: -37.81969, longitude: 144.966085))

  override func loadView() {
    let sydneyMarker = GMSMarker(
      position: CLLocationCoordinate2D(latitude: -33.8683, longitude: 151.2086))
    sydneyMarker.map = mapView
    melbourneMarker.map = mapView
    mapView.delegate = self
    view = mapView
  }
}

extension MarkerEventsViewController: GMSMapViewDelegate {
  func mapView(_ mapView: GMSMapView, markerInfoWindow marker: GMSMarker) -> UIView? {
    if marker == melbourneMarker {
      return UIImageView(image: UIImage(named: "Icon"))
    }
    return nil
  }

  func mapView(_ mapView: GMSMapView, didTap marker: GMSMarker) -> Bool {
    // Animate to the marker
    CATransaction.begin()
    CATransaction.setAnimationDuration(3)
    let camera = GMSCameraPosition(target: marker.position, zoom: 8, bearing: 50, viewingAngle: 60)
    mapView.animate(to: camera)
    CATransaction.commit()

    // Melbourne marker has a InfoWindow so return false to allow markerInfoWindow to
    // fire. Also check that the marker isn't already selected so that the InfoWindow
    // doesn't close.
    if marker == melbourneMarker && mapView.selectedMarker != melbourneMarker {
      return false
    }
    return true
  }
}
MarkerEventsViewController.swift
      

Objective-C

#import "GoogleMapsDemos/Samples/MarkerEventsViewController.h"

#import <QuartzCore/QuartzCore.h>

#import <GoogleMaps/GoogleMaps.h>

@implementation MarkerEventsViewController {
  GMSMapView *_mapView;
  GMSMarker *_melbourneMarker;
  BOOL _rotating;
}

- (void)viewDidLoad {
  [super viewDidLoad];
  GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:-37.81969
                                                          longitude:144.966085
                                                               zoom:4];
  _mapView = [GMSMapView mapWithFrame:CGRectZero camera:camera];

  GMSMarker *sydneyMarker = [[GMSMarker alloc] init];
  sydneyMarker.position = CLLocationCoordinate2DMake(-33.8683, 151.2086);
  sydneyMarker.map = _mapView;

  _melbourneMarker = [[GMSMarker alloc] init];
  _melbourneMarker.position = CLLocationCoordinate2DMake(-37.81969, 144.966085);
  _melbourneMarker.map = _mapView;

  _mapView.delegate = self;
  self.view = _mapView;
}

#pragma mark - GMSMapViewDelegate

- (UIView *)mapView:(GMSMapView *)mapView markerInfoWindow:(GMSMarker *)marker {
  if (marker == _melbourneMarker) {
    return [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"Icon"]];
  }

  return nil;
}

- (BOOL)mapView:(GMSMapView *)mapView didTapMarker:(GMSMarker *)marker {
  GMSCameraPosition *camera = [[GMSCameraPosition alloc] initWithTarget:marker.position
                                                                   zoom:8
                                                                bearing:50
                                                           viewingAngle:60];
  // Animate to the marker
  [CATransaction begin];
  [CATransaction setAnimationDuration:3.f];  // 3 second animation
  [CATransaction setCompletionBlock:^{
    if (_rotating) {  // Animation was interrupted by orientation change.
      [CATransaction
          setDisableActions:true];  // Disable animation to avoid interruption from rotation.
      [_mapView animateToCameraPosition:camera];
    }
  }];

  [mapView animateToCameraPosition:camera];
  [CATransaction commit];

  // Melbourne marker has a InfoWindow so return NO to allow markerInfoWindow to fire. Also check
  // that the marker isn't already selected so that the InfoWindow doesn't close.
  if (marker == _melbourneMarker && mapView.selectedMarker != _melbourneMarker) {
    return NO;
  }

  // The Tap has been handled so return YES
  return YES;
}

- (void)viewWillTransitionToSize:(CGSize)size
       withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator {
  _rotating = true;
  [coordinator
      animateAlongsideTransition:nil
                      completion:^(
                          id<UIViewControllerTransitionCoordinatorContext> _Nonnull context) {
                        _rotating = false;
                      }];
  [super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];
}

@end
MarkerEventsViewController.m
      

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.

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-main/GoogleMaps-Swift
   pod install
   open GoogleMapsSwiftDemos.xcworkspace

   Objective-C

   cd maps-sdk-for-ios-samples-main/GoogleMaps
   pod install
   open GoogleMapsDemos.xcworkspace

3. 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.swift file for Swift orSDKDemoAPIKey.h file for Objective-C.
4. If you don't yet have an API key, follow the instructions to set up a project on the Google Cloud console and get an API key. When configuring the key on the Cloud console, you can restrict the key to the sample app's bundle identifier to ensure that only your app can use the key. The default bundle identifier of the SDK samples app is com.example.GoogleMapsDemos.
5. Edit the SDKConstants.swift file for Swift orSDKDemoAPIKey.h file for Objective-C and paste your API key into the definition of either the apiKey or kAPIKey constant. For example:

   Swift

   static let apiKey = "YOUR_API_KEY"

   Objective-C

   static NSString *const kAPIKey = @"YOUR_API_KEY";

6. In the SDKConstants.swift file (Swift) orSDKDemoAPIKey.h file (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.

7. Build and run the project. The iOS simulator window appears, showing a list of Maps SDK Demos.
8. Choose one of the options displayed, to experiment with a feature of the Maps SDK for iOS.
9. If prompted to allow GoogleMapsDemos to access your location, choose Allow.