I use MKMapRectMake to mark north east and south west to display a region. Here's how I do that:
routeRect = MKMapRectMake(southWestPoint.x, southWestPoint.y, northEastPoint.x - southWestPoint.x, northEastPoint.y - southWestPoint.y);
[self.mapView setVisibleMapRect:routeRect];
After I set up this display region, how can I zoom out the map a little? What is the best way to do this?
UPDATE
This is code that I use to get rect for setVisibleMapRect function:
for(Path* p in ar)
{
self.routeLine = nil;
self.routeLineView = nil;
// while we create the route points, we will also be calculating the bounding box of our route
// so we can easily zoom in on it.
MKMapPoint northEastPoint;
MKMapPoint southWestPoint;
// create a c array of points.
MKMapPoint* pointArr = malloc(sizeof(CLLocationCoordinate2D) * ar.count);
for(int idx = 0; idx < ar.count; idx++)
{
Path *m_p = [ar objectAtIndex:idx];
[NSCharacterSet characterSetWithCharactersInString:#","]];
CLLocationDegrees latitude = m_p.Latitude;
CLLocationDegrees longitude = m_p.Longitude;
// create our coordinate and add it to the correct spot in the array
CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(latitude, longitude);
MKMapPoint point = MKMapPointForCoordinate(coordinate);
// adjust the bounding box
// if it is the first point, just use them, since we have nothing to compare to yet.
if (idx == 0) {
northEastPoint = point;
southWestPoint = point;
}
else
{
if (point.x > northEastPoint.x)
northEastPoint.x = point.x;
if(point.y > northEastPoint.y)
northEastPoint.y = point.y;
if (point.x < southWestPoint.x)
southWestPoint.x = point.x;
if (point.y < southWestPoint.y)
southWestPoint.y = point.y;
}
pointArr[idx] = point;
}
// create the polyline based on the array of points.
self.routeLine = [MKPolyline polylineWithPoints:pointArr count:ar.count];
_routeRect = MKMapRectMake(southWestPoint.x, southWestPoint.y, northEastPoint.x - southWestPoint.x, northEastPoint.y - southWestPoint.y);
// clear the memory allocated earlier for the points
free(pointArr);
[self.mapView removeOverlays: self.mapView.overlays];
// add the overlay to the map
if (nil != self.routeLine) {
[self.mapView addOverlay:self.routeLine];
}
// zoom in on the route.
[self zoomInOnRoute];
}
Try this: (Edit)
MKCoordinateRegion region;
MKCoordinateSpan span;
span.latitudeDelta = 0.01;
span.longitudeDelta = 0.01;
CLLocationCoordinate2D zoomLocation = newLocation.coordinate;
region.center = zoomLocation;
region.span = span;
region = [mapViewObject regionThatFits:region];
[mapViewObject setRegion:region animated:NO];
You can use this custom function to center the Map around two points
- (void)centerMapAroundSourceAndDestination
{
MKMapRect rect = MKMapRectNull;
MKMapPoint sourcePoint = MKMapPointForCoordinate(southWestPoint);
rect = MKMapRectUnion(rect, MKMapRectMake(sourcePoint.x, sourcePoint.y, 0, 0));
MKMapPoint destinationPoint = MKMapPointForCoordinate(_northEastPoint);
rect= MKMapRectUnion(rect, MKMapRectMake(destinationPoint.x, destinationPoint.y, 0, 0));
MKCoordinateRegion region = MKCoordinateRegionForMapRect(rect);
[_mapView setRegion:region animated:YES];
}
So in that case you need to find Centroid of a polygon and then pass that centroid values to this method so it would zoom to center of polygon i.e Centroid.
- (void)zoomMapView:(MKMapView *)mapview withLatitude:(Float32 )latitude andLongitude:(Float32 )longitude {
MKCoordinateRegion region;
region.span.latitudeDelta =0.005; //Change values to zoom. lower the value to zoom in and vice-versa
region.span.longitudeDelta = 0.009;//Change values to zoom. lower the value to zoom in and vice-versa
CLLocationCoordinate2D location;
location.latitude = latitude; // Add your Current Latitude here.
location.longitude = longitude; // Add your Current Longitude here.
region.center = location;
[mapview setRegion:region];
}
To use this method you need to pass three thing mapView, latitude and longitude i.e Position where to zoom.
how can I zoom out the map a little?
Unfortunatley MkMapView setRegion behaves so strange that this does not work on iPhone. (ios 6.1.3)
It works on iPad (ios 6.1.3)
setRegion and setVisibleMapRect
both changes the zoom factor only by steps of two. So you cannot programmatically zoom out by e.g 10%. Although Apple maps are vector based, they still snap the next higher zoom level that (would) fit the map tile pixels 1:1. Maybe to be compatible to map satellite display mode, which uses prerendered bitmaps.
Although bot methods should only correct the aspect ratio if you provided one of the lat/lon spans not perfectly, they additonally snap to said zoom levels.
Try it out: display map, then on button press: get the current region, make the longitude span 10% bigger (factor 1.1), set the region, then read it back, you will see on iphone simu and on iphone4 device the longitude span is now double the size, instead of factor 1.1.
Till today there exists no good solution.
Shame on you Apple.
I have a center location I want my MKMapView to zoom to and also a list of locations (latitude/longitude). I would like to set the zoom level (distance) based on this list of locations so that as many of these locations are visible on the MKMapView at the same time, but with a minimum zoom level (or max distance) so that my MKMapView does not zoom out to much.
So lets say I have a list of 10 locations but one of those locations is so far away from my center location that if I show that one location on the MKMapView it will be zoomed out to much, how do I calculate the distance parameters for MKCoordinateRegionMakeWithDistance?
I hope I explained my problem well enough, I have difficulties explaining it I think.
Thank you
Søren
I got it working with the following solution.
I use the Great-circle distance formula to calculate the distance between my center point and all the found lat/long points, and if this distance is greater than my minimum distance and my maximum distance and larger than my "last found distance" I set this distance to be my zoom distance. It works like a charm and was actually quite simple.
Here is my distance calculation code:
-(double)distanceBetweenLocations:(CLLocationCoordinate2D)c1 :(CLLocationCoordinate2D)c2 {
int r = 6371 * 1000;//meters
double dLat = (c2.latitude - c1.latitude) * M_PI / 180;
double dLon = (c2.longitude - c1.longitude) * M_PI / 180;
double lat1 = c1.latitude * M_PI / 180;
double lat2 = c2.latitude * M_PI / 180;
double a = sin(dLat / 2) * sin(dLat / 2) + sin(dLon / 2) * sin(dLon / 2) * cos(lat1) * cos(lat2);
double c = 2 * atan2(sqrt(a), sqrt(1 - a));
double d = r * c;
return d;
}
And here is my code that zooms to my center point with the calculated distance:
-(void)zoomToLocation {
double MAX_DISTANCE = 10000.0;
double MIN_DISTANCE = 600.0;
double zoomDistance = MIN_DISTANCE;
CLLocationCoordinate2D center;
center.latitude = self.searchLocationLatitude;
center.longitude = self.searchLocationLongitude;
BOOL treaterVisible = NO;
for (Treater *treater in treaters) {
CLLocationCoordinate2D c2;
c2.latitude = treater.latitude;
c2.longitude = treater.longitude;
double distance = [self distanceBetweenLocations:center :c2];
if(distance > zoomDistance && distance < MAX_DISTANCE) {
zoomDistance = distance;
treaterVisible = YES;
}
}
if(!treaterVisible) {
zoomDistance = MAX_DISTANCE;
}
CLLocationCoordinate2D location;
location.latitude = self.searchLocationLatitude;
location.longitude = self.searchLocationLongitude;
MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(location, zoomDistance, zoomDistance);
MKCoordinateRegion adjustedRegion = [self.mapView regionThatFits:region];
[self.mapView setRegion:adjustedRegion];
}
Just if anybody should need something similar.
Best regards
Søren
Edit didAddAnnotationViews method. I hope this is what you are looking for,
-(void) mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views
{
MKMapRect zoomRect = MKMapRectNull;
for (id <MKAnnotation> annotation in mapView.annotations)
{
MKMapPoint annotationPoint = MKMapPointForCoordinate(annotation.coordinate);
MKMapRect pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0.1, 0.1);
if (MKMapRectIsNull(zoomRect)) {
zoomRect = pointRect;
} else {
zoomRect = MKMapRectUnion(zoomRect, pointRect);
}
}
[mapView setVisibleMapRect:zoomRect animated:YES];
}
DDAnnotation is custom class for display pin(PlaceMark)
-(void)zoomToFitMapAnnotations:(MKMapView*)mapView
{
if([mapView.annotations count] == 0)
return;
CLLocationCoordinate2D topLeftCoord;
topLeftCoord.latitude = -90;
topLeftCoord.longitude = 180;
CLLocationCoordinate2D bottomRightCoord;
bottomRightCoord.latitude = 90;
bottomRightCoord.longitude = -180;
for(DDAnnotation* annotation in mapView.annotations)
{
topLeftCoord.longitude = fmin(topLeftCoord.longitude, annotation.coordinate.longitude);
topLeftCoord.latitude = fmax(topLeftCoord.latitude, annotation.coordinate.latitude);
bottomRightCoord.longitude = fmax(bottomRightCoord.longitude, annotation.coordinate.longitude);
bottomRightCoord.latitude = fmin(bottomRightCoord.latitude, annotation.coordinate.latitude);
}
NSLog(#"A%f, B%f, C%f, D%f,", topLeftCoord.latitude, topLeftCoord.longitude, bottomRightCoord.latitude, bottomRightCoord.longitude);
MKCoordinateRegion region;
region.center.latitude = topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5;
region.center.longitude = topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5;
region.span.latitudeDelta = fabs(topLeftCoord.latitude - bottomRightCoord.latitude) * 1.1;
region.span.longitudeDelta = fabs(bottomRightCoord.longitude - topLeftCoord.longitude) * 1.1;
region = [mapView regionThatFits:region];
[mapView setRegion:region animated:YES];
}
Some days ago i have read a solution to your problem in a book, I think it is Preparata Shamos, Computational Geometry.
Unfortunatley the solution is komplex: it is the question: find the best/max subset of points that are visible withing a given radius.
if your point count is not to high, less than ten thousands, i would do it as follows
0) add all point to current selected subset.
1) iterate through all points insubset, calcualte gravity point, calc all distances to gravity point, does it fit the max zoom level desired distance? yes the ready.
2) No? the remove the point from subset, with highest distance, and do step 1 again.
Do that till all points are within the desired distance from the current subset center.
The gravity point is that point in the subset with average x (or longitude) and average y ( or latitude) coordinate.
(If you accept, please dont upvote)
For this we need to find the minimum and maximum latitude and longitude, after that we need make the region with average sum of these latitude and longitude. then assign the region to the mapview and fit the region on it. thats it.
I am using MKMapView and have added a number of annotation pins to the map about a 5-10 kilometre area. When I run the application my map starts zoomed out to show the whole world, what is the best way to zoom the map so the pins fit the view?
EDIT:
My initial thinking would be to use MKCoordinateRegionMake and calculate the coordinate centre, longitudeDelta and latitudeDelta from my annotations. I am pretty sure this will work, but I just wanted to check I was not missing anything obvious.
Code added, BTW: FGLocation is an class that conforms to MKAnnotation, locationFake is an NSMutableArray of these objects. Comments are always welcome ....
- (MKCoordinateRegion)regionFromLocations {
CLLocationCoordinate2D upper = [[locationFake objectAtIndex:0] coordinate];
CLLocationCoordinate2D lower = [[locationFake objectAtIndex:0] coordinate];
// FIND LIMITS
for(FGLocation *eachLocation in locationFake) {
if([eachLocation coordinate].latitude > upper.latitude) upper.latitude = [eachLocation coordinate].latitude;
if([eachLocation coordinate].latitude < lower.latitude) lower.latitude = [eachLocation coordinate].latitude;
if([eachLocation coordinate].longitude > upper.longitude) upper.longitude = [eachLocation coordinate].longitude;
if([eachLocation coordinate].longitude < lower.longitude) lower.longitude = [eachLocation coordinate].longitude;
}
// FIND REGION
MKCoordinateSpan locationSpan;
locationSpan.latitudeDelta = upper.latitude - lower.latitude;
locationSpan.longitudeDelta = upper.longitude - lower.longitude;
CLLocationCoordinate2D locationCenter;
locationCenter.latitude = (upper.latitude + lower.latitude) / 2;
locationCenter.longitude = (upper.longitude + lower.longitude) / 2;
MKCoordinateRegion region = MKCoordinateRegionMake(locationCenter, locationSpan);
return region;
}
This is the one I found here that worked for me:
(EDIT: I have updated the solution using #Micah's suggestion to increase the pointRect by 0.1 to ensure the rect doesn't end up being infinitesimally small!)
MKMapRect zoomRect = MKMapRectNull;
for (id <MKAnnotation> annotation in mapView.annotations)
{
MKMapPoint annotationPoint = MKMapPointForCoordinate(annotation.coordinate);
MKMapRect pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0.1, 0.1);
zoomRect = MKMapRectUnion(zoomRect, pointRect);
}
[mapView setVisibleMapRect:zoomRect animated:YES];
You could also update this to include the userLocation pin by replacing the first line with:
MKMapPoint annotationPoint = MKMapPointForCoordinate(mapView.userLocation.coordinate);
MKMapRect zoomRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0.1, 0.1);
You've got it right.
Find your maximum and minimum latitudes and longitudes, apply some simple arithmetic, and use MKCoordinateRegionMake.
For iOS 7 and above, use showAnnotations:animated:, from MKMapView.h:
// Position the map such that the provided array of annotations are all visible to the fullest extent possible.
- (void)showAnnotations:(NSArray *)annotations animated:(BOOL)animated NS_AVAILABLE(10_9, 7_0);
Apple has added a new method for IOS 7 to simplify life a bit.
[mapView showAnnotations:yourAnnotationArray animated:YES];
You can easily pull from an array stored in the map view:
yourAnnotationArray = mapView.annotations;
and quickly adjust the camera too!
mapView.camera.altitude *= 1.4;
this won't work unless the user has iOS 7+ or OS X 10.9+ installed. check out custom animation here
I use this this code and works fine for me:
-(void)zoomToFitMapAnnotations:(MKMapView*)aMapView
{
if([aMapView.annotations count] == 0)
return;
CLLocationCoordinate2D topLeftCoord;
topLeftCoord.latitude = -90;
topLeftCoord.longitude = 180;
CLLocationCoordinate2D bottomRightCoord;
bottomRightCoord.latitude = 90;
bottomRightCoord.longitude = -180;
for(MapViewAnnotation *annotation in mapView.annotations)
{
topLeftCoord.longitude = fmin(topLeftCoord.longitude, annotation.coordinate.longitude);
topLeftCoord.latitude = fmax(topLeftCoord.latitude, annotation.coordinate.latitude);
bottomRightCoord.longitude = fmax(bottomRightCoord.longitude, annotation.coordinate.longitude);
bottomRightCoord.latitude = fmin(bottomRightCoord.latitude, annotation.coordinate.latitude);
}
MKCoordinateRegion region;
region.center.latitude = topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5;
region.center.longitude = topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5;
region.span.latitudeDelta = fabs(topLeftCoord.latitude - bottomRightCoord.latitude) * 1.1; // Add a little extra space on the sides
region.span.longitudeDelta = fabs(bottomRightCoord.longitude - topLeftCoord.longitude) * 1.1; // Add a little extra space on the sides
region = [aMapView regionThatFits:region];
[mapView setRegion:region animated:YES];
}
In Swift use
mapView.showAnnotations(annotationArray, animated: true)
In Objective c
[mapView showAnnotations:annotationArray animated:YES];
I created an extension to show all the annotations using some code from here and there in swift. This will not show all annotations if they can't be shown even at maximum zoom level.
import MapKit
extension MKMapView {
func fitAllAnnotations() {
var zoomRect = MKMapRectNull;
for annotation in annotations {
let annotationPoint = MKMapPointForCoordinate(annotation.coordinate)
let pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0.1, 0.1);
zoomRect = MKMapRectUnion(zoomRect, pointRect);
}
setVisibleMapRect(zoomRect, edgePadding: UIEdgeInsets(top: 50, left: 50, bottom: 50, right: 50), animated: true)
}
}
I have converted the answer by Rafael Moreira. The credit goes to him.
For those of you looking for the Swift version, here is the code:
func zoomToFitMapAnnotations(aMapView: MKMapView) {
guard aMapView.annotations.count > 0 else {
return
}
var topLeftCoord: CLLocationCoordinate2D = CLLocationCoordinate2D()
topLeftCoord.latitude = -90
topLeftCoord.longitude = 180
var bottomRightCoord: CLLocationCoordinate2D = CLLocationCoordinate2D()
bottomRightCoord.latitude = 90
bottomRightCoord.longitude = -180
for annotation: MKAnnotation in myMap.annotations as! [MKAnnotation]{
topLeftCoord.longitude = fmin(topLeftCoord.longitude, annotation.coordinate.longitude)
topLeftCoord.latitude = fmax(topLeftCoord.latitude, annotation.coordinate.latitude)
bottomRightCoord.longitude = fmax(bottomRightCoord.longitude, annotation.coordinate.longitude)
bottomRightCoord.latitude = fmin(bottomRightCoord.latitude, annotation.coordinate.latitude)
}
var region: MKCoordinateRegion = MKCoordinateRegion()
region.center.latitude = topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5
region.center.longitude = topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5
region.span.latitudeDelta = fabs(topLeftCoord.latitude - bottomRightCoord.latitude) * 1.4
region.span.longitudeDelta = fabs(bottomRightCoord.longitude - topLeftCoord.longitude) * 1.4
region = aMapView.regionThatFits(region)
myMap.setRegion(region, animated: true)
}
Swift 3 This is de correct way for fit all annotations in map.
func zoomMapaFitAnnotations() {
var zoomRect = MKMapRectNull
for annotation in mapview.annotations {
let annotationPoint = MKMapPointForCoordinate(annotation.coordinate)
let pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0, 0)
if (MKMapRectIsNull(zoomRect)) {
zoomRect = pointRect
} else {
zoomRect = MKMapRectUnion(zoomRect, pointRect)
}
}
self.mapview.setVisibleMapRect(zoomRect, edgePadding: UIEdgeInsetsMake(50, 50, 50, 50), animated: true)
}
#jowie's solution works great. One catch, if a map has only one annotation you'll end up with a fully zoomed out map. I added 0.1 to the rect make size to make sure setVisibleMapRect has something to zoom to.
MKMapRect pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0.1, 0.1);
If your are looking for iOS 8 and above, the simplest way to do it is to set the var layoutMargins: UIEdgeInsets { get set } of your map view before calling func showAnnotations(annotations: [MKAnnotation], animated: Bool)
For instance (Swift 2.1):
#IBOutlet weak var map: MKMapView! {
didSet {
map.delegate = self
map.mapType = .Standard
map.pitchEnabled = false
map.rotateEnabled = false
map.scrollEnabled = true
map.zoomEnabled = true
}
}
// call 'updateView()' when viewWillAppear or whenever you set the map annotations
func updateView() {
map.layoutMargins = UIEdgeInsets(top: 25, left: 25, bottom: 25, right: 25)
map.showAnnotations(map.annotations, animated: true)
}
Added this If loop within the for loop to exclude the users location pin from this method (required in my case, and maybe others)
if (![annotation isKindOfClass:[MKUserLocation class]] ) {
//Code Here...
}
For iOS 7 and above (Referring MKMapView.h) :
// Position the map such that the provided array of annotations are all visible to the fullest extent possible.
- (void)showAnnotations:(NSArray *)annotations animated:(BOOL)animated NS_AVAILABLE(10_9, 7_0);
remark from – Abhishek Bedi
You just call:
[yourMapView showAnnotations:#[yourAnnotation] animated:YES];
var zoomRect: MKMapRect = MKMapRect.null
for annotation in mapView.annotations {
let annotationPoint = MKMapPoint(annotation.coordinate)
let pointRect = MKMapRect(x: annotationPoint.x, y: annotationPoint.y, width: 0.1, height: 0.1)
zoomRect = zoomRect.union(pointRect)
}
mapView.setVisibleMapRect(zoomRect, animated: true)
// Edited for swift 5
In Swift
var zoomRect = MKMapRectNull;
for i in 0..<self.map.annotations.count {
let annotation: MKAnnotation = self.map.annotations[i]
let annotationPoint = MKMapPointForCoordinate(annotation.coordinate);
let pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0.1, 0.1);
zoomRect = MKMapRectUnion(zoomRect, pointRect);
}
self.map.setVisibleMapRect(zoomRect, animated: true)
Thanks to jowie I've updated my old category to more elegant solution. Sharing complete, almost copy&paste ready solution
MKMapView+AnnotationsRegion.h
#import <MapKit/MapKit.h>
#interface MKMapView (AnnotationsRegion)
-(void)updateRegionForCurrentAnnotationsAnimated:(BOOL)animated;
-(void)updateRegionForCurrentAnnotationsAnimated:(BOOL)animated edgePadding:(UIEdgeInsets)edgePadding;
-(void)updateRegionForAnnotations:(NSArray *)annotations animated:(BOOL)animated;
-(void)updateRegionForAnnotations:(NSArray *)annotations animated:(BOOL)animated edgePadding:(UIEdgeInsets)edgePadding;
#end
MKMapView+AnnotationsRegion.m
#import "MKMapView+AnnotationsRegion.h"
#implementation MKMapView (AnnotationsRegion)
-(void)updateRegionForCurrentAnnotationsAnimated:(BOOL)animated{
[self updateRegionForCurrentAnnotationsAnimated:animated edgePadding:UIEdgeInsetsZero];
}
-(void)updateRegionForCurrentAnnotationsAnimated:(BOOL)animated edgePadding:(UIEdgeInsets)edgePadding{
[self updateRegionForAnnotations:self.annotations animated:animated edgePadding:edgePadding];
}
-(void)updateRegionForAnnotations:(NSArray *)annotations animated:(BOOL)animated{
[self updateRegionForAnnotations:annotations animated:animated edgePadding:UIEdgeInsetsZero];
}
-(void)updateRegionForAnnotations:(NSArray *)annotations animated:(BOOL)animated edgePadding:(UIEdgeInsets)edgePadding{
MKMapRect zoomRect = MKMapRectNull;
for(id<MKAnnotation> annotation in annotations){
MKMapPoint annotationPoint = MKMapPointForCoordinate(annotation.coordinate);
MKMapRect pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0.1, 0.1);
zoomRect = MKMapRectUnion(zoomRect, pointRect);
}
[self setVisibleMapRect:zoomRect edgePadding:edgePadding animated:animated];
}
#end
Hope it helps someone and thanks again jowie!
- (void)zoomMapViewToFitAnnotationsWithExtraZoomToAdjust:(double)extraZoom
{
if ([self.annotations count] == 0) return;
int i = 0;
MKMapPoint points[[self.annotations count]];
for (id<MKAnnotation> annotation in [self annotations])
{
points[i++] = MKMapPointForCoordinate(annotation.coordinate);
}
MKPolygon *poly = [MKPolygon polygonWithPoints:points count:i];
MKCoordinateRegion r = MKCoordinateRegionForMapRect([poly boundingMapRect]);
r.span.latitudeDelta += extraZoom;
r.span.longitudeDelta += extraZoom;
[self setRegion: r animated:YES];
}
As Abhishek Bedi points out in a comment, For iOS7 forward the best way to do this is:
//from API docs:
//- (void)showAnnotations:(NSArray *)annotations animated:(BOOL)animated NS_AVAILABLE(10_9, 7_0);
[self.mapView showAnnotations:self.mapView.annotations animated:YES];
For my personal project (prior to iOS7) I simply added a category on the MKMapView class to encapsulate the "visible area" functionality for a very common operation: setting it to be able to see all the currently-loaded annotations on the MKMapView instance (this includes as many pins as you might have placed, as well as the user's location). the result was this:
.h file
#import <MapKit/MapKit.h>
#interface MKMapView (Extensions)
-(void)ij_setVisibleRectToFitAllLoadedAnnotationsAnimated:(BOOL)animated;
-(void)ij_setVisibleRectToFitAnnotations:(NSArray *)annotations animated:(BOOL)animated;
#end
.m file
#import "MKMapView+Extensions.h"
#implementation MKMapView (Extensions)
/**
* Changes the currently visible portion of the map to a region that best fits all the currently loadded annotations on the map, and it optionally animates the change.
*
* #param animated is the change should be perfomed with an animation.
*/
-(void)ij_setVisibleRectToFitAllLoadedAnnotationsAnimated:(BOOL)animated
{
MKMapView * mapView = self;
NSArray * annotations = mapView.annotations;
[self ij_setVisibleRectToFitAnnotations:annotations animated:animated];
}
/**
* Changes the currently visible portion of the map to a region that best fits the provided annotations array, and it optionally animates the change.
All elements from the array must conform to the <MKAnnotation> protocol in order to fetch the coordinates to compute the visible region of the map.
*
* #param annotations an array of elements conforming to the <MKAnnotation> protocol, holding the locations for which the visible portion of the map will be set.
* #param animated wether or not the change should be perfomed with an animation.
*/
-(void)ij_setVisibleRectToFitAnnotations:(NSArray *)annotations animated:(BOOL)animated
{
MKMapView * mapView = self;
MKMapRect r = MKMapRectNull;
for (id<MKAnnotation> a in annotations) {
ZAssert([a conformsToProtocol:#protocol(MKAnnotation)], #"ERROR: All elements of the array MUST conform to the MKAnnotation protocol. Element (%#) did not fulfill this requirement", a);
MKMapPoint p = MKMapPointForCoordinate(a.coordinate);
//MKMapRectUnion performs the union between 2 rects, returning a bigger rect containing both (or just one if the other is null). here we do it for rects without a size (points)
r = MKMapRectUnion(r, MKMapRectMake(p.x, p.y, 0, 0));
}
[mapView setVisibleMapRect:r animated:animated];
}
#end
As you can see, I've added 2 methods so far: one for setting the visible region of the map to the one that fits all currently-loaded annotations on the MKMapView instance, and another method to set it to any array of objects.
So to set the mapView's visible region the code would then be as simple as:
//the mapView instance
[self.mapView ij_setVisibleRectToFitAllLoadedAnnotationsAnimated:animated];
I hope it helps =)
All the answers on this page assume that the map occupies the full screen. I actually have a HUD display (ie buttons scattered at the top and bottom) that give information ontop of the map.. and so the algorithms on the page will display the pins all right, but some of them will appear under the HUD display buttons.
My solution zooms the map in to display the annotations in a subset of the screen and works for different screen sizes (ie 3.5" vs 4.0" etc):
// create a UIView placeholder and throw it on top of the original mapview
// position the UIView to fit the maximum area not hidden by the HUD display buttons
// add an *other* mapview in that uiview,
// get the MKCoordinateRegion that fits the pins from that fake mapview
// kill the fake mapview and set the region of the original map
// to that MKCoordinateRegion.
Here is what I did in code (note: i use NSConstraints with some helper methods to make my code work in different screen sizes.. while the code is quite readable.. my answer here explains it better.. it's basically the same workflow:)
// position smallerMap to fit available space
// don't store this map, it will slow down things if we keep it hidden or even in memory
[#[_smallerMapPlaceholder] mapObjectsApplyingBlock:^(UIView *view) {
[view removeFromSuperview];
[view setTranslatesAutoresizingMaskIntoConstraints:NO];
[view setHidden:NO];
[self.view addSubview:view];
}];
NSDictionary *buttonBindingDict = #{ #"mapPlaceholder": _smallerMapPlaceholder};
NSArray *constraints = [#[#"V:|-225-[mapPlaceholder(>=50)]-176-|",
#"|-40-[mapPlaceholder(<=240)]-40-|"
] mapObjectsUsingBlock:^id(NSString *formatString, NSUInteger idx){
return [NSLayoutConstraint constraintsWithVisualFormat:formatString options:0 metrics:nil views:buttonBindingDict];
}];
[self.view addConstraints:[constraints flattenArray]];
[self.view layoutIfNeeded];
MKMapView *smallerMap = [[MKMapView alloc] initWithFrame:self.smallerMapPlaceholder.frame];
[_smallerMapPlaceholder addSubview:smallerMap];
MKCoordinateRegion regionThatFits = [smallerMap getRegionThatFits:self.mapView.annotations];
[smallerMap removeFromSuperview];
smallerMap = nil;
[_smallerMapPlaceholder setHidden:YES];
[self.mapView setRegion:regionThatFits animated:YES];
here is the code that gets region that fits:
- (MKCoordinateRegion)getRegionThatFits:(NSArray *)routes {
MKCoordinateRegion region;
CLLocationDegrees maxLat = -90.0;
CLLocationDegrees maxLon = -180.0;
CLLocationDegrees minLat = 90.0;
CLLocationDegrees minLon = 180.0;
for(int idx = 0; idx < routes.count; idx++)
{
CLLocation* currentLocation = [routes objectAtIndex:idx];
if(currentLocation.coordinate.latitude > maxLat)
maxLat = currentLocation.coordinate.latitude;
if(currentLocation.coordinate.latitude < minLat)
minLat = currentLocation.coordinate.latitude;
if(currentLocation.coordinate.longitude > maxLon)
maxLon = currentLocation.coordinate.longitude;
if(currentLocation.coordinate.longitude < minLon)
minLon = currentLocation.coordinate.longitude;
}
region.center.latitude = (maxLat + minLat) / 2.0;
region.center.longitude = (maxLon + minLon) / 2.0;
region.span.latitudeDelta = 0.01;
region.span.longitudeDelta = 0.01;
region.span.latitudeDelta = ((maxLat - minLat)<0.0)?100.0:(maxLat - minLat);
region.span.longitudeDelta = ((maxLon - minLon)<0.0)?100.0:(maxLon - minLon);
MKCoordinateRegion regionThatFits = [self regionThatFits:region];
return regionThatFits;
}
I've made a little modification of Rafael's code for MKMapView Category.
- (void)zoomToFitMapAnnotations {
if ([self.annotations count] == 0)
return;
CLLocationCoordinate2D topLeftCoord;
topLeftCoord.latitude = -90;
topLeftCoord.longitude = 180;
CLLocationCoordinate2D bottomRightCoord;
bottomRightCoord.latitude = 90;
bottomRightCoord.longitude = -180;
for (id <MKAnnotation> annotation in self.annotations) {
topLeftCoord.longitude = fmin(topLeftCoord.longitude, annotation.coordinate.longitude);
topLeftCoord.latitude = fmax(topLeftCoord.latitude, annotation.coordinate.latitude);
bottomRightCoord.longitude = fmax(bottomRightCoord.longitude, annotation.coordinate.longitude);
bottomRightCoord.latitude = fmin(bottomRightCoord.latitude, annotation.coordinate.latitude);
}
MKCoordinateRegion region;
region.center.latitude = topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5;
region.center.longitude = topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5;
region.span.latitudeDelta = fabs(topLeftCoord.latitude - bottomRightCoord.latitude) * 1.1; // Add a little extra space on the sides
region.span.longitudeDelta = fabs(bottomRightCoord.longitude - topLeftCoord.longitude) * 1.1; // Add a little extra space on the sides
[self setRegion:[self regionThatFits:region] animated:YES];
}
Based on answers above you can use universal method to zoom map to fit all annotations and overlays at the same time.
-(MKMapRect)getZoomingRectOnMap:(MKMapView*)map toFitAllOverlays:(BOOL)overlays andAnnotations:(BOOL)annotations includeUserLocation:(BOOL)userLocation {
if (!map) {
return MKMapRectNull;
}
NSMutableArray* overlaysAndAnnotationsCoordinateArray = [[NSMutableArray alloc]init];
if (overlays) {
for (id <MKOverlay> overlay in map.overlays) {
MKMapPoint overlayPoint = MKMapPointForCoordinate(overlay.coordinate);
NSArray* coordinate = #[[NSNumber numberWithDouble:overlayPoint.x], [NSNumber numberWithDouble:overlayPoint.y]];
[overlaysAndAnnotationsCoordinateArray addObject:coordinate];
}
}
if (annotations) {
for (id <MKAnnotation> annotation in map.annotations) {
MKMapPoint annotationPoint = MKMapPointForCoordinate(annotation.coordinate);
NSArray* coordinate = #[[NSNumber numberWithDouble:annotationPoint.x], [NSNumber numberWithDouble:annotationPoint.y]];
[overlaysAndAnnotationsCoordinateArray addObject:coordinate];
}
}
MKMapRect zoomRect = MKMapRectNull;
if (userLocation) {
MKMapPoint annotationPoint = MKMapPointForCoordinate(map.userLocation.coordinate);
zoomRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0.1, 0.1);
}
for (NSArray* coordinate in overlaysAndAnnotationsCoordinateArray) {
MKMapRect pointRect = MKMapRectMake([coordinate[0] doubleValue], [coordinate[1] doubleValue], 0.1, 0.1);
zoomRect = MKMapRectUnion(zoomRect, pointRect);
}
return zoomRect;
}
And then:
MKMapRect mapRect = [self getZoomingRectOnMap:mapView toFitAllOverlays:YES andAnnotations:YES includeUserLocation:NO];
[mapView setVisibleMapRect:mapRect edgePadding:UIEdgeInsetsMake(10.0, 10.0, 10.0, 10.0) animated:YES];
Swift 5+ in 2021
// Position the map such that the provided array of annotations are all visible to the fullest extent possible.
#available(iOS 7.0, *)
open func showAnnotations(_ annotations: [MKAnnotation], animated: Bool)
so you can just:
mapView.showAnnotations(mapView.annotations, animated: true)
Just sharing my observations on this:
If you are using xCode > 6 with "inferred" sizes for the screens (see "simulated metrics" on the file inspector) in storyboard, calling
- (void)showAnnotations:(NSArray *)annotations
animated:(BOOL)animated
in viewDidLoad will result in a too large zoom level on iPhones with 4 inches because the layout for the map is still on the size of the wider screens from the storyboard.
You can move your call to showAnnotations... to viewDidAppear. Then the size of the map has already been adjusted to the smaller screen of an iPhone 4.
Or alternatively change the value "inferred" in the file inspector under "simulated metrics" to iphone 4-inch.
You can select which shapes you want to show along with the Annotations.
extension MKMapView {
func setVisibleMapRectToFitAllAnnotations(animated: Bool = true,
shouldIncludeUserAccuracyRange: Bool = true,
shouldIncludeOverlays: Bool = true,
edgePadding: UIEdgeInsets = UIEdgeInsets(top: 35, left: 35, bottom: 35, right: 35)) {
var mapOverlays = overlays
if shouldIncludeUserAccuracyRange, let userLocation = userLocation.location {
let userAccuracyRangeCircle = MKCircle(center: userLocation.coordinate, radius: userLocation.horizontalAccuracy)
mapOverlays.append(MKOverlayRenderer(overlay: userAccuracyRangeCircle).overlay)
}
if shouldIncludeOverlays {
let annotations = self.annotations.filter { !($0 is MKUserLocation) }
annotations.forEach { annotation in
let cirlce = MKCircle(center: annotation.coordinate, radius: 1)
mapOverlays.append(cirlce)
}
}
let zoomRect = MKMapRect(bounding: mapOverlays)
setVisibleMapRect(zoomRect, edgePadding: edgePadding, animated: animated)
}
}
extension MKMapRect {
init(bounding overlays: [MKOverlay]) {
self = .null
overlays.forEach { overlay in
let rect: MKMapRect = overlay.boundingMapRect
self = self.union(rect)
}
}
}
#"I'm not sure if this is because of some other factors in my implementation, but I find that showAnnotations doesn't do as close a zoom/fit of the annotations as the manual implementation does, so I've stuck with the manual one. – Ted Avery Apr 17 at 0:35"
I had the same problem, but then I tried doing showAnnotations twice (like below), and for some reason, it worked.
[mapView showAnnotations:yourAnnotationArray animated:YES];
[mapView showAnnotations:yourAnnotationArray animated:YES];
An iOS 7 compatible way is to use the following. First call showAnnotation in order to get a rectangle including all annotations. Afterwards create and UIEdgeInset with an top inset of the pin height. Thus you ensure to show the whole pin on the map.
[self.mapView showAnnotations:self.mapView.annotations animated:YES];
MKMapRect rect = [self.mapView visibleMapRect];
UIEdgeInsets insets = UIEdgeInsetsMake(pinHeight, 0, 0, 0);
[self.mapView setVisibleMapRect:rect edgePadding:insets animated:YES];
Put this in to your code accordingly:
- (void)mapView:(MKMapView *)mv didAddAnnotationViews:(NSArray *)views
{
id<MKAnnotation> mp = [annotationView annotation];
MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance([mp coordinate] ,250,250);
[mv setRegion:region animated:YES];
}
Quick background of what I have going on. UIMapView loads and shows a single annotation (Never more than one). On the menu bar, there is a Locate Me button, on tap the userLocation is found and displayed as a second annotation. I then I have MapView zoom out to fit both those annotations in range but I am unable to find a suitable way of doing so. Depending on where the first annotation is placed in relation to the user location, sometimes it doesn't zoom out enough.
For example, if the annotation is North West of the User, it zooms out fine. But if the annotation is South East of the User, it only zooms out enough that they are just getting cut off and you have to manually zoom out a bit more. Here's the code I am using, variation of some others I have found on SO.
CLLocation *whereIAm = mapView.userLocation.location;
float lat = whereIAm.coordinate.latitude;
float lon = whereIAm.coordinate.longitude;
CLLocationCoordinate2D southWest = {[currentLatitude floatValue], [currentLongitude floatValue]};
CLLocationCoordinate2D northEast = southWest;
southWest.latitude = MIN(southWest.latitude, lat);
southWest.longitude = MIN(southWest.longitude, lon);
northEast.latitude = MAX(northEast.latitude, lat);
northEast.longitude = MAX(northEast.longitude, lon);
CLLocation *locSouthWest = [[CLLocation alloc] initWithLatitude:southWest.latitude longitude:southWest.longitude];
CLLocation *locNorthEast = [[CLLocation alloc] initWithLatitude:northEast.latitude longitude:northEast.longitude];
CLLocationDistance meters = [locSouthWest distanceFromLocation:locNorthEast];
MKCoordinateRegion region;
region.center.latitude = (southWest.latitude + northEast.latitude) / 2.0;
region.center.longitude = (southWest.longitude + northEast.longitude) / 2.0;
region.span.latitudeDelta = meters / 111319.5
region.span.longitudeDelta = 7.0;
MKCoordinateRegion savedRegion = [mapView regionThatFits:region];
[mapView setRegion:savedRegion animated:YES];
[locSouthWest release];
[locNorthEast release];
Is there a better way built into MapKit to just zoom out so that both annotations have, lets say half an inch between them at the outer frame? I don't really care if the user has to zoom in after, I just want it to zoom out properly.
-(void)zoomToFitMapAnnotations:(MKMapView*)mapView
{
if([mapView.annotations count] == 0)
return;
CLLocationCoordinate2D topLeftCoord;
topLeftCoord.latitude = -90;
topLeftCoord.longitude = 180;
CLLocationCoordinate2D bottomRightCoord;
bottomRightCoord.latitude = 90;
bottomRightCoord.longitude = -180;
for(MapAnnotation* annotation in mapView.annotations)
{
topLeftCoord.longitude = fmin(topLeftCoord.longitude, annotation.coordinate.longitude);
topLeftCoord.latitude = fmax(topLeftCoord.latitude, annotation.coordinate.latitude);
bottomRightCoord.longitude = fmax(bottomRightCoord.longitude, annotation.coordinate.longitude);
bottomRightCoord.latitude = fmin(bottomRightCoord.latitude, annotation.coordinate.latitude);
}
MKCoordinateRegion region;
region.center.latitude = topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5;
region.center.longitude = topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5;
region.span.latitudeDelta = fabs(topLeftCoord.latitude - bottomRightCoord.latitude) * 1.1; // Add a little extra space on the sides
region.span.longitudeDelta = fabs(bottomRightCoord.longitude - topLeftCoord.longitude) * 1.1; // Add a little extra space on the sides
region = [mapView regionThatFits:region];
[mapView setRegion:region animated:YES];
}
Taken from: http://codisllc.com/blog/zoom-mkmapview-to-fit-annotations/
(Use it all the time.)
In iOS7 there's a method that does just that. Just call:
[yourMapView showAnnotations:yourAnnotationsArray animated:YES];
Those who do the monotouch c# coding
BasicMapAnnotation is inherit class from MKAnnotation
private void GetRegion(MKMapView mapView)
{
var userWasVisible = mapView.ShowsUserLocation;
mapView.ShowsUserLocation = false; // ignoring the blue blip
// start with the widest possible viewport
var tl = new CLLocationCoordinate2D(-90, 180); // top left
var br = new CLLocationCoordinate2D(90, -180); // bottom right
foreach (var an in mapView.Annotations)
{
// narrow the viewport bit-by-bit
CLLocationCoordinate2D coordinate = ((BasicMapAnnotation) an).Coordinate;
tl.Longitude = Math.Min(tl.Longitude, coordinate.Longitude);
tl.Latitude = Math.Max(tl.Latitude, coordinate.Latitude);
br.Longitude = Math.Max(br.Longitude, coordinate.Longitude);
br.Latitude = Math.Min(br.Latitude, coordinate.Latitude);
}
var center = new CLLocationCoordinate2D
{
// divide the range by two to get the center
Latitude = tl.Latitude - (tl.Latitude - br.Latitude)*0.5,Longitude = tl.Longitude + (br.Longitude - tl.Longitude)*0.5
};
var span = new MKCoordinateSpan
{
// calculate the span, with 20% margin so pins aren’t on the edge
LatitudeDelta = Math.Abs(tl.Latitude - br.Latitude)*1.2,LongitudeDelta = Math.Abs(br.Longitude - tl.Longitude)*1.2
};
var region = new MKCoordinateRegion {Center = center, Span = span};
region = mapView.RegionThatFits(region); // adjusts zoom level too
mapView.SetRegion(region, true); // animated transition
mapView.ShowsUserLocation =
userWasVisible;
}
You can use this code to show all annotations
MKMapRect zoomRect = MKMapRectNull;
for (id <MKAnnotation> annotation in mapView.annotations)
{
MKMapPoint annotationPoint = MKMapPointForCoordinate(annotation.coordinate);
MKMapRect pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0.1, 0.1);
zoomRect = MKMapRectUnion(zoomRect, pointRect);
}
[mapView setVisibleMapRect:zoomRect animated:YES];
if you want to include user location just replace two lines below with the first line of above code
MKMapPoint annotationPoint = MKMapPointForCoordinate(mapView.userLocation.coordinate);
MKMapRect zoomRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0.1, 0.1);