You can find the slides with speaker notes here : http://bit.ly/lifeofapp During this talk we live the life of your app on the user's point of view. The idea is to follow the user experience from the Play Store to the daily use, measure each time its frustration to find ways for us, as developers, to avoid them.

1. THE LIFE
OF
YOUR APP

2. Eyal LEZMY
SLIDES
http://bit.ly/lifeofapp
http://eyal.fr

3. AGENDA
CODEURS EN SEINE
01
02
03
04
Install it
Launch it
Look at it
Use it

4. 01
IT ALL STARTS ON THE
PLAY STORE

7. MINIMISE PERMISSIONS
Users should
prefer apps
requesting the
least
permissions
Request only what your app
requires
1/3 of apps request more permissions
than they need

8. MINIMISE PERMISSIONS
Users should
prefer apps
requesting the
least
permissions
You don’t need permission
Use ContentProviders

9. MINIMISE PERMISSIONS
Permission are not required to
launch another activity that has
the permission

10. MINIMISE PERMISSIONS
Need a
contact?

11. MINIMISE PERMISSIONS
Use the force,
Luke

12. MINIMISE PERMISSIONS
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType(Phone.CONTENT_ITEM_TYPE);
startActivityForResult(intent, MY_REQUEST_CODE);
void onActivityResult(int requestCode, int resultCode, Intent
data) {
if (data != null) {
Uri uri = data.getData();
if (uri != null) {
Cursor c = getContentResolver().query(uri, new String[]
{Contacts.DISPLAY_NAME, Phone.NUMBER}, null, null, null);}
}
}
}

13. MINIMISE PERMISSIONS
Start the contact app
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType(Phone.CONTENT_ITEM_TYPE);
startActivityForResult(intent, MY_REQUEST_CODE);
void onActivityResult(int requestCode, int resultCode, Intent
data) {
if (data != null) {
Uri uri = data.getData();
if (uri != null) {
Cursor c = getContentResolver().query(uri, new String[]
{Contacts.DISPLAY_NAME, Phone.NUMBER}, null, null, null);}
}
}
}

14. MINIMISE PERMISSIONS
Start the contact app
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType(Phone.CONTENT_ITEM_TYPE);
startActivityForResult(intent, MY_REQUEST_CODE);
void onActivityResult(int requestCode, int resultCode, Intent
data) {
if (data != null) {
Uri uri = data.getData();
if (uri != null) {
Cursor c = getContentResolver().query(uri, new String[]
{Contacts.DISPLAY_NAME, Phone.NUMBER}, null, null, null);}
}
}
}
Handle the result

15. MINIMISE PERMISSIONS
Need an
UUID?
TelephonyManager.getDeviceId()
Requires READ_PHONE_STATE permission
Settings.Secure.ANDROID_ID
Reset at every wipe
Not applicable on multi user environment

16. MINIMISE PERMISSIONS
Need an
UUID?
TelephonyManager.getDeviceId()
Requires READ_PHONE_STATE permission
Settings.Secure.ANDROID_ID
Reset at every wipe
Not applicable on multi user environment
NO!

17. MINIMISE PERMISSIONS
Need an
UUID?
Generate your own UUID and use
Backup API !
String id = UUID.randomUUID().
toString();

18. MINIMISE PERMISSIONS
Need an
UUID?
Generate your own UUID and use
Backup API !
String id = UUID.randomUUID().
toString();
YES!

19. MINIMISE PERMISSIONS
Android Backup API
· API is available on all Android devices.
· Manufacturors can implements their own
transport and storage for the API
· Each device as its own backup data
· A new device will take a backup from a device
associated with your google account.
· IT'S NOT A SYNC API !

20. 02
THE FIRST LAUNCH

21. THE FIRST LAUNCH
Make a
good
impression

22. THE FIRST LAUNCH
Lets start!

23. http://cyrilmottier.com

24. THE FIRST LAUNCH
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/Theme.MyTheme"
... >
We define our personal theme
including the correct styles and colors

25. THE FIRST LAUNCH
Let’s start...
Again!

26. My Big
BR
D
AN

27. LOADING ...

28. THE FIRST LAUNCH
A bunch of
data to
insert?
Use SQL transactions to save
time!

29. THE FIRST LAUNCH
Start transaction
db.beginTransaction();
try{
for(int i=0; i<selectedIds.length; i++){
values.put(COLUMN_ID,selectedIds[i]);
values.put(COLUMN_STARRED,starred);
db.insert(TABLE_STARRED,null,values);
db.yieldIfContendedSafely();
}
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}

30. THE FIRST LAUNCH
Start transaction
db.beginTransaction();
try{
for(int i=0; i<selectedIds.length; i++){
values.put(COLUMN_ID,selectedIds[i]);
values.put(COLUMN_STARRED,starred);
db.insert(TABLE_STARRED,null,values);
db.yieldIfContendedSafely();
}
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}
End transaction

31. THE FIRST LAUNCH
Start transaction
db.beginTransaction();
try{
for(int i=0; i<selectedIds.length; i++){
values.put(COLUMN_ID,selectedIds[i]);
values.put(COLUMN_STARRED,starred);
db.insert(TABLE_STARRED,null,values);
db.yieldIfContendedSafely();
}
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}
End transaction
Optimise multi-threaded insertion

32. THE FIRST LAUNCH
Faster?
Import directly, ready to use
databases

33. THE FIRST LAUNCH
ON THE SERVER
· Create your db file using SQlite and fill it
· Name your primary key columns "_id"
· Create the table : "android_metadata"
· And insert a single row containing the local
if defined (ex: "en_US"), or open your database
using :
openDatabase(dbPath, null,
SQLiteDatabase.NO_LOCALIZED_COLLATORS |
SQLiteDatabase.CREATE_IF_NECESSARY);

34. THE FIRST LAUNCH
ON THE MOBILE
· Grab the zipped database from assets or
network
· Unzip it to your getDatabaseDir()
· Open the database
Be careful of the SQLite version !

35. 03
LOOK AND FEEL

36. ?
?
?

37. LOOK AND FEEL
HOTMAIL
OUTLOOK.COM

38. LOOK AND FEEL
SAME!
HOTMAIL
OUTLOOK.COM

39. LOOK AND FEEL
FOLLOW THE GUIDELINES!
http://d.android.com/design

40. LOOK AND FEEL
Redesigned by Taylor Ling

41. LOOK AND FEEL
By Microsoft

42. LOOK AND FEEL

43. LOOK AND FEEL

44. LOOK AND FEEL
FOLLOW THE GUIDELINES!
http://d.android.com/design

45. LOOK AND FEEL
PLEASE!
FOLLOW THE GUIDELINES!
http://d.android.com/design

46. 04
A DAILY USE

47. SMOOTHEN YOUR UI
UI Thread
=
Events+Draw
16 ms to draw a frame (~60 fps)
Garbage Collector may take 10ms
And stop all threads

48. SMOOTHEN YOUR UI
Flatten the
View
Hierarchy
· Use RelativeLayout instead of
LinearLayout
· Use the <merge/> tag when possible
· Use hierarchyviewer to inspect
your layouts

49. SMOOTHEN YOUR UI
Avoid
overdraws
· Do not draw your background several times
· Use the “GPU Overdraw” tool from Android
4.2

50. SMOOTHEN YOUR UI
Avoid
autoboxing
Use SparseArray

51. SMOOTHEN YOUR UI
Hashmap<Integer, Object> hashmap = new HashMap<Integer, Object>();
hashmap.put(1789, mRevolution);
...
hashmap.get(1789);
SparseArray<Object> sparseArray = new SparseArray<Object>();
sparseArray.put(1789, mRevolution);
...
sparseArray.get(1789);

52. SMOOTHEN YOUR UI
Hashmap<Integer, Object> hashmap = new HashMap<Integer, Object>();
hashmap.put(1789, mRevolution);
...
hashmap.get(1789);
new Integer(1789)
SparseArray<Object> sparseArray = new SparseArray<Object>();
sparseArray.put(1789, mRevolution);
...
sparseArray.get(1789);

53. SMOOTHEN YOUR UI
Hashmap<Integer, Object> hashmap = new HashMap<Integer, Object>();
hashmap.put(1789, mRevolution);
...
hashmap.get(1789);
new Integer(1789)
new Integer(1789)
SparseArray<Object> sparseArray = new SparseArray<Object>();
sparseArray.put(1789, mRevolution);
...
sparseArray.get(1789);

54. SMOOTHEN YOUR UI
Hashmap<Integer, Object> hashmap = new HashMap<Integer, Object>();
hashmap.put(1789, mRevolution);
...
hashmap.get(1789);
new Integer(1789)
new Integer(1789)
SparseArray<Object> sparseArray = new SparseArray<Object>();
sparseArray.put(1789, mRevolution);
...
sparseArray.get(1789);
Low memory footprint and no more GC!

55. SMOOTHEN YOUR UI
Load
bitmap
cleverly
·
Reuse it
· Use sampling

56. SMOOTHEN YOUR UI
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.inBitmap = myOldBitmap;
Bitmap scaledBitmap = BitmapFactory.decode...(..., bitmapOptions);
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.inSampleSize = sampleSize;

57. SMOOTHEN YOUR UI
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.inBitmap = myOldBitmap;
Bitmap scaledBitmap = BitmapFactory.decode...(..., bitmapOptions);
Define the bitmap to reuse (API level 11)
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.inSampleSize = sampleSize;

58. SMOOTHEN YOUR UI
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.inBitmap = myOldBitmap;
Bitmap scaledBitmap = BitmapFactory.decode...(..., bitmapOptions);
Define the bitmap to reuse (API level 11)
Use the option for loading
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.inSampleSize = sampleSize;

59. SMOOTHEN YOUR UI
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.inBitmap = myOldBitmap;
Bitmap scaledBitmap = BitmapFactory.decode...(..., bitmapOptions);
Define the bitmap to reuse (API level 11)
Use the option for loading
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmapOptions.inSampleSize = sampleSize;
Define the subsampling level (API Level 1)

60. PRESERVE THE BATTERY

61. PRESERVE THE BATTERY
Screen: 1st item of consumtion
30 to 70% of the battery life

62. PRESERVE THE BATTERY
WakeLocks
Basically you don’t need it
Only a few kind of applications should need to
stay the device awake (Reader, Games, …)
Think about the context
Release wake lock if you have good
assumptions that the user is not using your
app anymore

63. PRESERVE THE BATTERY
Geolocation
GPS
· Permission ACCESS_FINE_LOCATION
· Drains a lot of power
· Works offline
Network location
·
·
·
·
Permission ACCESS_COARSE_LOCATION
Need to be online
Fast
Precise in urban area

64. PRESERVE THE BATTERY
Geolocation
Define a strategy
· What is the needed precision for my app?
· Define the measure interval wisely
· Consider the GPS fix time
Use Fused Location Provider
On Google Play Services

65. PRESERVE THE BATTERY
Network
Radio drains a lot of power
Group data to minimize the number of
requests
Use caching!

66. PRESERVE THE BATTERY
private void enableHttpResponseCache() {
try {
long httpCacheSize = 10 * 1024 * 1024; // 10 MiB
File httpCacheDir = new File(getCacheDir(), “http”);
Class.forName(“android.net.http.HttpResponseCache”)
.getMethod(“install”, File.class, long.class)
.invoke(null, httpCacheDir, httpCacheSize);
} catch (Exception httpResponseCacheNotAvailable) {
Log.d(TAG, “HTTP response cache is unavailable.”);
}
}
Enable cache, if available (API level 13)
Or use a backport like HttpResponseCache

67. PRESERVE THE BATTERY
Network
Enable GZIP on the server
30 to 50% less trafic
Use ETAGs

68. PRESERVE THE BATTERY

69. BE INSPIRED
Gestures Text to Speech Accelerometer
Voice recognition Proximity sensor Bluetooth
NFC
Direct Wifi Second Screen

70. BE INSPIRED
Explore all the device’s possibilities

72. Thank You for your time !
SLIDES
http://bit.ly/lifeofapp
http://eyal.fr