schedule a caldav sync for every 4 hours

app/src/main/AndroidManifest.xml

@@ -127,6 +127,8 @@
 
         <receiver android:name=".receivers.NotificationReceiver"/>
 
+        <receiver android:name=".receivers.CalDAVSyncReceiver"/>
+
         <receiver android:name=".receivers.BootCompletedReceiver">
             <intent-filter>
                 <action android:name="android.intent.action.BOOT_COMPLETED"/>

app/src/main/kotlin/com/simplemobiletools/calendar/activities/MainActivity.kt

@@ -87,6 +87,8 @@ class MainActivity : SimpleActivity(), NavigationListener {
         if (!hasCalendarPermission()) {
             config.caldavSync = false
         }
+
+        recheckCalDAVCalendars()
     }
 
     override fun onResume() {

app/src/main/kotlin/com/simplemobiletools/calendar/activities/SettingsActivity.kt

@@ -151,11 +151,7 @@ class SettingsActivity : SimpleActivity() {
                             dbHelper.insertEventType(eventType)
                         }
                     }
-
+                    CalDAVEventsHandler(applicationContext).refreshCalendars()
-                    calendars.forEach {
-                        val eventTypeId = dbHelper.getEventTypeIdWithTitle(it.displayName)
-                        CalDAVEventsHandler(applicationContext).fetchCalDAVCalendarEvents(it.id, eventTypeId)
-                    }
                 }
 
                 oldCalendarIds.filter { !newCalendarIds.contains(it) }.forEach {

app/src/main/kotlin/com/simplemobiletools/calendar/extensions/Context.kt

@@ -21,6 +21,7 @@ import com.simplemobiletools.calendar.activities.EventActivity
 import com.simplemobiletools.calendar.helpers.*
 import com.simplemobiletools.calendar.helpers.Formatter
 import com.simplemobiletools.calendar.models.Event
+import com.simplemobiletools.calendar.receivers.CalDAVSyncReceiver
 import com.simplemobiletools.calendar.receivers.NotificationReceiver
 import com.simplemobiletools.calendar.services.SnoozeService
 import com.simplemobiletools.commons.extensions.getContrastColor
@@ -234,6 +235,25 @@ fun Context.getNewEventTimestampFromCode(dayCode: String) = Formatter.getLocalDa
 
 fun Context.getCurrentOffset() = SimpleDateFormat("Z", Locale.getDefault()).format(Date())
 
+fun Context.recheckCalDAVCalendars() {
+    if (config.caldavSync) {
+        CalDAVEventsHandler(this).refreshCalendars()
+    }
+}
+
+fun Context.scheduleCalDAVSync(activate: Boolean) {
+    val syncIntent = Intent(this, CalDAVSyncReceiver::class.java)
+    val pendingIntent = PendingIntent.getBroadcast(this, 0, syncIntent, PendingIntent.FLAG_CANCEL_CURRENT)
+    val alarm = getSystemService(Context.ALARM_SERVICE) as AlarmManager
+
+    if (activate) {
+        val syncCheckInterval = 4 * AlarmManager.INTERVAL_HOUR
+        alarm.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + syncCheckInterval, syncCheckInterval, pendingIntent)
+    } else {
+        alarm.cancel(pendingIntent)
+    }
+}
+
 val Context.config: Config get() = Config.newInstance(this)
 
 val Context.dbHelper: DBHelper get() = DBHelper.newInstance(this)

app/src/main/kotlin/com/simplemobiletools/calendar/helpers/CalDAVEventsHandler.kt

@@ -6,8 +6,10 @@ import android.content.Context
 import android.database.Cursor
 import android.provider.CalendarContract
 import android.provider.CalendarContract.Reminders
+import com.simplemobiletools.calendar.extensions.config
 import com.simplemobiletools.calendar.extensions.dbHelper
 import com.simplemobiletools.calendar.extensions.hasCalendarPermission
+import com.simplemobiletools.calendar.extensions.scheduleCalDAVSync
 import com.simplemobiletools.calendar.models.CalDAVCalendar
 import com.simplemobiletools.calendar.models.Event
 import com.simplemobiletools.commons.extensions.getIntValue
@@ -16,6 +18,14 @@ import com.simplemobiletools.commons.extensions.getStringValue
 import java.util.*
 
 class CalDAVEventsHandler(val context: Context) {
+    fun refreshCalendars() {
+        getCalDAVCalendars(context.config.caldavSyncedCalendarIDs).forEach {
+            val eventTypeId = context.dbHelper.getEventTypeIdWithTitle(it.displayName)
+            CalDAVEventsHandler(context).fetchCalDAVCalendarEvents(it.id, eventTypeId)
+        }
+        context.scheduleCalDAVSync(true)
+    }
+
     fun getCalDAVCalendars(ids: String = ""): List<CalDAVCalendar> {
         val calendars = ArrayList<CalDAVCalendar>()
         if (!context.hasCalendarPermission()) {

app/src/main/kotlin/com/simplemobiletools/calendar/helpers/Config.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import android.media.RingtoneManager
 import android.text.format.DateFormat
 import com.simplemobiletools.calendar.R
+import com.simplemobiletools.calendar.extensions.scheduleCalDAVSync
 import com.simplemobiletools.commons.helpers.BaseConfig
 import java.util.*
 
@@ -72,7 +73,10 @@ class Config(context: Context) : BaseConfig(context) {
 
     var caldavSync: Boolean
         get() = prefs.getBoolean(CALDAV_SYNC, false)
-        set(caldavSync) = prefs.edit().putBoolean(CALDAV_SYNC, caldavSync).apply()
+        set(caldavSync) {
+            context.scheduleCalDAVSync(caldavSync)
+            prefs.edit().putBoolean(CALDAV_SYNC, caldavSync).apply()
+        }
 
     var caldavSyncedCalendarIDs: String
         get() = prefs.getString(CALDAV_SYNCED_CALENDAR_IDS, "")

app/src/main/kotlin/com/simplemobiletools/calendar/receivers/BootCompletedReceiver.kt

@@ -4,6 +4,7 @@ import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
 import com.simplemobiletools.calendar.extensions.notifyRunningEvents
+import com.simplemobiletools.calendar.extensions.recheckCalDAVCalendars
 import com.simplemobiletools.calendar.extensions.scheduleAllEvents
 
 class BootCompletedReceiver : BroadcastReceiver() {
@@ -12,6 +13,7 @@ class BootCompletedReceiver : BroadcastReceiver() {
         context.apply {
             scheduleAllEvents()
             notifyRunningEvents()
+            recheckCalDAVCalendars()
         }
     }
 }

app/src/main/kotlin/com/simplemobiletools/calendar/receivers/CalDAVSyncReceiver.kt

@@ -0,0 +1,12 @@
+package com.simplemobiletools.calendar.receivers
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import com.simplemobiletools.calendar.extensions.recheckCalDAVCalendars
+
+class CalDAVSyncReceiver : BroadcastReceiver() {
+    override fun onReceive(context: Context, intent: Intent) {
+        context.recheckCalDAVCalendars()
+    }
+}