fix #573, listen to CalDAV events in the background, update asap

app/src/main/AndroidManifest.xml

@@ -177,6 +177,11 @@
 
         <service android:name=".services.SnoozeService"/>
 
+        <service
+            android:name=".jobs.CalDAVUpdateListener"
+            android:exported="true"
+            android:permission="android.permission.BIND_JOB_SERVICE"/>
+
         <receiver android:name=".receivers.NotificationReceiver"/>
 
         <receiver android:name=".receivers.CalDAVSyncReceiver"/>

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

@@ -31,6 +31,7 @@ import com.simplemobiletools.calendar.pro.extensions.*
 import com.simplemobiletools.calendar.pro.fragments.*
 import com.simplemobiletools.calendar.pro.helpers.*
 import com.simplemobiletools.calendar.pro.helpers.Formatter
+import com.simplemobiletools.calendar.pro.jobs.CalDAVUpdateListener
 import com.simplemobiletools.calendar.pro.models.Event
 import com.simplemobiletools.calendar.pro.models.EventType
 import com.simplemobiletools.calendar.pro.models.ListEvent
@@ -102,6 +103,10 @@ class MainActivity : SimpleActivity(), RefreshRecyclerViewListener {
         }
 
         checkAppOnSDCard()
+
+        if (savedInstanceState == null) {
+            checkCalDAVUpdateListener()
+        }
     }
 
     override fun onResume() {
@@ -265,6 +270,19 @@ class MainActivity : SimpleActivity(), RefreshRecyclerViewListener {
         mSearchMenuItem?.collapseActionView()
     }
 
+    private fun checkCalDAVUpdateListener() {
+        if (isNougatPlus()) {
+            val updateListener = CalDAVUpdateListener()
+            if (config.caldavSync) {
+                if (!updateListener.isScheduled(applicationContext)) {
+                    updateListener.scheduleJob(applicationContext)
+                }
+            } else {
+                updateListener.cancelJob(applicationContext)
+            }
+        }
+    }
+
     @SuppressLint("NewApi")
     private fun checkShortcuts() {
         val appIconColor = config.appIconColor

app/src/main/kotlin/com/simplemobiletools/calendar/pro/jobs/CalDAVUpdateListener.kt

@@ -0,0 +1,65 @@
+package com.simplemobiletools.calendar.pro.jobs
+
+import android.annotation.TargetApi
+import android.app.job.JobInfo
+import android.app.job.JobParameters
+import android.app.job.JobScheduler
+import android.app.job.JobService
+import android.content.ComponentName
+import android.content.Context
+import android.os.Build
+import android.os.Handler
+import android.provider.CalendarContract
+import com.simplemobiletools.calendar.pro.extensions.recheckCalDAVCalendars
+
+// based on https://developer.android.com/reference/android/app/job/JobInfo.Builder.html#addTriggerContentUri(android.app.job.JobInfo.TriggerContentUri)
+@TargetApi(Build.VERSION_CODES.N)
+class CalDAVUpdateListener : JobService() {
+    companion object {
+        const val CALDAV_EVENT_CONTENT_JOB = 1
+    }
+
+    private val mHandler = Handler()
+    private val mWorker = Runnable {
+        scheduleJob(this@CalDAVUpdateListener)
+        jobFinished(mRunningParams, false)
+    }
+
+    private var mRunningParams: JobParameters? = null
+
+    fun scheduleJob(context: Context) {
+        val componentName = ComponentName(context, CalDAVUpdateListener::class.java)
+        val uri = CalendarContract.Calendars.CONTENT_URI
+        JobInfo.Builder(CALDAV_EVENT_CONTENT_JOB, componentName).apply {
+            addTriggerContentUri(JobInfo.TriggerContentUri(uri, JobInfo.TriggerContentUri.FLAG_NOTIFY_FOR_DESCENDANTS))
+            context.getSystemService(JobScheduler::class.java).schedule(build())
+        }
+    }
+
+    fun isScheduled(context: Context): Boolean {
+        val jobScheduler = context.getSystemService(JobScheduler::class.java)
+        val jobs = jobScheduler.allPendingJobs ?: return false
+        return jobs.any { it.id == CALDAV_EVENT_CONTENT_JOB }
+    }
+
+    fun cancelJob(context: Context) {
+        val js = context.getSystemService(JobScheduler::class.java)
+        js.cancel(CALDAV_EVENT_CONTENT_JOB)
+    }
+
+    override fun onStartJob(params: JobParameters): Boolean {
+        mRunningParams = params
+
+        if (params.triggeredContentAuthorities != null && params.triggeredContentUris != null) {
+            recheckCalDAVCalendars {}
+        }
+
+        mHandler.post(mWorker)
+        return true
+    }
+
+    override fun onStopJob(params: JobParameters): Boolean {
+        mHandler.removeCallbacks(mWorker)
+        return false
+    }
+}