1. Intro to Android
for iOS developers
Chiu-Ki Chan
@chiuki

2. @chiuki@chiuki

3. @chiuki@chiuki
Hello World
Layouts
Intents & Components

4. Hello World

5. @chiuki

6. @chiuki
ViewController

7. @chiuki

8. @chiuki

9. @chiuki
xib

10. @chiuki

11. @chiuki

12. @chiuki

13. @chiuki

14. @chiuki
IBOutlet

15. @chiuki

16. @chiuki@chiuki
Center
<TextView
android:id="@+id/text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center" />

17. @chiuki

18. @chiuki@chiuki
Button
<Button
android:id="@+id/text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="@string/add" />

19. @chiuki
LinearLayout

20. @chiuki

21. @chiuki@chiuki
LinearLayout
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical" >
<TextView
android:id="@+id/count"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="128sp" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/add"
android:onClick="add" />
</LinearLayout>

22. @chiuki@chiuki
IBAction
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical" >
<TextView
android:id="@+id/count"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="128sp" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/add"
android:onClick="add" />
</LinearLayout>

23. @chiuki@chiuki
IBAction
public class MainActivity extends Activity {
private TextView countView;
private int count = 0;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
countView = (TextView) findViewById(R.id.count);
updateCount();
}
public void add(View v) {
count += 1;
updateCount();
}
private void updateCount() {
countView.setText(String.valueOf(count));
}
}
android:onClick="add"

24. @chiuki@chiuki
Update view
public class MainActivity extends Activity {
private TextView countView;
private int count = 0;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
countView = (TextView) findViewById(R.id.count);
updateCount();
}
public void add(View v) {
count += 1;
updateCount();
}
private void updateCount() {
countView.setText(String.valueOf(count));
}
}

25. @chiuki

26. @chiuki

27. @chiuki
RelativeLayout

28. @chiuki

29. @chiuki

30. @chiuki

31. @chiuki

32. @chiuki
<RelativeLayout>
<TextView
android:id="@+id/count"
android:layout_centerInParent="true" />
<Button
android:id="@+id/reset"
android:layout_below="@id/count"
android:layout_centerHorizontal="true"
android:text="@string/reset" />
<Button
android:layout_below="@id/count"
android:layout_toLeftOf="@id/reset"
android:text="@string/subtract" />
<Button
android:layout_below="@id/count"
android:layout_toRightOf="@id/reset"
android:text="@string/add" />
</RelativeLayout>

33. @chiuki
<RelativeLayout>
<TextView
android:id="@+id/count"
android:layout_centerInParent="true" />
<Button
android:id="@+id/reset"
android:layout_below="@id/count"
android:layout_centerHorizontal="true"
android:text="@string/reset" />
<Button
android:layout_below="@id/count"
android:layout_toLeftOf="@id/reset"
android:text="@string/subtract" />
<Button
android:layout_below="@id/count"
android:layout_toRightOf="@id/reset"
android:text="@string/add" />
</RelativeLayout>

34. @chiuki
<RelativeLayout>
<TextView
android:id="@+id/count"
android:layout_centerInParent="true" />
<Button
android:id="@+id/reset"
android:layout_below="@id/count"
android:layout_centerHorizontal="true"
android:text="@string/reset" />
<Button
android:layout_below="@id/count"
android:layout_toLeftOf="@id/reset"
android:text="@string/subtract" />
<Button
android:layout_below="@id/count"
android:layout_toRightOf="@id/reset"
android:text="@string/add" />
</RelativeLayout>

35. @chiuki
<RelativeLayout>
<TextView
android:id="@+id/count"
android:layout_centerInParent="true" />
<Button
android:id="@+id/reset"
android:layout_below="@id/count"
android:layout_centerHorizontal="true"
android:text="@string/reset" />
<Button
android:layout_toLeftOf="@id/reset"
android:text="@string/subtract" />
<Button
android:layout_below="@id/count"
android:layout_toRightOf="@id/reset"
android:text="@string/add" />
</RelativeLayout>

36. @chiuki
<RelativeLayout>
<TextView
android:id="@+id/count"
android:layout_centerInParent="true" />
<Button
android:id="@+id/reset"
android:layout_below="@id/count"
android:layout_centerHorizontal="true"
android:text="@string/reset" />
<Button
android:layout_below="@id/count"
android:layout_toLeftOf="@id/reset"
android:text="@string/subtract" />
<Button
android:layout_below="@id/count"
android:layout_toRightOf="@id/reset"
android:text="@string/add" />
</RelativeLayout>

37. @chiuki@chiuki
Device Preview

38. @chiuki@chiuki
Bigger text on tablets

39. Resource Folders

40. @chiuki@chiuki
textSize
<TextView
android:id="@+id/count"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="128sp" />
res/layout/activity_main.xml

41. @chiuki@chiuki
res/values/dimens.xml
<TextView
android:id="@+id/count"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="@dimen/counter_size" />
res/layout/activity_main.xml
<dimen name="counter_size" value="128sp" />
res/values/dimens.xml

42. @chiuki@chiuki
res/values-sw600dp/dimens.xml
<TextView
android:id="@+id/count"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="@dimen/counter_size" />
res/layout/activity_main.xml
<dimen name="counter_size" value="128sp" />
<dimen name="counter_size" value="256sp" />
res/values/dimens.xml
res/values-sw600dp/dimens.xml

43. @chiuki@chiuki
Resource Folders
Type Variation
layout
values
drawable
menu
Language & Region: en, fr, fr-rCA, ja
Screen size: small, large, sw600dp, h400dp
Screen orientation: port, land
Screen density: ldpi, mdpi, hdpi, xhdpi, nodpi, tvdpi
Platform version: v4, v11, v14
UI mode: car, desk, television, appliance
http://developer.android.com/guide/topics/resources/providing-resources.html

44. @chiuki@chiuki
Resource Folders
Type Variation
layout
values
drawable
menu
Language & Region: en, fr, fr-rCA, ja
Screen size: small, large, sw600dp, h400dp
Screen orientation: port, land
Screen density: ldpi, mdpi, hdpi, xhdpi, nodpi, tvdpi
Platform version: v4, v11, v14
UI mode: car, desk, television, appliance
http://developer.android.com/guide/topics/resources/providing-resources.html
res/values-sw600dp/dimens.xml

45. @chiuki@chiuki
Resource Folders
Type Variation
layout
values
drawable
menu
Language & Region: en, fr, fr-rCA, ja
Screen size: small, large, sw600dp, h400dp
Screen orientation: port, land
Screen density: ldpi, mdpi, hdpi, xhdpi, nodpi, tvdpi
Platform version: v4, v11, v14
UI mode: car, desk, television, appliance
http://developer.android.com/guide/topics/resources/providing-resources.html
res/drawable-hdpi/ic_launcher.png

46. @chiuki@chiuki
Resource Folders
Type Variation
layout
values
drawable
menu
Language & Region: en, fr, fr-rCA, ja
Screen size: small, large, sw600dp, h400dp
Screen orientation: port, land
Screen density: ldpi, mdpi, hdpi, xhdpi, nodpi, tvdpi
Platform version: v4, v11, v14
UI mode: car, desk, television, appliance
http://developer.android.com/guide/topics/resources/providing-resources.html
res/drawable-hdpi/ic_launcher.png
@2x

47. @chiuki@chiuki
Resource Folders
Type Variation
layout
values
drawable
menu
Language & Region: en, fr, fr-rCA, ja
Screen size: small, large, sw600dp, h400dp
Screen orientation: port, land
Screen density: ldpi, mdpi, hdpi, xhdpi, nodpi, tvdpi
Platform version: v4, v11, v14
UI mode: car, desk, television, appliance
http://developer.android.com/guide/topics/resources/providing-resources.html
res/layout-ja/name.xml

48. Activity Lifecycle

49. @chiuki@chiuki
onCreate()
Activity Lifecycle

50. @chiuki@chiuki
onCreate()
Activity Lifecycle

51. @chiuki@chiuki
onCreate() viewDidLoad:
Activity Lifecycle

52. @chiuki@chiuki
onCreate() viewDidLoad:
onStart()
Activity Lifecycle

53. @chiuki@chiuki
onCreate() viewDidLoad:
onStart()
onResume()
Activity Lifecycle

54. @chiuki@chiuki
onCreate() viewDidLoad:
onStart()
onResume()
viewWillAppear:
viewDidAppear:
Activity Lifecycle

55. @chiuki@chiuki
onCreate() viewDidLoad:
onStart()
onResume()
viewWillAppear:
viewDidAppear:
onPause()
Activity Lifecycle

56. @chiuki@chiuki
onCreate() viewDidLoad:
onStart()
onResume()
viewWillAppear:
viewDidAppear:
onPause()
onStop()
Activity Lifecycle

57. @chiuki@chiuki
onCreate() viewDidLoad:
onStart()
onResume()
viewWillAppear:
viewDidAppear:
onPause()
onStop()
viewWillDisappear:
viewDidDisappear:
Activity Lifecycle

58. @chiuki@chiuki
onCreate() viewDidLoad:
onStart()
onResume()
viewWillAppear:
viewDidAppear:
onPause()
onStop()
viewWillDisappear:
viewDidDisappear:
onDestroy()
Activity Lifecycle

59. @chiuki@chiuki
onCreate() viewDidLoad:
onStart()
onResume()
viewWillAppear:
viewDidAppear:
onPause()
onStop()
viewWillDisappear:
viewDidDisappear:
onDestroy() viewDidUnload:
Activity Lifecycle

60. @chiuki@chiuki
onCreate() viewDidLoad:
onStart()
onResume()
viewWillAppear:
viewDidAppear:
onPause()
onStop()
viewWillDisappear:
viewDidDisappear:
onDestroy() viewDidUnload:
Activity Lifecycle

61. @chiuki@chiuki
Visibility

62. More Activities

63. @chiuki@chiuki
startActivity (explicit)
Intent intent = new Intent(this, NumberActivity.class);
intent.putExtra("count", count);
startActivity(intent);

64. @chiuki@chiuki
startActivity (explicit)
Intent intent = new Intent(this, NumberActivity.class);
intent.putExtra("count", count);
startActivity(intent);

65. @chiuki@chiuki
startActivity (explicit)
Intent intent = new Intent(this, NumberActivity.class);
intent.putExtra("count", count);
startActivity(intent);

66. @chiuki@chiuki
startActivity (implicit)
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse("http://twitter.com/chiuki"));
startActivity(intent);

67. @chiuki@chiuki
startActivity (implicit)
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse("http://twitter.com/chiuki"));
startActivity(intent);

68. @chiuki@chiuki
startActivity (implicit)
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse("http://twitter.com/chiuki"));
startActivity(intent);

69. @chiuki@chiuki
startActivity (implicit)
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse("http://twitter.com/chiuki"));
startActivity(intent);

70. @chiuki@chiuki
Register your Activity
<activity android:name=".YourActivity">
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="http" android:host="twitter.com" />
</intent-filter>
</activity>
AndroidManifest.xml
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse("http://twitter.com/chiuki"));
startActivity(intent);
Info.plist

71. @chiuki@chiuki
IntentFilter: Action
<activity android:name=".YourActivity">
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="http" android:host="twitter.com" />
</intent-filter>
</activity>
AndroidManifest.xml
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse("http://twitter.com/chiuki"));
startActivity(intent);

72. @chiuki@chiuki
IntentFilter: Data
<activity android:name=".YourActivity">
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="http" android:host="twitter.com" />
</intent-filter>
</activity>
AndroidManifest.xml
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse("http://twitter.com/chiuki"));
startActivity(intent);

73. @chiuki@chiuki
IntentFilter: Category
<activity android:name=".YourActivity">
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="http" android:host="twitter.com" />
</intent-filter>
</activity>
AndroidManifest.xml
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse("http://twitter.com/chiuki"));
startActivity(intent);

74. @chiuki@chiuki
IntentFilter: Category
<activity android:name=".YourActivity">
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="http" android:host="twitter.com" />
</intent-filter>
</activity>
AndroidManifest.xml
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse("http://twitter.com/chiuki"));
startActivity(intent);

75. @chiuki@chiuki
Intent Data
<activity android:name=".YourActivity">
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="http" android:host="twitter.com" />
</intent-filter>
</activity>
Uri uri = getIntent().getData();
AndroidManifest.xml
YourActivity.java

76. @chiuki@chiuki
startActivityForResult
private static final int REQUEST_CODE_CAMERA = 1;
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, REQUEST_CODE_CAMREA);
protected void onActivityResult(
int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_CODE_CAMERA &&
resultCode == RESULT_OK) {
Bitmap bitmap = (Bitmap) data.getExtras().get("data");
}
}

77. @chiuki@chiuki
startActivityForResult
private static final int REQUEST_CODE_CAMERA = 1;
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, REQUEST_CODE_CAMERA);
protected void onActivityResult(
int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_CODE_CAMERA &&
resultCode == RESULT_OK) {
Bitmap bitmap = (Bitmap) data.getExtras().get("data");
}
}

78. @chiuki@chiuki
Providing Result
Intent data = new Intent();
data.putExtra("data", bitmap);
setResult(RESULT_OK, data);
finish();
protected void onActivityResult(
int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_CODE_CAMERA &&
resultCode == RESULT_OK) {
Bitmap bitmap = (Bitmap) data.getExtras().get("data");
}
}

79. @chiuki@chiuki
Intent Data
Intent data = new Intent();
data.putExtra("data", bitmap);
setResult(RESULT_OK, data);
finish();
protected void onActivityResult(
int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_CODE_CAMERA &&
resultCode == RESULT_OK) {
Bitmap bitmap = (Bitmap) data.getExtras().get("data");
}
}

80. @chiuki@chiuki
Result Code
Intent data = new Intent();
data.putExtra("data", bitmap);
setResult(RESULT_OK, data);
finish();
protected void onActivityResult(
int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_CODE_CAMERA &&
resultCode == RESULT_OK) {
Bitmap bitmap = (Bitmap) data.getExtras().get("data");
}
}

81. @chiuki@chiuki
Share intent
Intent intent = new Intent(Intent.ACTION_SEND);
intent.putExtra(Intent.EXTRA_SUBJECT, subject);
intent.putExtra(Intent.EXTRA_TEXT, message);
intent.setType("image/*");
Uri uri = Uri.fromFile(new File(path));
intent.putExtra(Intent.EXTRA_STREAM, uri);

82. @chiuki@chiuki
IntentFilter: Type
<activity android:name=".YourActivity">
<intent-filter>
<action android:name="android.intent.action.ACTION_SEND" />
<category android:name="android.intent.category.DEFAULT" />
<data android:mimeType="image/*" />
</intent-filter>
</activity>
AndroidManifest.xml
Intent intent = new Intent(Intent.ACTION_SEND);
intent.setType("image/*");

83. @chiuki@chiuki
Intent Data
String subject = intent.getStringExtra(Intent.EXTRA_SUBJECT);
String message = intent.getStringExtra(Intent.EXTRA_TEXT);
Uri imageUri = (Uri) intent.getParcelableExtra(Intent.EXTRA_STREAM);
YourActivity.java
Intent intent = new Intent(Intent.ACTION_SEND);
intent.putExtra(Intent.EXTRA_SUBJECT, subject);
intent.putExtra(Intent.EXTRA_TEXT, message);
intent.setType("image/*");
Uri uri = Uri.fromFile(new File(path));
intent.putExtra(Intent.EXTRA_STREAM, uri);

84. Beyond Activities

85. @chiuki@chiuki
Service BroadcastReceiver
ContentProvider Notification

86. @chiuki@chiuki
Service
Look ma, no UI!

87. @chiuki@chiuki
Service
Long-running

88. @chiuki@chiuki
BroadcastReceiver
Respond

89. @chiuki@chiuki
BroadcastReceiver
Respond
Battery low
Wifi connected
Incoming SMS
App installed
Screen off

90. @chiuki@chiuki
ContentProvider
Provide data to other apps

91. @chiuki@chiuki
ContentProvider
Provide data to other apps
Contacts
Images Music
Calendar

92. @chiuki@chiuki
ContentProvider
Internal data
(unless you need SQLite interface)

93. @chiuki@chiuki
Notification
Notify

94. @chiuki@chiuki
Notify

95. @chiuki@chiuki
Notification
Communicate with background Service

96. @chiuki@chiuki
Background Service

97. Case study

98. @chiuki
Email Outbox

99. @chiuki

100. @chiuki@chiuki
Notification

101. @chiuki@chiuki
AlarmService

102. @chiuki@chiuki
Connectivity change

103. Summary

104. @chiuki@chiuki
Summary
Hello World
Layouts
Resource Folders
Activity Lifecycle
Intents & Components
Case Study

105. @chiuki@chiuki
Thank you!
http://eepurl.com/lR5uD
http://blog.sqisland.com
http://twitter.com/chiuki