Delegated propertyで Android開発をもっと便利に @ Gunosy Beer Bash #12

Library list introduced in this presentation
- KotterKnife https://github.com/JakeWharton/kotterknife
- Kotpref https://github.com/chibatching/Kotpref
- Kodein https://github.com/SalomonBrys/Kodein
- remote-konfig https://github.com/chibatching/remote-konfig

Transcript

1. %FMFHBUFE
   QSPQFSUZͰ
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2. w ઍ༿ོ༤
   !DIJCBUDIJOH
   w גࣜձࣾτΫόΠ
   w "OESPJE
   ΤϯδχΞ ࣗݾ঺հ
3. w /VMM҆શ
   w ֦ுؔ਺
   w WBSWBM ,PUMJOͱ͍͑͹ʁ
4. w /VMM҆શ
   w ֦ுؔ਺
   w WBSWBM
   w %FMFHBUFE
   1SPQFSUZ ,PUMJOͱ͍͑͹ʁ
5. %FMFHBUFE
   1SPQFSUZ
6. w ϓϩύςΟͷHFUUFSTFUUFSॲཧΛ ผͷΫϥεΦϒδΣΫτʹҕৡͰ͖Δ ࢓૊Έ
   w CZΩʔϫʔυͰҕৡઌΛࢦఆ͢Δ %FMFHBUFE
   1SPQFSUZ
7. ҕৡ͢Δଆ var foo1: String by Foo() var foo2: String by getFoo() fun getFoo() = Foo() fun main(vararg args: String) { var foo2: String by getFoo() } CZͷޙΖʹҕৡઌͷ
   ΫϥεΠϯελϯε
8. ҕৡ͢Δଆ var foo1: String by Foo() var foo2: String by getFoo() fun getFoo() = Foo() fun main(vararg args: String) { var foo2: String by getFoo() } CZͷޙΖʹҕৡઌͷ
   ΫϥεΠϯελϯε ҕৡઌΛฦ͢
   ؔ਺Ͱ΋Մ
9. ҕৡ͞ΕΔଆ var foo1: String by Foo() var foo2: String by getFoo() fun getFoo() = Foo() fun main(vararg args: String) { var foo2: String by getFoo() } CZͷޙΖʹҕৡઌͷ
   ΫϥεΠϯελϯε ҕৡઌΛฦ͢
   ؔ਺Ͱ΋Մ ,PUMJO
   ͔Β͸
   ϩʔΧϧม਺Ͱ΋ར༻Մೳʹʂ
10. ҕৡ͞ΕΔଆ class Foo { operator fun getValue(thisRef: Any?, property: KProperty<*>): String { return "get value through delegation" } operator fun setValue(thisRef: Any?, property: KProperty<*>, value: String) { Log.d(TAG, "set value $value through delegation") } }
11. ҕৡ͞ΕΔଆ class Foo { operator fun getValue(thisRef: Any?, property: KProperty<*>): String { return "get value through delegation" } operator fun setValue(thisRef: Any?, property: KProperty<*>, value: String) { Log.d(TAG, “set value $value through delegation") } } HFU7BMVF
    TFU7BMVF
    PQFSBUPSΛ࣮૷
12. ҕৡ͞ΕΔଆ class Foo : ReadWriteProperty<Any?, String> { override fun getValue(thisRef: Any?, property: KProperty<*>): String { return "get value through delegation" } override fun setValue(thisRef: Any?, property: KProperty<*>, value: String) { Log.d(TAG, "set value $value through delegation") } } ΠϯλʔϑΣʔεΛ
    ࣮૷͢Δͱগָ͠
13. HFUUFSTFUUFSͷ
    ΧελϚΠζͱԿ͕ҧ͏ͷʁ
14. %FMFHBUFE
    QSPQFSUZ class Foo { operator fun getValue(thisRef: Any?, property: KProperty<*>): String { return "get value through delegation" } operator fun setValue(thisRef: Any?, property: KProperty<*>, value: String) { Log.d(TAG, “set value $value through delegation") } }
15. HFUUFSTFUUFS var foo: String get() = "get value through getter" set(value) { Log.d(TAG, "set value $value through delegation") }
16. HFUUFSTFUUFS
    ࣮૷ͷ΄͏͕ѹ౗తʹ؆୯
17. %FMFHBUFE
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    1SPQFSUZΛ࢖͏΂͖৔໘
19. ڞ௨Խͯ͠੾Γग़ͯ͠
    ҕৡݩ΍ϓϩύςΟͷ৘ใ͕
    Θ͔Βͳ͘ͳΒͳ͍ʁ
20. w ҕৡݩΫϥεͷऔಘɾ੍ݶ
    w ϓϩύςΟͷϝλσʔλࢀর %FMFHBUF
    1SPQFSUZͰͰ͖Δ͜ͱ
21. ϓϩύςΟͷϝλσʔλ class Foo { operator fun getValue(thisRef: Any?, property: KProperty<*>): String { return "get value through delegation" } operator fun setValue(thisRef: Any?, property: KProperty<*>, value: String) { Log.d(TAG, "set value $value through delegation") } } 
    ҕৡݩͷϓϩύςΟ͕ଐ͢ΔΫϥε
    
    ܕͰ੍ݶ͢Δ͜ͱ΋Մೳ
22. ϓϩύςΟͷϝλσʔλ class Foo { operator fun getValue(thisRef: Any?, property: KProperty<*>): String { return "get value through delegation" } operator fun setValue(thisRef: Any?, property: KProperty<*>, value: String) { Log.d(TAG, "set value $value through delegation") } } ҕৡݩͷϓϩύςΟͷ
    ϝλσʔλΛࢀরՄೳ
23. ϓϩύςΟͷϝλσʔλ class Bar { … operator fun provideDelegate(thisRef: Any?, property: KProperty<*>): ReadOnlyProperty<Any?, T> { return this } } ,PUMJO
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24. ϓϩύςΟͷϝλσʔλ class Sample { var bar: String by Bar() } ΫϥεͷΠϯελϯεΛ
    ੜ੒ͨ͠ஈ֊ͰϓϩύςΟͷ৘ใΛ
    ಘΒΕΔΑ͏ʹͳͬͨ
25. w HFUUFSTFUUFSͷΧελϚΠζͰ
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 ϥΠϒϥϦΛ༗ޮ׆༻͢Δ %FMFHBUFE
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26. "OESPJEͰ
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27. ඪ४ϥΠϒϥϦ
28. MB[Z
29. w ϓϩύςΟʹॳΊͯΞΫηεͨ࣌͠ʹ ϒϩοΫͷ಺༰Λ࣮ߦ
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31. MB[Z var param: String? = null override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) param = intent.getStringExtra("param") Log.d(TAG, param) } ,PUMJOͷϓϩύςΟ͸
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32. lateinit var param: String override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) param = intent.getStringExtra("param") Log.d(TAG, param) } MB[Z MBUFJOJUͰॳظ஋ෆཁʹͰ͖Δ
33. lateinit var param: String override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) param = intent.getStringExtra("param") Log.d(TAG, param) } MB[Z Ͱ΋Ұ౓୅ೖͨ͠Βมߋ͢Δඞཁ͕
    ͳ͍ͷʹWBSʹ͢Δͷ͸ؾ࣋ͪѱ͍ʜ
34. val param: String by lazy { intent.getStringExtra("param") } override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) Log.d(TAG, param) } MB[Z Πϯελϯεੜ੒࣌ʹ͸࣮ߦ͞Εͳ͍ WBMͰએݴ
35. val param: String by lazy { intent.getStringExtra("param") } override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) Log.d(TAG, param) } MB[Z ࠷ॳʹΞΫηεͨ࣌͠ʹॳΊͯॳظԽ
36. w ϥΠϑαΠΫϧʹ஫ҙ͕ඞཁ
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37. PCTFSWBCMF
    
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38. w ϓϩύςΟͷมߋΛݕ஌
    w WFUPBCMFͰ͸มߋΛड͚ೖΕΔ͔
 ൑ఆ͢Δ͜ͱ͕Ͱ͖Δ PCTFSWBCMF
    
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39. w XBZ
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40. w &EJU5FYUʹԿ͔ೖྗ͞Ε͍ͯͨΒ
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41. PCTFSWBCMF
    
    WFUPBCMF class ViewModel { var inputText: String by Delegates.observable("") { property, oldValue, newValue -> buttonEnabled.set(newValue.isNotEmpty()) } var buttonEnabled = ObservableBoolean(false) } ςΩετ͕ۭͰͳ͚Ε͹ϘλϯΛ༗ޮʹ͢Δ
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42. PCTFSWBCMF
    
    WFUPBCMF class ViewModel { var inputText: String by Delegates.observable("") { property, oldValue, newValue -> buttonEnabled.set(newValue.isNotEmpty()) } val buttonEnabled = ObservableBoolean(false) } Ϙλϯͷ༗ޮແޮΛ%BUB#JOEJOHʹ௨஌͢Δ
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43. PCTFSWBCMF
    
    WFUPBCMF <layout> <data> <variable name="viewModel" type="com.example.ViewModel"/> </data> <LinearLayout android:orientation="vertical"> <EditText android:hint="Please input some text" android:text="@={viewModel.inputText}" /> <Button android:enabled="@{viewModel.buttonEnabled}" android:text="Send" /> </LinearLayout> </layout>
44. PCTFSWBCMF
    
    WFUPBCMF <layout> <data> <variable name="viewModel" type="com.example.ViewModel"/> </data> <LinearLayout android:orientation="vertical"> <EditText android:hint="Please input some text" android:text="@={viewModel.inputText}" /> <Button android:enabled="@{viewModel.buttonEnabled}" android:text="Send" /> </LinearLayout> </layout>
45. PCTFSWBCMF
    
    WFUPBCMF class MainActivity : AppCompatActivity() { val binding by lazy { DataBindingUtil.setContentView<ActivityMainBinding>( this@MainActivity, R.layout.activity_main) } override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) binding.viewModel = ViewModel() } }
46. PCTFSWBCMF
    
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47. αʔυύʔςΟ
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50. ,PUUFS,OJGF val firstName: TextView by bindView(R.id.first_name) val lastName: TextView by bindView(R.id.last_name) // Optional binding. val details: TextView? by bindOptionalView(R.id.details)
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52. ,PUQSFG IUUQTHJUIVCDPNDIJCBUDIJOH,PUQSFG
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