I'm having alot of trouble trying to identify which callout bubble has been clicked.
Is there a way of identifying the callout bubbles some how as I've tried a number of examples on here but because I'm quite new to Objective C I can't seem to work out how to use them.
The following answers I've been trying to use but I'm confused with them
How to track which annotation callout clicked
I'm looking at tagging the annotations but thats even confusing me. :(
Taken from the second answer in the above link:
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
if ([annotation isKindOfClass:[MKUserLocation class]]){
return nil;
if(annotation.tag == 111)
//Do something
else
//Do some other thing
}
How does the first part of this snippet work, perhaps if I understood it better I'd know what I'm working with.
Also how would I go about retrieving the tags when the callout is clicked so I can make the app respond respectively.
You can subclass MKPinAnnotationView so you can identify it when
- (void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKPinAnnotationView *)view
is called.
You have to create class which extends MKAnnotation and create some property like tag and assign unique value or tag and add in mapview like.
Place* home = [[Place alloc] init] ;
home.name = [dForMap valueForKey:#"shortaddress"];
home.latitude = [[dForMap valueForKey:#"latitude"]floatValue];
home.longitude = [[dForMap valueForKey:#"longitude"]floatValue];
home.description = [dForMap valueForKey:#"shortaddress"];
home.flierid = count;
PlaceMark* from = [[PlaceMark alloc] initWithPlace:home] ;
from.flierid = count;
from.mapAnnotationType = MapAnnotationTypeProperty;
[self addAnnotation:from];
you can check the property in didSelectAnnotationView method like this way when callout bubble is clicked.
- (void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKAnnotationView *)view
{
PlaceMark *a = (PlaceMark*)view.annotation;
Place *test = a.place;
int tag = test.flierid;
}
Thanks.
Related
I have a custom class for my MKAnnotations, I want to override the default mapView:viewForAnnotatation method so that I can add extra information in the callout. When I set my delegate in code (as per the code below) the annotations are dropped on the map and are selectable but my mapView:viewForAnnoation is never called.
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation{
NSLog(#"viewForAnnotation: called");
MKAnnotationView *aView = [mapView dequeueReusableAnnotationViewWithIdentifier:#"mapPin"];
if(!aView){
aView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:#"mapPin"];
}
aView.annotation = annotation;
return aView;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
self.mapView.delegate = self;
}
I know the delegate is being set as I can override the method -(void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKAnnotationView *)view and I see an NSLog when I select an annotation.
When I change from setting the delegate in code to setting it in the Storyboard the method is called (NSLog(#"viewForAnnotation: called"); statements appear) but the annotations don't appear on the map and sometimes this error appears:
<Error>: ImageIO: CGImageReadSessionGetCachedImageBlockData *** CGImageReadSessionGetCachedImageBlockData: bad readSession [0x8618480]
This seems like two separate issues:
Regarding the setting delegate in code v storyboard, it's hard to reconcile your various observations (delegate method didSelectAnnotationView is getting called in both scenarios, but viewForAnnotation is not). The only difference between setting it in code v in the storyboard is the timing of when the delegate is getting set. You're not showing us the process of adding the annotations, so it's hard to diagnose on the basis of what you've described. If none of your delegate methods were getting called, I'd suspect the mapView IBOutlet, but if some are working and others aren't, I can only suspect a timing issue.
Regarding the setting of the MKAnnotationView, the default implementation does nothing. You either need to write your own subclass of MKAnnotationView, set its image if you're using your own image, or, much easier, just use MKPinAnnotationView. But just creating a MKAnnotationView won't do anything. You really want:
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation{
// If it's the user location, just return nil.
if ([annotation isKindOfClass:[MKUserLocation class]])
return nil;
// Handle any custom annotations.
MKAnnotationView *aView = [mapView dequeueReusableAnnotationViewWithIdentifier:#"mapPin"];
if(aView){
aView.annotation = annotation;
} else {
aView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:#"mapPin"];
}
aView.canShowCallout = NO;
return aView;
}
(Note, I'm not only creating a MKPinAnnotationView, but I'm also making sure that it's not a MKUserLocation, in case you ever choose to show user location on the map. I'm also going to explicitly set the canShowCallout, as that's presumably the reason you're writing this method at all.)
Bottom line, if you want to show a simple pin annotation view, use MKPinAnnotationView. Using MKAnnotationView alone will result in no annotations from appearing.
In case someone else is searching for a reason why mapView:viewForAnnotatation is not being called when the delegate is set in code, there is a bug in iOS 6 - http://openradar.appspot.com/12346693
I came across the same issue and I wanted to share my solution:
I also override
(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation
But I realised that these Annotations work similar to TableView and iOS will reuse the annotations like the cells in TVC (table view controller)
Since I was only using one Identifier mapView dequeueReusableAnnotationViewWithIdentifier:#"mapPin" it would not need to call ViewForAnnotation again if it had enough 'annotation' in memory.
So my solution was to create multiple Identifier the first time the map load based on my conditions.
This solved my problem.
i just dropped to this question accidentally when i was searching for the same problem.
I solved my problem, in my case im resizing the mapview.
I added delegate after i resize the mapview. it works now perfectly.!
I have a map view with annotations, and these annotations display a callout. When the callout's disclosure detail button is clicked, it segues into a new view.
My MKAnnotations are a custom class that implements <MKAnnotation>. Let's call that class MyClass. They are stored in an NSMutableArray. During viewdidload of this view, I add each object of MyClass in this array to the map view's annotations. Using the debugger, I can see that once all of this adding is done, the [self.MapView annotations] order is the same as the NSMutableArray.
Now I set another breakpoint within mapView:viewForAnnotation: and check out the order of 1) my NSMutableArray and 2) [self.MapView annotations]. The array is of course in the same order. However, the order of the annotations has been scrambled.
This was a big problem for me, because I needed to use the specific instance of MyClass that the user selected in the next view. AKA, I wanted to look at the annotation, find its index, and then use that to get the same index within the array.
I've now realized that I can just save the annotation directly (coming from an Android background, this was very cool to me). However, I am still conceptually at a loss as to why the order became scrambled. Can someone help me? Code below:
- (void)viewDidLoad
{
if([fromString isEqualToString:#"FromList"])
self.navigationItem.hidesBackButton = TRUE;
else {
self.navigationItem.rightBarButtonItem = nil;
}
self.array = [MySingleton getArray];
//set up map
//declare latitude and longitude of map center
CLLocationCoordinate2D center;
center.latitude = 45;
center.longitude = 45;
//declare span of map (height and width in degrees)
MKCoordinateSpan span;
span.latitudeDelta = .4;
span.longitudeDelta = .4;
//add center and span to a region,
//adjust the region to fit in the mapview
//and assign to mapview region
MKCoordinateRegion region;
region.center = center;
region.span = span;
MapView.region = [MapView regionThatFits:region];
for(MyClass *t in self.array){
[MapView addAnnotation:t];
}
[super viewDidLoad];
}
//this is the required method implementation for MKMapView annotations
- (MKAnnotationView *) mapView:(MKMapView *)thisMapView
viewForAnnotation:(MyClass *)annotation
{
static NSString *identifier = #"MyIdentifier";
//the result of the call is being cast (MKPinAnnotationView *) to the correct
//view class or else the compiler complains
MKPinAnnotationView *annotationView = (MKPinAnnotationView *)[thisMapView
dequeueReusableAnnotationViewWithIdentifier:identifier];
if(annotationView == nil)
{
annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier];
}
annotationView.pinColor = MKPinAnnotationColorGreen;
//pin drops when it first appears
annotationView.animatesDrop=TRUE;
//tapping the pin produces a gray box which shows title and subtitle
annotationView.canShowCallout = YES;
UIButton *infoButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
annotationView.rightCalloutAccessoryView = infoButton;
return annotationView;
}
When you call addAnnotation or addAnnotations, the map view adds the reference(s) to its internal list of annotations.
The annotations property of MKMapView simply returns this internal list (whatever type it might be) as an NSArray.
I don't know of any place in the documentation where it states that the annotations property returns the array in the same order that you added the annotations in. If you have showsUserLocation turned on, the array will include that annotation even though you didn't explicitly add it.
You do not need to be concerned about nor should you depend on the order of the objects in the annotations property.
Just a few suggestions regarding the code:
Since your array contains objects that implement <MKAnnotation>, instead of looping through it, you can add all the annotations in one shot by calling addAnnotations (plural) and pass it the array
In viewForAnnotation, none of the properties you are setting depend on any specific annotation so you can set them all inside the if (av == nil) block. This way you get maximum reuse.
Also in viewForAnnotation, after and outside the if, you should set the annotation property of the view to the current annotation. This is in case the view is being reused from another annotation.
Finally, in viewForAnnotation, don't assume the annotation will be of type MyClass. If you turn on showsUserLocation, that won't be the case. It's safer to declare the parameter as id<MKAnnotation> and then if necessary check what its class is and then cast it.
#Anna, you state you should not be concerned for the order of the annotations. That's not true in my case. Some annotationviews might overlap, and I always need a specific one to be on the top of the two overlapping views. So the order DO makes sense for the annotations, as I hope the - (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation gets called in the same order as i added the annotations.
EDIT:
and the solution is here :-)
In my application I have a MKMapView where several annotations are shown. The map rotates based on the heading of the device. To rotate the map the following statement is performed (called by the method locationManager: didUpdateHeading:)
self.navigationMapView.mapView.transform = CGAffineTransformMakeRotation(-heading);
where the heading (magnetic) is expressed in radians. What I noticed it's that even the annotations in the map rotate and I don't want it. I tried to fix it in the following method:
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation{
static NSString *identifier = #"AnnotationViewIdentifier";
MKAnnotationView *av = [mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
if (av == nil) {
av = [[[MKPinAnnotationView alloc]initWithAnnotation:annotation reuseIdentifier:identifier] autorelease];
}
else{
av.annotation = annotation;
}
av.transform = CGAffineTransformMakeRotation(degreesToRadians(self.arController.currentHeading.magneticHeading));
av.canShowCallout = YES;
return av;
}
and I want to call this method from "didUpdateHeading:" but I really don't know how to do it. The TableView class has the reloadData function that calls the delegate method but here the things seem different. Any suggestions?!
Another question, my annotations on the map show the distance from the user, I would like to update them (distance label) as soon as the user change location. Any suggestions?!
So with a MKMapView having that be called properly is a little bit annoying. Essentially you have one of two options. Option 1: Create an array of the annotation on the screen and remove that from the map_view and then re-add them to the map_view. Essentially creating your own reload data function. Option 2: Do something simple such as
CGLocationCoordinate2D coordinate = map_view.center;
map_view.center = coordinate;
-- Essentially the point is to reset a property of the map causing it to redraw. However this option is not always going to work. Option 1 has a higher chance of working however that one can also fail, so if simply taking the annotations off and re-adding them causes nothing to happen then simply decreate the map and then recreate the map at the end of your map refresh function something like.
[my_map_view removeFromSuperView];
[my_map_view release];
my_map_view = nil;
my_map_view = [[MKMapView alloc] initWithFrame:CGRectMake(0,0,320,480)];
one of these options should work. I had to do option one for my solution however I know some people are lucky and option 2 works just as well.
:)
I have a really strange problem when trying to retrieve the properties of a selected annotation. Here is the short description of my problem:
I pass the first object of the selected annotations array to a new array as it's the only one I need (acc. to Apple doc, passing the selectedAnnotations array to a new array only selects the first object. But I did tried to pull the object directly from the selectedAnnotations array at index path 0 and it's the same problem).
Then I transform the object into a Custom annotation object (as this is what the object should be).
Afterwards I try to access the properties of my custom annotation temp object. Here is when everything breaks loose. NSLog of the object only shows memory address. Text property is null. So basically I can't access it.
I would appreciate any help on what am I doing wrong or what approach should I use.
Thank you kindly!
Here is the code:
-(void) mapView:(MKMapView *)aMapView didSelectAnnotationView:(MKAnnotationView *)view
{
if ([view isUserInteractionEnabled])
// NSLog(#"Tapped!!!");
{
NSArray* selectedAnnotation=mapView.selectedAnnotations;
CustomAnnotations *selectedAnn=[selectedAnnotation objectAtIndex:0];
NSLog(#"selected annotation text is %#", selectedAnn.text);
My custom annotation class has a coordinate and a text property and it's being placed on map with this code:
CustomAnnotations* commentAnnotation = [[[CustomAnnotations alloc] initWithLocation:mapView.userLocation.location.coordinate andTitle:#"comment" andText:text]autorelease];
[mapView addAnnotation:commentAnnotation];
Furthermore, the view for annotation has the following coding:
-(MKAnnotationView *) mapView:(MKMapView *) aMapView viewForAnnotation:(id<MKAnnotation>)annotation
{
if ([annotation isKindOfClass:[MKUserLocation class]])
return nil;
MKAnnotationView *customAnnotation = (MKAnnotationView*)[mapView dequeueReusableAnnotationViewWithIdentifier:#"pin"];
if(!customAnnotation)
{
customAnnotation = [[[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:#"pin"]autorelease];
}
customAnnotation.centerOffset=CGPointMake(10, -30);
if ([annotation title]==#"comment")
{
customAnnotation.userInteractionEnabled=YES;
customAnnotation.image=[UIImage imageNamed:#"NewCommentsPin.png"];
}
return customAnnotation;
}
Any help would be much appreciated!
I figured out the problem: My custom annotation class was releasing the text in dealloc.
I still have a long way to go until I understand when to release and when not to but one step at a time!:)
Here is your release cheat sheet.
When you create an object, and it has any of the words new, alloc,
copy or retain in the constructor then you own it and you have
to release it if you do not need the reference any more.
Using a MKMapView I have a pile of annoatations loaded onto it and I want to be able to filter the annotations displayed with a segmented control.
I'm using custom annotations with a type variable so I can tell them apart from one another but I haven't been able to find a way to hide and display a subset of annotation views at will.
Sure, try this:
Objective-C solution:
[[yourMapView viewForAnnotation:yourAnnotation] setHidden:YES]
Swift 4 solution:
yourMapView.view(for: yourAnnotation)?.isHidden = true
This will return you the view associated with the specified annotation object, then you can set the view to hidden. Here is the documentation.
if you want to hide the MKAnnotationView (bubble) you can create a custom one:
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
if (annotation==self.map.mapView.userLocation)
return nil;
MKAnnotationView *annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:#"loc"];
if([annotation isKindOfClass:[AnnotationCustomClass class]] ) {
annotationView.canShowCallout = NO; // <- hide the bubble
}
return annotationView;
}