Ankoは甘くて美味しい〜Ankoに見るKotlinの表現力〜 #gunosybeer

エムスリー x Gunosy Beer bash！で発表した資料です

Transcript

1. Anko͸؁ͯ͘ඒຯ͍͠ ʙAnkoʹݟΔKotlinͷදݱྗʙ 
   ΤϜεϦʔ
   Y
   (VOPTZ
   #FFS
   CBTIʂ
   HVOPTZCFFS
   
 ௕ᖒ
   ଠ࿠
   !OHTX@UBSP
2. ࣗݾ঺հ w ௕ᖒ
   ଠ࿠
   !OHTX@UBSP
   w "OESPJEΤϯδχΞ
   w ,PUMJOΤϰΝϯδΣϦετ
   ࣗশ
   w ࡀɺֈ࠲ɺͱ͕େ޷͖
3. Kotlinͱ͸ w +FU#SBJOT։ൃͷ+7.ݴޠ
   w "OESPJE΋αϙʔτ
   w ೥ൃදɺ·ͩϕʔλ൛
   w "OESPJE
   +BWB͔Β,PUMJO৐Γ׵͑ϫϯνϟϯ
   w ࠷ۙɺ঺հهࣄ͕ཚཱͯ͠ΔͷͰͦͪΒࢀর
4. Ankoͱ͸ w ,PUMJOͰهड़͞Εͨ"OESPJEϥΠϒϥϦ
   w +FU#SBJOT։ൃʢઆಘྗɾ҆৺ײ͕͋Δʣ
   w ओʹ6*Λ૊ΈཱͯΔ%4-
5. UIΛ૊ΈཱͯΔDSL w جຊతʹ"OESPJEͰ͸9.-Ͱ6*Λදݱ͢Δ
   w ࠶ར༻ੑɺ҆શੑɺύϑΥʔϚϯεͷ໘Ͱෆར
   w ͱ͸͍͑ίʔυͰ໋ྩతʹ6*Λߏங͢Δͷμα Πʢ4XJOHΈ͍ͨͳΠϝʔδʣ
   w %4-Ͱએݴతʹ6*Λߏங͢Δ
 ʢ+BWB'9
   4DSJQUΈ͍ͨͳΠϝʔδʣ
6. ඪ४APIͰΰϦΰϦ΍Δ val act = this! val layout = LinearLayout(act)! layout.orientation = LinearLayout.VERTICAL! val name = EditText(act)! val button = Button(act)! button.text = "Say Hello"! button.setOnClickListener {! Toast.makeText(act,! "Hello, ${name.text}!”,! Toast.LENGTH_SHORT).show()! }! layout.addView(name)! layout.addView(button)
7. AnkoͰDSL verticalLayout {! val name = editText()! button("Say Hello") {! onClick {! toast("Hello, ${name.text}!”)! }! }! }
8. Ͳ͏ಈ͍͍ͯΔͷ͔ There is no .
9. ϥϜμࣜ Lambda Expression
10. ߴ֊ؔ਺ͱϥϜμࣜ // Ҿ਺ʹAΛऔͬͯBΛฦؔ͢਺fΛҾ਺ʹऔΔؔ਺! fun <A, B> convert(target: A,! f: (A)->B) = f(target)! ! convert(1, { x: Int -> x * 2 }) //=> 2! convert(2, { x -> x * 2}) //=> 4! convert(3, { it * 2 }) //=> 6! convert(4) { it * 2 } //=> 8
11. ֦ுؔ਺ Extension Function
12. ֦ுؔ਺ fun String.hello() = “Hello, $this”! ! “world”.hello() //=> “Hello, world”
13. ֦ுؔ਺ × ϥϜμࣜ fun <A, B> A.convert(f: (A)->B) = f(this)! ! 3.convert({ x: Int -> x * 2}) //=> 6! 3 convert { it * 2 } //=> 6
14. Anko class MainActivity : Activity() {! override fun onCreate(savedInstanceState: Bundle?) {! super.onCreate(savedInstanceState)! ! verticalLayout {! val name = editText()! button("Say Hello") {! onClick { toast("Hello, ${name.text}!") }! }! }! }! }
15. Anko class MainActivity : Activity() {! override fun onCreate(savedInstanceState: Bundle?) {! super.onCreate(savedInstanceState)! ! verticalLayout {! val name = editText()! button("Say Hello") {! onClick { toast("Hello, ${name.text}!") }! }! }! }! } "DUJWJUZͷ֦ுؔ਺
    UIJT͕লུ͞ΕͯΔ
16. Anko class MainActivity : Activity() {! override fun onCreate(savedInstanceState: Bundle?) {! super.onCreate(savedInstanceState)! ! verticalLayout {! val name = editText()! button("Say Hello") {! onClick { toast("Hello, ${name.text}!") }! }! }! }! } ͜ͷUIJT͸
    WFSUJDBM-BZPVU
17. Anko class MainActivity : Activity() {! override fun onCreate(savedInstanceState: Bundle?) {! super.onCreate(savedInstanceState)! ! this.verticalLayout {! val name = this.editText()! this.button(“Say Hello") {! onClick { toast("Hello, ${name.text}!") }! }! }! }! } UIJT͕ผͷ΋ͷΛࢦ͢
    Կނ͔ʁ
18. ֦ுؔ਺ΛҾ਺ʹऔΔߴ֊ؔ਺ class Builder { fun foo() {} }! ! fun build(f: Builder.() -> Unit) {! Builder().f()! }! ! build {! foo()! }
19. Կ͕خ͍͠ͷ͔ verticalLayout {! button(“foo”)! verticalLayout {! button(“bar”)! verticalLayout {! button(“baz”)! }! }! }
20. Կ͕خ͍͠ͷ͔ verticalLayout {! button(“foo”)! verticalLayout {! button(“bar”)! verticalLayout {! button(“baz”)! }! }! } ֊૚ߏ଄ΛදݱͰ͖Δ ϝιουͷείʔϓ ΛߜΕΔ ܕ҆શ
    OVMM҆શ
21. XMLͰฤू͢Δͱ ը໘ϓϨϏϡʔ ݟΕΔ͡ΌΜʁ
23. ͦΕɺAnkoͰ΋ Ͱ͖·͢ʂ
25. ࢖Θͳ͍ख͸ͳ͍
26. ͝ਗ਼ௌ͋Γ͕ͱ͏͍͟͝·ͨ͠