Notification: ignore seen notifications

app/src/main/java/com/keylesspalace/tusky/entity/Notification.kt

@@ -16,13 +16,19 @@
 package com.keylesspalace.tusky.entity
 
 import com.google.gson.*
+import com.google.gson.annotations.SerializedName
 import com.google.gson.annotations.JsonAdapter
 
+data class PleromaNotification(
+    @SerializedName("is_seen") val seen: Boolean
+)
+
 data class Notification(
         val type: Type,
         val id: String,
         val account: Account,
-        val status: Status?) {
+        val status: Status?,
+        val pleroma: PleromaNotification? = null) {
 
     @JsonAdapter(NotificationTypeAdapter::class)
     enum class Type(val presentation: String) {

app/src/main/java/com/keylesspalace/tusky/util/NotificationHelper.java

@@ -138,6 +138,11 @@ public class NotificationHelper {
         if (!filterNotification(account, body, context)) {
             return;
         }
+        
+        // Pleroma extension: don't notify about seen notifications
+        if (body.getPleroma() != null && body.getPleroma().getSeen()) {
+            return;
+        }
 
         String rawCurrentNotifications = account.getActiveNotifications();
         JSONArray currentNotifications;