Actively poll public chat group if the app is in the foreground

src/org/thoughtcrime/securesms/loki/LokiGroupChatPoller.kt

@@ -1,6 +1,7 @@
 package org.thoughtcrime.securesms.loki
 
 import android.content.Context
+import android.os.Handler
 import android.util.Log
 import org.thoughtcrime.securesms.jobs.PushDecryptJob
 import org.whispersystems.libsignal.util.guava.Optional
@@ -10,10 +11,33 @@ import org.whispersystems.signalservice.api.messages.SignalServiceGroup
 import org.whispersystems.signalservice.api.push.SignalServiceAddress
 import org.whispersystems.signalservice.loki.api.LokiGroupChatAPI
 
-object LokiGroupChatPoller {
+class LokiGroupChatPoller(private val context: Context, private val groupID: Long) {
+    private val handler = Handler()
+    private var hasStarted = false
 
-    @JvmStatic
-    fun poll(context: Context, groupID: Long) {
+    private val task = object : Runnable {
+
+        override fun run() {
+            poll()
+            handler.postDelayed(this, pollInterval)
+        }
+    }
+
+    companion object {
+        private val pollInterval: Long = 5 * 1000
+    }
+
+    fun startIfNeeded() {
+        if (hasStarted) return
+        task.run()
+        hasStarted = true
+    }
+
+    fun stop() {
+        handler.removeCallbacks(task)
+    }
+
+    private fun poll() {
         LokiGroupChatAPI.getMessages(groupID).success { messages ->
             messages.map { message ->
                 val id = "loki-group-chat-$groupID".toByteArray()