Using the Maps SDK for iOS, you can listen to events that occur on the
map, such as camera change events or marker tap events.
Introduction
To listen to events, you must implement theGMSMapViewDelegateprotocol. Typically, you implement
this protocol on the view controller that displays the map. Below is an example:
When theGMSMapViewis created, you can set its delegate to your view
controller. TheGMSMapViewDelegateprovides only optional methods. To listen
to any particular event, you must implement the relevant method.
-(void)loadView{[superloadView];GMSCameraPosition*camera=[GMSCameraPositioncameraWithLatitude:1.285longitude:103.848zoom:12];GMSMapView*mapView=[GMSMapViewmapWithFrame:CGRectZerocamera:camera];mapView.delegate=self;self.view=mapView;}#pragma mark - GMSMapViewDelegate-(void)mapView:(GMSMapView*)mapViewdidTapAtCoordinate:(CLLocationCoordinate2D)coordinate{NSLog(@"You tapped at %f,%f",coordinate.latitude,coordinate.longitude);}
Camera position
Using theGMSMapViewDelegate, you can listen to changes to the camera position
used to render the map. There are three distinct events.
mapView:willMove:indicates that the camera position is about to change.
If thegestureargument is set toYES, this is due to a user performing
a natural gesture on theGMSMapView, such as a pan or tilt.
Otherwise,NOindicates that this is part of a programmatic change -
for example, via methods such asanimateToCameraPosition:or updating the
map's layer directly. This may also beNOif a user has tapped on the My
Location or compass buttons, which generate animations that change the
camera.
This method may be called several times beforemapView:idleAtCameraPosition:is invoked, although this typically
happens only if animations and gestures occur at the same time - a gesture
will cancel any current animation, for instance, and will callmapView:willMove:a second time.
mapView:didChangeCameraPosition:is called repeatedly during a gesture or
animation, always after a call tomapView:willMove:. It is passed the
intermediate camera position.
Finally,mapView:idleAtCameraPosition:is invoked once the camera position
onGMSMapViewbecomes idle, and specifies the relevant camera position.
At this point, all animations and gestures have stopped.
Applications can use this event to trigger a refresh of markers or other
content being displayed on theGMSMapView, rather than, for example,
reloading the content on every camera change.
For example, an application can clear theGMSMapViewon move, and then
reverse geocode the position the camera comes to rest on.
By default, points of interest (POIs) appear on the base map along with their corresponding icons. POIs include parks, schools, government buildings, and more, as well as business POIs such as shops, restaurants, and hotels.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[[["\u003cp\u003eThe Maps SDK for iOS allows you to listen to events like camera changes and marker taps by implementing the \u003ccode\u003eGMSMapViewDelegate\u003c/code\u003e protocol.\u003c/p\u003e\n"],["\u003cp\u003eYou can track camera position changes using events such as \u003ccode\u003ewillMove\u003c/code\u003e, \u003ccode\u003edidChangeCameraPosition\u003c/code\u003e, and \u003ccode\u003eidleAtCameraPosition\u003c/code\u003e to update map content dynamically.\u003c/p\u003e\n"],["\u003cp\u003eRespond to clicks on businesses and points of interest (POIs) using dedicated event handling mechanisms.\u003c/p\u003e\n"],["\u003cp\u003eRefer to the \u003ccode\u003eGMSMapViewDelegate\u003c/code\u003e reference for a comprehensive list of available events and methods.\u003c/p\u003e\n"]]],["To listen to events on the Maps SDK for iOS, implement the `GMSMapViewDelegate` protocol in your view controller. Set the `GMSMapView`'s delegate to your view controller during creation. Implement relevant methods from the `GMSMapViewDelegate` to listen to specific events. For camera position changes, use `mapView:willMove:`, `mapView:didChangeCameraPosition:`, and `mapView:idleAtCameraPosition:`. The example provided demonstrates how to clear the map on move and reverse geocode the final camera position.\n"],null,["\u003cbr /\u003e\n\nSelect platform: [Android](/maps/documentation/android-sdk/events \"View this page for the Android platform docs.\") [iOS](/maps/documentation/ios-sdk/events \"View this page for the iOS platform docs.\") [JavaScript](/maps/documentation/javascript/events \"View this page for the JavaScript platform docs.\")\n\n\u003cbr /\u003e\n\nUsing the Maps SDK for iOS, you can listen to events that occur on the\nmap, such as camera change events or marker tap events.\n\nIntroduction\n\nTo listen to events, you must implement the\n[`GMSMapViewDelegate`](/maps/documentation/ios-sdk/reference/objc/Protocols/GMSMapViewDelegate) protocol. Typically, you implement\nthis protocol on the view controller that displays the map. Below is an example:\n\n\nSwift \n\n```swift\nimport GoogleMaps\n\nclass Events: UIViewController, GMSMapViewDelegate {\n // ...\n}\n \n```\n\nObjective-C \n\n```objective-c\n@import GoogleMaps;\n\n@interface Events : UIViewController \u003cGMSMapViewDelegate\u003e\n\n@end\n \n```\n\n\u003cbr /\u003e\n\nWhen the `GMSMapView` is created, you can set its delegate to your view\ncontroller. The `GMSMapViewDelegate` provides only optional methods. To listen\nto any particular event, you must implement the relevant method.\n\n\nSwift \n\n```swift\noverride func loadView() {\n super.loadView()\n let camera = GMSCameraPosition.camera(\n withLatitude: 1.285,\n longitude: 103.848,\n zoom: 12\n )\n let mapView = GMSMapView.map(withFrame: .zero, camera: camera)\n mapView.delegate = self\n self.view = mapView\n}\n\n// MARK: GMSMapViewDelegate\n\nfunc mapView(_ mapView: GMSMapView, didTapAt coordinate: CLLocationCoordinate2D) {\n print(\"You tapped at \\(coordinate.latitude), \\(coordinate.longitude)\")\n}\n \n```\n\nObjective-C \n\n```objective-c\n- (void)loadView {\n [super loadView];\n GMSCameraPosition *camera = [GMSCameraPosition cameraWithLatitude:1.285\n longitude:103.848\n zoom:12];\n GMSMapView *mapView = [GMSMapView mapWithFrame:CGRectZero camera:camera];\n mapView.delegate = self;\n self.view = mapView;\n}\n\n#pragma mark - GMSMapViewDelegate\n\n- (void)mapView:(GMSMapView *)mapView didTapAtCoordinate:(CLLocationCoordinate2D)coordinate {\n NSLog(@\"You tapped at %f,%f\", coordinate.latitude, coordinate.longitude);\n}\n \n```\n\n\u003cbr /\u003e\n\nCamera position\n\nUsing the `GMSMapViewDelegate`, you can listen to changes to the camera position\nused to render the map. There are three distinct events.\n\n- `mapView:willMove:` indicates that the camera position is about to change.\n If the `gesture` argument is set to `YES`, this is due to a user performing\n a natural gesture on the `GMSMapView`, such as a pan or tilt.\n Otherwise, `NO` indicates that this is part of a programmatic change -\n for example, via methods such as `animateToCameraPosition:` or updating the\n map's layer directly. This may also be `NO` if a user has tapped on the My\n Location or compass buttons, which generate animations that change the\n camera.\n\n This method may be called several times before\n `mapView:idleAtCameraPosition:` is invoked, although this typically\n happens only if animations and gestures occur at the same time - a gesture\n will cancel any current animation, for instance, and will call\n `mapView:willMove:` a second time.\n- `mapView:didChangeCameraPosition:` is called repeatedly during a gesture or\n animation, always after a call to `mapView:willMove:`. It is passed the\n intermediate camera position.\n\n- Finally, `mapView:idleAtCameraPosition:` is invoked once the camera position\n on `GMSMapView` becomes idle, and specifies the relevant camera position.\n At this point, all animations and gestures have stopped.\n\n Applications can use this event to trigger a refresh of markers or other\n content being displayed on the `GMSMapView`, rather than, for example,\n reloading the content on every camera change.\n\nFor example, an application can clear the `GMSMapView` on move, and then\nreverse geocode the position the camera comes to rest on.\n\n\nSwift \n\n```swift\nlet geocoder = GMSGeocoder()\n\nfunc mapView(_ mapView: GMSMapView, willMove gesture: Bool) {\n mapView.clear()\n}\n\nfunc mapView(_ mapView: GMSMapView, idleAt cameraPosition: GMSCameraPosition) {\n geocoder.reverseGeocodeCoordinate(cameraPosition.target) { (response, error) in\n guard error == nil else {\n return\n }\n\n if let result = response?.firstResult() {\n let marker = GMSMarker()\n marker.position = cameraPosition.target\n marker.title = result.lines?[0]\n marker.snippet = result.lines?[1]\n marker.map = mapView\n }\n }\n }\n \n```\n\nObjective-C \n\n```objective-c\nGMSGeocoder *geocoder;\n\n- (void)mapView:(GMSMapView *)mapView willMove:(BOOL)gesture {\n [mapView clear];\n}\n\n- (void)mapView:(GMSMapView *)mapView idleAtCameraPosition:(GMSCameraPosition *)cameraPosition {\n id handler = ^(GMSReverseGeocodeResponse *response, NSError *error) {\n if (error != nil) {\n return;\n }\n GMSReverseGeocodeResult *result = response.firstResult;\n GMSMarker *marker = [GMSMarker markerWithPosition:cameraPosition.target];\n marker.title = result.lines[0];\n marker.snippet = result.lines[1];\n marker.map = mapView;\n };\n [geocoder reverseGeocodeCoordinate:cameraPosition.target completionHandler:handler];\n}\n \n```\n\n\u003cbr /\u003e\n\nEvents on businesses and other points of interest\n\nBy default, points of interest (POIs) appear on the base map along with their corresponding icons. POIs include parks, schools, government buildings, and more, as well as business POIs such as shops, restaurants, and hotels.\n\nYou can respond to click events on a POI. See the guide to\n[businesses and other points of interest](/maps/documentation/ios-sdk/poi).\n\nOther events\n\nTo learn about the full list of methods on `GMSMapViewDelegate`, see\n[the reference guide](/maps/documentation/ios-sdk/reference/objc/Protocols/GMSMapViewDelegate)."]]
