configure a block explorer url, and open a txid in the configured block explorer

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

@@ -811,6 +811,20 @@ public class AppServices {
         }
     }
 
+    public static void openBlockExplorer(String txid) {
+        Server blockExplorer = Config.get().getBlockExplorer() == null ? BlockExplorer.MEMPOOL_SPACE.getServer() : Config.get().getBlockExplorer();
+        String url = blockExplorer.getUrl();
+        if(url.contains("{0}")) {
+            url = url.replace("{0}", txid);
+        } else {
+            if(Network.get() != Network.MAINNET) {
+                url += "/" + Network.get().getName();
+            }
+            url += "/tx/" + txid;
+        }
+        AppServices.get().getApplication().getHostServices().showDocument(url);
+    }
+
     static void parseFileUriArguments(List<String> fileUriArguments) {
         for(String fileUri : fileUriArguments) {
             try {

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

@@ -537,6 +537,13 @@ public class EntryCell extends TreeTableCell<Entry, Entry> implements Confirmati
                 getItems().add(createCpfp);
             }
 
+            MenuItem openBlockExplorer = new MenuItem("Open in Block Explorer");
+            openBlockExplorer.setOnAction(AE -> {
+                hide();
+                AppServices.openBlockExplorer(blockTransaction.getHashAsString());
+            });
+            getItems().add(openBlockExplorer);
+
             MenuItem copyTxid = new MenuItem("Copy Transaction ID");
             copyTxid.setOnAction(AE -> {
                 hide();
@@ -558,6 +565,12 @@ public class EntryCell extends TreeTableCell<Entry, Entry> implements Confirmati
                 EventManager.get().post(new ViewTransactionEvent(this.getOwnerWindow(), blockTransaction));
             });
 
+            MenuItem openBlockExplorer = new MenuItem("Open in Block Explorer");
+            openBlockExplorer.setOnAction(AE -> {
+                hide();
+                AppServices.openBlockExplorer(blockTransaction.getHashAsString());
+            });
+
             MenuItem copyDate = new MenuItem("Copy Date");
             copyDate.setOnAction(AE -> {
                 hide();
@@ -582,7 +595,7 @@ public class EntryCell extends TreeTableCell<Entry, Entry> implements Confirmati
                 Clipboard.getSystemClipboard().setContent(content);
             });
 
-            getItems().addAll(viewTransaction, copyDate, copyTxid, copyHeight);
+            getItems().addAll(viewTransaction, openBlockExplorer, copyDate, copyTxid, copyHeight);
         }
     }
 

src/main/java/com/sparrowwallet/sparrow/glyphfont/FontAwesome5.java

@@ -76,6 +76,7 @@ public class FontAwesome5 extends GlyphFont {
         TOGGLE_OFF('\uf204'),
         TOGGLE_ON('\uf205'),
         TOOLS('\uf7d9'),
+        UP_RIGHT_FROM_SQUARE('\uf35d'),
         UNDO('\uf0e2'),
         USER('\uf007'),
         USER_FRIENDS('\uf500'),

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

@@ -30,6 +30,7 @@ public class Config {
     private Mode mode;
     private BitcoinUnit bitcoinUnit;
     private UnitFormat unitFormat;
+    private Server blockExplorer;
     private FeeRatesSource feeRatesSource;
     private FeeRatesSelection feeRatesSelection;
     private OptimizationStrategy sendOptimizationStrategy;
@@ -150,6 +151,15 @@ public class Config {
         flush();
     }
 
+    public Server getBlockExplorer() {
+        return blockExplorer;
+    }
+
+    public void setBlockExplorer(Server blockExplorer) {
+        this.blockExplorer = blockExplorer;
+        flush();
+    }
+
     public FeeRatesSource getFeeRatesSource() {
         return feeRatesSource;
     }

src/main/java/com/sparrowwallet/sparrow/net/BlockExplorer.java

@@ -0,0 +1,18 @@
+package com.sparrowwallet.sparrow.net;
+
+import com.sparrowwallet.sparrow.io.Server;
+
+public enum BlockExplorer {
+    MEMPOOL_SPACE("https://mempool.space"),
+    BLOCKSTREAM_INFO("https://blockstream.info");
+
+    private final Server server;
+
+    BlockExplorer(String url) {
+        this.server = new Server(url);
+    }
+
+    public Server getServer() {
+        return server;
+    }
+}

src/main/java/com/sparrowwallet/sparrow/preferences/GeneralPreferencesController.java

@@ -1,32 +1,44 @@
 package com.sparrowwallet.sparrow.preferences;
 
-import com.sparrowwallet.drongo.BitcoinUnit;
 import com.sparrowwallet.drongo.wallet.Wallet;
+import com.sparrowwallet.sparrow.AppServices;
 import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.control.UnlabeledToggleSwitch;
 import com.sparrowwallet.sparrow.event.*;
 import com.sparrowwallet.sparrow.io.Config;
+import com.sparrowwallet.sparrow.io.Server;
+import com.sparrowwallet.sparrow.net.BlockExplorer;
 import com.sparrowwallet.sparrow.net.ExchangeSource;
 import com.sparrowwallet.sparrow.net.FeeRatesSource;
+import javafx.application.Platform;
 import javafx.beans.value.ChangeListener;
 import javafx.beans.value.ObservableValue;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
 import javafx.fxml.FXML;
 import javafx.scene.control.ComboBox;
+import javafx.scene.control.TextInputDialog;
+import javafx.util.StringConverter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.Arrays;
 import java.util.Currency;
 import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
 
 public class GeneralPreferencesController extends PreferencesDetailController {
     private static final Logger log = LoggerFactory.getLogger(GeneralPreferencesController.class);
 
-    @FXML
-    private ComboBox<BitcoinUnit> bitcoinUnit;
+    private static final Server CUSTOM_BLOCK_EXPLORER = new Server("http://custom.block.explorer");
 
     @FXML
     private ComboBox<FeeRatesSource> feeRatesSource;
 
+    @FXML
+    private ComboBox<Server> blockExplorers;
+
     @FXML
     private ComboBox<Currency> fiatCurrency;
 
@@ -63,17 +75,6 @@ public class GeneralPreferencesController extends PreferencesDetailController {
 
     @Override
     public void initializeView(Config config) {
-        if(config.getBitcoinUnit() != null) {
-            bitcoinUnit.setValue(config.getBitcoinUnit());
-        } else {
-            bitcoinUnit.setValue(BitcoinUnit.AUTO);
-        }
-
-        bitcoinUnit.valueProperty().addListener((observable, oldValue, newValue) -> {
-            config.setBitcoinUnit(newValue);
-            EventManager.get().post(new BitcoinUnitChangedEvent(newValue));
-        });
-
         if(config.getFeeRatesSource() != null) {
             feeRatesSource.setValue(config.getFeeRatesSource());
         } else {
@@ -86,6 +87,62 @@ public class GeneralPreferencesController extends PreferencesDetailController {
             EventManager.get().post(new FeeRatesSourceChangedEvent(newValue));
         });
 
+        blockExplorers.setItems(getBlockExplorerList());
+        blockExplorers.setConverter(new StringConverter<>() {
+            @Override
+            public String toString(Server server) {
+                if(server == null) {
+                    return "None Available";
+                }
+
+                if(server == CUSTOM_BLOCK_EXPLORER) {
+                    return "Custom...";
+                }
+
+                return server.getHost();
+            }
+
+            @Override
+            public Server fromString(String string) {
+                return null;
+            }
+        });
+        blockExplorers.valueProperty().addListener((observable, oldValue, newValue) -> {
+            if(newValue != null) {
+                if(newValue == CUSTOM_BLOCK_EXPLORER) {
+                    TextInputDialog textInputDialog = new TextInputDialog();
+                    textInputDialog.setTitle("Enter Block Explorer URL");
+                    textInputDialog.setHeaderText("Enter the URL of the block explorer.\n\nIf present, the characters {0} will be replaced with the txid.\nFor example, https://localhost or https://localhost/tx/{0}\n");
+                    textInputDialog.getEditor().setPromptText("https://localhost");
+                    Optional<String> optUrl = textInputDialog.showAndWait();
+                    if(optUrl.isPresent() && !optUrl.get().isEmpty()) {
+                        try {
+                            Server server = getBlockExplorer(optUrl.get());
+                            config.setBlockExplorer(server);
+                            Platform.runLater(() -> {
+                                blockExplorers.getSelectionModel().select(-1);
+                                blockExplorers.setItems(getBlockExplorerList());
+                                blockExplorers.setValue(Config.get().getBlockExplorer());
+                            });
+                        } catch(Exception e) {
+                            AppServices.showErrorDialog("Invalid URL", "The URL " + optUrl.get() + " is not valid.");
+                            blockExplorers.setValue(oldValue);
+                        }
+                    } else {
+                        blockExplorers.setValue(oldValue);
+                    }
+                } else {
+                    Config.get().setBlockExplorer(newValue);
+                }
+            }
+        });
+
+        if(config.getBlockExplorer() != null) {
+            blockExplorers.setValue(config.getBlockExplorer());
+        } else {
+            blockExplorers.getSelectionModel().select(0);
+        }
+
         if(config.getExchangeSource() != null) {
             exchangeSource.setValue(config.getExchangeSource());
         } else {
@@ -134,6 +191,23 @@ public class GeneralPreferencesController extends PreferencesDetailController {
         });
     }
 
+    private static Server getBlockExplorer(String serverUrl) {
+        String url = serverUrl.trim();
+        if(url.endsWith("/")) {
+            url = url.substring(0, url.length() - 1);
+        }
+        return new Server(url);
+    }
+
+    private ObservableList<Server> getBlockExplorerList() {
+        List<Server> servers = Arrays.stream(BlockExplorer.values()).map(BlockExplorer::getServer).collect(Collectors.toList());
+        if(Config.get().getBlockExplorer() != null && !servers.contains(Config.get().getBlockExplorer())) {
+            servers.add(Config.get().getBlockExplorer());
+        }
+        servers.add(CUSTOM_BLOCK_EXPLORER);
+        return FXCollections.observableList(servers);
+    }
+
     private void updateCurrencies(ExchangeSource exchangeSource) {
         ExchangeSource.CurrenciesService currenciesService = new ExchangeSource.CurrenciesService(exchangeSource);
         currenciesService.setOnSucceeded(event -> {

src/main/java/com/sparrowwallet/sparrow/transaction/HeadersController.java

@@ -78,6 +78,12 @@ public class HeadersController extends TransactionFormController implements Init
     @FXML
     private IdLabel id;
 
+    @FXML
+    private ToggleButton copyTxid;
+
+    @FXML
+    private ToggleButton openBlockExplorer;
+
     @FXML
     private TransactionDiagram transactionDiagram;
 
@@ -806,11 +812,13 @@ public class HeadersController extends TransactionFormController implements Init
             addStyleClass(size, UNFINALIZED_TXID_CLASS);
             addStyleClass(virtualSize, UNFINALIZED_TXID_CLASS);
             addStyleClass(feeRate, UNFINALIZED_TXID_CLASS);
+            openBlockExplorer.setDisable(true);
         } else {
             id.getStyleClass().remove(UNFINALIZED_TXID_CLASS);
             size.getStyleClass().remove(UNFINALIZED_TXID_CLASS);
             virtualSize.getStyleClass().remove(UNFINALIZED_TXID_CLASS);
             feeRate.getStyleClass().remove(UNFINALIZED_TXID_CLASS);
+            openBlockExplorer.setDisable(false);
         }
     }
 
@@ -821,11 +829,18 @@ public class HeadersController extends TransactionFormController implements Init
     }
 
     public void copyId(ActionEvent event) {
+        copyTxid.setSelected(false);
         ClipboardContent content = new ClipboardContent();
         content.putString(headersForm.getTransaction().calculateTxId(false).toString());
         Clipboard.getSystemClipboard().setContent(content);
     }
 
+    public void openInBlockExplorer(ActionEvent event) {
+        openBlockExplorer.setSelected(false);
+        String txid = headersForm.getTransaction().calculateTxId(false).toString();
+        AppServices.openBlockExplorer(txid);
+    }
+
     public void setLocktimeToCurrentHeight(ActionEvent event) {
         if(AppServices.getCurrentBlockHeight() != null && locktimeBlock.isEditable()) {
             locktimeBlock.getValueFactory().setValue(AppServices.getCurrentBlockHeight());