I am working with mapkit in Xcode 5.1 and am trying to display the map scale in regionDidChangeAnimated. I have no idea now to accomplish this though. I tried to look around and was unsuccessful. Any ideas?
EDIT:
-(void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated {
CGPoint nePoint = CGPointMake(self.mapView.bounds.origin.x + mapView.bounds.size.width, mapView.bounds.origin.y);
CGPoint swPoint = CGPointMake((self.mapView.bounds.origin.x), (mapView.bounds.origin.y + mapView.bounds.size.height));
CLLocationCoordinate2D neCoord;
neCoord = [self.mapView convertPoint:nePoint toCoordinateFromView:self.mapView];
CLLocationCoordinate2D swCoord;
swCoord = [self.mapView convertPoint:swPoint toCoordinateFromView:self.mapView];
CLLocationDistance distance = [neCoord distanceFromLocation:swCoord];
}
Any reason why I am getting an error with the last line, CLLocationDistance?
Use the methods that translate between the coordinates on the map and the points on the map view, such as convertPoint:toCoordinateFromView:. Use the edge points of your view for this.
Now you have the coordinates - you can calculate the distances between the points with CLLocation's distanceFromLocation:. You can make some assumptions about the width of your view based on the physical properties of, day an iPhone or iPad and calculate the scale.
I am using following codes
MKCoordinateRegion viewRegion = MKCoordinateRegionMakeWithDistance(CLLocationCoordinate2DMake(annView.annotation.coordinate.latitude, annView.annotation.coordinate.longitude - .04), Some KM, Some KM);
MKCoordinateRegion adjustedRegion = [self.mapView regionThatFits:viewRegion];
[self.mapView setRegion:adjustedRegion animated:YES];
Otherway around is
MKCoordinateRegionMake(CLLocationCoordinate2DMake(annView.annotation.coordinate.latitude, annView.annotation.coordinate.longitude - .04), ADD SPAN HERE)
Both of these makes the map zoom. How is it possible that I change the Region without any zoom.
Get the current region and just change the center point.
// get current region
MKCoordinateRegion region = self.mapView.region;
// Update the center
region.center = CLLocationCoordinate2DMake(annView.annotation.coordinate.latitude, annView.annotation.coordinate.longitude - .04);
// apply the new region
self.mapView.region = region;
If you have a coordinate to set, use the MKMapView -setCenterCoordinate:animated: method. Animating the position change gives the user a clue about what's happened.
CLLocationCoordinate2D coordinate = annView.annotation.coordinate;
[myMapView setCenterCoordinate:coordinate animated:YES];
Also, no need to make a new coordinate, just use the one already in the annotation view.
I am using the HGMovingAnnotation and HGMovingAnnotationView code off of github to animate a MKAnnotation on an MKmap. When I run the example project from HG project everything works fine.
I have altred the original HG project to allow me to manually push a new coordinate to the HGMapPath and then move the annotation where I want it.
I have placed a button, for testing, to run the manual process and everything works fine. The annotation moves around the screen. The issue is, when I try to now call this manual method with data from a live socket.io connection, the map annotation won't move.
Also, when the map first loads the annotation won't show up until I move the map a little bit. The same thing for the moving annotation manually, it won't show the movement from the stream of data, until I zoom the map. But if I do the push button way, avoiding the io stream, the annotation moves without needing to zoom or pan the map?
PLACING THE VIEW ANNOTATIONS
if(doubleLat && doubleLng) {
CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(doubleLat, doubleLng);
//Create path object
self.assignedAmbPath = [[HGMapPath alloc] initWithCoordinate:coordinate];
HGMovingAnnotation *movingObject = [[HGMovingAnnotation alloc] initWithMapPath:self.assignedAmbPath];
self.movingAssignedAmbObject = movingObject;
// add the annotation to the map
[self.mapView addAnnotation:movingObject];
// zoom the map around the moving object
MKCoordinateSpan span = MKCoordinateSpanMake(0.01, 0.01);
MKCoordinateRegion region = MKCoordinateRegionMake(MKCoordinateForMapPoint(self.movingAssignedAmbObject.currentLocation), span);
[self.mapView setRegion:region animated:YES];
// start moving the object
[movingObject start];
}
CODE THAT WORKS
- (IBAction)testMoveBtnPressed:(id)sender {
//TODO: move x and y
DLog(#"============== Test move button was pressed ================ ");
NSLog(#"");
int randn = (random() % 15)+15;
float pscale = (float)randn / 10000;
double lat = 39.9813855 + pscale;
double lng = -75.1502155 + pscale;
for (id<MKAnnotation> annotation in self.mapView.annotations){
MKAnnotationView* anView = [self.mapView viewForAnnotation: annotation];
if (![annotation isKindOfClass:[PhoneAnnotation class]]){
// Process annotation view
[((HGMovingAnnotation *)annotation) trackToNewPosition:CLLocationCoordinate2DMake(lat, lng)];
}
}
}
CODE THAT DOESN'T WORK
{
//TODO: move thing to new location
double doubleLat = [lat doubleValue];
double doubleLng = [lng doubleValue];
// NSLog(#"--------------- Jason it is ------------- Latitude being passed in is %f", doubleLat);
// NSLog(#"--------------- Jason it is ------------- Longitude being passed in is %f", doubleLng);
//
// [self.movingAssignedAmbObject trackToNewPosition:CLLocationCoordinate2DMake(doubleLat, doubleLng)];
for (id<MKAnnotation> annotation in self.mapView.annotations){
MKAnnotationView* anView = [self.mapView viewForAnnotation: annotation];
if (![annotation isKindOfClass:[PhoneAnnotation class]]){
// Process annotation view
[((HGMovingAnnotation *)annotation) trackToNewPosition:CLLocationCoordinate2DMake(doubleLat, doubleLng)];
}
}
}
The issue is the HG library though works as described doesn't work proper, unless your using the path, if you don't create the annotation with a coordinate attached, which it doesn't.
I'm displaying an MKMapView inside a Path-style parallax table view header. To create the effect, the mapView bounds is larger than the area visible to the user. I need to set the map view region such that all the map's annotations are contained within the visible rect of MKMapView. What's the best way to do this?
Edit for clarity: Here's a use-case. The mapView size is 320 x 380. The visible area, however, is defined by the rect (0.0, 20.0, 320.0, 100.0). I need to set the region such that all the annotations appear in this rect within the mapView.
Setting the map region so that all annotations are contained in a certain part of an MKMapView can be done in three steps. Input are the mapView and the annotationsFrame.
Calculate an MKMapRect mapRect that contains all annotations.
Calculate the padding insets from mapView.bounds and annotationsFrame.
Call -setVisibleMapRect:edgePadding:animated: on the map view.
Below is a screen shot of a test. The red overlay shows the annotationsFrame.
Here is the code. Beware: It's all in one method to simplify adding it to your code, and it is not tested for edge cases like passing in n annotations with the same coordinate, or having the annotations so far apart that the map would have to get zoomed out too much, or having coordinates that span the edge of the map at +/-180 degrees longitude.
- (void)zoomAnnotationsOnMapView:(MKMapView *)mapView toFrame:(CGRect)annotationsFrame animated:(BOOL)animated
{
if (_mapView.annotations.count < 2) return;
// Step 1: make an MKMapRect that contains all the annotations
NSArray *annotations = _mapView.annotations;
id <MKAnnotation> firstAnnotation = [annotations objectAtIndex:0];
MKMapPoint minPoint = MKMapPointForCoordinate(firstAnnotation.coordinate);
MKMapPoint maxPoint = minPoint;
for (id <MKAnnotation> annotation in annotations) {
MKMapPoint point = MKMapPointForCoordinate(annotation.coordinate);
if (point.x < minPoint.x) minPoint.x = point.x;
if (point.y < minPoint.y) minPoint.y = point.y;
if (point.x > maxPoint.x) maxPoint.x = point.x;
if (point.y > maxPoint.y) maxPoint.y = point.y;
}
MKMapRect mapRect = MKMapRectMake(minPoint.x, minPoint.y, maxPoint.x - minPoint.x, maxPoint.y - minPoint.y);
// Step 2: Calculate the edge padding
UIEdgeInsets edgePadding = UIEdgeInsetsMake(
CGRectGetMinY(annotationsFrame),
CGRectGetMinX(annotationsFrame),
CGRectGetMaxY(mapBounds) - CGRectGetMaxY(annotationsFrame),
CGRectGetMaxX(mapBounds) - CGRectGetMaxX(annotationsFrame)
);
// Step 3: Set the map rect
[mapView setVisibleMapRect:mapRect edgePadding:edgePadding animated:animated];
}
If you go for a perfect placement (and who doesn't), here are three things to consider:
The code assures that all the coordinates are in the annotationsFrame, but the annotations themselves may be outside. To prevent that, simply use more padding. For example, if your annotations are 20x20 and centered on the coordinate, use 10 more padding on all sides.
Below iOS 7, the map was not zooming to the perfect zoom scale, but to the next tile size (power of two). So there will be more space around the annotations than needed, just as shown on the screenshot.
On iOS 7, the map view will not only zoom perfectly, but automatically care about the status bar. To make the calculation correct, you need to subtract the status bar height from the top padding on iOS 7.
Starting from iOS 7.0, this can be easily achieved with showAnnotations.
Swift:
mapView.showAnnotations(mapView.annotations, animated: true)
Objective-C:
[mapView showAnnotations:mapView.annotations animated:YES];
The above statement will adjust the map view's visible rect in order to display all annotations.
You first need to add the annotations:
(of course this is after you already have a list of annotations)
Swift4:
self.mapView.addAnnotations(annotations)
let currentView = mapView.visibleMapRect
mapView.annotations(in: currentView)
You can use the currentView constant or directly place the MKMapRect as such: Below: (.visibleMapRect returns:
"The area currently displayed by the map view."
mapView.annotations(in: mapView.visibleMapRect)
I found an easier way without calculating is let the map view calculate it, then we adjust the edges.
//1: Show all annotation on the map view, but without animation
self.mapView.showAnnotations(self.mapView.annotations, animated: false)
//2: Get the current visible map rect
let currentMapRect = self.mapView.visibleMapRect
//3: Create the edges inset that you want the map view to show all annotation within
let padding = UIEdgeInsets(top: 100, left: 100, bottom: 100, right: 100)
//4: Set current map rect but with new padding, also set animation to true to see effect
self.mapView.setVisibleMapRect(currentMapRect, edgePadding: padding, animated: true)
If you're prepared to approximate the calculations you can do it using some clever scaling.
Your target area is 80 tall out of a mapView that is 380. Therefore you want a region that is 4.75x taller than the region calculated to fit your annotations. (0.25 extra above and 3.5 extra below).
First you need to get a region (or maprect, what ever you prefer working in) and make it the same proportions as your target viewable area. This is because a really wide and short region would not be touching the top and bottom of the viewable area and therefore multiplying its height would not make something that touched the top and bottom of your map view. So if viewable_height/viewable_width > annotations_height/annotations_width you should set the annotations_height to annotations_width * (viewable_height/viewable_width).
With that you then add 25% on to the north of the annotations box and 350% on to the south. You can do this by moving the center 212.5% (of the current height) south and increasing the vertical span by 475%.
Now, all of this is an approximation given that the world is sphere and we're not looking at a planar projection (i.e. 1 degree of latitude near the equator is drawn smaller than 1 degree near the poles). But if you wally want to be accurate you could look into scaling the numbers according to latitude and such. If you're only dealing with annotations on a city-sized scale you'll probably be ok.
Hope that helps.
if you want to find the annotations that are in a given rect:
- (NSArray*)allAnnotationsInMapRect:(MKMapRect)mapRect {
NSMutableArray *annotationsInRect = [NSMutableArray array];
for(id<MKAnnotation *ann in self.allAnnotations) {
MKMapPoint pt = MKMapPointForCoordinate(ann.coordinate);
if(MKMapRectContainsPoint(mapRect, pt)) {
[annotationsInRect addObject:ann];
}
}
return annotationsInRect;
}
and to assure the annotation VIEWS are in the rect, get the region for the annotations,
then walk through them and get each view's bounds see if the bounds fit inside the visibleRect of the map and if not modify the region!
~~ like this:
- (void)assureAnnotationViewsAreVisible:(NSArray*)annotations originalRegion:(MKCoordinateRegion)originalRegion {
CGFloat smallestX = MAXFLOAT;
CGFloat smallestY = MAXFLOAT;
CGFloat biggestX = -100;
CGFloat biggestY = -100;
//NSLog(#"---: %d", annotations.count);
for(id<MKAnnotation> *annotation in annotations) {
UIView *annotationView = [self.mapView viewForAnnotation:v];
CGRect annotationViewFrame = annotationView.bounds;
annotationViewFrame.origin = [self.mapView convertCoordinate:annotationView.coordinate toPointToView:self.mapView];
annotationViewFrame.origin = CGPointMake(annotationViewFrame.origin.x-annotationViewFrame.size.width/2,
annotationViewFrame.origin.y-annotationViewFrame.size.height);
smallestX = MIN(annotationViewFrame.origin.x, smallestX);
smallestY = MIN(annotationViewFrame.origin.y, smallestY);
biggestX = MAX(annotationViewFrame.origin.x+annotationViewFrame.size.width, biggestX);
biggestY = MAX(annotationViewFrame.origin.y+annotationViewFrame.size.height, biggestY);
}
//NSLog(#"---");
CGRect bounds = self.mapView.bounds;
if(smallestX < bounds.origin.x || smallestY < bounds.origin.y || biggestX > bounds.origin.x+bounds.size.width || biggestY > bounds.origin.y+bounds.size.height) {
CGRect neededRect = bounds;
neededRect.origin = CGPointMake(MIN(bounds.origin.x, smallestX), MIN(bounds.origin.y, smallestY));
neededRect.size = CGSizeMake(MAX(bounds.size.width, biggestX), MAX(bounds.size.height, biggestY));
MKCoordinateRegion neededRegion = [self.mapView convertRect:neededRect toRegionFromView:self.mapView];
_ignoreRegionChange = YES;
[self.mapView setRegion:originalRegion animated:NO];
_ignoreRegionChange = NO;
[self.mapView setRegion:neededRegion animated:YES];
}
else {
MKCoordinateRegion currentRegion = self.mapView.region;
_ignoreRegionChange = YES;
[self.mapView setRegion:originalRegion animated:NO];
_ignoreRegionChange = NO;
[self.mapView setRegion:currentRegion animated:YES];
}
}
Try to get from all your annotation edges value (max and min) for lan and lon.
Define this value on the beginning:
static float maxLat = FLT_MIN;
static float maxLon = FLT_MIN;
static float minLat = FLT_MAX;
static float minLon = FLT_MAX;
and then use this function to calculate span and region:
- (void) zoomAndFit {
for(int i = 0; i < [self.points count]; i++) {
PRPlaceModel *place = [self.points objectAtIndex:i];
CLLocationCoordinate2D location;
location.latitude = [place.lat floatValue];
location.longitude = [place.lon floatValue];
minLat = MIN(minLat, location.latitude);
minLon = MIN(minLon, location.longitude);
maxLat = MAX(maxLat, location.latitude);
maxLon = MAX(maxLon, location.longitude);
}
MKCoordinateRegion region;
MKCoordinateSpan span;
span.latitudeDelta = 1.2*(maxLat - minLat);
span.longitudeDelta = 1.2*(maxLon - minLon);
CLLocationCoordinate2D location;
location.latitude = (minLat + maxLat)/2;
location.longitude = (minLon + maxLon)/2;
region.span=span;
region.center=location;
[self.mapView setRegion:region animated:TRUE];
[self.mapView regionThatFits:region];
}
And use it in viewDidLoad method:
-(void)viewDidLoad
{
[super viewDidLoad];
[self zoomAndFit];
}
I'm trying to add the distance from the user's position to a selected annotation's subtitle in a mapview. The mechanics of it are working, but the actual callout gets messed up the first time it's displayed. There appears to be a redraw problem.
Subsequent taps on the pin show the correct layout.
Here's the relevant code:
// called when selecting annotations
- (void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKAnnotationView *)view{
MKPointAnnotation *selectedAnnotation = view.annotation;
//attempt to add distance on annotation
CLLocation *pointALocation = [[CLLocation alloc]
initWithLatitude:selectedAnnotation.coordinate.latitude
longitude:selectedAnnotation.coordinate.longitude];
float distanceMeters = [pointALocation distanceFromLocation:locationManager.location];
//for sending info to detail
myPinTitle = selectedAnnotation.title;
[selectedAnnotation setSubtitle:[NSString stringWithFormat:#"%.2f miles away", (distanceMeters / 1609.344)]];
}
I've tried calling [view setNeedsDisplay], but to no avail.
Thanks in advance for your help.
The Solution that Worked
Here's the solution I finally came up with. It seems to work.
I edited out the duplicate code from the didSelectAnnotationView method, above, and came up with:
//called when user location changes
- (void)updatePinsDistance
{
for (int x=0; x< [[mapView annotations]count]; x++) {
MKPointAnnotation *thisPin =[[mapView annotations] objectAtIndex:x];
//attempt to add distance on annotation
CLLocation *pointALocation = [[CLLocation alloc]
initWithLatitude:thisPin.coordinate.latitude
longitude:thisPin.coordinate.longitude];
float distanceMeters = [pointALocation distanceFromLocation:locationManager.location];
NSString *distanceMiles = [NSString stringWithFormat:#"%.2f miles from you",
(distanceMeters / 1609.344)];
[thisPin setSubtitle:distanceMiles];
}
}
You should set your subtitle in another place than didSelectAnnotationView. Actually all annotationViews should have their title and subtitle set before they are returned by the mapView:viewForAnnotation: method.
The fact that you set a long subtitle certainly explains that the callout is not the right size. The size must be calculated before the didSelectAnnotationView is called.