Android Bootcamp 2012

The definitive guide to understanding Android Application development. Check out the accompanying videos at http://shar.es/fxgx4

Transcript

1. Marko Gargenta marakana.com ANDROID   OVERVIEW  
2. About  Marko  Gargenta   Developer of Android Bootcamp for Marakana. Instructor for 1,000s of developers on Android at Qualcomm, Cisco, Motorola, DoD and other great orgs. Author of Learning Android published by O’Reilly. Speaker at OSCON (3x), ACM, IEEE, SDC, AnDevCon. Co-Founder of SFAndroid.org Co-Chair of Android Open conference: AndroidOpen.com
3. Agenda   •  Android  Then  &  Now   •  Android  versions   •  The  Stack   •  Opera<ng  System  Features   •  Hello  World!   •  Main  Building  Blocks   •  Architec<ng  an  App   •  Android UI •  Debugging & Logging •  Android  Security   •  Summary  
4. ANDROID  THEN  &  NOW  
5. History  and  Possible  Future   2005   Google  buys  Android,  Inc.   Work  on  Dalvik  starts   2007   Open  Handset  Alliance  announced   Early  SoOware  Development  Kit   2008-­‐2010   Android  becomes  the  dominant   mobile  plaTorm   2011   Games,  Tablets,  TVs   Future?   Beyond  phones  
6. Vision  for  Android   Our goal is not just a single device. Our vision is a mobile platform that runs on many many different devices. – Eric Schmidt
7. PlaTorm  Versions   Version   API  Level   Nickname   Android  1.0   1   Android   Android  1.1   2   Android   Android  1.5   3   Cupcake   Android  1.6   4   Donut   Android  2.0   5   Éclair   Android  2.01   6   Éclair   Android  2.1   7   Éclair   Android  2.2   8   FroYo   Android  2.3   9   Gingerbread   Android  2.3.3   10   Gingerbread   Android  3.x   11,  12,  13   Honeycomb   Android  4.0   14   Ice  Cream  Sandwich  
8. Version  Distribu<on   Source: Android.com
9. Historical  Distribu<on   Source: Android.com
10. Add-­‐Ons   TouchWiz   MotoBlur   SenseUI  
11. “With  Google”   Devices that have “with Google” add-on feature a set of Google’s proprietary applications, such as Maps, Gmail, Gtalk, and many others. OEMs and carriers typically enter into a licensing agreement with Google in order to distribute Google version of Android.
12. ANDROID  STACK  
13. The  Stack   Linux Kernel Libraries Application Framework Applications Home Contacts Phone Browser Other Activity Manager Window Manager Content Providers View System Package Manager Telephony Manager Resource Manager Location Manager Notiication Manager Surface Manager OpenGL SGL Media Framework FreeType SSL SQLite WebKit libc Android Runtime Core Libs Dalvik VM Display Driver Keypad Driver Camera Driver WiFi Driver Flash Driver Audio Driver Binder Driver Power Mgmt
14. Linux  Kernel   Android runs on Linux. Linux provides: Hardware abstraction layer Memory management Process management Networking Users never see Linux sub system The adb shell command opens Linux shell Linux Kernel Libraries Application Framework Applications Home Contacts Phone Browser Other Activity Manager Window Manager Content Providers View System Package Manager Telephony Manager Resource Manager Location Manager Notiication Manager Surface Manager OpenGL SGL Media Framework FreeType SSL SQLite WebKit libc Android Runtime Core Libs Dalvik VM Display Driver Keypad Driver Camera Driver WiFi Driver Flash Driver Audio Driver Binder Driver Power Mgmt Android™ Stack
15. Na<ve  Libraries   Pieces borrowed from other open source projects: Bionic, a super fast and small license-friendly libc library optimized for Android WebKit library for fast HTML rendering OpenGL for graphics Media codecs offer support for major audio/video codecs SQLite database Much more… Linux Kernel Libraries Application Framework Applications Home Contacts Phone Browser Other Activity Manager Window Manager Content Providers View System Package Manager Telephony Manager Resource Manager Location Manager Notiication Manager Surface Manager OpenGL SGL Media Framework FreeType SSL SQLite WebKit libc Android Runtime Core Libs Dalvik VM Display Driver Keypad Driver Camera Driver WiFi Driver Flash Driver Audio Driver Binder Driver Power Mgmt
16. Dalvik   Dalvik VM is Android implementation of Java VM Dalvik is optimized for mobile devices: •  Battery consumption •  CPU capabilities Key Dalvik differences: •  Register-based versus stack-based VM •  Dalvik runs .dex files •  More efficient and compact implementation •  Different set of Java libraries than JDK
17. Applica<on  Framework   The rich set of system services wrapped in an intuitive Java API. This ecosystem that developers can easily tap into is what makes writing apps for Android easy. Location, web, telephony, WiFi, Bluetooth, notifications, media, camera, just to name a few. Linux Kernel Libraries Application Framework Applications Home Contacts Phone Browser Other Activity Manager Window Manager Content Providers View System Package Manager Telephony Manager Resource Manager Location Manager Notiication Manager Surface Manager OpenGL SGL Media Framework FreeType SSL SQLite WebKit libc Android Runtime Core Libs Dalvik VM Display Driver Keypad Driver Camera Driver WiFi Driver Flash Driver Audio Driver Binder Driver Power Mgmt
18. Applica<ons   Dalvik Executable + Resources = APK Must be signed (but debug key is okay for development) Many markets with different policies
19. App  Distribu<on   •  One  of  the  markets   •  Side  loading   •  Internal  app  directory  
20. Markets   •  Google  Android  Market   •  Amazon  Android  Market   •  Other  emerging  markets  
21. Side  Loading  
22. Internal  App  Directory  
23. OPERATING  SYSTEM  FEATURES    
24. Mul<media   AudioPlayer lets you simply specify the audio resource and play it. VideoView is a View that you can drop anywhere in your activity, point to a video file and play it. XML: <VideoView android:id="@+id/video" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_gravity="center” /> Java: player = (VideoView) findViewById(R.id.video); player.setVideoPath("/sdcard/samplevideo.3gp"); player.start();
25. Supported  Media  Formats   Audio   AAC  LC/LTP,  HE-­‐AACv1  (AAC+),  HE-­‐ AACv2,  AMR-­‐NB,  AMR-­‐WB,  MP3,   MIDI,  RTTTL/RTX,  Ogg,  PCM/WAVE   Video   H.263,  H.264,  MPEG-­‐4,  VP8   Image   JPEG,  GIF,  PNG,  BMP   RTSP and HTTP progressive streaming. HTTP live streaming coming soon. More native support in the works. Native support available via Khronos OpenMax IL
26. Cloud  to  Device  Push   Big deal for many pull-based apps. Will make devices use less battery.
27. C2DM  –  The  Big  Picture  
28. Device  Administra<on   New in FroYo: Android Device Admin API. Administrator can set: Enable passwords Set password quality Max failed logins Prompt for new password Remotely wipe device data Lock the device App requests Device Admin permissions. If granted, admin policies apply. If not, app doesn’t work. Policies could be hard-coded or dynamic. Third-party enterprise solutions use this framework to build DM policies.
29. File  System   The file system has three main mount points. One for system, one for the apps, and one for whatever. Each app has its own sandbox easily accessible to it. No one else can access its data. The sandbox is in /data/data/com.marakana.yamba/ SDCard is expected to always be there. It’s a good place for large files, such as movies and music. Everyone can access it. System partition is where the entire Android operating system is, customized by OEM or not.
30. HELLO  WORLD!  
31. Android  SDK  -­‐  What’s  In  The  Box   SDK Tools Docs Platforms Data Skins Images Samples Add-ons Google
32. Create  New  Project   Use the Eclipse tool to create a new Android project. Here are some key constructs: Project   Eclipse  construct   Target   minimum  to  run   App  name   whatever   Package   Java  package   Ac<vity   Java  class  
33. Anatomy   of  An  App   Java Code + XML and Other Resources + Manifest File = Android App
34. Running  on  Emulator   Emulator, not a simulator
35. MAIN  BUILDING  BLOCKS  
36. Yamba  Demo   Let’s see a real-world medium complexity Android app in action: Yamba: Yet Another Micro Blogging App
37. Ac<vi<es   Android Application Main Activity Another Activity Another Activity An Activity represents a screen or a window. Sort of.
38. Ac<vity  Lifecycle   Activities have a well- defined lifecycle. The Android OS manages your activity by changing its state. You fill in the blanks.
39. Intents   Intents represent events or actions. They are to Android apps what hyperlinks are to websites. Sort of. Intents can be implicit or explicit.
40. Services   Services are code that runs in the background. They can be started and stopped. Services doesn’t have UI.
41. Service  Lifecycle   Service also has a lifecycle, but it’s much simpler than activity’s. An activity typically starts and stops a service to do some work for it in the background, such as play music, check for new tweets, etc. Services can be bound or unbound.
42. Remote  Services  
43. Content  Providers   Content Providers share content with applications across application boundaries. Examples of built-in Content Providers are: Contacts, MediaStore, Settings and more.
44. Content  Provider  Example  
45. Broadcast  Receivers   An Intent-based publish-subscribe mechanism. Great for listening system events such as SMS messages.
46. Architecture  of  An  App   An Android application is a collection of many different building blocks. They are loosely coupled and can be reconfigured by the developer easily, or at least that’s the intention. Let’s look at 7 stages of Yamba next.
47. Yamba  Part  1  
48. Yamba  Part  2  
49. Yamba  Part  3  
50. Yamba  Part  4  
51. Yamba  Part  5  
52. Yamba  Part  6  
53. Yamba  Part  7  
54. ANDROID  USER  INTERFACE  
55. Two  UI  Approaches   Procedural   DeclaraKve   You  write  Java  code   Similar  to  Swing  or  AWT   You  write  XML  code   Similar  to  HTML  of  a  web  page   You can mix and match both styles. Best practice: •  Start with XML and declare most of UI •  Switch to Java and implement the UI logic
56. XML-­‐Based  User  Interface   Use WYSIWYG tools to build powerful XML-based UI. Easily customize it from Java. Separate concerns.
57. Views  and  Layouts   Layouts contain widgets and other layouts forming a “composite” pattern.
58. Linear  Layout   One of the most commonly used layouts. It lays its children next to each other, either horizontally or vertically.
59. Rela<ve  Layout   Children of relative layout are placed in relationship to each other. This layout is efficient.
60. Table  Layout   Table layout puts its children into table rows and columns. It is similar to an HTML table.
61. Frame  Layout   Frame layout places its children on top of each other, like a deck of cards. It is useful for widgets such as tabs or as a placeholder for views added programmatically.
62. Common  UI  Components   Android UI includes many common modern UI widgets, such as Buttons, Tabs, Progress Bars, Date and Time Pickers, etc.
63. Selec<on  Components   Some UI widgets may be linked to zillion pieces of data. Examples are ListView and Spinners (pull-downs).
64. Adapters   To make sure they run smoothly, Android uses Adapters to connect them to their data sources. A typical data source is an Array or a Database. Data Source Adapter
65. Complex  Components   Certain high-level components are simply available just like Views. Adding a Map or a Video to your application is almost like adding a Button or a piece of text.
66. Menus  and  Dialogs  
67. Graphics  &  Anima<on   Android has rich support for 2D graphics. You can draw & animate from XML. You can use OpenGL for 3D graphics.
68. Mul<media   AudioPlayer lets you simply specify the audio resource and play it. VideoView is a View that you can drop anywhere in your activity, point to a video file and play it. XML: <VideoView android:id="@+id/video" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_gravity="center” /> Java: player = (VideoView) findViewById(R.id.video); player.setVideoPath("/sdcard/samplevideo.3gp"); player.start();
69. DEBUGGING     ANDROID  APPS  
70. LogCat   The universal, most versatile way to track what is going on in your app. Can be viewed via command line or Eclipse. Logs can be generated both from SDK Java code, or low-level C code via Bionic libc extension.
71. Debugger   Your standard debugger is included in SDK, with all the usual bells & whistles.
72. TraceView   TraceView helps you profile you application and find bottlenecks. It shows execution of various calls through the entire stack. You can zoom into specific calls.
73. Hierarchy  Viewer   Hierarchy Viewer helps you analyze your User Interface. Base UI tends to be the most “expensive” part of your application, this tool is very useful.
74. ANDROID   SECURITY  
75. Security  Overview   No app can adversely impact other apps, user, or OS Cannot read/write user’s private data Cannot read other app’s data Cannot perform network access Cannot keep device awake, and so on Each application is its own sandbox To share resources, apps need to request permissions User must grant permissions at install time Linux manages security Not up to Dalvik (Java) but outsourced to Linux Native code (NDK) also adheres to sandboxing
76. Applica<on  Sandboxing   An application is an island on its own. It contains any number of Activities, Services, Receivers and Providers. It has its own file system, database, place to store native libraries. No other app can access any of its data without prior permission.
77. Permissions   A component that does something potentially dangerous can require callers to have permission to access it. App that wants to use it must have user grant it permission. Permissions are granted at install time. All or nothing. Forever.
78. Some  System  Permissions   ACCESS_COARSE_LOCATION   ACCESS_FINE_LOCATION   ACCESS_NETWORK_STATE   ACCESS_WIFI_STATE   BATTERY_STATS   BLUETOOTH   CALL_PHONE   CALL_PRIVILEGED   CAMERA   DEVICE_POWER   GET_ACCOUNTS   GET_TASKS   INSTALL_PACKAGES   INTERNET   KILL_BACKGROUND_PROCESSES   NFC   READ_CALENDAR   READ_CONTACTS   RECEIVE_SMS   RECORD_AUDIO   WRITE_EXTERNAL_STORAGE   WRITE_SETTINGS  
79. Summary   Android is open and complete system for mobile development. It is based on Java and augmented with XML. It takes about 3-5 days of intensive training to learn Android application development for someone who has basic Java (or similar) experience. Marko Gargenta, Marakana.com marko@marakana.com +1-415-647-7000