Java で書かれた Android アプリを Kotlin で書き直すまでの話 / Talk of rewrite Android app for Java to Kotlin

集まれ Kotlin 好き ! Kotlin 愛好会 vol 2 @ DeNA

Transcript

1. +BWB
   Ͱॻ͔Εͨ
   "OESPJE
   ΞϓϦΛ
 ,PUMJO
   Ͱॻ͖௚͢·Ͱͷ࿩ ू·Ε
   ,PUMJO
   ޷͖
   
   ,PUMJO
   Ѫ޷ձ
   WPM
   
2. ٶԼ
   ཽେ࿠ $IBU8PSL
   גࣜձࣾ ΫϥΠΞϯτΞϓϦέʔγϣϯ։ൃ෦ !SZVHPP@ ޷͖ͳ
   ,PUMJO
   ͷػೳ͸
   4NBSU
   $BTU
3. $IBU8PSL
4. $IBU8PSL ‣ Ϗδωε޲͚ͷνϟοταʔϏε
    8FC
   
   J04
   
   "OESPJE
   
   σεΫτοϓΞϓϦͰఏڙ
    "OESPJE
   ΞϓϦ͸
   
   ೥຤͔Β
   +BWB
   ੡
   ‣ 
   ʙ
   
   ·Ͱ͸
   5JUBOJVN
   +BWB4DSJQU
   ੡ͩͬͨ
   ‣ +BWB
   ൛͸
   
   
   
   ͔Β։ൃΛ։࢝
   ‣ ,PUMJO
   Λݕ౼͢ΔͨΊʹ
   
   
   
   ͷ
   ,PUMJO
   ษڧձʹࢀՃ
   ‣ ࠾༻ڧԽத
    J04
   
   "OESPJE
   
   4DBMB
   
   1)1
   
   43&
   ͳͲ
    ৄ͘͠͸
   8FC
   αΠτͰ
   ‣ IUUQTDPSQDIBUXPSLDPNKBSFDSVJU
   ‣ ؾʹͳΔ͜ͱ͕͋ͬͨΒ੠͔͚ͯԼ͍͞
5. ,PUMJO
6. ,PUMJO ‣ (PPHMF
   *0
   
   Ͱ
   "OESPJE
   ެࣜݴޠԽ
    ͦΕ·Ͱ΋
   ,PUMJO
   ͷ։ൃࣄྫ͸ଟ͋ͬͨ͘
    ެࣜݴޠʹͳΔ͜ͱͰ҆৺ΛखʹೖΕͨ
    طଘͷΞϓϦͱͷ෇͖߹͍ํΛͲ͏͢Δ͔ʁ
   ‣ ෦෼తʹಋೖ
   PS
   શ໘తʹಋೖ
    ͜Εͱ͍ͬͨਖ਼ղ͸ͳ͍
    ৽نϓϩδΣΫτͳΒ͹
   ,PUMJO
   Ͱྑ͍
    $IBU8PSL
   Ͱ͸શ໘తͳಋೖΛܾఆͨ͠
7. Ͳ͔͜Β ‣ ಋೖ౰ॳ͸શ໘తͳಋೖ༧ఆ͸ͳ͔ͬͨ
    খ͞ͳμΠΞϩά
   
   ͔ͭΒಋೖΛ։࢝
   ‣ (PPHMF
   *0
   
   ͷཌ೔͔Βελʔτ
    ࣍ʹطଘͷը໘Λ
   
   ͭॻ͖׵͑ͯΈͨ
    ৽͍͠ػೳͷ௥ՃΛ
   ,PUMJO
   Ͱॻ͍ͯΈͨ
   ‣ +BWB
   ͱͷͭͳ͗ࠐΈ͕ωοΫʹͳ͍ͬͯͬͨ
    ͔֬ʹ
   ,PUMJO
   ͸
   +BWB
   ͱͷ࿈ܞ͸όονϦͰ͖Δ
    ͏·͘࿈ܞ͢Δʹ͸ಛผͳҙࣝ෇͚͕ඞཁ
   ‣ !+WN'JFME
   
   !+WN4UBUJD
   
   !+WN0WFSMPBET
   ‣ SFUVSO
   6OJU*/45"/$&
   ‣ 1MBUGPSN
   5ZQFT
8. !+WNʙΞ ϊςʔγϣϯ ‣ +BWB
   ͔ΒͷΞΫηεΛҙࣝ͢Δඞཁ͕͋Δ class MyFragment : Fragment() { companion object { @JvmField val TAG: String = MyFragment::class.java.simpleName } @JvmOverloads fun logic(label: String = "") {} } ,PUMJO
9. SFUVSO
   6OJU*/45"/$& ‣ ,PUMJO
   ʹ͸
   lWPJEz
   ͸ଘࡏ͠ͳ͍ class BusinessLogic { fun async(callback: () -> Unit) { // Some async logic callback(); } } BusinessLogic logic = new BusinessLogic(); logic.async(() -> { return Unit.INSTANCE; }); ,PUMJO +BWB
10. IUUQTEJTDVTTLPUMJOMBOHPSHUKBWBJOUFSPQVOJUDMPTVSFTSFRVJSFEUPSFUVSOLPUMJOVOJU !+WN7PJE
    ͷఏҊ 
    ೥ʹಉ͡໰୊ఏى
11. 1MBUGPSN
    5ZQFT ‣ /PO/VMM
    ͔
    /VMMBCMF
    ͔એݴ͞Ε͍ͯͳ͍ܕ
     ܕ৘ใΛݟΔͱ
    lz
    ϚʔΫ͕෇͍͍ͯΔ
    ‣ "OESPJE
    4%,
    ͸جຊతʹ
    1MBUGPSN
    5ZQFT
    ‣ !/PO/VMM
    
    !/VMMBCMF
    ͕෇͍ͯͨΒϥοΩʔ
12. 1MBUGPSN
    5ZQFT ‣ "OESPJE
    4%,
    Ͱ͋Ε͹ίʔυΛಡΜͰܕΛܾఆ͢Δ val inflater: LayoutInflater = LayoutInflater.from(this) ,PUMJO
13. ,PUMJO
    ͷ͏·ຯΛ
    
    Ҿ͖ग़͍ͨ͠ ‣ ,PUMJO
    Λ෦෼తʹಋೖ͢Δͱ
    +BWB
    ʹ΋Өڹ͕ग़Δ
     ٯʹ
    +BWB
    ͷ࣮૷͕
    ,PUMJO
    ʹ΋Өڹ͢Δ
    ‣ +BWB
    
    0QUJPOBM
    WT
    ,PUMJO
    /PO/VMM
    
    /VMMBCMF
    5ZQF
     ࣗ෼ୡ͕ॻ͍ͨ
    +BWB
    ͷίʔυΛݟฦ͢
    ‣ !/PO/VMM
    
    !/VMMBCMF
    Ξ ϊςʔγϣϯΛ෇͚͍ͯ͘ʁ
    ‣ ͍ͬͦͷ͜ͱ
    ,PUMJO
    ʹஔ͖׵͑ͨํ͕ྑ͍ͷͰ͸ͳ͍͔ʁ
    ‣ 
    ͭͣͭஸೡʹ
    ,PUMJO
    ԽΛਐΊ͍ͯ͘
     
    ਓͷνʔϜ಺Ͱ΋
    ,PUMJO
    ͷशख़౓͸όϥόϥ
     ૬ޓʹϨϏϡʔΛ͠ͳ͕ΒཧղΛਂΊ͍ͯ͘
     1VMM
    3FRVFTU
    ʹ
    ,PUMJO
    ͷݴޠػೳͷઆ໌Λॻ͘
14. ,PUMJO
    ͷ͏·ຯΛҾ͖ग़͢ಓఔ  (PPHMF
    *0
    b  $IBU8PSL
    "OESPJE
 7FSTJPO
    
    'VMM
    +BWB
    
     
    ߦ  $IBU8PSL
    "OESPJE
 7FSTJPO
    
    'VMM
    ,PUMJO
    
     
    ߦ Ի੠௨࿩ "OESPJE
      
    ߦ
15. ,PUMJO
    ͷ͏·ຯΛҾ͖ग़ͨ݁͠Ռ ‣ ϲ݄ͰશͯͷίʔυΛ
    ,PUMJO
    Խͨ͠
     ͦͷؒʹػೳ௥Ճ΍ϦϑΝΫλϦϯά΋Ͱ͖ͨ
     ,PUMJO
    ԽલޙͰίʔυͷྔ͸
    
    ʹͳͬͨ
    ‣ νʔϜ΁ͷਁಁͱޮՌ
     /VMM1PJOUFS&YDFQUJPO
    ͷ๾໓
    ‣ ΄΅ग़ձ͍ͬͯͳ͍
    ‣ 1MBUGPSN
    5ZQFT
    ͷऔΓѻ͍͕పఈ͞Εͨ
    ‣ +BWB
    ͷ
    0QUJPOBM
    ΑΓ΋औΓѻָ͍͕
     ίʔυͷՄಡੑͷ޲্
    ‣ جຊ͸
    WBM
    Ͱڱ͍ൣғͰ
    WBS
    Λ࢖͏ͳͲͷҙࣝ෇͚
16. ,PUMJO
    ͷ͏·ຯΛ
    
    Ҿ͖ग़ͨ͢Ίʹ ‣ ,PUMJO
    ଆͷ࣮૷΋ݟͨํ͕ྑ͍
     ྫ͑͹
    NBQ
    ˠ
    UP-JTU
    ͷྲྀΕ
    ‣ +BWB
    
    ͷ
    4USFBN
    Λ࢖ͬͯΔͱ͍ͭ΍Γͨ͘ͳΔ
    ‣ ࣮ࡍ͸
    NBQ
    ͷ࣌఺Ͱ
    -JTU3
    ͕ಘΒΕΔ val results: List<R> = someCollection .map { it.convert() } .toList() ,PUMJO
17. ,PUMJO
    ͷ͏·ຯΛ
    
    Ҿ͖ग़ͨ͢Ίʹ ‣ 4IPX
    ,PUMJO
    #ZUFDPEF
    ˠ
    %FDPNQJMF
    ͢Δ val source = listOf(1, 2, 3, 4, 5) val results: List<String> = source .map { it.toString(10) } ,PUMJO UP-JTU
    ແ UP-JTU
    ༗
18. ,PUMJO
    ͷ͏·ຯΛҾ͖ग़͠ଛͶͨࣄྫ ‣ ,PUMJOͱ
    "OESPJE
    +%,
    ͷ
    "1*
    ͕ಉ໊͡લ ‣ ਖ਼ղ͸
    
    ൪Լͷ
    GPS&BDI
    Ͱͨ͠ʂ
     
    ൪Լ͸
    LPUMJODPMMFDUJPOTGPS&BDI
    ‣ .BQ
    ͷ֦ுؔ਺ͱͯ͠ఆٛ͞Ε͍ͯΔ
     ্͔Β
    
    ͭΊ͸
    KBWBVUJM.BQGPS&BDI
    ‣ "OESPJE
    Ͱ࢖͑ΔΑ͏ʹͳͬͨͷ͸
    -W
    ͔Β
    ‣ /P$MBTT%FG'PVOE&SSPS
    ͕ൃੜͨ͠
19. ࠷ޙʹ
20. ࠷ޙʹ ‣ طଘͷΞϓϦ΋ஈ֊తʹ
    ,PUMJO
    Խ͍͚ͯ͠Δ
    ͨ
     +BWB
    ͱͷ૬ޓӡ༻ੑͷߴ͞
    ‣ த్൒୺ʹಋೖ͢Δ͙Β͍ͳΒ͹શͯॻ͖׵͍͑ͨ
     +BWB
    ͱ
    ,PUMJO
    ؒͰͦΕͧΕΛҙࣝ͢Δखؒ
    ‣ ਓखͰؾΛ͚ͭͳ͍ͱ͍͚ͳ͍Օॴ͸ඞͣࣄނ͕ੜ·ΕΔ
    ‣ ଞνʔϜ͔Βݟͨ৺ཧతোน͕Լ͕ͬͨ
     ෭࣍తͳޮՌ
    ‣ J04
    νʔϜ͕
    ,PUMJO
    ͷίʔυΛಡΜͰ
    4XJGU
    ʹҠ২
    ‣ 4DBMB
    ؚ
    4DBMB+4
    
    5ZQF4DSJQU
    ࢖͍΋༰қʹಡΊΔ
21. ͓͠·͍