add ping service

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

@@ -5,7 +5,8 @@ import com.google.common.eventbus.Subscribe;
 import com.google.common.io.ByteSource;
 import com.sparrowwallet.drongo.SecureString;
 import com.sparrowwallet.drongo.Utils;
-import com.sparrowwallet.drongo.crypto.*;
+import com.sparrowwallet.drongo.crypto.InvalidPasswordException;
+import com.sparrowwallet.drongo.crypto.Key;
 import com.sparrowwallet.drongo.policy.PolicyType;
 import com.sparrowwallet.drongo.protocol.ScriptType;
 import com.sparrowwallet.drongo.protocol.Transaction;
@@ -25,6 +26,7 @@ import javafx.animation.Animation;
 import javafx.animation.KeyFrame;
 import javafx.animation.KeyValue;
 import javafx.animation.Timeline;
+import javafx.concurrent.Worker;
 import javafx.event.ActionEvent;
 import javafx.fxml.FXML;
 import javafx.fxml.FXMLLoader;
@@ -45,6 +47,9 @@ import java.text.ParseException;
 import java.util.*;
 
 public class AppController implements Initializable {
+    private static final int SERVER_PING_PERIOD = 10 * 1000;
+    private static final int ENUMERATE_HW_PERIOD = 30 * 1000;
+
     private static final String TRANSACTION_TAB_TYPE = "transaction";
     public static final String DRAG_OVER_CLASS = "drag-over";
 
@@ -63,16 +68,18 @@ public class AppController implements Initializable {
     @FXML
     private StatusBar statusBar;
 
+    @FXML
+    private UnlabeledToggleSwitch serverToggle;
+
     private Timeline statusTimeline;
 
+    private ElectrumServer.PingService pingService;
+
     public static boolean showTxHexProperty;
 
     @Override
     public void initialize(URL location, ResourceBundle resources) {
         EventManager.get().register(this);
-
-        ElectrumServer.PingService pingService = new ElectrumServer.PingService();
-        //pingService.
     }
 
     void initializeView() {
@@ -124,7 +131,45 @@ public class AppController implements Initializable {
         showTxHexProperty = true;
         exportWallet.setDisable(true);
 
-        //addWalletTab("newWallet", new Wallet(PolicyType.SINGLE, ScriptType.P2WPKH));
+        serverToggle.selectedProperty().addListener((observable, oldValue, newValue) -> {
+            Config.get().setMode(newValue ? Mode.ONLINE : Mode.OFFLINE);
+            if(newValue) {
+                if(pingService.getState() == Worker.State.CANCELLED) {
+                    pingService.reset();
+                }
+
+                if(!pingService.isRunning()) {
+                    pingService.start();
+                }
+            } else {
+                pingService.cancel();
+            }
+        });
+
+        pingService = createPingService();
+        Config config = Config.get();
+        if(config.getMode() == Mode.ONLINE && config.getElectrumServer() != null && !config.getElectrumServer().isEmpty()) {
+            pingService.start();
+        }
+    }
+
+    private ElectrumServer.PingService createPingService() {
+        ElectrumServer.PingService pingService = new ElectrumServer.PingService();
+        pingService.setPeriod(new Duration(SERVER_PING_PERIOD));
+        pingService.setOnSucceeded(successEvent -> {
+            serverToggle.setSelected(true);
+            if(pingService.getValue() != null) {
+                statusBar.setText("Connected: " + pingService.getValue().split(System.lineSeparator(), 2)[0]);
+            } else {
+                statusBar.setText("");
+            }
+        });
+        pingService.setOnFailed(failEvent -> {
+            serverToggle.setSelected(false);
+            statusBar.setText(failEvent.getSource().getException().getMessage());
+        });
+
+        return pingService;
     }
 
     public void openFromFile(ActionEvent event) {
@@ -387,7 +432,7 @@ public class AppController implements Initializable {
 
             if(!storage.getWalletFile().exists() || wallet.containsSource(KeystoreSource.HW_USB)) {
                 Hwi.ScheduledEnumerateService enumerateService = new Hwi.ScheduledEnumerateService(null);
-                enumerateService.setPeriod(new Duration(30 * 1000));
+                enumerateService.setPeriod(new Duration(ENUMERATE_HW_PERIOD));
                 enumerateService.setOnSucceeded(workerStateEvent -> {
                     List<Device> devices = enumerateService.getValue();
                     EventManager.get().post(new UsbDeviceEvent(devices));

src/main/java/com/sparrowwallet/sparrow/control/WelcomeDialog.java

@@ -7,7 +7,6 @@ import javafx.geometry.Insets;
 import javafx.scene.control.*;
 import javafx.scene.image.Image;
 import javafx.scene.image.ImageView;
-import javafx.scene.layout.Region;
 import javafx.scene.layout.VBox;
 import org.controlsfx.control.HyperlinkLabel;
 import org.controlsfx.control.StatusBar;
@@ -42,8 +41,8 @@ public class WelcomeDialog extends Dialog<Mode> {
             dialogPane.setGraphic(imageView);
         }
 
-        final ButtonType onlineButtonType = new javafx.scene.control.ButtonType("Configure Now", ButtonBar.ButtonData.OK_DONE);
-        final ButtonType offlineButtonType = new javafx.scene.control.ButtonType("Configure Later or Use Offline", ButtonBar.ButtonData.CANCEL_CLOSE);
+        final ButtonType onlineButtonType = new javafx.scene.control.ButtonType("Configure Server", ButtonBar.ButtonData.OK_DONE);
+        final ButtonType offlineButtonType = new javafx.scene.control.ButtonType("Later or Offline Mode", ButtonBar.ButtonData.CANCEL_CLOSE);
         dialogPane.getButtonTypes().addAll(onlineButtonType, offlineButtonType);
 
         final VBox content = new VBox(20);

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

@@ -7,6 +7,7 @@ import com.sparrowwallet.drongo.KeyPurpose;
 import com.sparrowwallet.drongo.Utils;
 import com.sparrowwallet.drongo.protocol.*;
 import com.sparrowwallet.drongo.wallet.*;
+import javafx.concurrent.ScheduledService;
 import javafx.concurrent.Service;
 import javafx.concurrent.Task;
 import org.jetbrains.annotations.NotNull;
@@ -76,7 +77,7 @@ public class ElectrumServer {
 
     public void ping() throws ServerException {
         JsonRpcClient client = new JsonRpcClient(getTransport());
-        client.createRequest().returnAs(Void.class).method("server.ping").id(1).execute();
+        client.createRequest().method("server.ping").id(1).executeNullable();
     }
 
     public List<String> getServerVersion() throws ServerException {
@@ -526,17 +527,43 @@ public class ElectrumServer {
         }
     }
 
-    public static class PingService extends Service<Boolean> {
+    public static class PingService extends ScheduledService<String> {
+        private boolean firstCall = true;
+
         @Override
-        protected Task<Boolean> createTask() {
+        protected Task<String> createTask() {
             return new Task<>() {
-                protected Boolean call() throws ServerException {
+                protected String call() throws ServerException {
                     ElectrumServer electrumServer = new ElectrumServer();
-                    electrumServer.ping();
-                    return true;
+                    if(firstCall) {
+                        electrumServer.getServerVersion();
+                        firstCall = false;
+                        return electrumServer.getServerBanner();
+                    } else {
+                        electrumServer.ping();
+                    }
+
+                    return null;
                 }
             };
         }
+
+        @Override
+        public boolean cancel() {
+            try {
+                closeActiveConnection();
+            } catch (ServerException e) {
+                e.printStackTrace();
+            }
+
+            return super.cancel();
+        }
+
+        @Override
+        public void reset() {
+            super.reset();
+            firstCall = true;
+        }
     }
 
     public static class TransactionHistoryService extends Service<Boolean> {