Android, the life of your app

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.

Transcript

1. THE LIFE OF YOUR APP
2. Eyal LEZMY http://eyal.fr SLIDES http://bit.ly/lifeofapp
3. AGENDA CODEURS EN SEINE 01 Install it 02 Launch it 03 Look at it 04 Use it
4. IT ALL STARTS ON THE PLAY STORE 01
7. Request only what your app requires 1/3 of apps request more permissions than they need MINIMISE PERMISSIONS Users should prefer apps requesting the least permissions
8. You don’t need permission Use ContentProviders MINIMISE PERMISSIONS Users should prefer apps requesting the least permissions
9. Permission are not required to launch another activity that has the permission MINIMISE PERMISSIONS
10. Need a contact? MINIMISE PERMISSIONS
11. Use the force, Luke MINIMISE PERMISSIONS
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 Intent intent = new Intent(Intent.ACTION_GET_CONTENT); intent.setType(Phone.CONTENT_ITEM_TYPE); startActivityForResult(intent, MY_REQUEST_CODE); Start the contact app 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 Intent intent = new Intent(Intent.ACTION_GET_CONTENT); intent.setType(Phone.CONTENT_ITEM_TYPE); startActivityForResult(intent, MY_REQUEST_CODE); Start the contact app Handle the result 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);} } } }
15. Need an UUID? TelephonyManager.getDeviceId() Requires READ_PHONE_STATE permission MINIMISE PERMISSIONS Settings.Secure.ANDROID_ID Reset at every wipe Not applicable on multi user environment
16. Need an UUID? TelephonyManager.getDeviceId() Requires READ_PHONE_STATE permission MINIMISE PERMISSIONS Settings.Secure.ANDROID_ID Reset at every wipe Not applicable on multi user environment NO!
17. Need an UUID? Generate your own UUID and use Backup API ! MINIMISE PERMISSIONS String id = UUID.randomUUID(). toString();
18. Need an UUID? Generate your own UUID and use Backup API ! MINIMISE PERMISSIONS String id = UUID.randomUUID(). toString(); YES!
19. 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 ! MINIMISE PERMISSIONS
20. THE FIRST LAUNCH 02
21. Make a good impression THE FIRST LAUNCH
22. Lets start! THE FIRST LAUNCH
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. Let’s start... Again! THE FIRST LAUNCH
26. My Big BRAND
27. LOADING ...
28. A bunch of data to insert? Use SQL transactions to save time! THE FIRST LAUNCH
29. THE FIRST LAUNCH 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(); } Start transaction
30. THE FIRST LAUNCH 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(); } Start transaction End transaction
31. THE FIRST LAUNCH 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(); } Start transaction End transaction Optimise multi-threaded insertion
32. Import directly, ready to use databases Faster? THE FIRST LAUNCH
33. openDatabase(dbPath, null, SQLiteDatabase.NO_LOCALIZED_COLLATORS | SQLiteDatabase.CREATE_IF_NECESSARY); · 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 : THE FIRST LAUNCH ON THE SERVER
34. · Grab the zipped database from assets or network · Unzip it to your getDatabaseDir() · Open the database THE FIRST LAUNCH ON THE MOBILE Be careful of the SQLite version !
35. LOOK AND FEEL 03
36. ? ? ?
37. LOOK AND FEEL HOTMAIL OUTLOOK.COM
38. LOOK AND FEEL HOTMAIL OUTLOOK.COM SAME!
39. LOOK AND FEEL FOLLOW THE GUIDELINES! http://d.android.com/design
40. Redesigned by Taylor Ling LOOK AND FEEL
41. By Microsoft LOOK AND FEEL
42. LOOK AND FEEL
43. LOOK AND FEEL
44. LOOK AND FEEL FOLLOW THE GUIDELINES! http://d.android.com/design
45. LOOK AND FEEL FOLLOW THE GUIDELINES! http://d.android.com/design PLEASE!
46. A DAILY USE 04
47. UI Thread = Events+Draw 16 ms to draw a frame (~60 fps) SMOOTHEN YOUR UI Garbage Collector may take 10ms And stop all threads
48. Flatten the View Hierarchy · Use RelativeLayout instead of LinearLayout · Use the <merge/> tag when possible · Use hierarchyviewer to inspect your layouts SMOOTHEN YOUR UI
49. Avoid overdraws · Do not draw your background several times · Use the “GPU Overdraw” tool from Android 4.2 SMOOTHEN YOUR UI
50. Use SparseArray SMOOTHEN YOUR UI Avoid autoboxing
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) Low memory footprint and no more GC! SparseArray<Object> sparseArray = new SparseArray<Object>(); sparseArray.put(1789, mRevolution); ... sparseArray.get(1789);
55. · Reuse it · Use sampling SMOOTHEN YOUR UI Load bitmap cleverly
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); BitmapFactory.Options bitmapOptions = new BitmapFactory.Options(); bitmapOptions.inSampleSize = sampleSize; Define the bitmap to reuse (API level 11)
58. 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; Use the option for loading Define the bitmap to reuse (API level 11)
59. SMOOTHEN YOUR UI BitmapFactory.Options bitmapOptions = new BitmapFactory.Options(); bitmapOptions.inBitmap = myOldBitmap; Bitmap scaledBitmap = BitmapFactory.decode...(..., bitmapOptions); Define the subsampling level (API Level 1) BitmapFactory.Options bitmapOptions = new BitmapFactory.Options(); bitmapOptions.inSampleSize = sampleSize; Use the option for loading Define the bitmap to reuse (API level 11)
60. PRESERVE THE BATTERY
61. Screen: 1st item of consumtion 30 to 70% of the battery life PRESERVE THE BATTERY
62. 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 WakeLocks PRESERVE THE BATTERY
63. 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 Geolocation PRESERVE THE BATTERY
64. 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 Geolocation PRESERVE THE BATTERY
65. Radio drains a lot of power Group data to minimize the number of requests Use caching! Network PRESERVE THE BATTERY
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. Enable GZIP on the server 30 to 50% less trafic Use ETAGs Network PRESERVE THE BATTERY
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 ! http://eyal.fr SLIDES http://bit.ly/lifeofapp