This document provides information on using Google Maps, GPS, camera, and SD card functionality in Android applications. It discusses setting up a Maps API key, controlling map views, displaying the user's location, taking photos via intents and the camera API, permissions for hardware access, and reading/writing to the SD card. Tips are also provided such as using version control, testing on low-end devices, and using developer tools.

1. Google maps + GPS,
camera, SD card
Nikola Kapraljević
Infinum Ltd.

2. About me
twitter@nixa
nikola.kapraljevic@gmail.com
Android
Ruby on Rails
iPhone

3. About Infinum Ltd.
www.infinumdigital.com
Mobile and web development company
10 people
Offices in Ljubljana and Zagreb

4. Google Maps API + GPS

5. Google APIs Add-On
be careful when testing
examples you’ll need
emulator with “Google
APIs”
maps don’t work
offline

6. New project ...
Google APIs not Android x.x

7. Maps API key
register for Maps API key
http://code.google.com/android/maps-api-signup.html
nixa-macbook:~ nixa$ keytool -list -keystore .android/
debug.keystore
Enter keystore password: android
Your keystore contains 1 entry
Certificate fingerprint (MD5): 43:9D:9B:
48:83:27:69:02:21:61:78:A7:F5:01:7D:F7

8. Maps API key
place api key in something like prefs.xml
production/development keys are different

9. AndroidManifest.xml

10. MapActivity

11. main.xml
android:clickable=”true”

12. Controlling MapView
shows map
MapController controls the map
MapController controller = map.getController()
controller.setZoom(10)
controller.setCenter(GeoPoint gp)
controller.animateTo(GeoPoint gp)

13. MyLocationOverlay
myLocationOverlay = new MyLocationOverlay(this,
map);
myLocationOverlay.runOnFirstFix(Runnable r)
myLocationOverlay.enableMyLocation()
myLocationOverlay.disableMyLocation()

14. CustomLocationOverlay
extend MyLocationOverlay for custom POI icon

15. POIs on MapView
MyPOIOverlay extends ItemizedOverlay<OverlayItem>
similar to ArrayAdapter
override
protected OverlayItem createItem(int i)
public int size()
boundCenterBottom(Drawable)
keep local copy of data in overlay in case you need to show
some info for POI

16. MapViewBallons
https://github.com/jgilfelt/android-mapviewballoons

17. GPS ...
and why I hate GPS

18. Permissions
First you’ll need permissions
INTERNET
ACCESS_FINE_LOCATION
ACCESS_COARSE_LOCATION
Sometimes users complain about FINE_LOCATION.
Use only if you really need it.

19. LocationManager
Context.getSystemService(Context.LOCATION_SERVICE)
GPS_PROVIDER
NETWORK_PROVIDER (cell tower and Wi-Fi based
location)
locationManager.requestLocationUpdates(LocationManag
er.NETWORK_PROVIDER, time, distance,
locationListener);

20. LocationListener
void onLocationChanged(Location location)
void onProviderDisabled(String provider)
void onProviderEnabled(String provider)
void onStatusChanged(String provider, int status,
Bundle extras)

21. GPS testing
Emulator
telnet localhost 555x
geo fix 45.0 22.0
Device
My Fake Location com.my.fake.location
Applications -> Development -> Allow mock locations

22. GPS more info
http://developer.android.com/guide/topics/location/
obtaining-user-location.html
http://stackoverflow.com/questions/3145089/what-is-
the-simplest-and-most-robust-way-to-get-the-users-
current-location-in-a/3145655#3145655
we use this in most of our applications

23. Camera

24. Permissions
<uses-permission
android:name="android.permission.CAMERA" />
<uses-feature
android:name="android.hardware.camera" />
<uses-feature
android:name="android.hardware.camera.autofocus"
android:required="false" />

25. Camera via Intent
Intent intent = new
Intent(MediaStore.ACTION_IMAGE_CAPTURE);
//extra to save full-image somewhere
intent.putExtra(MediaStore.EXTRA_OUTPUT,
Uri.fromFile(destination));
destination = new
File(Environment.getExternalFilesDir(null),"image.jpg");

26. Camera via SurfaceHolder
for creating camera applications etc...
in 99% cases you don’t need this
http://developer.android.com/reference/android/
hardware/Camera.html

27. Crop
doesn’t work on all devices!

28. Crop
intent.putExtra("crop", "true");
intent.putExtra("aspectX", 1);
intent.putExtra("aspectY", 1);
intent.putExtra("outputX", 116);
intent.putExtra("outputY", 116);
intent.putExtra("return-data", true);
Bitmap userImage = (Bitmap) data.getExtras().get("data");

29. SD card

30. SD card
<uses-permission
android:name="android.permission.WRITE_EXTERNAL
_STORAGE" />
Include an empty file named .nomedia in your external
files directory (note the dot prefix in the filename). This
will prevent Android's media scanner from reading your
media files and including them in apps like Gallery or
Music.

31. SD card
Check for presence and availability before using SD
String state = Environment.getExternalStorageState();
MEDIA_MOUNTED
MEDIA_MOUNTED_READ_ONLY

32. External folders
File getExternalStoragePublicDirectory (String type)
DIRECTORY_MUSIC, DIRECTORY_PODCASTS,
DIRECTORY_RINGTONES, DIRECTORY_ALARMS,
DIRECTORY_NOTIFICATIONS, DIRECTORY_PICTURES, or
DIRECTORY_MOVIES
gets scanned by media scanner
files aren’t deletes on app uninstall
File getExternalFilesDir (String type)
doesn’t get scanned by media scanner
files are deleted on app uninstall

33. App 2 SDcard
<manifest xmlns:android="http://
schemas.android.com/apk/res/android"
android:installLocation="preferExternal" ... >
use location “auto”

34. Tips & tricks

35. Droidscreen
https://github.com/ribomation/DroidAtScreen1

36. Emulator sucks.

37. Google Analytics also suck.
Use Flurry.

38. Use version control.

39. Once again, use version
control!

40. Use drawable selectors.
different images for normal and pressed state

41. Test on crapy devices.

42. Threads are you friends.
runOnUiThread, Handler

43. Check out Fragments.
They’re cool!

44. SDK/tools/layoutopt

45. Standardise your res/*
naming convention

46. Designing app for landscape
mode is 2x the work.

47. Use Dev Tools
ICS devices

48. coloredlogcat.py
http://jsharkey.org/blog/2009/04/22/modifying-the-
android-logcat-stream-for-full-color-debugging/

49. Pitanja ...