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Android Architecture Componentͷ
LifecyleରԠίϯϙʔωϯτͷ
͓͞Β͍
Androidݚڀ&ൃදձ #4
2020/01/25
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• Տຊ ହ(͔Θͱ ͔ͨ͢)
• ॴଐɿגࣜձࣾ tech vein
(େࡕࢢதԝ۠ຊொ)
• ϞόΠϧΞϓϦΤϯδχΞ
(AndroidଟΊɺiOSŧŔŕŪũƄŝſ)
• GitHub: kwmt ɺtwitter: kwmt27
• Google I/O2018 ॳࢀՃ
• Ԭग़
• ΫϥϑτϏʔϧ͖
ࣗݾհ
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• Android Architecture Componentͱʁ
• ViewModelͰ؆୯ը໘ճస
• LiveDataΛͬͯUIΛߋ৽
• LifecycleͰActivityFragmentΛεοΩϦ
• ViewModelͷڞ༗
• Tips
• ·ͱΊ
ΞδΣϯμ
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Android Architecture Componentͱ
https://www.youtube.com/watch?v=LmkKFCfmnhQ&feature=youtu.be&hl=ja
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Android Architecture Componentͱ
https://www.youtube.com/watch?v=pErTyQpA390
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ViewModel, LiveData, Lifecycle
ࠓͷओ
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ViewModelͰ؆୯ը໘ճస
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՝
Activity
ViewModelΛΘͣ
࣮ͨ͠߹
ը໘ճసͷͱ͖ɺ
ʢͳʹ͠ͳ͍ͱʣ
λΠϚʔ͕ΫϦΞ͞ΕΔ
※savedInstanceStateΛ͑
ΫϦΞ͞Εͳ͍Α͏ʹ͢Δ͜ͱͰ͖·͕͢ɺ
͜͜Ͱߟ͑·ͤΜɻ
ྫɿλΠϚʔΞϓϦ
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՝
Activity
ViewModelΛΘͣ
࣮ͨ͠߹
ը໘ճసͷͱ͖ɺ
ʢͳʹ͠ͳ͍ͱʣ
λΠϚʔ͕ΫϦΞ͞ΕΔ
※savedInstanceStateΛ͑
ΫϦΞ͞Εͳ͍Α͏ʹ͢Δ͜ͱͰ͖·͕͢ɺ
͜͜Ͱߟ͑·ͤΜɻ
ྫɿλΠϚʔΞϓϦ
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ViewModelΛ͏ͱ
Activity
viewModel
ը໘ճసͷͱ͖ɺ
λΠϚʔ͕ΫϦΞ͞Εͳ͍Α͏ʹ
؆୯ʹͰ͖Δ
ViewModel
timer
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ViewModelΛ͏ͱ
Activity
viewModel
ը໘ճసͷͱ͖ɺ
λΠϚʔ͕ΫϦΞ͞Εͳ͍Α͏ʹ
؆୯ʹͰ͖Δ
ViewModel
timer
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ViewModelͷੜଘظؒ
࣌ؒ
Activity ViewModel
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ViewModelͷੜଘظؒ
࣌ؒ
ىಈ
Activity ViewModel
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ViewModelͷੜଘظؒ
onCreate
࣌ؒ
ViewModelੜ
onStart
onResume
ىಈ
Activity ViewModel
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ViewModelͷੜଘظؒ
onCreate
࣌ؒ
ViewModelੜ
onStart
onResume
ىಈ
ճస
Activity ViewModel
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ViewModelͷੜଘظؒ
onCreate
࣌ؒ
ViewModelੜ
onStart
onResume
onPause
onStop
onDestroy
onCreate
onStart
onResume
ىಈ
ճస
Activity ViewModel
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ViewModelͷੜଘظؒ
onCreate
࣌ؒ
ViewModelੜ
onStart
onResume
onPause
onStop
onDestroy
onCreate
onStart
onResume
ىಈ
ճస
όοΫΩʔͰΞϓϦऴྃ
Activity ViewModel
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ViewModelͷੜଘظؒ
onCreate
࣌ؒ
ViewModelੜ
onStart
onResume
onPause
onStop
onDestroy
onCreate
onStart
onResume
onPause
onStop
onDestroy
ىಈ
ճస
όοΫΩʔͰΞϓϦऴྃ
onCleared
Activity ViewModel
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ViewModelͷੜଘظؒ
onCreate
࣌ؒ
ViewModelੜ
onStart
onResume
onPause
onStop
onDestroy
onCreate
onStart
onResume
onPause
onStop
onDestroy
ىಈ
ճస
όοΫΩʔͰΞϓϦऴྃ
onCleared
Activity ViewModel
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override fun onCreate(savedInstanceState: Bundle?) {
// লུ
val chronometer = findViewById(R.id.chronometer)
val startTime = viewModel.startTime
if (startTime == null) {
val time = SystemClock.elapsedRealtime()
viewModel.startTime = time
chronometer.base = time
} else {
chronometer.base = startTime
}
chronometer.start()
}
Activity
class ChronoViewModel: ViewModel() {
var startTime: Long? = null
}
ViewModel
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• Kotlin ϓϩύςΟσϦήʔτΛ͏ํ๏
ViewModelΠϯελϯεͷऔಘํ๏
(ҙ)fragment-ktxͷ1.1.0Ҏ্Λ͏ඞཁ͋Γ
val viewModel by viewModels()
https://developer.android.com/jetpack/androidx/releases/lifecycle#2.2.0-alpha03
ViewModelProviders.of(this)
.get(MyViewModel::class.java)
• ViewModelProviderΛ͏ํ๏
viewModel = ViewModelProvider(this)
.get(MyViewModel::class.java)
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• Kotlin ϓϩύςΟσϦήʔτΛ͏ํ๏
ViewModelΠϯελϯεͷऔಘํ๏
(ҙ)fragment-ktxͷ1.1.0Ҏ্Λ͏ඞཁ͋Γ
val viewModel by viewModels()
https://developer.android.com/jetpack/androidx/releases/lifecycle#2.2.0-alpha03
ViewModelProviders.of(this)
.get(MyViewModel::class.java)
• ViewModelProviderΛ͏ํ๏
viewModel = ViewModelProvider(this)
.get(MyViewModel::class.java)
2.2.0-alpha03͔ΒDeprecated
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• ActivityFragmentͷϥΠϑαΠΫϧશମͰσʔλΛอ࣋
Ͱ͖Δ
• ActivityFragmentΑΓੜଘظ͕͍ؒΦϒδΣΫτ
• ViewModelΫϥεͷ࡞ɺViewModel()Λܧঝ͢Δ͚ͩ
• ViewModelΠϯελϯεΛऔಘ͢Δʹɺ
KotlinϓϩύςΟσϦήʔτͱViewModelProviderΛ͏
ํ๏͕͋Δ
ViewModel ·ͱΊ
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LiveDataΛͬͯUIΛߋ৽
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• ઌఔͷλΠϚʔΞϓϦͰɺ
UIΛ1ඵִؒͰ
ʮʙඵܦաʯ
ͱද͍ࣔͨ͠
• ͔ͭɺը໘ճసߟྀ͍ͨ͠
͜͜Ͱղܾ͍ͨ͠՝
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• ઌఔͷλΠϚʔΞϓϦͰɺ
UIΛ1ඵִؒͰ
ʮʙඵܦաʯ
ͱද͍ࣔͨ͠
• ͔ͭɺը໘ճసߟྀ͍ͨ͠
͜͜Ͱղܾ͍ͨ͠՝
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ViewModelʹߋ৽͍ͨ͠ViewΛ
࣋ͨͤͨΒ͍͍Μ͡Όʁ
class MyViewModel : ViewModel() {
val initialTime = SystemClock.elapsedRealtime()
private val timer = Timer()
var timerTextView: TextView? = null
init{
timer.scheduleAtFixedRate(object : TimerTask() {
override fun run() {
timerTextView?.text = "$ඵ ඵܦա"
}
}, 1000, 1000)
}
}
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ViewModelʹߋ৽͍ͨ͠ViewΛ
࣋ͨͤͨΒ͍͍Μ͡Όʁ
class MyViewModel : ViewModel() {
val initialTime = SystemClock.elapsedRealtime()
private val timer = Timer()
var timerTextView: TextView? = null
init{
timer.scheduleAtFixedRate(object : TimerTask() {
override fun run() {
timerTextView?.text = "$ඵ ඵܦա"
}
}, 1000, 1000)
}
}
• ΞϓϦऴྃ࣌ʹϝϞϦϦʔΫ͢ΔͷͰɺͰ͖·ͤΜɻ
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ViewModelʹߋ৽͍ͨ͠ViewΛ
࣋ͨͤͨΒ͍͍Μ͡Όʁ
class MyViewModel : ViewModel() {
val initialTime = SystemClock.elapsedRealtime()
private val timer = Timer()
var timerTextView: TextView? = null
init{
timer.scheduleAtFixedRate(object : TimerTask() {
override fun run() {
timerTextView?.text = "$ඵ ඵܦա"
}
}, 1000, 1000)
}
}
• ΞϓϦऴྃ࣌ʹϝϞϦϦʔΫ͢ΔͷͰɺͰ͖·ͤΜɻ
AACͷLiveDataΛ͍·͢ʂ
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LiveDataΛ͏
class MyViewModel : ViewModel() {
val initialTime = SystemClock.elapsedRealtime()
private val timer = Timer()
private val elapsedTime = MutableLiveData()
fun getElapsedTime(): LiveData = elapsedTime
init{
timer.scheduleAtFixedRate(object : TimerTask() {
override fun run() {
elapsedTime.postValue(ඵ)
}
}, 1000, 1000)
}
}
viewModel.getElapsedTime()
.observe(this, Observer {
timerTextView.text = "${t}ඵܦա"
})
• Activityଆ
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LiveDataΛ͏
class MyViewModel : ViewModel() {
val initialTime = SystemClock.elapsedRealtime()
private val timer = Timer()
private val elapsedTime = MutableLiveData()
fun getElapsedTime(): LiveData = elapsedTime
init{
timer.scheduleAtFixedRate(object : TimerTask() {
override fun run() {
elapsedTime.postValue(ඵ)
}
}, 1000, 1000)
}
}
viewModel.getElapsedTime()
.observe(this, Observer {
timerTextView.text = "${t}ඵܦա"
})
• Activityଆ
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LiveDataΛ͏
ViewModel
Activity
viewModel elapsedTime
timerTextView.text
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LiveDataΛ͏
ViewModel
Activity
viewModel elapsedTime
observeͰࢹ
timerTextView.text
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LiveDataΛ͏
ViewModel
Activity
viewModel elapsedTime
observeͰࢹ
1ඵ͝ͱʹߋ৽
timerTextView.text
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LiveDataΛ͏
ViewModel
Activity
viewModel elapsedTime
observeͰࢹ
1ඵ͝ͱʹߋ৽
timerTextView.text
௨
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• ViewModelʹViewΛ࣋ͨͤΔͷɺ
ϝϞϦϦʔΫ͢ΔͷͰμϝ
• ViewModelʹLiveDataΛ࣋ͨͤͯɺActivityFragment͔
Βࢹ(observe)͠ɺViewModel͔Β௨͢Δ
LiveData ·ͱΊ
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LifecycleͰActivityFragmentΛεοΩϦ
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• ͨͱ͑ɺݱࡏΛऔಘ͢ΔͨΊʹɺ LocationManager
Λ͏ͱ͠·͢ɻ
͜ͷΑ͏ͳAPIΛ͏ͨΊʹɺ
onResumeͰॳظԽɾsubscribeͨ͠Γ
onPauseͰετοϓͨ͠Γɺunsubscribe͢Δ͜ͱ͕ඞཁ
Ͱ͢ɻ
͜͜Ͱղܾ͍ͨ͠՝
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͜͜Ͱղܾ͍ͨ͠՝
Activity
override fun onResume(){
locationManager.requestLocationUpdates(লུ)
}
override fun onPause(){
locationManager.removeUpdates(লུ)
}
• AndroidͷϥΠϒϥϦAPI͜ͷΑ͏ͳॲཧΛ͢Δͷ
͕ଟ͍ͷͰɺActivityFragmentΫϥε͕ΒΜͰ͖ͯɺ
ಡΈʹ͘͘ͳΓ·͢ɻ
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Activity override fun onCreate(){
LocationLifecyle(this)
}
Lifecycle
class LocationLifecycle(lifecycleOwner: LifecycleOwner)
ɹɹɹ: LifecycleObserver
{
init { lifecycleOwner.lifecycle.addObserver(this) }
@OnLifecycleEvent(ON_RESUME)
fun addLocationListener() {
locationManager.requestLocationUpdates(লུ) }
@OnLifecycleEvent(ON_PAUSE)
fun removeLocationListener() {
locationManager.removeUpdates(লུ)
}
}
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Activity override fun onCreate(){
LocationLifecyle(this)
}
Lifecycle
class LocationLifecycle(lifecycleOwner: LifecycleOwner)
ɹɹɹ: LifecycleObserver
{
init { lifecycleOwner.lifecycle.addObserver(this) }
@OnLifecycleEvent(ON_RESUME)
fun addLocationListener() {
locationManager.requestLocationUpdates(লུ) }
@OnLifecycleEvent(ON_PAUSE)
fun removeLocationListener() {
locationManager.removeUpdates(লུ)
}
}
interfaceΛ࣮
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Activity override fun onCreate(){
LocationLifecyle(this)
}
Lifecycle
class LocationLifecycle(lifecycleOwner: LifecycleOwner)
ɹɹɹ: LifecycleObserver
{
init { lifecycleOwner.lifecycle.addObserver(this) }
@OnLifecycleEvent(ON_RESUME)
fun addLocationListener() {
locationManager.requestLocationUpdates(লུ) }
@OnLifecycleEvent(ON_PAUSE)
fun removeLocationListener() {
locationManager.removeUpdates(লུ)
}
}
interfaceΛ࣮
observerΛొ
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Activity override fun onCreate(){
LocationLifecyle(this)
}
Lifecycle
class LocationLifecycle(lifecycleOwner: LifecycleOwner)
ɹɹɹ: LifecycleObserver
{
init { lifecycleOwner.lifecycle.addObserver(this) }
@OnLifecycleEvent(ON_RESUME)
fun addLocationListener() {
locationManager.requestLocationUpdates(লུ) }
@OnLifecycleEvent(ON_PAUSE)
fun removeLocationListener() {
locationManager.removeUpdates(লུ)
}
}
interfaceΛ࣮
observerΛొ
ϥΠϑαΠΫϧʹґ
ଘ͍ͨ͠ϝιουʹ
ΞϊςʔγϣϯΛͭ
͚Δ
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• AndroidϥΠϑαΠΫϧʹؔΘΔAPIϥΠϒϥϦΛ͏
࣌ʹɺAAC LifecycleΛ͏ͱActivityFragmentҎ֎ͷ
ΫϥεͰϥΠϑαΠΫϧݕ͕Ͱ͖Δɻ
Lifecycle ·ͱΊ
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ViewModelͷڞ༗
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• Fragment͔ΒActivityʹͳʹ͔௨͍ͨͬͯ͠໘ͩͬͨ
ΑͶʁ
͜͜Ͱղܾ͍ͨ͠՝
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class FugaFragment : Fragment() {
interface OnClickListener {
fun onClick()
}
private var onClickListener: OnClickListener? = null
// লུ
override fun onActivityCreated {
// লུ
onClickListener = requireActivity() as? OnClickListener
// ϘλϯͳͲͷΫϦοΫΠϕϯτͰonClickΛݺͿ
onClickListener?.onClick()
}
}
class HogeActivity : AppCompatActivity(),
FugaFragment.OnClickListener {
// লུ
override fun onClick() {
// ͳʹ͔
}
}
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class FugaFragment : Fragment() {
interface OnClickListener {
fun onClick()
}
private var onClickListener: OnClickListener? = null
// লུ
override fun onActivityCreated {
// লུ
onClickListener = requireActivity() as? OnClickListener
// ϘλϯͳͲͷΫϦοΫΠϕϯτͰonClickΛݺͿ
onClickListener?.onClick()
}
}
class HogeActivity : AppCompatActivity(),
FugaFragment.OnClickListener {
// লུ
override fun onClick() {
// ͳʹ͔
}
}
௨༻interfaceΛఆٛ
ϑΟʔϧυʹม༻ҙ
Activity͕interfaceΛ࣮ͯͨ͠ΒΩϟετ
௨༻ͷinterfaceΛ࣮
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• ActivityͱFragmentͰViewModelΛڞ༗ͯ͠ɺ
ಉ͜͡ͱΛͬͯΈΔ
ViewModelΛڞ༗
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class HogeActivity : AppCompatActivity() {
private val viewModel by viewModels()
override fun onCreate(savedInstanceState: Bundle?) {
// লུ
viewModel.clickEvent.observe(this) {
textView.text = it
}
}
}
private val viewModel
by viewModels ({ requireActivity() })
viewModel.onClick()
class HogeViewModel : ViewModel() {
val clickEvent = MutableLiveData()
fun onClick() {
clickEvent.value = "Ϙλϯ͕ԡ͞ΕͨΑ"
}
}
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͜ΕΛಈ͔͢ͱ
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͜ΕΛಈ͔͢ͱ
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• Fragment͔ΒActivityͷ௨͕؆୯
• (͜͜Ͱઆ໌ͯ͠·ͤΜ͕)Fragmentಉ࢜ͷڞ༗Մೳ
ViewModelڞ༗ͷ·ͱΊ
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͜͜·Ͱ΄΅Codelabͷ༰
https://codelabs.developers.google.com/codelabs/android-lifecycles/#0
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Tips
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• 2ͭͷLiveDataΛ݁߹͍ͨ͠
• LiveDataͷൃՐΛҰ͚ͩʹ͍ͨ͠
Tips
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• 2ͭͷLiveDataΛ݁߹͍ͨ͠
• LiveDataͷൃՐΛҰ͚ͩʹ͍ͨ͠
Tips
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2ͭͷLiveDataΛ݁߹͍ͨ͠
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MediatorLiveDataΛ͏
class ZipLIveDataViewModel : ViewModel() {
val editText1 = MutableLiveData()
val editText2 = MutableLiveData()
val isEnabled = MediatorLiveData()
init {
val observer = Observer {
isEnabled.value =
editText1.value?.isNotEmpty() ?: false
&& editText2.value?.isNotEmpty() ?: false
}
isEnabled.addSource(editText1, observer)
isEnabled.addSource(editText2, observer)
}
}
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MediatorLiveDataͷϥούʔؔΛ࡞Δ
fun zipLiveData(a: LiveData, b: LiveData): LiveData> {
return MediatorLiveData>().apply {
var lastA: A? = null
var lastB: B? = null
fun update() {
val localLastA = lastA
val localLastB = lastB
if (localLastA != null && localLastB != null) {
this.value = Pair(localLastA, localLastB)
}
}
addSource(a) {
lastA = it
update()
}
addSource(b) {
lastB = it
update()
}
}
}
https://medium.com/@gauravgyal/combine-results-from-multiple-async-requests-90b6b45978f7
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MediatorLiveDataͷϥούʔؔΛ͏
class ZipLIveDataViewModel : ViewModel() {
val editText1 = MutableLiveData()
val editText2 = MutableLiveData()
val isEnabled: LiveData =
zipLiveData(editText1, editText2)
.map { (t1, t2) ->
t1.isNotEmpty() && t2.isNotEmpty()
}
}
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ൺΔ
class ZipLIveDataViewModel : ViewModel() {
val editText1 = MutableLiveData()
val editText2 = MutableLiveData()
val isEnabled: LiveData =
zipLiveData(editText1, editText2)
.map { (t1, t2) ->
t1.isNotEmpty() && t2.isNotEmpty()
}
}
class ZipLIveDataViewModel : ViewModel() {
val editText1 = MutableLiveData()
val editText2 = MutableLiveData()
val isEnabled = MediatorLiveData()
init {
val observer = Observer {
isEnabled.value =
editText1.value?.isNotEmpty() ?: false
&& editText2.value?.isNotEmpty() ?: false
}
isEnabled.addSource(editText1, observer)
isEnabled.addSource(editText2, observer)
}
}
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ಈ͔͢
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ಈ͔͢
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• 2ͭͷLiveDataΛ݁߹͍ͨ͠
• LiveDataͷൃՐΛҰ͚ͩʹ͍ͨ͠
Tips
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• ը໘ભҠʹLiveDataΛ͏ͱɺΔ͜ͱ͕Ͱ͖ͳ͍
LiveDataͷൃՐΛҰ͚ͩʹ͍ͨ͠
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ભҠݩʹΕͳ͍࣮ྫ
override fun onViewCreated() {
viewModel.nextLiveData
.observe(viewLifecycleOwner) { nextViewType ->
// ը໘ભҠ͢Δ
}
button
.setOnClickListener{viewModel.onClickNextButton()}
}
fun onClickNextButton() {
// APIϨεϙϯεͷ݁ՌʹΑͬͯɺը໘ભҠΛม͍͑ͨ߹
val data = repository.fetchData()
// লུ
_nextLiveData.value = nextType
}
Fragment
ViewModel
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ભҠݩʹΕͳ͍࣮ྫ
override fun onViewCreated() {
viewModel.nextLiveData
.observe(viewLifecycleOwner) { nextViewType ->
// ը໘ભҠ͢Δ
}
button
.setOnClickListener{viewModel.onClickNextButton()}
}
fun onClickNextButton() {
// APIϨεϙϯεͷ݁ՌʹΑͬͯɺը໘ભҠΛม͍͑ͨ߹
val data = repository.fetchData()
// লུ
_nextLiveData.value = nextType
}
Fragment
ViewModel
όοΫͰ͖ͬͯͨͱ͖ʹɺ
onViewCreated͕ݺΕͯɺ
observe͍ͯ͠ΔonChanged͕ݺΕΔͨΊ
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LiveDataͷϥούʔΫϥεΛ࡞Δ
https://medium.com/androiddevelopers/livedata-with-snackbar-navigation-and-other-events-the-singleliveevent-case-ac2622673150
data class Event(private val content: T) {
var hasBeenHandled = false
private set
fun getContentIfNotHandled(): T? {
return if (hasBeenHandled) {
null
} else {
hasBeenHandled = true
content
}
}
}
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LiveDataͷϥούʔΫϥε(Event)Λ͏
override fun onViewCreated() {
viewModel.nextLiveData
.observe(viewLifecycleOwner) { event ->
event.getContentIfNotHandled()?.let {nextViewType ->
// ը໘ભҠ͢Δ
}
}
button
.setOnClickListener{viewModel.onClickNextButton()}
}
fun onClickNextButton() {
// APIϨεϙϯεͷ݁ՌʹΑͬͯɺը໘ભҠΛม͍͑ͨ߹
val data = repository.fetchData()
// লུ
_nextLiveData.value = Event(nextType)
}
Fragment
ViewModel
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LiveDataͷϥούʔΫϥε(Event)Λ͏
override fun onViewCreated() {
viewModel.nextLiveData
.observe(viewLifecycleOwner) { event ->
event.getContentIfNotHandled()?.let {nextViewType ->
// ը໘ભҠ͢Δ
}
}
button
.setOnClickListener{viewModel.onClickNextButton()}
}
fun onClickNextButton() {
// APIϨεϙϯεͷ݁ՌʹΑͬͯɺը໘ભҠΛม͍͑ͨ߹
val data = repository.fetchData()
// লུ
_nextLiveData.value = Event(nextType)
}
Fragment
ViewModel
EventΛηοτ͢ΔΑ͏ʹมߋ
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LiveDataͷϥούʔΫϥε(Event)Λ͏
override fun onViewCreated() {
viewModel.nextLiveData
.observe(viewLifecycleOwner) { event ->
event.getContentIfNotHandled()?.let {nextViewType ->
// ը໘ભҠ͢Δ
}
}
button
.setOnClickListener{viewModel.onClickNextButton()}
}
fun onClickNextButton() {
// APIϨεϙϯεͷ݁ՌʹΑͬͯɺը໘ભҠΛม͍͑ͨ߹
val data = repository.fetchData()
// লུ
_nextLiveData.value = Event(nextType)
}
Fragment
ViewModel
getContentIfNotHandled()ͷΈͰɺ
όοΫͰ͖ͬͯͨͱ͖null͕ฦΔ
ͨΊɺը໘ભҠ͠ͳ͘ͳΓɺ
ݩͷը໘ʹΔ͜ͱ͕Ͱ͖Δ
EventΛηοτ͢ΔΑ͏ʹมߋ
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ಈ͔͢
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Slide 74 text
ಈ͔͢
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• ActivityFragment͕ը໘ճసͳͲͰ࠶ੜ͞Εͯอ͓͖࣋ͯͨ͠
͍ใΛViewModelʹอ࣋͢ΔͱͤʹͳΔ
• ViewModelͰܭࢉͨ͠Γอ࣋ͨ͠σʔλͰUIΛߋ৽͢Δʹɺ
LiveDataΛͬͯUIʹ௨͢Δɻ
• AACͷLifecycleActivityFragmentͷϥΠϑαΠΫϧͰॳظԽഁغ
Λ͍ͯͨ͠ίϯϙʔωϯτΛɺผΫϥεʹΓग़ͤͯεοΩϦͰ͖Δ
• ViewModelΛڞ༗͢Δ͜ͱͰɺFragment−ActivityؒΛָʹڞ༗Ͱ͖Δ
• ը໘ભҠͰLiveDataΛ͏ͱ͖ɺϥούʔΫϥεΛ࡞͓ͬͯ͘ඞཁ
͕͋Γͦ͏
·ͱΊ
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• ͬͱৄ͍͠ΈΛϒϩάʹ·ͱΊͯ·͢ͷͰɺ͝
ڵຯ͕͋ΔํݟͯΈ͍ͯͩ͘͞ɻ
࠷ޙʹ
https://kwmt27.net/2019/09/19/android-lifecycle-codelab/