Programming Android Application in Scala @ OSDC.tw 2010

Transcript

1. Programming Android Application in Scala BrianHsu / OSDC.2010

2. 關於我

3. 墳墓 (BrianHsu)

4. 表面上 軟體工程師

5. 實際上 萌系阿宅

6. 用 萌 化 的 手 機 入 侵 藍 星

   是 也

7. 寫 Android 萌 程 式

   是 燃 的 我 最 喜 歡 女 僕 了 ! 我 要 讓 手 上 機 全 都 是 女 僕 !

8. 用 Java 寫程式卻燃不起來

9. 高手大師兄

10. 聽說高手都要精通 Multiple Language......

11. ASE+Ruby/Python/Perl

12. 寫作 Dynamic Scripting Language

13. 唸作 快、狠、準

14. 等等

15. 還要先裝 Runtime 啊?

16. 等等

17. 動態型別?

18. 執行期爆炸 def boom puts "Hello World" end puts " 一個小小的

    typo" booom

19. 結論

20. 我是懦夫 不敢用 ASE

21. None

22. What is Scala?

23. 樓 梯

24. A Postfunctional Programming Language on Java Virtual Machine

25. Compile to JVM .class Byte Code

26. 理論上 Full Java Interoperability

27. 可以直接拿來寫 Android Application

28. What is Scala?

29. A Scalable Language

30. 會隨 User 變形的程式語言

31. A Scalable Language

32. A Scalable Language

33. Why Scala?

34. None

35. 三個願望一次滿足

36. REPL Scripting Compiling

37. REPL

38. Scripting

39. Compiling

40. 三個願望一次滿足

41. Procedure Object Oriented Functional

42. Procedure Programming

43. Object Oriented Programming

44. Functional Programming

45. 三個願望一次滿足

46. Concise Static Typing Duck Typing

47. Concise (Ruby)

48. Concise (Scala)

49. Static Typing (Ruby)

50. Static Typing (Scala)

51. 真、 Duck Typing (Ruby)

52. 偽‧ Duck Typing (Scala)

53. 結論

54. 有 Scala 、無懦夫

55. 用 Scala 寫 萌 程 式

    是 燃 的 我 最 喜 歡 女 僕 了 ! 我 要 讓 手 上 機 全 都 是 女 僕 !

56. Scala vs Java

57. Scala compared to Java Scala adds Scala removes + a

    pure object system - static members + operator overloading - primitive types + closures - break, continue + mixin composition with traits - special treatment of interfaces + existential types - wildcards + abstract types - raw types + pattern matching - enums Modeled in libraries: assert, enums, properties, events, actors, using, queries, ...

58. Scala cheat sheet (1): Definitions Scala method definitions: def fun(x:

    Int): Int = { result } def fun = result Scala variable definitions: var x: Int = expression val x: String = expression Java method definition: int fun(int x) { return result } (no parameterless methods) Java variable definitions: int x = expression final String x = expression

59. Scala cheat sheet (2): Expressions Scala method calls: obj.meth(arg) obj

    meth arg Scala choice expressions: if (cond) expr1 else expr2 expr match { case pat 1 => expr 1 .... case pat n => expr n } Java method call: obj.meth(arg) (no operator overloading) Java choice expressions, stmts: cond ? expr1 : expr2 if (cond) return expr1; else return expr2; switch (expr) { case pat 1 : return expr 1 ; ... case pat n : return expr n ; } // statement only

60. Scala cheat sheet (3): Objects and Classes Scala Class and

    Object class Sample(x: Int, val p: Int) { def instMeth(y: Int) = x + y } object Sample { def staticMeth(x: Int, y: Int) = x * y } Java Class with statics class Sample { private final int x; public final int p; Sample(int x, int p) { this.x = x; this.p = p; } int instMeth(int y) { return x + y; } static int staticMeth(int x, int y) { return x * y; } }

61. Scala cheat sheet (4): Traits Scala Trait trait T {

    def abstractMth(x: String): Int def concreteMth(x: String) = x + field var field = "!" } Scala mixin composition: class C extends Super with T Java Interface interface T { int abstractMth(String x) } (no concrete methods) (no fields) Java extension + implementation: class C extends Super implements T

62. 當機器人爬上樓梯

63. Android Application 開發流程

64. Java / ANT

65. $ android create project -p ... $ vim ..... $

    ant install

66. http://asantoso.wordpress.com/2009/09/15/how-to-build-android-application-package- apk-from-the-command-line-using-the-sdk-tools-continuously-integrated-using- cruisecontrol/

67. http://asantoso.wordpress.com/2009/09/15/how-to-build-android-application-package- apk-from-the-command-line-using-the-sdk-tools-continuously-integrated-using- cruisecontrol/

68. How?

69. XML 地獄 ANT

70. Perfect SBT

71. Simple Build Tool

72. 以 Scala 為 Host Language

73. Rake=>Ruby SBT =>Scala

74. 不用任何設定 支援連續編譯

75. Android-Plugin

76. android-plugin http://github.com/jberkel/android-plugin project/build/MyProject.scala

77. android-plugin

78. 我不會用 功能完整

79. 阿宅的通病 自己寫一個

80. sbt-android project/build/MyProject.scala

81. sbt-android project/plugins/Plugins.scala

82. Live Demo

83. Install SBT/SBT-Android • Install SBT • http://code.google.com/p/simple-build-tool/ • Download SBT-Android

    • $ git clone http://github.com/brianhsu/sbt-android.git • Install SBT-Android • $ cd sbt-android • $ sbt publish-local

84. Create Android/Scala Project • Create SBT project • $ mkdir

    AndroidTest • $ cd AndroidTest • $ sbt • Edit project/build/MyProject.scala • Edit project/plugins/Plugins.scala • $ sbt update

85. Android/Scala Project Struture

86. Build Scala/Android Project • $ sbt action • $ sbt

    install • $ sbt android-compile • $ sbt proguard • $ sbt zipalign • $ ...

87. Scala in Android

88. Trait 是好幫手

89. SQL 再見! Collection 最高!

90. 善用偽 Duck Typing

91. 結論 可以把 Java 丟了......應該唄?

92. 等等,這是孔明的陷阱!

93. Scala 的限制與臭蟲 • 限制 • Cannot acess static protected Java

    field. – 對不起, Google Maps API 用到了。 • 臭蟲 • Static Java Inner class 造成 classfile borken / missing dependcy – Google Maps API 踩到地雷了 • Cyclic dependcy – Google Data API 中計了 – 以於 Scala 2.8 main trunk 中修正 • 解決方式 • 用 Java 寫個 Wrapper 唄 Missing dependency

94. Thanks!