Restore notifications when app starts

uhabits-android/src/main/AndroidManifest.xml

@@ -217,6 +217,14 @@
             </intent-filter>
         </receiver>
 
+        <receiver
+            android:name=".receivers.UpdateReceiver"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MY_PACKAGE_REPLACED" />
+            </intent-filter>
+        </receiver>
+
         <receiver android:name=".receivers.WidgetReceiver"
             android:exported="true"
             android:permission="false">

uhabits-android/src/main/java/org/isoron/uhabits/HabitsApplication.kt

@@ -94,6 +94,7 @@ class HabitsApplication : Application() {
         taskRunner.execute {
             reminderScheduler.scheduleAll()
             widgetUpdater.updateWidgets()
+            notificationTray.reshowAll()
         }
     }
 

uhabits-android/src/main/java/org/isoron/uhabits/inject/HabitsModule.kt

@@ -72,9 +72,10 @@ class HabitsModule(dbFile: File) {
         taskRunner: TaskRunner,
         commandRunner: CommandRunner,
         preferences: Preferences,
-        screen: AndroidNotificationTray
+        screen: AndroidNotificationTray,
+        habitList: HabitList
     ): NotificationTray {
-        return NotificationTray(taskRunner, commandRunner, preferences, screen)
+        return NotificationTray(taskRunner, commandRunner, preferences, screen, habitList)
     }
 
     @Provides

uhabits-android/src/main/java/org/isoron/uhabits/notifications/AndroidNotificationTray.kt

@@ -66,10 +66,11 @@ class AndroidNotificationTray
         habit: Habit,
         notificationId: Int,
         timestamp: Timestamp,
-        reminderTime: Long
+        reminderTime: Long,
+        silent: Boolean
     ) {
         val notificationManager = NotificationManagerCompat.from(context)
-        val notification = buildNotification(habit, reminderTime, timestamp)
+        val notification = buildNotification(habit, reminderTime, timestamp, silent = silent)
         createAndroidNotificationChannel(context)
         try {
             notificationManager.notify(notificationId, notification)
@@ -83,7 +84,8 @@ class AndroidNotificationTray
                 habit,
                 reminderTime,
                 timestamp,
-                disableSound = true
+                disableSound = true,
+                silent = silent
             )
             notificationManager.notify(notificationId, n)
         }
@@ -94,7 +96,8 @@ class AndroidNotificationTray
         habit: Habit,
         reminderTime: Long,
         timestamp: Timestamp,
-        disableSound: Boolean = false
+        disableSound: Boolean = false,
+        silent: Boolean = false
     ): Notification {
 
         val addRepetitionAction = Action(
@@ -132,6 +135,7 @@ class AndroidNotificationTray
             .setSound(null)
             .setWhen(reminderTime)
             .setShowWhen(true)
+            .setSilent(silent)
             .setOngoing(preferences.shouldMakeNotificationsSticky())
 
         if (habit.isNumerical) {

uhabits-android/src/main/java/org/isoron/uhabits/receivers/ReminderController.kt

@@ -37,10 +37,6 @@ class ReminderController @Inject constructor(
     private val notificationTray: NotificationTray,
     private val preferences: Preferences
 ) {
-    fun onBootCompleted() {
-        reminderScheduler.scheduleAll()
-    }
-
     fun onShowReminder(
         habit: Habit,
         timestamp: Timestamp,

uhabits-android/src/main/java/org/isoron/uhabits/receivers/ReminderReceiver.kt

@@ -96,7 +96,7 @@ class ReminderReceiver : BroadcastReceiver() {
                 }
                 Intent.ACTION_BOOT_COMPLETED -> {
                     Log.d("ReminderReceiver", "onBootCompleted")
-                    reminderController.onBootCompleted()
+                    // NOTE: Some activity is executed after boot through HabitsApplication, so receiving ACTION_BOOT_COMPLETED is essential.
                 }
             }
         } catch (e: RuntimeException) {

uhabits-android/src/main/java/org/isoron/uhabits/receivers/UpdateReceiver.kt

@@ -0,0 +1,14 @@
+package org.isoron.uhabits.receivers
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.util.Log
+
+class UpdateReceiver : BroadcastReceiver() {
+
+    override fun onReceive(context: Context, intent: Intent) {
+        // Dummy receiver, relevant code is executed through HabitsApplication.
+        Log.d("UpdateReceiver", "Update receiver called.")
+    }
+}

uhabits-core/build.gradle.kts

@@ -19,6 +19,7 @@
 
 plugins {
     kotlin("multiplatform")
+    kotlin("plugin.serialization") version "1.7.10"
     id("org.jlleitschuh.gradle.ktlint")
 }
 
@@ -30,6 +31,7 @@ kotlin {
             dependencies {
                 implementation(kotlin("stdlib-common"))
                 implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core-common:1.3.8")
+                implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.4.0")
             }
         }
 

uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/models/Timestamp.kt

@@ -18,6 +18,7 @@
  */
 package org.isoron.uhabits.core.models
 
+import kotlinx.serialization.Serializable
 import org.isoron.platform.time.LocalDate
 import org.isoron.uhabits.core.utils.DateFormats.Companion.getCSVDateFormat
 import org.isoron.uhabits.core.utils.DateFormats.Companion.getDialogDateFormat
@@ -29,6 +30,7 @@ import java.util.Date
 import java.util.GregorianCalendar
 import java.util.TimeZone
 
+@Serializable
 data class Timestamp(var unixTime: Long) : Comparable<Timestamp> {
 
     constructor(cal: GregorianCalendar) : this(cal.timeInMillis)

uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/preferences/Preferences.kt

@@ -18,11 +18,18 @@
  */
 package org.isoron.uhabits.core.preferences
 
+import kotlinx.serialization.SerializationException
+import kotlinx.serialization.builtins.MapSerializer
+import kotlinx.serialization.builtins.serializer
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
 import org.isoron.platform.time.DayOfWeek
 import org.isoron.platform.utils.StringUtils.Companion.joinLongs
 import org.isoron.platform.utils.StringUtils.Companion.splitLongs
+import org.isoron.uhabits.core.models.Habit
 import org.isoron.uhabits.core.models.HabitList
 import org.isoron.uhabits.core.models.Timestamp
+import org.isoron.uhabits.core.ui.NotificationTray
 import org.isoron.uhabits.core.ui.ThemeSwitcher
 import org.isoron.uhabits.core.utils.DateUtils.Companion.getFirstWeekdayNumberAccordingToLocale
 import java.util.LinkedList
@@ -135,6 +142,32 @@ open class Preferences(private val storage: Storage) {
             storage.putBoolean("pref_short_toggle", enabled)
         }
 
+    internal open fun setActiveNotifications(activeNotifications: Map<Habit, NotificationTray.NotificationData>) {
+        val activeById = activeNotifications.mapKeys { it.key.id }
+        val serialized = Json.encodeToString(activeById)
+        storage.putString("pref_active_notifications", serialized)
+    }
+
+    internal open fun getActiveNotifications(habitList: HabitList): HashMap<Habit, NotificationTray.NotificationData> {
+        val serialized = storage.getString("pref_active_notifications", "")
+        return if (serialized == "") {
+            HashMap()
+        } else {
+            try {
+                val activeById = Json.decodeFromString(
+                    MapSerializer(Long.serializer(), NotificationTray.NotificationData.serializer()),
+                    serialized
+                )
+                val activeByHabit = activeById.mapNotNull { (id, v) -> habitList.getById(id)?.let { it to v } }
+                activeByHabit.toMap(HashMap())
+            } catch (e : IllegalArgumentException) {
+                HashMap()
+            } catch (e : SerializationException) {
+                HashMap()
+            }
+        }
+    }
+
     fun removeListener(listener: Listener) {
         listeners.remove(listener)
     }

uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/ui/NotificationTray.kt

@@ -18,17 +18,18 @@
  */
 package org.isoron.uhabits.core.ui
 
+import kotlinx.serialization.Serializable
 import org.isoron.uhabits.core.AppScope
 import org.isoron.uhabits.core.commands.Command
 import org.isoron.uhabits.core.commands.CommandRunner
 import org.isoron.uhabits.core.commands.CreateRepetitionCommand
 import org.isoron.uhabits.core.commands.DeleteHabitsCommand
 import org.isoron.uhabits.core.models.Habit
+import org.isoron.uhabits.core.models.HabitList
 import org.isoron.uhabits.core.models.Timestamp
 import org.isoron.uhabits.core.preferences.Preferences
 import org.isoron.uhabits.core.tasks.Task
 import org.isoron.uhabits.core.tasks.TaskRunner
-import java.util.HashMap
 import java.util.Locale
 import java.util.Objects
 import javax.inject.Inject
@@ -38,9 +39,31 @@ class NotificationTray @Inject constructor(
     private val taskRunner: TaskRunner,
     private val commandRunner: CommandRunner,
     private val preferences: Preferences,
-    private val systemTray: SystemTray
+    private val systemTray: SystemTray,
+    private val habitList: HabitList
 ) : CommandRunner.Listener, Preferences.Listener {
-    private val active: HashMap<Habit, NotificationData> = HashMap()
+
+    /**
+     * A mapping from habits to active notifications, automatically persisting on removal.
+     */
+    private val active = object {
+        private val m: HashMap<Habit, NotificationData> =
+            preferences.getActiveNotifications(habitList)
+
+        val entries get() = m.entries
+
+        operator fun set(habit: Habit, notificationData: NotificationData) {
+            m[habit] = notificationData
+            persist()
+        }
+
+        fun remove(habit: Habit) {
+            m.remove(habit)?.let { persist() } // persist if changed
+        }
+
+        fun persist() = preferences.setActiveNotifications(m)
+    }
+
     fun cancel(habit: Habit) {
         val notificationId = getNotificationId(habit)
         systemTray.removeNotification(notificationId)
@@ -64,8 +87,7 @@ class NotificationTray @Inject constructor(
 
     fun show(habit: Habit, timestamp: Timestamp, reminderTime: Long) {
         val data = NotificationData(timestamp, reminderTime)
-        active[habit] = data
-        taskRunner.execute(ShowNotificationTask(habit, data))
+        taskRunner.execute(ShowNotificationTask(habit, data, silent = false))
     }
 
     fun startListening() {
@@ -83,9 +105,9 @@ class NotificationTray @Inject constructor(
         return (id % Int.MAX_VALUE).toInt()
     }
 
-    private fun reshowAll() {
+    fun reshowAll() {
         for ((habit, data) in active.entries) {
-            taskRunner.execute(ShowNotificationTask(habit, data))
+            taskRunner.execute(ShowNotificationTask(habit, data, silent = true))
         }
     }
 
@@ -95,18 +117,44 @@ class NotificationTray @Inject constructor(
             habit: Habit,
             notificationId: Int,
             timestamp: Timestamp,
-            reminderTime: Long
+            reminderTime: Long,
+            silent: Boolean = false
         )
 
         fun log(msg: String)
     }
 
-    internal class NotificationData(val timestamp: Timestamp, val reminderTime: Long)
-    private inner class ShowNotificationTask(private val habit: Habit, data: NotificationData) :
+    @Serializable
+    internal class NotificationData(
+        val timestamp: Timestamp,
+        val reminderTime: Long,
+    ) {
+        override fun equals(other: Any?): Boolean {
+            if (this === other) return true
+            if (javaClass != other?.javaClass) return false
+
+            other as NotificationData
+
+            if (timestamp != other.timestamp) return false
+            if (reminderTime != other.reminderTime) return false
+
+            return true
+        }
+
+        override fun hashCode(): Int {
+            var result = timestamp.hashCode()
+            result = 31 * result + reminderTime.hashCode()
+            return result
+        }
+    }
+
+    private inner class ShowNotificationTask(
+        private val habit: Habit,
+        private val data: NotificationData,
+        private val silent: Boolean
+    ) :
         Task {
         var isCompleted = false
-        private val timestamp: Timestamp = data.timestamp
-        private val reminderTime: Long = data.reminderTime
 
         override fun doInBackground() {
             isCompleted = habit.isCompletedToday()
@@ -122,6 +170,7 @@ class NotificationTray @Inject constructor(
                         habit.id
                     )
                 )
+                active.remove(habit)
                 return
             }
             if (!habit.hasReminder()) {
@@ -132,6 +181,7 @@ class NotificationTray @Inject constructor(
                         habit.id
                     )
                 )
+                active.remove(habit)
                 return
             }
             if (habit.isArchived) {
@@ -142,6 +192,7 @@ class NotificationTray @Inject constructor(
                         habit.id
                     )
                 )
+                active.remove(habit)
                 return
             }
             if (!shouldShowReminderToday()) {
@@ -152,21 +203,33 @@ class NotificationTray @Inject constructor(
                         habit.id
                     )
                 )
+                active.remove(habit)
                 return
             }
             systemTray.showNotification(
                 habit,
                 getNotificationId(habit),
-                timestamp,
-                reminderTime
+                data.timestamp,
+                data.reminderTime,
+                silent = silent
             )
+            if (silent) {
+                systemTray.log(
+                    String.format(
+                        Locale.US,
+                        "Showing notification for habit %d silently because it has been shown before.",
+                        habit.id
+                    )
+                )
+            }
+            active[habit] = data
         }
 
         private fun shouldShowReminderToday(): Boolean {
             if (!habit.hasReminder()) return false
             val reminder = habit.reminder
             val reminderDays = Objects.requireNonNull(reminder)!!.days.toArray()
-            val weekday = timestamp.weekday
+            val weekday = data.timestamp.weekday
             return reminderDays[weekday]
         }
     }