"Developing Apps for Android on 2.x/3.x/4.x" ->The presentation file on droidcon London 2012

1. Droidcon London 2012
Developing Apps
for Android on 2.x/3.x/4.x
Kenichi Kambara (@korodroid)
October 26, 2012

2. Who am I?
l Kenichi Kambara (Twitter @korodroid)
l iplatform.org（http://www.iplatform.org/） (Personal)
l NTT Software Corporation (Official)
l Activity（iplatform.org as Personal）
- My Android Apps on Google Play （20+ Apps)
9 10
2

3. Who am I?
l Kenichi Kambara (Twitter @korodroid)
l iplatform.org（http://www.iplatform.org/） (Personal)
l NTT Software Corporation (Official)
l Activity（iplatform.org as Personal）
-
My Android Apps on Google Play （20+ Apps)
9 10
“Sekai Phone”
l Google Developer Day 2011 Tokyo Keynote Demo
l Google Android Developer Lab Tokyo 2011 5th prize
3

4. Agenda
• Introduction
• Background
• Android Fundamentals
• Application Development Tips
4

5. My session topics
Some tips on developing Apps
for multi versions and multi devices.
2.x
3.x
4.x
Handsets Tablets 5

6. Introduction
(Sekai Phone)
6

7. What is “Sekai Phone”?
Real time translation phone services
(Supports Android 2.x/3.x/4.x & multi devices)
)
English German
Japanese
○
○
○
Italian
French
○
○
Chinese
Publishe Date: Jan, 2010, over 20+ ver.up
7

8. Use Case (1)
Phone mode
(Auto translating to receiver’s native language)
English Japanese
Hello!
Talking
Konnichiwa!
Talking
Paul
Kenichi
Thanks! Arigatou!
8

9. Use Case (2)
Talk mode
(Auto translating on the spot)
English Japanese
9

10. App Demos (1.Phone mode)
English Japanese
Hello!
Talking
Konnichiwa!
Talking
Paul
Kenichi
Thanks! Arigatou!
10

11. App Demos (2.Talk mode)
11

12. App Screenshots on Android 2.x
Portrait Landscape
12

13. App Screenshots on Android 3.x
Portrait Landscape
13

14. App Screenshots on Android 4.x
Portrait Landscape
14

15. Background
15

16. Current Android Devices
Handsets
Handsets
(Almost all)
& Tablets
2.x
Tablets 4.x
(All)
3.x
16

17. Platform Versions?
This data by Google on October 1, 2012
17

18. Platform Versions?
Honeycomb
ICS
JB
Gingerbread
Others
Froyo
This data by Google on October 1, 2012
In my App:
Main Target: Android 2.2+ (2.2,2.3,3.x,4.x)
18

19. Screen Sizes & Densities?
xhdpi
Normal
Small
ldpi
Xlarge
hdpi
Large
mdpi
This data by Google on October 1, 2012
19

20. Screen Sizes & Densities?
This data by Google on October 1, 2012
In my App:
Main Target: (normal,large,xlarge)x(mdpi,hdpi,xhdpi)
20

21. Android Fundamentals
21

22. Fragment?
Handset
Tablet
Activity A
Activity B
Activity A
22

23. Fragment?
Handset
Tablet
Fragment X Fragment Y Fragment X Fragment Y
Activity A
Activity B
Activity A
23

24. Menu?
Options Menu Action Bar
(2.x) (3.0+)
24

25. Application Development Tips
25

26. Support multi versions and multi devices?
1.Designing User Interface
l Screen size
l Screen density
l Screen orientation
…
2.Using APIs
l Fragment
l Menu
… 26

27. 1. Designing User Interface
[Some Approaches]
27

28. [UI]1 st Approach
Using layout-small/normal/large/xlarge
Screen Size
Classification
l Supports Android 1.6+
l Both 7” tablet and 5” handset mapped to “large”
l Pre 3.0 some devices mis-classified
28

29. [UI]Introduction of 2nd Approach
Using “dp(Density-Independent pixel)”
Width sizes
Devices
320dp
Typical Handsets
600dp
7” tablet
720dp
10” tablet
29

30. [UI]2 nd Approach
e.g.)Supporting Handsets & 2 Tablets
Handsets
7’’ Tablet
10’’ Tablet
l res/layout/main.xml
l res/layout-sw600dp/main.xml
l res/layout-sw720dp/main.xml 30

31. [UI]2 nd Approach
sw<N>dp?, w<N>dp?, h<N>dp?
(a)layout-sw600dp Width & Height ≥ 600dp
(b)layout-w720dp Width ≥ 720dp
(c)layout-h480dp Height ≥ 480dp
31

32. [UI]2 nd Approach
Using sw<N>dp,w<N>dp,h<N>dp
400 dp
960 dp
(a)layout-sw600dp false
(b)layout-w720dp true
(c)layout-h480dp false
32

33. [UI]2 nd Approach
Using sw<N>dp,w<N>dp,h<N>dp
(a)layout-sw600dp Width & Height ≥ 600dp
(b)layout-w720dp Width ≥ 720dp
(c)layout-h480dp Height ≥ 480dp
l Recommended by Google
l Supports only Android 3.2+
Note: Effect by Screen Orientation
33

34. [UI]3 rd Approach
Combination of 1st and 2nd
l res/layout-sw600dp/main.xml <- 3.2+ tablets
l res/layout-xlarge/main.xml <- 3.0/3.1 tablets
l res/layout/main.xml <- The others (Handsets)
l Supports Android 1.6
l Supports many devices (compared to 1st or 2nd)
l Any Problem?
34

35. [UI]3 rd Approach
It looks good but…
l res/layout-sw600dp/main.xml <- 3.2+ tablets
l res/layout-xlarge/main.xml <- 3.0/3.1 tablets
l res/layout/main.xml <- The others (Handsets)
• Needs to put the same file for tablets.
(Maintenance headache…)
35

36. [UI]3 rd Approach
It looks good but…
if ([Size is xlarge] or [width & height is at least 600dp])
// codes for tablets
}else{
// codes for others
}
• Complicated Java codes
(Development is complicated…)
36

37. Which is the Better Approach?
37

38. [UI]4 th Approach
Based on 3rd , plus some tips
• Put minimum requirement
for layouts
38

39. [UI]4 th Approach
Based on 3rd , plus some tips (Layout Aliases)
// for Tablets
<resources>
<item name "main_layout" type="layout">
@layout/main_twopanes
</item>
<bool name="has_two_panes">
true
</bool>
</resources> 39

40. [UI]4 th Approach
Based on 3rd , plus some tips (Layout Aliases)
// for Tablets
<resources>
<item name "main_layout" type="layout">
@layout/main_twopanes
</item>
<bool name="has_two_panes">
true
</bool>
</resources>
boolean hasTwoPanes =getResources().
getBoolean(R.bool.has_two_panes);
if (hasTwoPanes)
…
• Simple Java codes
40

41. 2.Using APIs?
[Some Points]
41

42. [API]Fragment
Using Support Library?
2.x
3.x
4.x
Without
Support Library
With
Support Library
42

43. [API]Fragment
Comparing Using with No-Using
With Without
Support Library
Support Library
• android.support.v4.Fragment
• android.app.Fragment
Class
• android.support.v4.FragmentActivity
• android.app.Activity
…
…
• getSupportFragmentManager() • getFragmentManager()
Method
(FragmentActivity)
(Activity)
…
…
43

44. [API]Options Menu vs Action Bar
Action Bar is good…
2.x
3.x
4.x
Options Menu
Action Bar
Note: ActionBarSherlock lib, Effect by style
44

45. [API]Effect by AndroidManifest
On Android 2.x / 3.x
Min Target 2.x
3.x
Sdk
Sdk
Pattern 1
-
-
(Fail 1)
Pattern 2
8
8
(Fail 2)
Pattern 3
8
16
Fail 2
Fail 1
45

46. [API]Effect by AndroidManifest
On Android 2.x / 4.x
Min Target 2.x
4.x
Sdk
Sdk
Pattern 1
-
-
(Fail 3)
Pattern 2
8
8
(Fail 4)
Pattern 3
8
16
Fail 3
Fail 4
46

47. [API]Effect by AndroidManifest
On Android 2.x / 3.x / 4.x
Min Target 2.x
3.x
4.x
Sdk
Sdk
Pattern 1
-
-
Pattern 2
8
8
Pattern 3
8
16
4.x
2.x
3.x
47

48. [API]Effect by AndroidManifest
On Android 2.x / 3.x / 4.x
Min Target 2.x
3.x
4.x
Sdk
Sdk
Pattern 1
-
-
Pattern 2
8
8
Pattern 3
8
16
Note: Google Official blogs, Split Action Bar
48

49. [API]Multi-Versioning
Development?, Management?, APK Size?
Single APK
Multiple APK
49

50. [API]Multi-Versioning
Single APK
In my App:
Developed by Single APK
50

51. [API]Multi-Versioning
How to use the newest API on Single APK
Reflection Well known approach
Lazy loading One of Design Patterns
51

52. [API]Multi-Versioning
How to use the newest API on Single APK
Reflection Well known approach
Lazy loading One of Design Patterns
In my App:
Compatibility with Lazy loading
52

53. [API]Multi-Versioning
Code Examples of Lazy loading
1 st step
public
abstract
class
NotificationUtilAbstract
{
public
static
NotificationUtilAbstract
newInstance()
{
NotificationUtilAbstract
instance
=
null;
if
(Integer.parseInt(Build.VERSION.SDK)=
16)
{
instance
=
new
NotificationUtilJB();
}
else
{
instance
=
new
NotificationUtilDefault();
}
return
instance;
}
public
abstract
void
showCaller;
} 53

54. [API]Multi-Versioning
2 nd step
public
class
NotificationUtilJB
extends
NotificationUtilAbstract{
@Override
public
void
showCaller(){
//
Code
by
Jelly
Bean
(API
16)
}
}
public
class
NotificationUtilDefault
extends
NotificationUtilAbstract{
@Override
public
void
showCaller(){
//
Code
by
Old
API
}
• Compatible
}
54

55. Appendix
1. Use “wrap_content”/“match_parent”,”sp”/”dp”
2. Supply alternative drawables / Use 9-patch
3. Use Fragment
4. Use “Dimension (Customize component size)”
5. Consider either “1 apk” or “multiple apk”
55

56. References
Android Developers Site
• Supporting Tablets and Handsets
http://developer.android.com/guide/practices/tablets-and-handsets.html
• Supporting Multiple Screens
http://developer.android.com/guide/practices/screens_support.html
• Supporting Different Screen Sizes
http://developer.android.com/training/multiscreen/screensizes.html
56

57. References
“Android Programming Nyumon v2”
• Language: Japanese (Sorry…)
• Release Date: August 30, 2012
• Publisher:ASCII MEDIA WORKS Inc.
• Authors:
- Takashi Egawa
- Kenichi Kambara
- Akimichi Yamada
- Tetsurou Sano
- Mariko Goda
57

58. Thank you!
• Facebook:http://fb.com/kanbara.kenichi
• Google+:+Kenichi Kambara
• Twitter:@korodroid