A view controller for picking a location. I wrote it to be a simple wrapper around automatic location detection, but also to offer manual location selection in case GPS isn't available.
You'll need to find the MBPlacePickerController subfolder in the repository and add it to your project. CocoaPods support is not available yet.
MBPlacePickerController was built in Objective-C with the iOS 7 SDK, ARC, and Core Location.
Note: There's also a copy of another library I'm working on, called CRLCoreLib, but that's a standalone and included for your use. Don't worry about that. I'm noting it here because that library may ship seperately in the future.
Whatever's in the MBPickerController folder. It's got a few folders in there, including CRLCoreLib, Place Picker, Map View, and Resources. Take all of the folders in there and add them to your project.
To show a place picker, you need to follow three easy steps:
// Step 0: Import the header.
#import "MBPlacePickerController.h"
// Step 1: Access the singleton picker
MBPlacePickerController *picker = [MBPlacePickerController sharedPicker];
// Step 2: Display the Picker
[picker display];
That's it!
To get a location when the user picks one, or to get a location when automatic updates come back, assign a delegate to the place picker. You'll need to implement one delegate method to catch those location updates. Assume the picker from "Showing a Picker," your code should look like the following:
picker.delegate = self; // Could be anything, really.
In your delegate, implement this one crazy method that handles almost all the work for you!
- (void)placePickerController:(MBPlacePickerController *)placePicker didChangeToPlace:(CLLocation *)place
{
// Do something with the location.
}
This method will fire whenever the user taps a place, or when Core Location passes a location back to the picker.
The list of places is something I compiled a while back. If you want to change it, you have two options.
-
You can edit the list of locations directly. Inside the
Resourcesfolder, there's a file namedlocations.json. -
You can keep the list fresh by keeping the latest version on your server. Set a string value to the
serverURLproperty on the picker to tell it where to look. It will update whenever itsviewDidAppearmethod is called.
In either case, you're going to want to follow the following convention for each location:
{
"name" : "Boston, Massachusetts, USA", // City name
"longitude" : -71.0597732, // Longitude
"latitude" : 42.3584308, // Latitude
"continent" : "North America" // Continent
}
If you don't provide a properly capitalized continent, the continent sorting will break. Valid continents are technically any string, but you should use these:
"North America"
"Central America"
"South America"
"Africa"
"Asia"
"Europe"
"Antarctica"
Note: You don't have to create a singleton picker, but if you want to use it to get a continuous stream of location updates across various parts of your app, or use the cached location, it's best to use the singleton for consistency.
If you're not into that, just call alloc] init] instead.
These are some nicities that exist for your fun and pleasure.
To get automatic location updates, call enableAutomaticUpdates on your picker. Note that in the event that a user selects a location, disableAutomaticUpdates will be called, and you'll have to re-enable automatic updates if you want them. You can call disableAutomaticUpdates by yourself if you'd like.
[picker enableAutomaticUpdates];
The corollary of that is disabling the automatic updates:
[picker disableAutomaticUpdates];
To customize the color of the marker that the map uses to show a manually chosen location, set the markerColor property of the picker's map view. (The automatic location marker is always purple.)
picker.map.markerColor = [UIColor orangeColor]; // Sets the marker to Orange.
To customize the size of the marker that the map uses to show a manually chosen location, set the markerDiameter property.
picker.map.markerDiameter = 30.0f; // Sets the marker to 30.0f. (30 is default size.)
The map view has a toggle for displaying user location (even if the location is manual.) The user's location is indicated by a purple circle.
picker.map.showUserLocation = YES; // Enables user location.
The source code here is released under the MIT License. See LICENSE for details.
This one goes out to Randall Munroe, because without XKCD #977, I'd still be searching the internet for the Plate Carrée map projection. That's the one where pixels equal latitude and longitude points. I had seen this video before, but watching it again after seeing the xkcd made me laugh out loud.
The map image I used comes from Wikipedia, and according to Wikipedia, is in the public domain.
The image used in the app icon is "Arrow by Alexander Smith from The Noun Project." (They made me write that, but I'm happy to share good work.)