Changing pin color when selecting annotation pin - ios

Question

My app is a map view where the user can enter an address which will put a purple pin on the map for the HQ. Secondly, the user can enter any address, which will put a red pin on the map. I would like to be able to change the pin color of the red pins to either red, green, or purple.
I stumbled across a tutorial that will allow the user to select an annotation pin and change its pin color by displaying a modal view. I followed the tutorial meticulously, but for some reason, it is not working correctly. The modal view with the pin selection is displayed, but when a pin color is selected, the pin color on the map view is not updated. Additionally, instead of using "png" images to display custom pins, I would like to use the built-in standard pins (since that's all I need). How can I adjust my code below to achieve this? I added my entire code.
FieldMapController.m
#import "FieldMapController.h"
#import "CustomAnnotation.h"
#define HQ_latitude #"headquarters_latitude"
#define HQ_longitude #"headquarters_longitude"
#define HQ_coordinates #"headquarters_coordinates"
#import "PinSelectionViewController.h"
#interface FieldMapController ()
#end
#implementation FieldMapController
#synthesize mapView;
#synthesize searchBar;
#synthesize geocoder = _geocoder;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
//ACCESS SAVED DATA FROM NSUSERDEFAULTS
-(void)viewWillAppear:(BOOL)animated{
NSUserDefaults *uDefaults = [NSUserDefaults standardUserDefaults];
if ([uDefaults boolForKey:#"headquarters_coordinates"])
{
CLLocationCoordinate2D savedCoordinate;
savedCoordinate.latitude = [uDefaults doubleForKey:#"headquarters_latitude"];
savedCoordinate.longitude = [uDefaults doubleForKey:#"headquarters_longitude"];
NSLog(#"Your HQ is at coordinates %f and %f",savedCoordinate.latitude, savedCoordinate.longitude);
CustomAnnotation *annHq =[[CustomAnnotation alloc] init];
annHq.title=#"HQ";
annHq.subtitle=#"";
annHq.coordinate= savedCoordinate;
[mapView addAnnotation:annHq];
MKCoordinateRegion viewRegion = {{0.0, 0.0}, {0.0, 0.0}};
viewRegion.center.latitude = savedCoordinate.latitude;
viewRegion.center.longitude = savedCoordinate.longitude;
viewRegion.span.longitudeDelta = 0.5f;
viewRegion.span.latitudeDelta = 0.5f;
[self.mapView setRegion:viewRegion animated:YES];
[self.mapView setDelegate:self];
}
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
self.mapView.delegate = self;
self.searchBar.delegate = self;
//SEARCH BAR TOOLBAR WITH "DONE" AND "CANCEL" BUTTON
UIToolbar* searchToolbar = [[UIToolbar alloc]initWithFrame:CGRectMake(0, 0, 320, 50)];
searchToolbar.barStyle = UIBarStyleBlackTranslucent;
searchToolbar.items = [NSArray arrayWithObjects:
[[UIBarButtonItem alloc]initWithTitle:#"Cancel" style:UIBarButtonItemStyleBordered target:self action:#selector(cancelSearchBar)],
[[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil],
nil];
[searchToolbar sizeToFit];
searchBar.inputAccessoryView = searchToolbar;
}
//WHEN PUSHING THE "CANCEL" BUTTON IN THE SEARCH BAR
-(void)cancelSearchBar
{
[searchBar resignFirstResponder];
searchBar.text = #"";
}
//PREPARE SEGUE FOR THE PIN SELECTOR VIEW
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if([segue.identifier isEqualToString:#"ShowPinChoicesSegue"])
{
PinSelectionViewController *pinVC = [segue destinationViewController];
CustomAnnotation *selectedAnnotation = (CustomAnnotation *)sender;
pinVC.currentPinType = selectedAnnotation.pinType;
pinVC.delegate = self;
}
}
//WHAT HAPPENS WHEN THE "SEARCH" BUTTON AT THE SEARCH BAR KEYBOARD IS TAPPED
- (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar
{
//Forward Geocoder
if (!self.geocoder)
{
self.geocoder = [[CLGeocoder alloc] init];
}
NSString *address = [NSString stringWithFormat:#"%#", self.searchBar.text];
[self.geocoder geocodeAddressString:address completionHandler:^(NSArray *placemarks, NSError *error) {
if ([placemarks count] > 0)
{
CLPlacemark *placemark = [placemarks objectAtIndex:0];
CLLocation *location = placemark.location;
CLLocationCoordinate2D coordinate = location.coordinate;
//Display Coordinates in Console
NSLog (#"%f %f", coordinate.latitude, coordinate.longitude);
MKCoordinateRegion region;
MKCoordinateSpan span;
span.latitudeDelta = 0.01;
span.longitudeDelta = 0.01;
region.span = span;
region.center = coordinate;
//Create Annotation with Callout Bubble that displays "No Information"
MKPointAnnotation *annotation = [[MKPointAnnotation alloc] init];
[annotation setCoordinate:coordinate];
[annotation setTitle:#"No Information"];
[[self mapView] addAnnotation:annotation];
[self.mapView setRegion:region animated:TRUE];
[self.mapView regionThatFits:region];
//Dismiss the Search Bar Keyboard
[self.searchBar resignFirstResponder];
//Delete text in Search Bar
self.searchBar.text = #"";
}
}];
}
//CUSTOM ANNOTATION VIEW
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
if ([annotation isKindOfClass:[MKUserLocation class]])
{
return nil;
}
if ([annotation isKindOfClass:[CustomAnnotation class]])
{
MKPinAnnotationView *annotationView =
(MKPinAnnotationView *)[self.mapView dequeueReusableAnnotationViewWithIdentifier:((CustomAnnotation *)annotation).annotationViewImageName];
if(annotationView == nil)
{
MKPinAnnotationView *customPinView =
[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:((CustomAnnotation *)annotation).annotationViewImageName];
if([[customPinView.annotation title] isEqualToString:#"HQ"])
{
//The pin for the HQ should be purple
customPinView.pinColor = MKPinAnnotationColorPurple;
}
else
{
//All other new pins should be "red" by default
customPinView.image = [UIImage imageNamed:((CustomAnnotation *)annotation).annotationViewImageName];
}
customPinView.canShowCallout = YES;
customPinView.animatesDrop = YES;
//Right Callout Accessory Button
UIButton *rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
customPinView.rightCalloutAccessoryView = rightButton;
return customPinView;
}
else
{
annotationView.annotation = annotation;
}
return annotationView;
}
return nil;
}
//SHOW ACCESSORY VIEW WHEN BUTTON ON CALLOUT BUBBLE IS TAPPED
-(void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control
{
if (![view.annotation isKindOfClass:[CustomAnnotation class]])
return;
CustomAnnotation *customAnnotation = (CustomAnnotation *)view.annotation;
if (control.tag == 0)
{
[self performSegueWithIdentifier:#"ShowPinChoicesSegue" sender:customAnnotation];
}
else
{
[self onRightCalloutAccessoryViewTouched:control];
}
}
-(void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKAnnotationView *)view
{
if(![view.annotation isKindOfClass:[CustomAnnotation class]])
return;
if (!view.rightCalloutAccessoryView)
{
UIButton *rightViewButton = [[UIButton alloc] initWithFrame:CGRectMake(0.0, 0.0, 48.0, 32.0)];
[rightViewButton addTarget:self action:#selector(onRightCalloutAccessoryViewtouched:) forControlEvents:UIControlEventTouchUpInside];
rightViewButton.tag = 1;
view.rightCalloutAccessoryView = rightViewButton;
}
}
-(void)onRightCalloutAccessoryViewTouched:(id)sender
{
CustomAnnotation *selectedAnnotation = (CustomAnnotation *)[mapView.selectedAnnotations objectAtIndex:0];
[self performSegueWithIdentifier:#"ShowPinChoicesSegue" sender:selectedAnnotation];
}
- (void)viewDidUnload
{
self.mapView = nil;
self.searchBar = nil;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
//BUTTON TO SELECT NEW HQ
- (IBAction)selectHq:(UIBarButtonItem *)sender
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Select Headquarters"
message:#"Enter Address"
delegate:self
cancelButtonTitle:#"Cancel"
otherButtonTitles:#"Ok", nil];
alert.alertViewStyle = UIAlertViewStylePlainTextInput;
[[alert textFieldAtIndex:0] setKeyboardType:UIKeyboardTypeDefault];
[alert show];
}
//REMOVING ALL PINS EXCEPT USER LOCATION
- (IBAction)resetPins:(UIBarButtonItem *)sender
{
id userLocation = [mapView userLocation];
NSMutableArray *pins = [[NSMutableArray alloc] initWithArray:[mapView annotations]];
if ( userLocation != nil )
{
[pins removeObject:userLocation]; //avoid removing user location
}
[mapView removeAnnotations:pins];
pins = nil;
[[NSUserDefaults standardUserDefaults] removeObjectForKey:HQ_coordinates];
[[NSUserDefaults standardUserDefaults] removeObjectForKey:HQ_longitude];
[[NSUserDefaults standardUserDefaults] removeObjectForKey:HQ_latitude];
}
//ALERT VIEW TO ENTER ADDRESS OF HQ
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
if (buttonIndex != alertView.cancelButtonIndex)
{
UITextField *field = [alertView textFieldAtIndex:0];
field.placeholder = #"Enter HQ Address";
if (!self.geocoder)
{
self.geocoder = [[CLGeocoder alloc] init];
}
NSString *hqAddress = [NSString stringWithFormat:#"%#", field.text];
[self.geocoder geocodeAddressString:hqAddress completionHandler:^(NSArray *placemarks, NSError *error) {
if ([placemarks count] > 0)
{
CLPlacemark *placemark = [placemarks objectAtIndex:0];
CLLocation *location = placemark.location;
CLLocationCoordinate2D hqCoordinate = location.coordinate;
NSLog (#"Your new HQ is at coordinates %f and %f", hqCoordinate.latitude, hqCoordinate.longitude);
MKCoordinateRegion region;
MKCoordinateSpan span;
span.latitudeDelta = 0.01;
span.longitudeDelta = 0.01;
region.span = span;
region.center = hqCoordinate;
MKPointAnnotation *hqAnnotation = [[MKPointAnnotation alloc] init];
[hqAnnotation setCoordinate:hqCoordinate];
[hqAnnotation setTitle:#"HQ"];
[[self mapView] addAnnotation:hqAnnotation];
[self.mapView setRegion:region animated:TRUE];
[self.mapView regionThatFits:region];
//Save to NSUserDefaults
NSUserDefaults *uDefaults = [NSUserDefaults standardUserDefaults];
[uDefaults setDouble:hqCoordinate.latitude forKey:HQ_latitude];
[uDefaults setDouble:hqCoordinate.longitude forKey:HQ_longitude];
[uDefaults setBool:YES forKey:HQ_coordinates];
[uDefaults synchronize];
}
}];
}
else
{
//any actions for "Cancel"
}
}
//DEFINES WHAT SELECTING THE NEW PIN COLOR DOES
-(void)userDidSelectPinType:(AnnotationPinType)aPinType
{
CustomAnnotation *selectedAnnotation = (CustomAnnotation *)[mapView.selectedAnnotations objectAtIndex:0];
selectedAnnotation.pinType = aPinType;
[mapView removeAnnotation:selectedAnnotation];
[mapView addAnnotation:selectedAnnotation];
[self.navigationController dismissViewControllerAnimated:YES completion:nil];
}
#end
CustomAnnotation.m
#import "CustomAnnotation.h"
#import <CoreLocation/CoreLocation.h>
#implementation CustomAnnotation
#synthesize title, subtitle, coordinate;
#synthesize pinType;
-(id) initWithCoordinate:(CLLocationCoordinate2D)aCoordinate title:(NSString *)aTitle subtitle:(NSString *)aSubtitle
{
if ((self = [super init]))
{
self.title = aTitle;
self.coordinate = aCoordinate;
self.subtitle = aSubtitle;
}
return self;
}
- (NSString *)annotationViewImageName
{
switch (self.pinType)
{
case 0:
return #"Red_Pin.png";
break;
case 1:
return #"Green_Pin.png";
break;
case 2:
return #"Purple_Pin.png";
break;
default:
break;
}
}
- (NSString *)title
{
return title;
}
- (NSString *)subtitle
{
return subtitle;
}
#end
PinSelectionViewController.m
#import "PinSelectionViewController.h"
#interface PinSelectionViewController ()
#end
#implementation PinSelectionViewController
#synthesize delegate;
#synthesize currentPinType;
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#pragma mark - Table view data source
- (void)tableView:(UITableView *) tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
if(indexPath.row ==currentPinType)
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
#pragma mark - Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[self.delegate userDidSelectPinType:indexPath.row];
}
#end
PinSelectionDelegateProtocol.h
#import <Foundation/Foundation.h>
typedef enum
{
RED_PIN,
GREEN_PIN,
PURPLE_PIN
} AnnotationPinType;
#protocol PinSelectionDelegate <NSObject>
#required
-(void)userDidSelectPinType:(AnnotationPinType)aPinType;
#end

Answer 1

The problem I see is early on in your viewForAnnotation method. You correctly reuse annotationviews but incorrectly assume that the reused view is configured properly. When you check if the view is nil you only configure brand new ones to have the pin colour that matches the annotation's name. What you need to do is check if it is nil, if is then make a new one and close that if. Then make sure both new and reused annotationviews have their pin colour, title, accessory view etc set up as you want it for that annotation.
Also you can't set the .image of an MKPinAnnotationView, it'll just get overwritten. If you really want to set a custom image you have to use a regular MKAnnotationView. If you are ok with using the standard red, green and blue pins then just set the .pinColor to whatever you want.