[gui] watch-only wallet: copy PSBT to clipboard

src/qt/sendcoinsdialog.cpp

@@ -21,11 +21,12 @@
 #include <chainparams.h>
 #include <interfaces/node.h>
 #include <key_io.h>
-#include <wallet/coincontrol.h>
-#include <ui_interface.h>
-#include <txmempool.h>
 #include <policy/fees.h>
+#include <txmempool.h>
+#include <ui_interface.h>
+#include <wallet/coincontrol.h>
 #include <wallet/fees.h>
+#include <wallet/psbtwallet.h>
 
 #include <QFontMetrics>
 #include <QScrollBar>
@@ -186,6 +187,11 @@ void SendCoinsDialog::setModel(WalletModel *_model)
         // set default rbf checkbox state
         ui->optInRBF->setCheckState(Qt::Checked);
 
+        if (model->privateKeysDisabled()) {
+            ui->sendButton->setText(tr("Cr&eate Unsigned"));
+            ui->sendButton->setToolTip(tr("Creates a Partially Signed Bitcoin Transaction (PSBT) for use with e.g. an offline %1 wallet, or a PSBT-compatible hardware wallet.").arg(PACKAGE_NAME));
+        }
+
         // set the smartfee-sliders default value (wallets default conf.target or last stored value)
         QSettings settings;
         if (settings.value("nSmartFeeSliderPosition").toInt() != 0) {
@@ -305,9 +311,19 @@ void SendCoinsDialog::on_sendButton_clicked()
         formatted.append(recipientElement);
     }
 
-    QString questionString = tr("Are you sure you want to send?");
+    QString questionString;
+    if (model->privateKeysDisabled()) {
+        questionString.append(tr("Do you want to draft this transaction?"));
+    } else {
+        questionString.append(tr("Are you sure you want to send?"));
+    }
+
     questionString.append("<br /><span style='font-size:10pt;'>");
-    questionString.append(tr("Please, review your transaction."));
+    if (model->privateKeysDisabled()) {
+        questionString.append(tr("Please, review your transaction proposal. This will produce a Partially Signed Bitcoin Transaction (PSBT) which you can copy and then sign with e.g. an offline %1 wallet, or a PSBT-compatible hardware wallet.").arg(PACKAGE_NAME));
+    } else {
+        questionString.append(tr("Please, review your transaction."));
+    }
     questionString.append("</span>%1");
 
     if(txFee > 0)
@@ -358,8 +374,9 @@ void SendCoinsDialog::on_sendButton_clicked()
     } else {
         questionString = questionString.arg("<br /><br />" + formatted.at(0));
     }
-
-    SendConfirmationDialog confirmationDialog(tr("Confirm send coins"), questionString, informative_text, detailed_text, SEND_CONFIRM_DELAY, this);
+    const QString confirmation = model->privateKeysDisabled() ? tr("Confirm transaction proposal") : tr("Confirm send coins");
+    const QString confirmButtonText = model->privateKeysDisabled() ? tr("Copy PSBT to clipboard") : tr("Send");
+    SendConfirmationDialog confirmationDialog(confirmation, questionString, informative_text, detailed_text, SEND_CONFIRM_DELAY, confirmButtonText, this);
     confirmationDialog.exec();
     QMessageBox::StandardButton retval = static_cast<QMessageBox::StandardButton>(confirmationDialog.result());
 
@@ -369,17 +386,35 @@ void SendCoinsDialog::on_sendButton_clicked()
         return;
     }
 
-    // now send the prepared transaction
-    WalletModel::SendCoinsReturn sendStatus = model->sendCoins(currentTransaction);
-    // process sendStatus and on error generate message shown to user
-    processSendCoinsReturn(sendStatus);
+    bool send_failure = false;
+    if (model->privateKeysDisabled()) {
+        CMutableTransaction mtx = CMutableTransaction{*(currentTransaction.getWtx())};
+        PartiallySignedTransaction psbtx(mtx);
+        bool complete = false;
+        const TransactionError err = model->wallet().fillPSBT(psbtx, complete, SIGHASH_ALL, false /* sign */, true /* bip32derivs */);
+        assert(!complete);
+        assert(err == TransactionError::OK);
+        // Serialize the PSBT
+        CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
+        ssTx << psbtx;
+        GUIUtil::setClipboard(EncodeBase64(ssTx.str()).c_str());
+        Q_EMIT message(tr("PSBT copied"), "Copied to clipboard", CClientUIInterface::MSG_INFORMATION);
+    } else {
+        // now send the prepared transaction
+        WalletModel::SendCoinsReturn sendStatus = model->sendCoins(currentTransaction);
+        // process sendStatus and on error generate message shown to user
+        processSendCoinsReturn(sendStatus);
 
-    if (sendStatus.status == WalletModel::OK)
-    {
+        if (sendStatus.status == WalletModel::OK) {
+            Q_EMIT coinsSent(currentTransaction.getWtx()->GetHash());
+        } else {
+            send_failure = true;
+        }
+    }
+    if (!send_failure) {
         accept();
         CoinControlDialog::coinControl()->UnSelectAll();
         coinControlUpdateLabels();
-        Q_EMIT coinsSent(currentTransaction.getWtx()->GetHash());
     }
     fNewRecipientAllowed = true;
 }
@@ -875,8 +910,8 @@ void SendCoinsDialog::coinControlUpdateLabels()
     }
 }
 
-SendConfirmationDialog::SendConfirmationDialog(const QString& title, const QString& text, const QString& informative_text, const QString& detailed_text, int _secDelay, QWidget* parent)
-    : QMessageBox(parent), secDelay(_secDelay)
+SendConfirmationDialog::SendConfirmationDialog(const QString& title, const QString& text, const QString& informative_text, const QString& detailed_text, int _secDelay, const QString& _confirmButtonText, QWidget* parent)
+    : QMessageBox(parent), secDelay(_secDelay), confirmButtonText(_confirmButtonText)
 {
     setIcon(QMessageBox::Question);
     setWindowTitle(title); // On macOS, the window title is ignored (as required by the macOS Guidelines).
@@ -913,11 +948,11 @@ void SendConfirmationDialog::updateYesButton()
     if(secDelay > 0)
     {
         yesButton->setEnabled(false);
-        yesButton->setText(tr("Send") + " (" + QString::number(secDelay) + ")");
+        yesButton->setText(confirmButtonText + " (" + QString::number(secDelay) + ")");
     }
     else
     {
         yesButton->setEnabled(true);
-        yesButton->setText(tr("Send"));
+        yesButton->setText(confirmButtonText);
     }
 }

src/qt/sendcoinsdialog.h

@@ -108,7 +108,7 @@ class SendConfirmationDialog : public QMessageBox
     Q_OBJECT
 
 public:
-    SendConfirmationDialog(const QString& title, const QString& text, const QString& informative_text = "", const QString& detailed_text = "", int secDelay = SEND_CONFIRM_DELAY, QWidget* parent = nullptr);
+    SendConfirmationDialog(const QString& title, const QString& text, const QString& informative_text = "", const QString& detailed_text = "", int secDelay = SEND_CONFIRM_DELAY, const QString& confirmText = "Send", QWidget* parent = nullptr);
     int exec();
 
 private Q_SLOTS:
@@ -119,6 +119,7 @@ private:
     QAbstractButton *yesButton;
     QTimer countDownTimer;
     int secDelay;
+    QString confirmButtonText;
 };
 
 #endif // BITCOIN_QT_SENDCOINSDIALOG_H

src/qt/walletmodel.cpp

@@ -183,7 +183,7 @@ WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransact
         std::string strFailReason;
 
         auto& newTx = transaction.getWtx();
-        newTx = m_wallet->createTransaction(vecSend, coinControl, true /* sign */, nChangePosRet, nFeeRequired, strFailReason);
+        newTx = m_wallet->createTransaction(vecSend, coinControl, !privateKeysDisabled() /* sign */, nChangePosRet, nFeeRequired, strFailReason);
         transaction.setTransactionFee(nFeeRequired);
         if (fSubtractFeeFromAmount && newTx)
             transaction.reassignAmounts(nChangePosRet);