I am working on an application with an mkmapview, which drops pins onto a mapview.
I need to be able to colour the pins based on information about the pin.
The current code that drops the map pins is:
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id)annotation {
if (annotation == self.mapView.userLocation) return nil;
NSLog(#"annotation = %#", annotation);
static NSString* AnnotationIdentifier = #"AnnotationIdentifier";
MKPinAnnotationView* customPin = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:AnnotationIdentifier];
customPin.pinColor = MKPinAnnotationColorRed;
customPin.animatesDrop = YES;
customPin.canShowCallout = YES;
UIButton* rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
customPin.rightCalloutAccessoryView = rightButton;
return customPin;
}
If I change the line:
customPin.pinColor = MKPinAnnotationColorRed;
Then I can change the colour of ALL the dropped pins, but how can I identify which pin is being dropped, so that I can only re-colour the pin if needed?
I added the log line:
NSLog(#"annotation = %#", annotation);
But it returns, for example:
annotation = <MapAnnotation: 0x7feabd749190>
annotation = <MapAnnotation: 0x7feac04edf50>
annotation = <MapAnnotation: 0x7feabd79f860>
How can I use this to identify the pin?
Or should I be colouring the annotation pins in a different location?
You can add any object that conforms to the MKAnnotation protocol to a map as an annotation.
I suggest creating a custom annotation object that has extra properties (like an enum for the pin type, for example)
Then in your viewForAnnotation method, once you make sure it's not the user location annotation, cast the id pointer to your custom annotation object type and check your custom properties to see what type of pin to display (it could be as simple as a switch statement.)
Related
I want to display different colour pins in a UIMapView based on the relative time they represent
but it seems the mapView:viewForAnnotation: method only does it's thing independent of when its called.
In my code example I have already retrieved earlier & newer locations from a file to self.fileArray .
the array holds objects called findings that has (among others) an age property .
newest findings start life as age #"0", and each time the array is reloaded ready to take new findings
they progress in age to #"1" and #"2" respectively after which they are then dropped.
Once they take on their new age property they are sent to the mapView:viewForAnnotation: method
to be displayed according to their new status as I iterate through the fileArray
the actual question is after the jump. A lot of interesting other-answers cropped up while formulating the question but none quite applied to my case
.
.
int size = [self.fileArray count];
for (int idx=(size-1); idx>0; idx--) // process backwards
{
annotationFlag = 0; // using a global just for now
self.finding = self.fileArray[idx];
if ([self.finding.age isEqualToString:#"2"]) {
[self.fileArray removeObjectAtIndex:idx];
}
if ([self.finding.age isEqualToString:#"1"]) {
self.finding.age = #"2";
[self.fileArray replaceObjectAtIndex:idx withObject:self.finding];
annotationFlag = 2;
// tried here , only displays the newest
}
if ([self.finding.age isEqualToString:#"0"]) {
self.finding.age = #"1";
[self.fileArray replaceObjectAtIndex:idx withObject:self.finding];
annotationFlag = 1;
// tried here, still only displays the same newest
}
} // end if
//<Breakpoint with Log here>
MKPointAnnotation* annotation = [[MKPointAnnotation alloc] init];
CLLocationCoordinate2D myCoordinate;
myCoordinate.latitude =[self.finding.myLat doubleValue];
myCoordinate.longitude=[self.finding.myLong doubleValue];
annotation.coordinate = myCoordinate;
[self.mapView addAnnotation:annotation];
} // end for
.
.
the annotation methods are fairly standard, as used by most everybody:
- (void)mapView:(MKMapView *)mapView didUpdateUserLocation: (MKUserLocation *)userLocation {
_mapView.centerCoordinate = userLocation.location.coordinate;
}
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id)annotation {
if([annotation isKindOfClass:[MKUserLocation class]])
return nil;
static NSString *identifier = #"myAnnotation";
MKPinAnnotationView * annotationView = (MKPinAnnotationView*)[ self.mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
if (!annotationView)
{
annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier];
//<Breakpoint with Log here>
switch (annotationFlag) {
case 1:
annotationView.pinColor = MKPinAnnotationColorGreen;
break;
case 2:
annotationView.pinColor = MKPinAnnotationColorRed;
break;
default:
annotationView.pinColor = MKPinAnnotationColorPurple;
break;
}
annotationView.animatesDrop = YES;
annotationView.canShowCallout = NO;
}else {
annotationView.annotation = annotation;
}
annotationView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeSystem]; // UIButtonTypeDetailDisclosure
return annotationView;
}
also under test is my neighbours dogs curiosity. the pins should show different colours for each foray
If I NSLog annotationFlag to console at various points mapView:viewForAnnotation: seems to be
ignoring the values in annotationFlag and only using the state last set, leading me to believe it is only acting when
the for loop is entirely finished, and not following iterations.
so the question is, why isn't the [self.mapView addAnnotation:annotation] call acting immediately. Ive put it within the for loop, and there is no doubling up happening there.
LATE EDIT:
using a combination of breakpoints and log-to-consoles as shown in the listings above, and commenting out the age increase processing results in an array of 42 elements ( including the old ones ready to be discarded ) and therefore 42 pins to be dropped.
When the mapView:viewForAnnotation method is reached I then have to step through for another 42 times and on the 43rd all the pins drop at once. Watching carefully its the same colour so I can verify the last colour used doesn't draw over any earlier ones. If that clarifies the problem.
There is no guarantee that the viewForAnnotation will be called immediately after addAnnotation or that it will be called only once.
The annotation could be added in a region that isn't currently visible or the user might pan or zoom the map which causes the annotation to come back into view. The map view will simply call it whenever or as often as it needs to.
This is by-design and simply how the delegate method approach works.
For this reason, your implementation of the delegate method should generally only use the annotation parameter passed to the method as the basis for all the logic inside the method. It should not rely on any external variables or make broad assumptions about when it will be called.
For other answers that may explain this in more detail, see:
Map view annotations with different pin colors
MKMapview annotation dynamic pin image changes after zooming
Map annotation display all the same image/pins for all points
Setting Map Pin colour dynamically for iOS, etc
For your question specifically, I suggest the following:
Right now you're adding annotations of type MKPointAnnotation which don't contain the "age" information that the viewForAnnotation method needs (I'm assuming this is what it needs).
Instead of using MKPointAnnotation, make your Finding class (or whatever the type is of the self.finding object) implement the MKAnnotation protocol itself. You should be able to find several examples of custom annotation classes on SO.
Then, instead of keeping an annotationFlag variable and creating MKPointAnnotation objects, add the Finding objects themselves (which contain their "age") directly to the map when calling addAnnotation.
In viewForAnnotation, set the pinColor after the if-else that creates/dequeues the view and just before the return. Be sure to set the pinColor based on the age property of the annotation object passed into the method (which will be a Finding type object). For example:
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id)annotation
{
if([annotation isKindOfClass:[MKUserLocation class]])
return nil;
static NSString *identifier = #"myAnnotation";
MKPinAnnotationView * annotationView = (MKPinAnnotationView*)[mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
if (!annotationView)
{
annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier];
annotationView.animatesDrop = YES;
annotationView.canShowCallout = NO;
annotationView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeSystem];
}else {
annotationView.annotation = annotation;
}
//update the pinColor in the view whether it's a new OR dequeued view...
if ([annotation isKindOfClass:[Finding class]])
{
Finding *f = (Finding *)annotation;
if ([f.age isEqualToString:#"2"]) {
annotationView.pinColor = MKPinAnnotationColorGreen;
}
else if ([f.age isEqualToString:#"1"]) {
annotationView.pinColor = MKPinAnnotationColorPurple;
}
else {
annotationView.pinColor = MKPinAnnotationColorRed;
}
}
return annotationView;
}
I can't figure out why a MKPinAnnotationView associated (in theory) with a MKPointAnnotation doesn't appear on the map. In fact, the pin appears but it isn't purple as it should be...
Here is the code:
MKPointAnnotation *myPersonalAnnotation= [[MKPointAnnotation alloc]init];
myPersonalAnnotation.title= [appDelegate.theDictionary objectForKey:#"theKey"];
myPersonalAnnotation.coordinate=CLLocationCoordinate2DMake(6.14, 10.7);
MKPinAnnotationView *myPersonalView=[[MKPinAnnotationView alloc] initWithAnnotation:myPersonalAnnotation reuseIdentifier:#"hello"];
myPersonalView.pinColor=MKPinAnnotationColorPurple;
[myMap addAnnotation:myPersonalAnnotation];
If you want to create an annotation view different from the default red pin, you have to create and return it in the map view's viewForAnnotation delegate method.
The map will automatically call the viewForAnnotation delegate method whenever it needs to show some annotation (either the built-in user location or annotations you add).
Remove the local creation of myPersonalView from before the call to addAnnotation and implement the viewForAnnotation method instead.
For example:
//in your current method...
MKPointAnnotation *myPersonalAnnotation= [[MKPointAnnotation alloc]init];
myPersonalAnnotation.title= [appDelegate.theDictionary objectForKey:#"theKey"];
myPersonalAnnotation.coordinate=CLLocationCoordinate2DMake(6.14, 10.7);
[myMap addAnnotation:myPersonalAnnotation];
//...
//add the viewForAnnotation delegate method...
-(MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
//if annotation is the user location, return nil to get default blue-dot...
if ([annotation isKindOfClass:[MKUserLocation class]])
return nil;
//create purple pin view for all other annotations...
static NSString *reuseId = #"hello";
MKPinAnnotationView *myPersonalView = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:reuseId];
if (myPersonalView == nil)
{
myPersonalView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:reuseId];
myPersonalView.pinColor = MKPinAnnotationColorPurple;
myPersonalView.canShowCallout = YES;
}
else
{
//if re-using view from another annotation, point view to current annotation...
myPersonalView.annotation = annotation;
}
return myPersonalView;
}
Make sure the map view's delegate property is set otherwise the delegate method won't get called.
In code, use myMap.delegate = self; (eg. in viewDidLoad) or make the connection in Interface Builder if myMap is an IBOutlet.
I am trying to learn MAP for iPhone.
What I have right now is below.
Created new project
Added framework for MAP
Brought map object on storyboard (UIViewController)
Run the project.
What I see is, its not showing any location. When I change location in xcode, it shows me the dot at location.
What I wanted is, by default it should show me the PIN to the location that I will set by using latitude and longitude. Also the map should be zoomed. What I meant by zoom is, I should see the location with lets say 13 zoom effect. Right now, I see world map on screen.
Any idea how to get this done?
You can center your map around a location by doing something like this:
MKCoordinateRegion mapRegion;
mapRegion.center.latitude = aLatitude;
mapRegion.center.longitude = aLongitude;
mapRegion.span.latitudeDelta = 0.005;
mapRegion.span.longitudeDelta = 0.005;
self.mapView.region = mapRegion;
Use the span values to determine the zoom level you want.
In order to show a pin you need to create an annotation with the coordinates of your location and then add it to the map.
Also, check out this tutorial.. http://www.raywenderlich.com/2847/introduction-to-mapkit-on-ios-tutorial
Dot is showing your current location.
If you want to add a pin with coordinate you should call addAnnotation method with object which conforms to MKAnnotation protocol. Such object has a property coordinate (you should add it to your class):
#property (nonatomic, assign) CLLocationCoordinate2D coordinate;
Also you should add MKMapViewDelegate protocol to your controller and implement -mapView:viewForAnnotation: method. It works as -tableView:viewForRowAtIndexPath:.
- (MKAnnotationView *)mapView:(MKMapView *)_mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
if ([annotation isKindOfClass:[MKUserLocation class]]) {
return nil;
}
static NSString *annotationIdentifier = #"annotation";
MKPinAnnotationView *annotationView = (MKPinAnnotationView *)[_mapView dequeueReusableAnnotationViewWithIdentifier:annotationIdentifier]; // Reusing
if (!annotationView) {
MKPinAnnotationView *pinView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:annotationIdentifier];
pinView.animatesDrop = YES;
annotationView = pinView;
}
else {
annotationView.annotation = annotation; // Reusing already created pin as UITableViewCell does
}
return annotationView;
}
Then when you call
MKMapView *mapView = ...;
id<MKAnnotation> obj = ...;
[mapView addAnnotation:obj];
The pin would be placed on map.
For zoom look there. There is a handy category for those purposes.
If you want to remove current location dot you should find an object with class MKUserLocation in mapView.annotations and then call [mapView removeAnnotation:userLocationDot].
For creating an application with Map you need to implement the MKAnnotation, MKMapViewDelegate delgates.
This is a good tutorial for you.
So I have a MKMapView with all my pins added, and the colour of the pin is dependent on whether a value is set for that pin. When I first load the app, viewForAnnotation is called and the colours are set accordingly. However, when I update the pin's details (such as location, title, etc...) I also update the pinColour to find it doesn't update. It looks like viewForAnnotation isn't called again after the initial add.
I have read many questions similar to this and I can confirm that mapView.delegate = self;
Here is my viewForAnnotation code:
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(MapAnnotation *)annotation
{
if([annotation class] == MKUserLocation.class)
return nil;
NSString *pinIdentifier = annotation.identifier; // This is a unique string for each pin and is getting populated every time!
MKPinAnnotationView *annotationView = (MKPinAnnotationView *) [mapView dequeueReusableAnnotationViewWithIdentifier:pinIdentifier];
if(annotationView == nil)
annotationView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:pinIdentifier];
else
annotationView.annotation = annotation; // Never had this line fire...
annotationView.canShowCallout = YES;
annotationView.animatesDrop = NO;
annotationView.enabled = YES;
annotationView.tag = annotation.counter;
if(annotation.pinColour == Stopped) // from enum
annotationView.pinColor = MKPinAnnotationColorRed;
else
annotationView.pinColor = MKPinAnnotationColorGreen;
UIButton *infoButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
[infoButton addTarget:self action:#selector(mapCalloutButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
infoButton.tag = annotation.counter;
annotationView.rightCalloutAccessoryView = infoButton;
return annotationView;
}
Here is the code where I add the pin:
CLLocationCoordinate2D annotationCoord;
annotationCoord.latitude = latestPosition.latitude;
annotationCoord.longitude = latestPosition.longitude;
MapAnnotation *annotation = [[MapAnnotation alloc] init];
annotation.coordinate = annotationCoord;
annotation.identifier = theIdentifier;
annotation.title = theTitle;
annotation.subtitle = theSubtitle
annotation.pinColour = [self getPinColour];
annotation.counter = theCounter;
[theMapView addAnnotation:annotation];
Here is the code where I update the pin (different method to add):
updatePin = true;
pinCounter = mapPin.counter;
CLLocationCoordinate2D annotationCoord;
annotationCoord.latitude = latestPosition.latitude;
annotationCoord.longitude = latestPosition.longitude;
[mapPin setCoordinate:annotationCoord];
mapPin.identifier = theIdentifier;
mapPin.subtitle = theSubtitle;
mapPin.pinColour = [self getPinColour];
I'm not sure what I'm missing. viewForAnnotation is obviously working, it's just not ever called after the initial add! If it were to call this function I'm 100% sure it would work as it does the colour change if I restart the app!
EDIT: Oh and I really don't want to start removing annotations and re-adding them. It's what I'm doing in the short term anyway!
Actually, I dont' know if this worked for you but this is how I did it.
I didn't need to delete the annotation from map. All I need to do is tell the map to give me the annotation view for a parameter annotation. The map will return the correct annotation. From there, I have a property for my custom annotation to identify whether it is an active item, if yes, show the normal pin image, else show full pin image.
-(void)updateAnnotationImage:(CustomAnnotation *)paramAnnotation
{
MKAnnotationView *av = [geoMap viewForAnnotation:paramAnnotation];
if (paramAnnotation.active)
{
av.image = [UIImage imageNamed:#"PinNormal.png"];
}
else
{
av.image = [UIImage imageNamed:#"PinFull.png"];
}
}
Bit late but hopefully it helps others who came across this problem.
Due to the way the map view caches its annotations, you NEED to remove and re-add the annotation if you need to make changes to its appearance. A simple remove & add is the way to go. There is no cache invalidating mechanism but this.
I also found this answer helpful: In which case that mapView:viewForAnnotation: will be called?
Whenever you call addAnnotation method
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id < MKAnnotation >)annotation gets called.
Swift 2.1:
I had the same issue, and found a quick solution, trigger this when needed, also sending it to the main thread would be wise:
var annotationsArray = mapView.annotations
mapView.removeAnnotations(mapView.annotations)
mapView.addAnnotations(arrayIncs)
arrayIncs.removeAll()
Just spent a couple of hours to get this to work on Xamarin; this is a warning for other Xamarin developers. Make sure you use the ViewForAnnotation method and not the GetViewForAnnotation delegate. I was using the wrong method which returned new annotation views instead of the existing ones... of course it wasn't working!
This may be a design error instead of a syntax error, so let me know if I'm coding in the wrong direction here.
I'm new to Cocoa Touch/Objective-C and I've been working through tutorials on Core Data and MapKit. So far the app places an annotation on a mapview for items fetched from Core Data. I made a custom annotation object (called MapPin) that also holds a URI (NSURL*) pointing to the object in Core Data that it represents. When the user selects an annotation I want to use the URI property of that annotation to find which object in coredata the annotation represents.
This works if I add the annotation to the mapview beforehand. Here I add a MapPin annotation for each object "thing"
//viewWillAppear function in my ViewController
NSURL *uri = [[thing objectID] URIRepresentation];
MapPin *annotation = [[[MapPin alloc] initWithName:thing.common description:thing.latin coordinate:coordinate uri:uri] autorelease];
NSLog(#"MapPin URI: %#", [annotation.uri absoluteString]); //This works!
[_mapView addAnnotation:annotation];
NSLog(#"Placed Map Pin: %#", thing.common);
Later, after the user selects an annotation and clicks a button in the annotationView callout, I want to access the URI for the selected annotation
//the UIButton click action in my view controller
MSPTreesAppDelegate *del = (MSPTreesAppDelegate *)[UIApplication sharedApplication].delegate;
NSArray *annArray = _mapView.selectedAnnotations;
MapPin *selectedPin = [annArray objectAtIndex:0];
NSLog(#"Selected Pin Name: %#", selectedPin.name); //Works fine
NSLog(#"URI PASSED: %#", [selectedPin.uri absoluteString]); //Doesn't work
NSURL* uriForTree = selectedPin.uri; //also doesn't work
I notice in the debugger that before I add the annotation to the mapview, the URI property shows the correct string. After the (MapPin) annotation is selected from the map view, the URI property in the debugger just shows "invalid summary".
When I try to access the URI property the program ends and I get a "Thread 1: Program Received signal: "EXC_BAD_ACCESS"." error. The Log doesn't show anything helpful besides that.
I assume that my custom URI property for my MKAnnotation object isn't supported by the MKAnnotationView or the MKMapView, but I can't figure out where the URI is getting lost. Is there a way I can retrieve my URI property from the selected annotation? Other suggestions for methods to accomplish the same concept are welcome.
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation {
static NSString *identifier = #"MapPin";
if ([annotation isKindOfClass:[MapPin class]]) {
NSLog(#"Annotation is a MapPin");
TreeAnnotationView *annotationView = (TreeAnnotationView *) [_mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
if (annotationView == nil) {
annotationView = [[TreeAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier];
} else {
annotationView.annotation = annotation;
}
annotationView.enabled = YES;
annotationView.canShowCallout = YES;
//Place details button in callout
UIButton * detailButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
[detailButton setTitle:annotation.title forState:UIControlStateNormal];
[detailButton addTarget:self action:#selector(showDetails:) forControlEvents:UIControlEventTouchUpInside];
annotationView.rightCalloutAccessoryView = detailButton;
return annotationView;
}
return nil;
}
Why not make your MapPin be a subclass of NSManagedObject and have it implement MKAnnotation?
#interface MapPin : NSManagedObject <MKAnnotation>
#end
That way you one and only one model object to represent the pin and that model object is persisted through CoreData.
But your "EXC_BAD_ACCESS" and "invalid summary" indicate that the URI isn't' being retained (strong if you're using ARC).