1. Location based services
Using Google Maps v2 etc.
in Android apps
Location based services

2. Some location-based services available in Android
Google maps
Showing and annotating maps
Geo-coding
Address -> location
Reverse geo-coding
Location -> address(es)
Getting live location information
Through GPS, mobile phone cell tower triangulation, or Wi-Fi positioning
Location based services

3. Location based services
Google maps
Google maps are NOT part of the Android API
It’s an add-on
This means that you will have to do a number of things to make it work …
Location based services

4. Google Maps API versions
Google Maps Android API
MapActivity, Overlay, etc.
Deprecated
Google Maps Android API v2
MapFragment, etc.
Google Maps for JavaScript v2
Google Maps for JavaScript v3
Location based services

5. Some Map related classes
Example: maps2013
GoogleMap
This is the main class
setOnMapClickListener(…)
Hitting the map you can add markers, etc.
MyLocation
Will send you to your current location
Requires permissions: ACCESS_COARSE_LOCATION and ACCESS_FINEL_LOCATION
UISettings
To change the default settings of the map
MapFragment
To show the map as part of an activity
Not used in the layout.xml (only “fragment”)
Used in the Activity (Java code)
Android ≥ 3 (API 11) only
SuppportMapFragment for older devices
MapView
Another way to show a map
Location based services

6. Location based services
Markers
Marker
An annotation on a map
Map. setOnMarkerClickListener(…)
Event when you hit a marker
MarkerOptions
The “constructor” parameters for Marker objects
Position, title, icon, etc.
Circle, and other annotation
You can add circles (and many other annotation) to a map
Location based services

7. How to make it work … when programming
Google Maps API v2 is part of Google Play services SDK
Use the Android SDK Manager to obtain the ”Google Play Services” API
It’s in “Extra” at the bottom of the screen
Android Studio can create a special Map activity
This is quite helpful
Location based services

8. How to make it work … when running
Google Maps API key
SHA1 + applications package name gives you a key
The key must be placed in AndroidManifest.xml
Permissions to use Internet, etc.
Stated in AndroidManifest.xml
Google Maps requires Open GL
Genymotion: Has no access to GooglePlay
It should be possible to upgrade GenyMotion, but I can’t make it work
It run the app on my Android phone
Location based services

9. Getting location data: Where am I?
Some applications needs to know the current position of the user’s device.
Three ways to obtain the position
GPS satellite
Most accurate
Mobile phone cell tower triangulation
Works indoors
Wi-Fi
The address of the connected Wi-Fi should be known
Least accurate
AndroidManifest.xml
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
Location based services

10. Getting location updates
locationManager.requestLocationUpdates( … )
Example: Maps3
Location based services

11. Different location providers: Pros and cons
GPS_PROVIDER
Accurate
Works only outdoors
Device must have satellite connection
Consumes battery
Satellite connection consumes battery
Slow
NETWORK_PROVIDER
Less accurate
Works indoors (Wi-Fi + cell-tower) and outdoors (cell-tower)
Consumes less battery
Faster
Source
Location based services

12. Location based services
Geocoding
Getting real addresses from a position
GeoCoder
List<Address> getFromLocationName(name, howMany)
Geocoding
Address includes ordinary address + (lat, long)
List<Address> getFromLocation(lat, long, howMany)
Reverse geocoding
Example: Maps3
Location based services

13. References and further readings
Google Maps Android API v2
Lars Vogel: Google Maps Android API v2 – Tutorial
George Mathew: Remove a single marker from Google Maps Android API V2 …
Making your app location-aware
Location based services