Migrate EventInfo to flows

Fixes: b/186633011
Change-Id: I85966e91eca7cfae1be0f07bc7b71fe03c1d1569

Author: Manuel Vivo

mobile/src/main/java/com/google/samples/apps/iosched/ui/info/EventFragment.kt

@@ -29,17 +29,18 @@ import androidx.core.view.updatePaddingRelative
 import androidx.databinding.BindingAdapter
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
-import androidx.lifecycle.Observer
 import com.google.samples.apps.iosched.R
 import com.google.samples.apps.iosched.databinding.FragmentInfoEventBinding
 import com.google.samples.apps.iosched.model.ConferenceWifiInfo
 import com.google.samples.apps.iosched.shared.di.AssistantAppEnabledFlag
 import com.google.samples.apps.iosched.shared.util.TimeUtils
 import com.google.samples.apps.iosched.ui.messages.SnackbarMessageManager
-import com.google.samples.apps.iosched.ui.setUpSnackbar
+import com.google.samples.apps.iosched.ui.setupSnackbarManager
 import com.google.samples.apps.iosched.util.doOnApplyWindowInsets
+import com.google.samples.apps.iosched.util.launchAndRepeatWithViewLifecycle
 import com.google.samples.apps.iosched.widget.FadingSnackbar
 import dagger.hilt.android.AndroidEntryPoint
+import kotlinx.coroutines.flow.collect
 import javax.inject.Inject
 
 @AndroidEntryPoint
@@ -73,20 +74,23 @@ class EventFragment : Fragment() {
         }
 
         val snackbarLayout = requireActivity().findViewById<FadingSnackbar>(R.id.snackbar)
-        setUpSnackbar(eventInfoViewModel.snackBarMessage, snackbarLayout, snackbarMessageManager)
+        setupSnackbarManager(snackbarMessageManager, snackbarLayout) { }
 
         return binding.root
     }
 
-    override fun onActivityCreated(savedInstanceState: Bundle?) {
-        super.onActivityCreated(savedInstanceState)
-        eventInfoViewModel.openUrlEvent.observe(
-            viewLifecycleOwner,
-            Observer {
-                val url = it?.getContentIfNotHandled() ?: return@Observer
-                startActivity(Intent(Intent.ACTION_VIEW, Uri.parse(url)))
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+
+        launchAndRepeatWithViewLifecycle {
+            eventInfoViewModel.navigationActions.collect { event ->
+                when (event) {
+                    is EventInfoNavigationAction.OpenUrl -> {
+                        startActivity(Intent(Intent.ACTION_VIEW, Uri.parse(event.url)))
+                    }
+                }
             }
-        )
+        }
     }
 }
 

mobile/src/main/java/com/google/samples/apps/iosched/ui/info/EventInfoViewModel.kt

@@ -17,48 +17,52 @@
 package com.google.samples.apps.iosched.ui.info
 
 import android.net.wifi.WifiConfiguration
-import androidx.lifecycle.LiveData
-import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
-import androidx.lifecycle.liveData
+import androidx.lifecycle.viewModelScope
 import com.google.samples.apps.iosched.R
 import com.google.samples.apps.iosched.model.ConferenceWifiInfo
 import com.google.samples.apps.iosched.shared.analytics.AnalyticsActions
 import com.google.samples.apps.iosched.shared.analytics.AnalyticsHelper
 import com.google.samples.apps.iosched.shared.domain.logistics.LoadWifiInfoUseCase
-import com.google.samples.apps.iosched.shared.result.Event
 import com.google.samples.apps.iosched.shared.result.data
-import com.google.samples.apps.iosched.shared.util.map
+import com.google.samples.apps.iosched.shared.util.tryOffer
 import com.google.samples.apps.iosched.ui.SnackbarMessage
+import com.google.samples.apps.iosched.ui.messages.SnackbarMessageManager
+import com.google.samples.apps.iosched.util.WhileViewSubscribed
 import com.google.samples.apps.iosched.util.wifi.WifiInstaller
 import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.receiveAsFlow
+import kotlinx.coroutines.flow.stateIn
 import javax.inject.Inject
 
 @HiltViewModel
 class EventInfoViewModel @Inject constructor(
     loadWifiInfoUseCase: LoadWifiInfoUseCase,
     private val wifiInstaller: WifiInstaller,
-    private val analyticsHelper: AnalyticsHelper
+    private val analyticsHelper: AnalyticsHelper,
+    private val snackbarMessageManager: SnackbarMessageManager
 ) : ViewModel() {
 
     companion object {
         private const val ASSISTANT_APP_URL =
             "https://assistant.google.com/services/invoke/uid/0000009fca77b068"
     }
 
-    private val _wifiConfig = liveData { emit(loadWifiInfoUseCase(Unit)) }
-    val wifiConfig: LiveData<ConferenceWifiInfo?> = _wifiConfig.map { it.data }
-    val showWifi: LiveData<Boolean> = wifiConfig.map {
-        it?.ssid?.isNotBlank() == true && it.password.isNotBlank()
-    }
+    val wifiConfig: StateFlow<ConferenceWifiInfo?> = flow {
+        emit(loadWifiInfoUseCase(Unit).data)
+    }.stateIn(viewModelScope, SharingStarted.Lazily, null)
 
-    private val _snackbarMessage = MutableLiveData<Event<SnackbarMessage>>()
-    val snackBarMessage: LiveData<Event<SnackbarMessage>>
-        get() = _snackbarMessage
+    val showWifi: StateFlow<Boolean> = wifiConfig.map {
+        it?.ssid?.isNotBlank() == true && it.password.isNotBlank()
+    }.stateIn(viewModelScope, WhileViewSubscribed, false)
 
-    private val _openUrlEvent = MutableLiveData<Event<String>>()
-    val openUrlEvent: LiveData<Event<String>>
-        get() = _openUrlEvent
+    private val _navigationActions = Channel<EventInfoNavigationAction>(Channel.CONFLATED)
+    val navigationActions = _navigationActions.receiveAsFlow()
 
     fun onWifiConnect() {
         val config = wifiConfig.value ?: return
@@ -76,12 +80,16 @@ class EventInfoViewModel @Inject constructor(
             )
         }
 
-        _snackbarMessage.postValue(Event(snackbarMessage))
+        snackbarMessageManager.addMessage(snackbarMessage)
         analyticsHelper.logUiEvent("Events", AnalyticsActions.WIFI_CONNECT)
     }
 
     fun onClickAssistantApp() {
-        _openUrlEvent.value = Event(ASSISTANT_APP_URL)
+        _navigationActions.tryOffer(EventInfoNavigationAction.OpenUrl(ASSISTANT_APP_URL))
         analyticsHelper.logUiEvent("Assistant App", AnalyticsActions.CLICK)
     }
 }
+
+sealed class EventInfoNavigationAction {
+    data class OpenUrl(val url: String) : EventInfoNavigationAction()
+}