fetch transaction output transactions, handle coinbase input

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

@@ -9,6 +9,7 @@ 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.Sha256Hash;
 import com.sparrowwallet.drongo.protocol.Transaction;
 import com.sparrowwallet.drongo.psbt.PSBT;
 import com.sparrowwallet.drongo.psbt.PSBTParseException;
@@ -23,6 +24,7 @@ import com.sparrowwallet.sparrow.wallet.WalletController;
 import com.sparrowwallet.sparrow.wallet.WalletForm;
 import de.codecentric.centerdevice.MenuToolkit;
 import javafx.animation.*;
+import javafx.application.Platform;
 import javafx.beans.property.BooleanProperty;
 import javafx.beans.property.SimpleBooleanProperty;
 import javafx.concurrent.Worker;
@@ -57,6 +59,9 @@ public class AppController implements Initializable {
     @FXML
     private Menu fileMenu;
 
+    @FXML
+    private MenuItem openTransactionIdItem;
+
     @FXML
     private CheckMenuItem showTxHex;
 
@@ -166,6 +171,8 @@ public class AppController implements Initializable {
             connectionService.start();
         }
 
+        openTransactionIdItem.disableProperty().bind(onlineProperty.not());
+
         openWalletFile(new File("/Users/scy/.sparrow/wallets/sparta.json"));
     }
 
@@ -294,6 +301,32 @@ public class AppController implements Initializable {
         }
     }
 
+    public void openTransactionFromId(ActionEvent event) {
+        TransactionIdDialog dialog = new TransactionIdDialog();
+        Optional<Sha256Hash> optionalTxId = dialog.showAndWait();
+        if(optionalTxId.isPresent()) {
+            Sha256Hash txId = optionalTxId.get();
+            ElectrumServer.TransactionReferenceService transactionReferenceService = new ElectrumServer.TransactionReferenceService(Set.of(txId));
+            transactionReferenceService.setOnSucceeded(successEvent -> {
+                BlockTransaction blockTransaction = transactionReferenceService.getValue().get(txId);
+                if(blockTransaction == null) {
+                    showErrorDialog("Invalid transaction ID", "A transaction with that ID could not be found.");
+                } else {
+                    Platform.runLater(() -> {
+                        EventManager.get().post(new ViewTransactionEvent(blockTransaction));
+                    });
+                }
+            });
+            transactionReferenceService.setOnFailed(failEvent -> {
+                Platform.runLater(() -> {
+                    Throwable e = failEvent.getSource().getException();
+                    showErrorDialog("Error fetching transaction", e.getCause() != null ? e.getCause().getMessage() : e.getMessage());
+                });
+            });
+            transactionReferenceService.start();
+        }
+    }
+
     public static boolean isOnline() {
         return onlineProperty.get();
     }
@@ -564,7 +597,7 @@ public class AppController implements Initializable {
             TabData tabData = (TabData)tab.getUserData();
             if(tabData instanceof TransactionTabData) {
                 TransactionTabData transactionTabData = (TransactionTabData)tabData;
-                if(transactionTabData.getTransaction() == transaction) {
+                if(transactionTabData.getTransaction().getTxId().equals(transaction.getTxId())) {
                     return tab;
                 }
             }

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

@@ -18,9 +18,9 @@ public class CoinLabel extends CopyableLabel {
 
     public static final DecimalFormat BTC_FORMAT = new DecimalFormat("0", DecimalFormatSymbols.getInstance(Locale.ENGLISH));
 
-    private final LongProperty value = new SimpleLongProperty();
+    private final LongProperty value = new SimpleLongProperty(-1);
-    private Tooltip tooltip;
+    private final Tooltip tooltip;
-    private CoinContextMenu contextMenu;
+    private final CoinContextMenu contextMenu;
 
     public CoinLabel() {
         this("Unknown");
@@ -62,11 +62,8 @@ public class CoinLabel extends CopyableLabel {
     }
 
     private class CoinContextMenu extends ContextMenu {
-        private MenuItem copySatsValue;
-        private MenuItem copyBtcValue;
-
         public CoinContextMenu() {
-            copySatsValue = new MenuItem("Copy Value in Satoshis");
+            MenuItem copySatsValue = new MenuItem("Copy Value in Satoshis");
             copySatsValue.setOnAction(AE -> {
                 hide();
                 ClipboardContent content = new ClipboardContent();
@@ -74,7 +71,7 @@ public class CoinLabel extends CopyableLabel {
                 Clipboard.getSystemClipboard().setContent(content);
             });
 
-            copyBtcValue = new MenuItem("Copy Value in BTC");
+            MenuItem copyBtcValue = new MenuItem("Copy Value in BTC");
             copyBtcValue.setOnAction(AE -> {
                 hide();
                 ClipboardContent content = new ClipboardContent();

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

@@ -0,0 +1,65 @@
+package com.sparrowwallet.sparrow.control;
+
+import com.sparrowwallet.drongo.Utils;
+import com.sparrowwallet.drongo.protocol.Sha256Hash;
+import com.sparrowwallet.sparrow.AppController;
+import com.sparrowwallet.sparrow.io.Storage;
+import javafx.application.Platform;
+import javafx.beans.binding.Bindings;
+import javafx.beans.binding.BooleanBinding;
+import javafx.scene.control.*;
+import javafx.scene.layout.VBox;
+import org.controlsfx.control.textfield.CustomTextField;
+import org.controlsfx.control.textfield.TextFields;
+import org.controlsfx.glyphfont.FontAwesome;
+import org.controlsfx.glyphfont.Glyph;
+import org.controlsfx.validation.ValidationResult;
+import org.controlsfx.validation.ValidationSupport;
+import org.controlsfx.validation.Validator;
+import org.controlsfx.validation.decoration.StyleClassValidationDecoration;
+
+public class TransactionIdDialog extends Dialog<Sha256Hash> {
+    private final CustomTextField txid;
+
+    public TransactionIdDialog() {
+        this.txid = (CustomTextField) TextFields.createClearableTextField();
+        final DialogPane dialogPane = getDialogPane();
+
+        setTitle("Load Transaction");
+        dialogPane.setHeaderText("Enter the transaction ID:");
+        dialogPane.getStylesheets().add(AppController.class.getResource("general.css").toExternalForm());
+        dialogPane.getButtonTypes().addAll(ButtonType.CANCEL);
+        dialogPane.setPrefWidth(380);
+        dialogPane.setPrefHeight(200);
+
+        Glyph wallet = new Glyph("FontAwesome", FontAwesome.Glyph.BITCOIN);
+        wallet.setFontSize(50);
+        dialogPane.setGraphic(wallet);
+
+        final VBox content = new VBox(10);
+        content.getChildren().add(txid);
+
+        dialogPane.setContent(content);
+
+        ValidationSupport validationSupport = new ValidationSupport();
+        Platform.runLater(() -> {
+            validationSupport.registerValidator(txid, Validator.combine(
+                    Validator.createEmptyValidator("Transaction id is required"),
+                    (Control c, String newValue) -> ValidationResult.fromErrorIf(c, "Transaction ID length incorrect", newValue.length() != 64),
+                    (Control c, String newValue) -> ValidationResult.fromErrorIf(c, "Transaction ID must be hexadecimal", !Utils.isHex(newValue))
+            ));
+            validationSupport.setValidationDecorator(new StyleClassValidationDecoration());
+        });
+
+        final ButtonType okButtonType = new javafx.scene.control.ButtonType("Open Transaction", ButtonBar.ButtonData.OK_DONE);
+        dialogPane.getButtonTypes().addAll(okButtonType);
+        Button okButton = (Button) dialogPane.lookupButton(okButtonType);
+        BooleanBinding isInvalid = Bindings.createBooleanBinding(() ->
+                txid.getText().length() != 64 || !Utils.isHex(txid.getText()), txid.textProperty());
+        okButton.disableProperty().bind(isInvalid);
+
+        txid.setPromptText("f4184fc596403b9d638783cf57adfe4c75c605f6356fbc91338530e9831e9e16");
+        txid.requestFocus();
+        setResultConverter(dialogButton -> dialogButton == okButtonType ? Sha256Hash.wrap(txid.getText()) : null);
+    }
+}

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

@@ -0,0 +1,24 @@
+package com.sparrowwallet.sparrow.event;
+
+import com.sparrowwallet.drongo.protocol.Sha256Hash;
+import com.sparrowwallet.drongo.wallet.BlockTransaction;
+
+import java.util.List;
+
+public class BlockTransactionOutputsFetchedEvent {
+    private final Sha256Hash txId;
+    private final List<BlockTransaction> outputTransactions;
+
+    public BlockTransactionOutputsFetchedEvent(Sha256Hash txId, List<BlockTransaction> outputTransactions) {
+        this.txId = txId;
+        this.outputTransactions = outputTransactions;
+    }
+
+    public Sha256Hash getTxId() {
+        return txId;
+    }
+
+    public List<BlockTransaction> getOutputTransactions() {
+        return outputTransactions;
+    }
+}

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

@@ -41,6 +41,8 @@ import java.util.stream.Collectors;
 public class ElectrumServer {
     private static final String[] SUPPORTED_VERSIONS = new String[]{"1.3", "1.4.2"};
 
+    public static final BlockTransaction UNFETCHABLE_BLOCK_TRANSACTION = new BlockTransaction(Sha256Hash.ZERO_HASH, 0, null, null, null);
+
     private static Transport transport;
 
     private static synchronized Transport getTransport() throws ServerException {
@@ -134,7 +136,8 @@ public class ElectrumServer {
 
     public void getHistory(Wallet wallet, KeyPurpose keyPurpose, Map<WalletNode, Set<BlockTransactionHash>> nodeTransactionMap) throws ServerException {
         getHistory(wallet, wallet.getNode(keyPurpose).getChildren(), nodeTransactionMap);
-        getMempool(wallet, wallet.getNode(keyPurpose).getChildren(), nodeTransactionMap);
+        //Not necessary, mempool transactions included in history
+        //getMempool(wallet, wallet.getNode(keyPurpose).getChildren(), nodeTransactionMap);
     }
 
     public void getHistory(Wallet wallet, Collection<WalletNode> nodes, Map<WalletNode, Set<BlockTransactionHash>> nodeTransactionMap) throws ServerException {
@@ -189,6 +192,47 @@ public class ElectrumServer {
         }
     }
 
+    @SuppressWarnings("unchecked")
+    public List<Set<BlockTransactionHash>> getOutputTransactionReferences(Transaction transaction) throws ServerException {
+        try {
+            JsonRpcClient client = new JsonRpcClient(getTransport());
+            BatchRequestBuilder<Integer, ScriptHashTx[]> batchRequest = client.createBatchRequest().keysType(Integer.class).returnType(ScriptHashTx[].class);
+            for(int i = 0; i < transaction.getOutputs().size(); i++) {
+                TransactionOutput output = transaction.getOutputs().get(i);
+                batchRequest.add(i, "blockchain.scripthash.get_history", getScriptHash(output));
+            }
+
+            Map<Integer, ScriptHashTx[]> result;
+            try {
+                result = batchRequest.execute();
+            } catch (JsonRpcBatchException e) {
+                result = (Map<Integer, ScriptHashTx[]>)e.getSuccesses();
+                for(Object index : e.getErrors().keySet()) {
+                    Integer i = (Integer)index;
+                    result.put(i, new ScriptHashTx[] {ScriptHashTx.ERROR_TX});
+                }
+            }
+
+            List<Set<BlockTransactionHash>> blockTransactionHashes = new ArrayList<>(transaction.getOutputs().size());
+            for(int i = 0; i < transaction.getOutputs().size(); i++) {
+                blockTransactionHashes.add(null);
+            }
+
+            for(Integer index : result.keySet()) {
+                ScriptHashTx[] txes = result.get(index);
+
+                Set<BlockTransactionHash> references = Arrays.stream(txes).map(ScriptHashTx::getBlockchainTransactionHash).filter(ref -> !ref.getHash().equals(transaction.getTxId())).collect(Collectors.toCollection(TreeSet::new));
+                blockTransactionHashes.set(index, references);
+            }
+
+            return blockTransactionHashes;
+        } catch (IllegalStateException e) {
+            throw new ServerException(e.getCause());
+        } catch (Exception e) {
+            throw new ServerException(e);
+        }
+    }
+
     public void getReferencedTransactions(Wallet wallet, Map<WalletNode, Set<BlockTransactionHash>> nodeTransactionMap) throws ServerException {
         Set<BlockTransactionHash> references = new TreeSet<>();
         for(Set<BlockTransactionHash> nodeReferences : nodeTransactionMap.values()) {
@@ -209,6 +253,7 @@ public class ElectrumServer {
         }
     }
 
+    @SuppressWarnings("unchecked")
     public Map<Integer, BlockHeader> getBlockHeaders(Set<BlockTransactionHash> references) throws ServerException {
         try {
             Set<Integer> blockHeights = new TreeSet<>();
@@ -221,7 +266,13 @@ public class ElectrumServer {
             for(Integer height : blockHeights) {
                 batchRequest.add(height, "blockchain.block.header", height);
             }
-            Map<Integer, String> result = batchRequest.execute();
+
+            Map<Integer, String> result;
+            try {
+                result = batchRequest.execute();
+            } catch (JsonRpcBatchException e) {
+                result = (Map<Integer, String>)e.getSuccesses();
+            }
 
             Map<Integer, BlockHeader> blockHeaderMap = new TreeMap<>();
             for(Integer height : result.keySet()) {
@@ -232,7 +283,7 @@ public class ElectrumServer {
             }
 
             if(!blockHeights.isEmpty()) {
-                throw new IllegalStateException("Could not retrieve blocks " + blockHeights);
+                System.out.println("Could not retrieve " + blockHeights.size() + " blocks");
             }
 
             return blockHeaderMap;
@@ -243,6 +294,7 @@ public class ElectrumServer {
         }
     }
 
+    @SuppressWarnings("unchecked")
     public Map<Sha256Hash, BlockTransaction> getTransactions(Set<BlockTransactionHash> references, Map<Integer, BlockHeader> blockHeaderMap) throws ServerException {
         try {
             Set<BlockTransactionHash> checkReferences = new TreeSet<>(references);
@@ -252,11 +304,28 @@ public class ElectrumServer {
             for(BlockTransactionHash reference : references) {
                 batchRequest.add(reference.getHashAsString(), "blockchain.transaction.get", reference.getHashAsString());
             }
-            Map<String, String> result = batchRequest.execute();
+
+            Map<String, String> result;
+            try {
+                result = batchRequest.execute();
+            } catch (JsonRpcBatchException e) {
+                result = (Map<String, String>)e.getSuccesses();
+                for(Object hash : e.getErrors().keySet()) {
+                    String txhash = (String)hash;
+                    result.put(txhash, Sha256Hash.ZERO_HASH.toString());
+                }
+            }
 
             Map<Sha256Hash, BlockTransaction> transactionMap = new HashMap<>();
             for(String txid : result.keySet()) {
                 Sha256Hash hash = Sha256Hash.wrap(txid);
+
+                if(hash.equals(Sha256Hash.ZERO_HASH)) {
+                    transactionMap.put(hash, UNFETCHABLE_BLOCK_TRANSACTION);
+                    checkReferences.removeIf(ref -> ref.getHash().equals(hash));
+                    continue;
+                }
+
                 byte[] rawtx = Utils.hexToBytes(result.get(txid));
                 Transaction transaction = new Transaction(rawtx);
 
@@ -268,7 +337,9 @@ public class ElectrumServer {
 
                 BlockHeader blockHeader = blockHeaderMap.get(reference.getHeight());
                 if(blockHeader == null) {
-                    throw new IllegalStateException("Block header at height " + reference.getHeight() + " not retrieved");
+                    transactionMap.put(hash, UNFETCHABLE_BLOCK_TRANSACTION);
+                    checkReferences.removeIf(ref -> ref.getHash().equals(hash));
+                    continue;
                 }
 
                 BlockTransaction blockchainTransaction = new BlockTransaction(reference.getHash(), reference.getHeight(), blockHeader.getTimeAsDate(), reference.getFee(), transaction);
@@ -400,7 +471,20 @@ public class ElectrumServer {
         return Utils.bytesToHex(reversed);
     }
 
+    private String getScriptHash(TransactionOutput output) {
+        byte[] hash = Sha256Hash.hash(output.getScript().getProgram());
+        byte[] reversed = Utils.reverseBytes(hash);
+        return Utils.bytesToHex(reversed);
+    }
+
     private static class ScriptHashTx {
+        public static final ScriptHashTx ERROR_TX = new ScriptHashTx() {
+            @Override
+            public BlockTransactionHash getBlockchainTransactionHash() {
+                return UNFETCHABLE_BLOCK_TRANSACTION;
+            }
+        };
+
         public int height;
         public String tx_hash;
         public long fee;
@@ -800,6 +884,62 @@ public class ElectrumServer {
         }
     }
 
+    public static class TransactionOutputsReferenceService extends Service<List<BlockTransaction>> {
+        private final Transaction transaction;
+
+        public TransactionOutputsReferenceService(Transaction transaction) {
+            this.transaction = transaction;
+        }
+
+        @Override
+        protected Task<List<BlockTransaction>> createTask() {
+            return new Task<>() {
+                protected List<BlockTransaction> call() throws ServerException {
+                    ElectrumServer electrumServer = new ElectrumServer();
+                    List<Set<BlockTransactionHash>> outputTransactionReferences = electrumServer.getOutputTransactionReferences(transaction);
+
+                    Set<BlockTransactionHash> setReferences = new HashSet<>();
+                    for(Set<BlockTransactionHash> outputReferences : outputTransactionReferences) {
+                        setReferences.addAll(outputReferences);
+                    }
+                    setReferences.remove(null);
+                    setReferences.remove(UNFETCHABLE_BLOCK_TRANSACTION);
+
+                    List<BlockTransaction> blockTransactions = new ArrayList<>(transaction.getOutputs().size());
+                    for(int i = 0; i < transaction.getOutputs().size(); i++) {
+                        blockTransactions.add(null);
+                    }
+
+                    Map<Sha256Hash, BlockTransaction> transactionMap = new HashMap<>();
+                    if(!setReferences.isEmpty()) {
+                        Map<Integer, BlockHeader> blockHeaderMap = electrumServer.getBlockHeaders(setReferences);
+                        transactionMap = electrumServer.getTransactions(setReferences, blockHeaderMap);
+                    }
+
+                    for(int i = 0; i < outputTransactionReferences.size(); i++) {
+                        Set<BlockTransactionHash> outputReferences = outputTransactionReferences.get(i);
+                        for(BlockTransactionHash reference : outputReferences) {
+                            if(reference == UNFETCHABLE_BLOCK_TRANSACTION) {
+                                blockTransactions.set(i, UNFETCHABLE_BLOCK_TRANSACTION);
+                            } else {
+                                BlockTransaction blockTransaction = transactionMap.get(reference.getHash());
+                                for(TransactionInput input : blockTransaction.getTransaction().getInputs()) {
+                                    if(input.getOutpoint().getHash().equals(transaction.getTxId())) {
+                                        if(blockTransactions.set(i, blockTransaction) != null) {
+                                            throw new IllegalStateException("Double spend detected on hash " + reference.getHash());
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+
+                    return blockTransactions;
+                }
+            };
+        }
+    }
+
     public enum Protocol {
         TCP {
             @Override

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

@@ -210,6 +210,8 @@ public class HeadersController extends TransactionFormController implements Init
         Long feeAmt = null;
         if(headersForm.getPsbt() != null) {
             feeAmt = headersForm.getPsbt().getFee();
+        } else if(headersForm.getTransaction().getInputs().size() == 1 && headersForm.getTransaction().getInputs().get(0).isCoinBase()) {
+            feeAmt = 0L;
         } else if(headersForm.getInputTransactions() != null) {
             feeAmt = calculateFee(headersForm.getInputTransactions());
         }
@@ -229,6 +231,10 @@ public class HeadersController extends TransactionFormController implements Init
     private long calculateFee(Map<Sha256Hash, BlockTransaction> inputTransactions) {
         long feeAmt = 0L;
         for(TransactionInput input : headersForm.getTransaction().getInputs()) {
+            if(input.isCoinBase()) {
+                return 0L;
+            }
+
             BlockTransaction inputTx = inputTransactions.get(input.getOutpoint().getHash());
             if(inputTx == null) {
                 throw new IllegalStateException("Cannot find transaction for hash " + input.getOutpoint().getHash());

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

@@ -121,7 +121,7 @@ public class InputController extends TransactionFormController implements Initia
 
     @Override
     public void initialize(URL location, ResourceBundle resources) {
-
+        EventManager.get().register(this);
     }
 
     public void initializeView() {
@@ -184,14 +184,17 @@ public class InputController extends TransactionFormController implements Initia
             BlockTransaction linkedTransaction = inputTransactions.get(txInput.getOutpoint().getHash());
             EventManager.get().post(new ViewTransactionEvent(linkedTransaction, TransactionView.OUTPUT, (int)txInput.getOutpoint().getIndex()));
         });
+        linkedOutpoint.setContextMenu(new TransactionReferenceContextMenu(linkedOutpoint.getText()));
     }
 
     private void updateSpends(Map<Sha256Hash, BlockTransaction> inputTransactions) {
         TransactionInput txInput = inputForm.getTransactionInput();
+        if(!txInput.isCoinBase()) {
             BlockTransaction blockTransaction = inputTransactions.get(txInput.getOutpoint().getHash());
             TransactionOutput output = blockTransaction.getTransaction().getOutputs().get((int)txInput.getOutpoint().getIndex());
             updateSpends(output);
         }
+    }
 
     private void updateSpends(TransactionOutput output) {
         if (output != null) {

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

@@ -113,6 +113,16 @@ public class InputsController extends TransactionFormController implements Initi
                 foundSigs += input.getScriptSig().getSignatures().size();
             }
 
+            if(input.isCoinBase()) {
+                long totalAmt = 0;
+                for(TransactionOutput output : inputsForm.getTransaction().getOutputs()) {
+                    totalAmt += output.getValue();
+                }
+                total.setValue(totalAmt);
+                signatures.setText("N/A");
+                addCoinbasePieData(inputsPie, totalAmt);
+                return;
+            } else {
                 BlockTransaction inputTx = inputTransactions.get(input.getOutpoint().getHash());
                 if(inputTx == null) {
                     throw new IllegalStateException("Cannot find transaction for hash " + input.getOutpoint().getHash());
@@ -121,6 +131,7 @@ public class InputsController extends TransactionFormController implements Initi
                 TransactionOutput output = inputTx.getTransaction().getOutputs().get((int)input.getOutpoint().getIndex());
                 outputs.add(output);
             }
+        }
 
         long totalAmt = 0;
         for(TransactionOutput output : outputs) {

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

@@ -1,17 +1,28 @@
 package com.sparrowwallet.sparrow.transaction;
 
+import com.google.common.eventbus.Subscribe;
 import com.sparrowwallet.drongo.address.Address;
 import com.sparrowwallet.drongo.protocol.NonStandardScriptException;
+import com.sparrowwallet.drongo.protocol.TransactionInput;
 import com.sparrowwallet.drongo.protocol.TransactionOutput;
+import com.sparrowwallet.drongo.wallet.BlockTransaction;
+import com.sparrowwallet.sparrow.EventManager;
 import com.sparrowwallet.sparrow.control.AddressLabel;
 import com.sparrowwallet.sparrow.control.CoinLabel;
 import com.sparrowwallet.sparrow.control.CopyableLabel;
+import com.sparrowwallet.sparrow.event.BlockTransactionOutputsFetchedEvent;
+import com.sparrowwallet.sparrow.event.ViewTransactionEvent;
+import com.sparrowwallet.sparrow.io.ElectrumServer;
 import javafx.fxml.FXML;
 import javafx.fxml.Initializable;
+import javafx.scene.control.Hyperlink;
+import javafx.scene.control.Label;
 import org.fxmisc.richtext.CodeArea;
+import tornadofx.control.Field;
 import tornadofx.control.Fieldset;
 
 import java.net.URL;
+import java.util.List;
 import java.util.ResourceBundle;
 
 public class OutputController extends TransactionFormController implements Initializable {
@@ -29,12 +40,24 @@ public class OutputController extends TransactionFormController implements Initi
     @FXML
     private AddressLabel address;
 
+    @FXML
+    private Field spentField;
+
+    @FXML
+    private Label spent;
+
+    @FXML
+    private Field spentByField;
+
+    @FXML
+    private Hyperlink spentBy;
+
     @FXML
     private CodeArea scriptPubKeyArea;
 
     @Override
     public void initialize(URL location, ResourceBundle resources) {
-
+        EventManager.get().register(this);
     }
 
     public void initializeView() {
@@ -56,12 +79,63 @@ public class OutputController extends TransactionFormController implements Initi
             //ignore
         }
 
+        spentField.managedProperty().bind(spentField.visibleProperty());
+        spentByField.managedProperty().bind(spentByField.visibleProperty());
+        spentByField.setVisible(false);
+
+        if(outputForm.getPsbt() != null) {
+            spent.setText("Unspent");
+        } else if(outputForm.getOutputTransactions() != null) {
+            updateSpent(outputForm.getOutputTransactions());
+        } else {
+            spent.setText("Unknown");
+        }
+
         scriptPubKeyArea.clear();
         appendScript(scriptPubKeyArea, txOutput.getScript(), null, null);
     }
 
+    private void updateSpent(List<BlockTransaction> outputTransactions) {
+        int outputIndex = outputForm.getTransactionOutputIndex();
+        spent.setText("Unspent");
+
+        if(outputIndex >= 0 && outputIndex < outputTransactions.size()) {
+            BlockTransaction outputBlockTransaction = outputTransactions.get(outputIndex);
+            if(outputBlockTransaction != null) {
+                spent.setText("Spent");
+
+                if(outputBlockTransaction == ElectrumServer.UNFETCHABLE_BLOCK_TRANSACTION) {
+                    spent.setText("Spent (Spending transaction history too large to fetch)");
+                    return;
+                }
+
+                for(int i = 0; i < outputBlockTransaction.getTransaction().getInputs().size(); i++) {
+                    TransactionInput input = outputBlockTransaction.getTransaction().getInputs().get(i);
+                    if(input.getOutpoint().getHash().equals(outputForm.getTransaction().getTxId()) && input.getOutpoint().getIndex() == outputIndex) {
+                        spentField.setVisible(false);
+                        spentByField.setVisible(true);
+
+                        final Integer inputIndex = i;
+                        spentBy.setText(outputBlockTransaction.getHash().toString() + ":" + inputIndex);
+                        spentBy.setOnAction(event -> {
+                            EventManager.get().post(new ViewTransactionEvent(outputBlockTransaction, TransactionView.INPUT, inputIndex));
+                        });
+                        spentBy.setContextMenu(new TransactionReferenceContextMenu(spentBy.getText()));
+                    }
+                }
+            }
+        }
+    }
+
     public void setModel(OutputForm form) {
         this.outputForm = form;
         initializeView();
     }
+
+    @Subscribe
+    public void blockTransactionOutputsFetched(BlockTransactionOutputsFetchedEvent event) {
+        if(event.getTxId().equals(outputForm.getTransaction().getTxId()) && outputForm.getPsbt() == null) {
+            updateSpent(event.getOutputTransactions());
+        }
+    }
 }

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

@@ -11,7 +11,7 @@ import javafx.scene.Node;
 import java.io.IOException;
 
 public class OutputForm extends TransactionForm {
-    private TransactionOutput transactionOutput;
+    private final TransactionOutput transactionOutput;
     private PSBTOutput psbtOutput;
 
     public OutputForm(PSBT psbt, PSBTOutput psbtOutput) {
@@ -38,6 +38,10 @@ public class OutputForm extends TransactionForm {
         return psbtOutput;
     }
 
+    public int getTransactionOutputIndex() {
+        return getTransaction().getOutputs().indexOf(transactionOutput);
+    }
+
     @Override
     public Node getContents() throws IOException {
         FXMLLoader loader = new FXMLLoader(getClass().getResource("output.fxml"));

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

@@ -62,7 +62,8 @@ public class TransactionController implements Initializable {
         initializeTxTree();
         transactionMasterDetail.setShowDetailNode(AppController.showTxHexProperty);
         refreshTxHex();
-        fetchBlockTransactions();
+        fetchThisAndInputBlockTransactions();
+        fetchOutputBlockTransactions();
     }
 
     private void initializeTxTree() {
@@ -134,7 +135,7 @@ public class TransactionController implements Initializable {
                         selectedOutputIndex = outputForm.getTransactionOutput().getIndex();
                     }
 
-                    refreshTxHex();
+                    Platform.runLater(this::refreshTxHex);
                 }
             } catch (IOException e) {
                 throw new IllegalStateException("Can't find pane", e);
@@ -167,6 +168,7 @@ public class TransactionController implements Initializable {
     }
 
     void refreshTxHex() {
+        //TODO: Handle large transactions like efd513fffbbc2977c2d3933dfaab590b5cab5841ee791b3116e531ac9f8034ed better by not replacing text
         txhex.clear();
 
         String hex = "";
@@ -242,15 +244,17 @@ public class TransactionController implements Initializable {
         }
     }
 
-    private void fetchBlockTransactions() {
+    private void fetchThisAndInputBlockTransactions() {
         if (AppController.isOnline()) {
             Set<Sha256Hash> references = new HashSet<>();
             if (psbt == null) {
                 references.add(transaction.getTxId());
             }
             for (TransactionInput input : transaction.getInputs()) {
+                if(!input.isCoinBase()) {
                     references.add(input.getOutpoint().getHash());
                 }
+            }
 
             ElectrumServer.TransactionReferenceService transactionReferenceService = new ElectrumServer.TransactionReferenceService(references);
             transactionReferenceService.setOnSucceeded(successEvent -> {
@@ -285,6 +289,22 @@ public class TransactionController implements Initializable {
         }
     }
 
+    private void fetchOutputBlockTransactions() {
+        if (AppController.isOnline() && psbt == null) {
+            ElectrumServer.TransactionOutputsReferenceService transactionOutputsReferenceService = new ElectrumServer.TransactionOutputsReferenceService(transaction);
+            transactionOutputsReferenceService.setOnSucceeded(successEvent -> {
+                List<BlockTransaction> outputTransactions = transactionOutputsReferenceService.getValue();
+                Platform.runLater(() -> {
+                    EventManager.get().post(new BlockTransactionOutputsFetchedEvent(transaction.getTxId(), outputTransactions));
+                });
+            });
+            transactionOutputsReferenceService.setOnFailed(failedEvent -> {
+                failedEvent.getSource().getException().printStackTrace();
+            });
+            transactionOutputsReferenceService.start();
+        }
+    }
+
     private String getIndexedStyleClass(int iterableIndex, int selectedIndex, String styleClass) {
         if (selectedIndex == -1 || selectedIndex == iterableIndex) {
             return styleClass;
@@ -346,4 +366,20 @@ public class TransactionController implements Initializable {
             setBlockTransaction(childItem, event);
         }
     }
+
+    @Subscribe
+    public void blockTransactionOutputsFetched(BlockTransactionOutputsFetchedEvent event) {
+        if (event.getTxId().equals(transaction.getTxId())) {
+            setBlockTransactionOutputs(txtree.getRoot(), event);
+        }
+    }
+
+    private void setBlockTransactionOutputs(TreeItem<TransactionForm> treeItem, BlockTransactionOutputsFetchedEvent event) {
+        TransactionForm form = treeItem.getValue();
+        form.setOutputTransactions(event.getOutputTransactions());
+
+        for (TreeItem<TransactionForm> childItem : treeItem.getChildren()) {
+            setBlockTransactionOutputs(childItem, event);
+        }
+    }
 }

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

@@ -7,6 +7,7 @@ import com.sparrowwallet.drongo.wallet.BlockTransaction;
 import javafx.scene.Node;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 public abstract class TransactionForm {
@@ -14,6 +15,7 @@ public abstract class TransactionForm {
     private PSBT psbt;
     private BlockTransaction blockTransaction;
     private Map<Sha256Hash, BlockTransaction> inputTransactions;
+    private List<BlockTransaction> outputTransactions;
 
     public TransactionForm(PSBT psbt) {
         this.transaction = psbt.getTransaction();
@@ -53,6 +55,14 @@ public abstract class TransactionForm {
         this.inputTransactions = inputTransactions;
     }
 
+    public List<BlockTransaction> getOutputTransactions() {
+        return outputTransactions;
+    }
+
+    public void setOutputTransactions(List<BlockTransaction> outputTransactions) {
+        this.outputTransactions = outputTransactions;
+    }
+
     public boolean isEditable() {
         return blockTransaction == null;
     }

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

@@ -7,7 +7,11 @@ import com.sparrowwallet.sparrow.BaseController;
 import javafx.collections.FXCollections;
 import javafx.collections.ObservableList;
 import javafx.scene.chart.PieChart;
+import javafx.scene.control.ContextMenu;
+import javafx.scene.control.MenuItem;
 import javafx.scene.control.Tooltip;
+import javafx.scene.input.Clipboard;
+import javafx.scene.input.ClipboardContent;
 
 import java.util.List;
 
@@ -33,9 +37,17 @@ public abstract class TransactionFormController extends BaseController {
             outputsPieData.add(new PieChart.Data(name, output.getValue()));
         }
 
-        pie.setData(outputsPieData);
+        addPieData(pie, outputsPieData);
+    }
 
-        final double totalSum = totalAmt;
+    protected void addCoinbasePieData(PieChart pie, long value) {
+        ObservableList<PieChart.Data> outputsPieData = FXCollections.observableList(List.of(new PieChart.Data("Coinbase", value)));
+        addPieData(pie, outputsPieData);
+    }
+
+    private void addPieData(PieChart pie, ObservableList<PieChart.Data> outputsPieData) {
+        pie.setData(outputsPieData);
+        final double totalSum = outputsPieData.stream().map(PieChart.Data::getPieValue).mapToDouble(Double::doubleValue).sum();
         pie.getData().forEach(data -> {
             Tooltip tooltip = new Tooltip();
             double percent = 100.0 * (data.getPieValue() / totalSum);
@@ -44,4 +56,17 @@ public abstract class TransactionFormController extends BaseController {
             data.pieValueProperty().addListener((observable, oldValue, newValue) -> tooltip.setText(newValue + "%"));
         });
     }
+
+    public static class TransactionReferenceContextMenu extends ContextMenu {
+        public TransactionReferenceContextMenu(String reference) {
+            MenuItem referenceItem = new MenuItem("Copy Reference");
+            referenceItem.setOnAction(AE -> {
+                hide();
+                ClipboardContent content = new ClipboardContent();
+                content.putString(reference);
+                Clipboard.getSystemClipboard().setContent(content);
+            });
+            getItems().add(referenceItem);
+        }
+    }
 }

src/main/resources/com/sparrowwallet/sparrow/app.fxml

@@ -18,6 +18,7 @@
                         <Menu mnemonicParsing="false" text="Open Transaction">
                             <items>
                                 <MenuItem text="File..." onAction="#openTransactionFromFile"/>
+                                <MenuItem fx:id="openTransactionIdItem" text="From ID..." onAction="#openTransactionFromId"/>
                                 <MenuItem text="From Text..." onAction="#openTransactionFromText"/>
                                 <MenuItem text="Examples" onAction="#openExamples"/>
                             </items>

src/main/resources/com/sparrowwallet/sparrow/transaction/input.fxml

@@ -33,7 +33,7 @@
         <Fieldset fx:id="inputFieldset" inputGrow="SOMETIMES" text="Input" wrapWidth="680">
             <Field text="Outpoint:" styleClass="label-button">
                 <IdLabel fx:id="outpoint" />
-                <Hyperlink fx:id="linkedOutpoint" visible="false" />
+                <Hyperlink fx:id="linkedOutpoint" styleClass="id" visible="false" />
                 <Button fx:id="outpointSelect" maxWidth="25" minWidth="-Infinity" prefWidth="30" text="Ed">
                     <graphic>
                         <Glyph fontFamily="FontAwesome" icon="EDIT" prefWidth="15" />

src/main/resources/com/sparrowwallet/sparrow/transaction/output.css

@@ -21,3 +21,11 @@
 .witness-data { -fx-fill: #e5e5e6 }
 
 .locktime { -fx-fill: #e5e5e6 }
+
+#spentField .input-container {
+    -fx-alignment: center-left;
+}
+
+#spentByField .input-container {
+    -fx-alignment: center-left;
+}

src/main/resources/com/sparrowwallet/sparrow/transaction/output.fxml

@@ -34,6 +34,12 @@
                 <CopyableLabel fx:id="to" text="to" />
                 <AddressLabel fx:id="address" />
             </Field>
+            <Field fx:id="spentField" text="Spent?">
+                <Label fx:id="spent" />
+            </Field>
+            <Field fx:id="spentByField" text="Spent By:">
+                <Hyperlink fx:id="spentBy" styleClass="id" />
+            </Field>
         </Fieldset>
     </Form>