Determine if MKMapView has been moved / moved

Question

Is there a way to determine if MKMapView has been moved?

I want to get the center location every time a user drags a map using CLLocationCoordinate2D centre = [locationMap centerCoordinate]; but I need a delegate method or something that fires as soon as the user moves around the map.

Thank you in advance

Answer 1

Take a look at the MKMapViewDelegate link.

In particular, these methods may be useful:

 - (void)mapView:(MKMapView *)mapView regionWillChangeAnimated:(BOOL)animated - (void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated 

Make sure that the delegate property of the map view is set so that the called methods are invoked.

Answer 2

The code in the accepted answer is triggered when the region changes for some reason. To correctly detect the dragging of a map, you must add a UIPanGestureRecognizer. Btw, this is a gesture recognizer (pan = drag).

Step 1: Add a gesture recognizer to viewDidLoad:

 -(void) viewDidLoad { [super viewDidLoad]; UIPanGestureRecognizer* panRec = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(didDragMap:)]; [panRec setDelegate:self]; [self.mapView addGestureRecognizer:panRec]; } 

Step 2: Add the UIGestureRecognizerDelegate protocol to the view controller so that it works as a delegate.

 @interface MapVC : UIViewController <UIGestureRecognizerDelegate, ...> 

Step 3: And add the following code for UIPanGestureRecognizer to work with existing gesture recognizers in MKMapView:

 - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer { return YES; } 

Step 4: If you want to call your method once instead of 50 times per drag, determine that your selector is in a “drag and drop” state:

 - (void)didDragMap:(UIGestureRecognizer*)gestureRecognizer { if (gestureRecognizer.state == UIGestureRecognizerStateEnded){ NSLog(@"drag ended"); } } 

Answer 3

This is the only way that worked for me that detects panning as well as zoom changes initiated by the user:

 - (BOOL)mapViewRegionDidChangeFromUserInteraction { UIView *view = self.mapView.subviews.firstObject; // Look through gesture recognizers to determine whether this region change is from user interaction for(UIGestureRecognizer *recognizer in view.gestureRecognizers) { if(recognizer.state == UIGestureRecognizerStateBegan || recognizer.state == UIGestureRecognizerStateEnded) { return YES; } } return NO; } static BOOL mapChangedFromUserInteraction = NO; - (void)mapView:(MKMapView *)mapView regionWillChangeAnimated:(BOOL)animated { mapChangedFromUserInteraction = [self mapViewRegionDidChangeFromUserInteraction]; if (mapChangedFromUserInteraction) { // user changed map region } } - (void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated { if (mapChangedFromUserInteraction) { // user changed map region } } 

Answer 4

(Just the) Fast version excellent solution @mobi :

 private var mapChangedFromUserInteraction = false private func mapViewRegionDidChangeFromUserInteraction() -> Bool { let view = self.mapView.subviews[0] // Look through gesture recognizers to determine whether this region change is from user interaction if let gestureRecognizers = view.gestureRecognizers { for recognizer in gestureRecognizers { if( recognizer.state == UIGestureRecognizerState.Began || recognizer.state == UIGestureRecognizerState.Ended ) { return true } } } return false } func mapView(mapView: MKMapView, regionWillChangeAnimated animated: Bool) { mapChangedFromUserInteraction = mapViewRegionDidChangeFromUserInteraction() if (mapChangedFromUserInteraction) { // user changed map region } } func mapView(mapView: MKMapView, regionDidChangeAnimated animated: Bool) { if (mapChangedFromUserInteraction) { // user changed map region } } 

Answer 5

Swift 3 solution for Jano answer above:

Add UIGestureRecognizerDelegate Protocol to Your ViewController

 class MyViewController: UIViewController, UIGestureRecognizerDelegate 

Create a UIPanGestureRecognizer in viewDidLoad and set the delegate to self

 viewDidLoad() { // add pan gesture to detect when the map moves let panGesture = UIPanGestureRecognizer(target: self, action: #selector(self.didDragMap(_:))) // make your class the delegate of the pan gesture panGesture.delegate = self // add the gesture to the mapView mapView.addGestureRecognizer(panGesture) } 

Add a protocol method for your gesture recognizer to work with existing MKMapView gestures

 func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool { return true } 

Add a method that will be called by the selector in your pan gesture

 func didDragMap(_ sender: UIGestureRecognizer) { if sender.state == .ended { // do something here } } 

Answer 6

In my experience, similar to “typing search,” I found that a timer is the most reliable solution. This eliminates the need to add additional gesture recognizers for panning, pinching, rotating, threading, double tap, etc.

The solution is simple:

• When the map area changes, set the / reset timer

• When the timer fires, load markers for the new area

   import MapKit class MyViewController: MKMapViewDelegate { @IBOutlet var mapView: MKMapView! var mapRegionTimer: NSTimer? // MARK: MapView delegate func mapView(mapView: MKMapView, regionDidChangeAnimated animated: Bool) { setMapRegionTimer() } func setMapRegionTimer() { mapRegionTimer?.invalidate() // Configure delay as bet fits your application mapRegionTimer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: "mapRegionTimerFired:", userInfo: nil, repeats: false) } func mapRegionTimerFired(sender: AnyObject) { // Load markers for current region: // mapView.centerCoordinate or mapView.region } } 

Answer 7

You can also add gesture recognizers to your map in Interface Builder. Associate it with the output for your action in your viewController, I named my "mapDrag" ...

Then you will do something like this in your viewController.m:

 - (IBAction)mapDrag:(UIPanGestureRecognizer *)sender { if(sender.state == UIGestureRecognizerStateBegan){ NSLog(@"drag started"); } } 

Make sure you have this too:

 - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer { return YES; } 

Of course, you need to make your viewController UIGestureRecognizerDelegate in your .h file for this to work.

Otherwise, the card responder is the only one who hears the gesture event.

Answer 8

Another possible solution is to implement touchtsMoved: (or touchesEnded: etc.) in the view controller that contains your map view, for example:

 -(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { [super touchesMoved:touches withEvent:event]; for (UITouch * touch in touches) { CGPoint loc = [touch locationInView:self.mapView]; if ([self.mapView pointInside:loc withEvent:event]) { #do whatever you need to do break; } } } 

This may be easier than using gesture recognizers in some cases.

Answer 9

To find out when a gesture ended on a map:

http://b2cloud.com.au/tutorial/mkmapview-determining-whether-region-change-is-from-user-interaction/

This is very useful for querying the database only after the user has zoomed / rotated / moved the map around.

For me, the zoneDidChangeAnimated method was called only after the gesture was made, and it was not called many times when dragging / scaling / rotating, but it is useful to know if it was due to gestures or not.

Answer 10

Many of these solutions are on the hacked / wrong side of Swift, so I chose a cleaner solution.

I just subclass MKMapView and override touchsMoved. Although this snippet does not include it, I would recommend creating a delegate or notification to convey any information that you need regarding the movement.

 import MapKit class MapView: MKMapView { override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) { super.touchesMoved(touches, with: event) print("Something moved") } } 

You will need to update the class in the storyboard files to point to this subclass, as well as change any maps created by other means.

Answer 11

Yano's answer worked for me, so I decided to leave an updated version for Swift 4 / XCode 9, since I am not very good at Objective-C and I am sure that there are others that are not.

Step 1: Add this code to viewDidLoad:

 let panGesture = UIPanGestureRecognizer(target: self, action: #selector(didDragMap(_:))) panGesture.delegate = self 

Step 2. Verify that your class matches UIGestureRecognizerDelegate:

 class MapViewController: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate, UIGestureRecognizerDelegate { 

Step 3: Add the following function to make your panGesture work simultaneously with other gestures:

 func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool { return true } 

Step 4. And make sure that your method is not called “50 times per drag”, as Jano rightly notes:

 @objc func didDragMap(_ gestureRecognizer: UIPanGestureRecognizer) { if (gestureRecognizer.state == UIGestureRecognizerState.ended) { redoSearchButton.isHidden = false resetLocationButton.isHidden = false } } 

* Note the addition of @objc in the last step. Xcode forcibly uses this prefix for your function to compile it.

Answer 12

You can check the animated property, if false, then the user dragged the map

  func mapView(_ mapView: MKMapView, regionDidChangeAnimated animated: Bool) { if animated == false { //user dragged map } } 

Answer 13

enter the code here I was able to implement this in the simplest way that handles all interaction with the card (pressing / double / N slicing with fingers with 1/2 / N fingers, panning with 1/2 fingers, clamping and rotating

• Create a gesture recognizer and add displays to the container
• Set gesture recognizer's delegate for some object that implements UIGestureRecognizerDelegate
• Implement gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldReceive touch: UITouch) method gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldReceive touch: UITouch)

 private func setupGestureRecognizers() { let gestureRecognizer = UITapGestureRecognizer(target: nil, action: nil) gestureRecognizer.delegate = self self.addGestureRecognizer(gestureRecognizer) } func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldReceive touch: UITouch) -> Bool { self.delegate?.mapCollectionViewBackgroundTouched(self) return false } 

Answer 14

I tried to create an annotation in the center of the map, which is always in the center of the map, no matter what the usage does. I tried several approaches mentioned above and none of them were good enough. In the end, I found a very simple way to solve this, borrowing the answer from Anna and combining with the answer of Eneko. It basically considers the WillChangeAnimated region as the start of a drag and drop, and the regionDidChangeAnimated as the end of one and uses a timer to update the output in real time:

 var mapRegionTimer: Timer? public func mapView(_ mapView: MKMapView, regionWillChangeAnimated animated: Bool) { mapRegionTimer?.invalidate() mapRegionTimer = Timer.scheduledTimer(withTimeInterval: 0.01, repeats: true, block: { (t) in self.myAnnotation.coordinate = CLLocationCoordinate2DMake(mapView.centerCoordinate.latitude, mapView.centerCoordinate.longitude); self.myAnnotation.title = "Current location" self.mapView.addAnnotation(self.myAnnotation) }) } public func mapView(_ mapView: MKMapView, regionDidChangeAnimated animated: Bool) { mapRegionTimer?.invalidate() } 

Answer 15

First , make sure your current view controller is a map delegate. Therefore, set your Map View delegate to yourself and add MKMapViewDelegate to your view controller. An example is below.

 class Location_Popup_ViewController: UIViewController, MKMapViewDelegate { // Your view controller stuff } 

And add this to your map view

 var myMapView: MKMapView = MKMapView() myMapView.delegate = self 

Secondly , add this function, which starts when you move the map. It will filter out any animations and will only work when interacting with it.

 func mapView(_ mapView: MKMapView, regionDidChangeAnimated animated: Bool) { if !animated { // User must have dragged this, filters out all animations // PUT YOUR CODE HERE } }