Switch to compose state and kotlin flows - 1. iteration

app/src/androidTest/java/at/bitfire/icsdroid/TestSettings.kt

@@ -0,0 +1,40 @@
+package at.bitfire.icsdroid
+
+import android.content.Context
+import androidx.test.platform.app.InstrumentationRegistry
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.withTimeout
+import org.junit.Test
+
+class TestSettings {
+    companion object {
+        val appContext: Context by lazy { InstrumentationRegistry.getInstrumentation().targetContext }
+    }
+
+    @Test
+    fun testForceDarkModeFlow() {
+        // Initialize settings
+        val settings = Settings(appContext)
+        // Create a variable for storing the value of the preference when updated
+        var forceDarkMode = false
+        // Launch a coroutine to collect the flow
+        CoroutineScope(Dispatchers.IO).launch {
+            settings.forceDarkModeFlow().collect { forceDarkMode = it }
+        }
+        // Set the preference to true
+        settings.forceDarkMode(true)
+        // Wait for the flow to update, or throw timeout
+        runBlocking {
+            withTimeout(1000) {
+                while (!forceDarkMode) {
+                    delay(10)
+                }
+            }
+        }
+        assert(forceDarkMode)
+    }
+}

app/src/main/java/at/bitfire/icsdroid/Settings.kt

@@ -7,6 +7,9 @@ package at.bitfire.icsdroid
 import android.content.Context
 import android.content.SharedPreferences
 import androidx.lifecycle.LiveData
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
 
 class Settings(context: Context) {
 
@@ -19,6 +22,10 @@ class Settings(context: Context) {
 
     fun forceDarkMode(): Boolean = prefs.getBoolean(FORCE_DARK_MODE, false)
 
+    @Deprecated(
+        message = "Replace LiveData by Flows",
+        replaceWith = ReplaceWith("forceDarkModeFlow()")
+    )
     fun forceDarkModeLive(): LiveData<Boolean> = object: LiveData<Boolean>() {
         val listener = SharedPreferences.OnSharedPreferenceChangeListener { prefs, key ->
             if (key == FORCE_DARK_MODE) {
@@ -37,6 +44,23 @@ class Settings(context: Context) {
         }
     }
 
+    fun forceDarkModeFlow(): Flow<Boolean> = callbackFlow {
+        val listener = SharedPreferences.OnSharedPreferenceChangeListener { prefs, key ->
+            if (key == FORCE_DARK_MODE) {
+                val forceDarkMode = prefs.getBoolean(key, false)
+                trySend(forceDarkMode)
+            }
+        }
+
+        prefs.registerOnSharedPreferenceChangeListener(listener)
+        listener.onSharedPreferenceChanged(prefs, FORCE_DARK_MODE)
+
+        awaitClose {
+            // Remove listener
+            prefs.unregisterOnSharedPreferenceChangeListener(listener)
+        }
+    }
+
     fun forceDarkMode(force: Boolean) {
         // save setting
         prefs.edit()

app/src/main/java/at/bitfire/icsdroid/SyncWorker.kt

@@ -8,7 +8,14 @@ import android.content.ContentProviderClient
 import android.content.ContentUris
 import android.content.Context
 import android.util.Log
-import androidx.work.*
+import androidx.work.Constraints
+import androidx.work.CoroutineWorker
+import androidx.work.ExistingWorkPolicy
+import androidx.work.NetworkType
+import androidx.work.OneTimeWorkRequestBuilder
+import androidx.work.WorkManager
+import androidx.work.WorkerParameters
+import androidx.work.workDataOf
 import at.bitfire.ical4android.AndroidCalendar
 import at.bitfire.ical4android.util.MiscUtils.closeCompat
 import at.bitfire.icsdroid.Constants.TAG
@@ -79,9 +86,16 @@ class SyncWorker(
                     .enqueue()
         }
 
+        @Deprecated(
+            message = "Replace LiveData by Flows",
+            replaceWith = ReplaceWith("statusFlow(context)")
+        )
         fun liveStatus(context: Context) =
             WorkManager.getInstance(context).getWorkInfosForUniqueWorkLiveData(NAME)
 
+        fun statusFlow(context: Context) =
+            WorkManager.getInstance(context).getWorkInfosForUniqueWorkFlow(NAME)
+
     }
 
     private val database = AppDatabase.getInstance(applicationContext)

app/src/main/java/at/bitfire/icsdroid/db/dao/SubscriptionsDao.kt

@@ -11,6 +11,7 @@ import androidx.room.Relation
 import androidx.room.Update
 import at.bitfire.icsdroid.db.entity.Credential
 import at.bitfire.icsdroid.db.entity.Subscription
+import kotlinx.coroutines.flow.Flow
 
 @Dao
 interface SubscriptionsDao {
@@ -21,9 +22,16 @@ interface SubscriptionsDao {
     @Delete
     fun delete(vararg subscriptions: Subscription)
 
+    @Deprecated(
+        message = "Replace LiveData by Flows",
+        replaceWith = ReplaceWith("getAllFlow()")
+    )
     @Query("SELECT * FROM subscriptions")
     fun getAllLive(): LiveData<List<Subscription>>
 
+    @Query("SELECT * FROM subscriptions")
+    fun getAllFlow(): Flow<List<Subscription>>
+
     @Query("SELECT * FROM subscriptions")
     fun getAll(): List<Subscription>
 
@@ -36,12 +44,26 @@ interface SubscriptionsDao {
     @Query("SELECT * FROM subscriptions WHERE url=:url")
     fun getByUrl(url: String): Subscription?
 
+    @Deprecated(
+        message = "Replace LiveData by Flows",
+        replaceWith = ReplaceWith("getWithCredentialsByIdFlow(id)")
+    )
     @Query("SELECT * FROM subscriptions WHERE id=:id")
     fun getWithCredentialsByIdLive(id: Long): LiveData<SubscriptionWithCredential>
 
+    @Query("SELECT * FROM subscriptions WHERE id=:id")
+    fun getWithCredentialsByIdFlow(id: Long): Flow<SubscriptionWithCredential>
+
+    @Deprecated(
+        message = "Replace LiveData by Flows",
+        replaceWith = ReplaceWith("getErrorMessageFlow(id)")
+    )
     @Query("SELECT errorMessage FROM subscriptions WHERE id=:id")
     fun getErrorMessageLive(id: Long): LiveData<String?>
 
+    @Query("SELECT errorMessage FROM subscriptions WHERE id=:id")
+    fun getErrorMessageFlow(id: Long): Flow<String?>
+
     @Update
     fun update(subscription: Subscription)