handle new blocks

build.gradle

@@ -34,6 +34,9 @@ dependencies {
     implementation('no.tornado:tornadofx-controls:1.0.4')
     implementation('com.google.zxing:javase:3.4.0')
     implementation('com.github.arteam:simple-json-rpc-client:1.0')
+    implementation('com.github.arteam:simple-json-rpc-server:1.0') {
+        exclude group: 'org.slf4j'
+    }
     implementation('de.codecentric.centerdevice:centerdevice-nsmenufx:2.1.7')
     implementation('org.controlsfx:controlsfx:11.0.1' ) {
         exclude group: 'org.openjfx', module: 'javafx-base'

src/main/java/com/sparrowwallet/sparrow/AppController.java

@@ -677,4 +677,10 @@ public class AppController implements Initializable {
         String status = "Connection error: " + reason;
         EventManager.get().post(new StatusEvent(status));
     }
+
+    @Subscribe
+    public void newBlock(NewBlockEvent event) {
+        String status = "Updating to new block height " + event.getHeight();
+        EventManager.get().post(new StatusEvent(status));
+    }
 }

src/main/java/com/sparrowwallet/sparrow/event/NewBlockEvent.java

@@ -0,0 +1,21 @@
+package com.sparrowwallet.sparrow.event;
+
+import com.sparrowwallet.drongo.protocol.BlockHeader;
+
+public class NewBlockEvent {
+    private final int height;
+    private final BlockHeader blockHeader;
+
+    public NewBlockEvent(int height, BlockHeader blockHeader) {
+        this.height = height;
+        this.blockHeader = blockHeader;
+    }
+
+    public int getHeight() {
+        return height;
+    }
+
+    public BlockHeader getBlockHeader() {
+        return blockHeader;
+    }
+}

src/main/java/com/sparrowwallet/sparrow/io/ElectrumServer.java

@@ -2,12 +2,19 @@ package com.sparrowwallet.sparrow.io;
 
 import com.github.arteam.simplejsonrpc.client.*;
 import com.github.arteam.simplejsonrpc.client.builder.BatchRequestBuilder;
+import com.github.arteam.simplejsonrpc.core.annotation.JsonRpcMethod;
+import com.github.arteam.simplejsonrpc.core.annotation.JsonRpcParam;
+import com.github.arteam.simplejsonrpc.core.annotation.JsonRpcService;
+import com.github.arteam.simplejsonrpc.server.JsonRpcServer;
 import com.google.common.net.HostAndPort;
 import com.sparrowwallet.drongo.KeyPurpose;
 import com.sparrowwallet.drongo.Utils;
 import com.sparrowwallet.drongo.protocol.*;
 import com.sparrowwallet.drongo.wallet.*;
+import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.event.ConnectionEvent;
+import com.sparrowwallet.sparrow.event.NewBlockEvent;
+import javafx.application.Platform;
 import javafx.concurrent.ScheduledService;
 import javafx.concurrent.Service;
 import javafx.concurrent.Task;
@@ -390,6 +397,14 @@ public class ElectrumServer {
         }
     }
 
+    @JsonRpcService
+    public static class SubscriptionService {
+        @JsonRpcMethod("blockchain.headers.subscribe")
+        public void newBlockHeaderTip(@JsonRpcParam("header") final BlockHeaderTip header) {
+            Platform.runLater(() -> EventManager.get().post(new NewBlockEvent(header.height, header.getBlockHeader())));
+        }
+    }
+
     public static class TcpTransport implements Transport, Closeable {
         public static final int DEFAULT_PORT = 50001;
 
@@ -404,6 +419,9 @@ public class ElectrumServer {
         private boolean running = false;
         private boolean reading = true;
 
+        private final JsonRpcServer jsonRpcServer = new JsonRpcServer();
+        private final SubscriptionService subscriptionService = new SubscriptionService();
+
         public TcpTransport(HostAndPort server) {
             this.server = server;
             this.socketFactory = SocketFactory.getDefault();
@@ -447,9 +465,10 @@ public class ElectrumServer {
                 try {
                     String received = readInputStream();
                     if(received.contains("method")) {
-                        //Handle notification
-                        System.out.println("Notification: " + received);
+                        //Handle subscription notification
+                        jsonRpcServer.handle(received, subscriptionService);
                     } else {
+                        //Handle client's response
                         response = received;
                         reading = false;
                         notifyAll();

src/main/java/com/sparrowwallet/sparrow/wallet/WalletForm.java

@@ -5,6 +5,7 @@ import com.sparrowwallet.drongo.KeyPurpose;
 import com.sparrowwallet.drongo.wallet.Wallet;
 import com.sparrowwallet.drongo.wallet.WalletNode;
 import com.sparrowwallet.sparrow.EventManager;
+import com.sparrowwallet.sparrow.event.NewBlockEvent;
 import com.sparrowwallet.sparrow.event.WalletChangedEvent;
 import com.sparrowwallet.sparrow.io.ElectrumServer;
 import com.sparrowwallet.sparrow.io.Storage;
@@ -119,4 +120,9 @@ public class WalletForm {
             }
         }
     }
+
+    @Subscribe
+    public void newBlock(NewBlockEvent event) {
+        refreshHistory();
+    }
 }

src/main/java/module-info.java

@@ -13,6 +13,7 @@ open module com.sparrowwallet.sparrow {
     requires com.google.zxing;
     requires com.google.zxing.javase;
     requires simple.json.rpc.client;
+    requires simple.json.rpc.server;
     requires simple.json.rpc.core;
     requires org.jetbrains.annotations;
     requires com.fasterxml.jackson.databind;