When I display a mapView using setusertrackingmode the userlocation is displayed always in the mapcenter.
// set tracking mode
[self.mapView setShowsUserLocation:YES];
[self.mapView setUserTrackingMode:MKUserTrackingModeFollowWithHeading animated:YES];
Is there a way to display the userlocation with an offset, so it will be e.g. displayed in the lower quarter of the map?
Related
I have a lot of pin annotations on the MKMapView in my app, the iPhone gets very slow and unresponsive when a lot of them are in view on the map. I would like the user to be able to zoom, but not out past a certain level, such as 2km squared or something.
Here's what I've got:
-(void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:YES];
[[BicycleLDNService sharedService] requestLocationForClient:self];
CLLocationCoordinate2D zoomLocation;
CLLocation *deviceLocation = [[BicycleLDNService sharedService] deviceLocation];
zoomLocation.latitude = deviceLocation.coordinate.latitude;
zoomLocation.longitude = deviceLocation.coordinate.longitude;
MKCoordinateRegion viewRegion = MKCoordinateRegionMakeWithDistance(zoomLocation, 0.5*kMetresPerKilometre, 0.5*kMetresPerKilometre);
MKCoordinateRegion adjustedRegion = [self.mapView regionThatFits:viewRegion];
[self.mapView setRegion:adjustedRegion animated:YES];
self.mapView.zoomEnabled = YES;
}
Is there some sort of property or delegate method I can employ? Couldn't find anything useful on google or here!
Thanks in advance!
The span defines how much of the map at the given point should be visible and is also how you set the zoom level.
You can access this by using
region.span.latitute=0.5;
region.span.longitude=0.6;
Check the zoom level of the map and then set the zoomEnabled Property NO.
mapView.zoomEnabled=NO;
I want to know is it possible to show only specific region on map not the full world map using Map Kit.
Like if i want to show Asia map in my application then map kit hides remaining part of the map.
To handle the "map kit hides remaining part of the map" requirement, one thing you can do is create a black polygon overlay that covers the whole world with a cutout over Asia (or wherever you like).
For example, where you initialize the map (eg. in viewDidLoad):
CLLocationCoordinate2D asiaCoords[4]
= { {55,60}, {55,150}, {0,150}, {0,60} };
//change or add coordinates (and update count below) as needed
self.asiaOverlay = [MKPolygon polygonWithCoordinates:asiaCoords count:4];
CLLocationCoordinate2D worldCoords[4]
= { {90,-180}, {90,180}, {-90,180}, {-90,-180} };
MKPolygon *worldOverlay
= [MKPolygon polygonWithCoordinates:worldCoords
count:4
interiorPolygons:[NSArray arrayWithObject:asiaOverlay]];
//the array can have more than one "cutout" if needed
[myMapView addOverlay:worldOverlay];
and implement the viewForOverlay delegate method:
-(MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id<MKOverlay>)overlay
{
if ([overlay isKindOfClass:[MKPolygon class]])
{
MKPolygonView *pv = [[[MKPolygonView alloc] initWithPolygon:overlay] autorelease];
pv.fillColor = [UIColor blackColor];
pv.alpha = 1.0;
return pv;
}
return nil;
}
This looks like this:
If you also want to restrict the user from scrolling beyond Asia or zooming too far out, then you'll need to do that manually as well. One possible way is described in Restrict MKMapView scrolling. Replace theOverlay in that answer with asiaOverlay.
You can specify the region as an MKCoordinateRegion and then tell an MKMapView instance to only show that region using the setRegion and regionThatFits message.
Alternatively you could use the visibleMapRect property instead of the region. This might better fit your needs.
In short read the MKMapView Class Reference document from Apple.
Lifting from some code I've done in the past that assumes a mapView and a given location called locationToShow I used an MKCoordinateRegion.
- (void) goToLocation {
MKCoordinateRegion region;
MKCoordinateSpan span;
span.latitudeDelta=0.01;
span.longitudeDelta=0.01;
region.span=span;
region.center=locationToShow;
[mapView setRegion:region animated:TRUE];
[mapView regionThatFits:region];
}
I have a MKCoordinateregion called region. I want to change span of this region without changing it's center. I am using following method to change zoom.
-(void) changeZoom
{
NSLog(#"before zoom span, center are %f, %f,%f,%f", region.span.latitudeDelta, region.span.longitudeDelta, mymap.centerCoordinate.latitude, mymap.centerCoordinate.longitude);
region.span.latitudeDelta = current_factor ;
region.span.longitudeDelta = current_factor ;
region.center.latitude = mymap.centerCoordinate.latitude ;
region.center.longitude = mymap.centerCoordinate.longitude ;
[mymap setRegion:region animated:TRUE];
NSLog(#"after zoom span, center are %f, %f,%f,%f", region.span.latitudeDelta, region.span.longitudeDelta, mymap.centerCoordinate.latitude, mymap.centerCoordinate.longitude);
}
Log shows :
before zoom span, center are 0.021950, 0.021950,19.068080,72.838111
after zoom span, center are 0.043901, 0.043901,19.068040,72.838154
This method set's span accurately as desired.But I dont want any change in the center's coordinate, Because when I zoom out and then zoom back I end up at a location different from starting location.
Is there any method so that zoom in and out are possible without any change in center?
Thanks for any help in advance.
Your before and after center coordinates are almost exactly the same, so it shouldn't be a problem. If you really want the exact same center coordinates, call setCenterCoordinate:animated: right after you use setRegion:animated: and pass some saved center coordinates.
CLLocationCoordinate2D originalCenter = mymap.centerCoordinate;
// ... adjust region
[mymap setCenterCoordinate:originalCenter animated:NO];
Also, you should use YES instead of TRUE for booleans:
[mymap setRegion:region animated:YES];
You need to adjust the region of the map to make sure the aspect ratio fits the frame size of the map view.
Once the region with the desired center is calculated, adjust the region as,
MKCoordinateRegion adjustedRegion = [mymap regionThatFits:region];
[mymap setRegion:adjustedRegion animated:TRUE];
See docs.
I have a method that works to move the the map so that it follows the current user location. This works fine, but currently the zoom scale doesn't work how I want. I would like the user to be able to zoom out or zoom in on the map how they want and still have it follow the current location at that NEW zoom scale that the user just set on the map.
I tried to do the following but it doesn't work well:
/**
* Centers the map on the current location
*
* #version $Revision: 0.1
*/
- (void)centerMapOnLocation:(CLLocation *)location {
// Make a region using our current zoom level
CLLocationDistance latitude = mapView.region.span.latitudeDelta*100;
CLLocationDistance longitude = mapView.region.span.longitudeDelta*100;
MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(location.coordinate, latitude, longitude);
[mapView setRegion:region animated:YES];
}//end
MKMapView Zoom and Region describes how to get the current view window.
When you're creating the new MKCoordinateRegion to set the new view to, use the constructor that allows you to specify the size:
UIKIT_STATIC_INLINE MKCoordinateRegion MKCoordinateRegionMake(
CLLocationCoordinate2D centerCoordinate,
MKCoordinateSpan span
);
You'll want to pass in the span from the current region and the centerCoordinate from the user location, which I'll take it you already got.
I have one application that shows maps. I need to show current position of user and manage to do that with
[mapView setShowsLocation:YES];
But when I zoom In or zoom Out map it needs a lot of time to show me that blue pin again.
Is it normal or I need to put something else to keep that blue pin on screen all time???
Thanks.
[self setCurrentLocation:self._mapView.userLocation.location.coordinate withZoom:1.0];
self._mapView.showsUserLocation = YES;
- (void)setCurrentLocation:(CLLocationCoordinate2D)coord withZoom:(float)zoomLevel {
MKCoordinateRegion region = self._mapView.region;
region.span.latitudeDelta = self.defaultSpanLevel.latitudeDelta*zoomLevel;
region.span.longitudeDelta = self.defaultSpanLevel.longitudeDelta*zoomLevel;
region.center = coord;
[self._mapView setRegion:region animated:YES];
}
You can use this in view will appear Method
Then You can use mapview delegate methods....
region did change animated:YES { and set map's region here.... take
current user location as region centre.. }
This will solve your problem
}