Inside Bitcoin

251                ui->scrollArea->ensureWidgetVisible(entry);
252                valid = false;
253            }
254        }
255    }
256
257    if(!valid || recipients.isEmpty())
258    {
259        return false;
260    }
261
262    fNewRecipientAllowed = false;
263    WalletModel::UnlockContext ctx(model->requestUnlock());
264    if(!ctx.isValid())
265    {
266        // Unlock wallet was cancelled
267        fNewRecipientAllowed = true;
268        return false;
269    }
270
271    // prepare transaction for getting txFee earlier
272    m_current_transaction = std::make_unique<WalletModelTransaction>(recipients);
273    WalletModel::SendCoinsReturn prepareStatus;
274
275    updateCoinControlState();
276
277    CCoinControl coin_control = *m_coin_control;
278    coin_control.m_allow_other_inputs = !coin_control.HasSelected(); // future, could introduce a checkbox to customize this value.
279    prepareStatus = model->prepareTransaction(*m_current_transaction, coin_control);
280
281    // process prepareStatus and on error generate message shown to user
282    processSendCoinsReturn(prepareStatus,
283        BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), m_current_transaction->getTransactionFee()));
284
285    if(prepareStatus.status != WalletModel::OK) {
286        fNewRecipientAllowed = true;
287        return false;
288    }
289
290    CAmount txFee = m_current_transaction->getTransactionFee();
291    QStringList formatted;
292    for (const SendCoinsRecipient &rcp : m_current_transaction->getRecipients())
293    {
294        // generate amount string with wallet name in case of multiwallet
295        QString amount = BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), rcp.amount);
296        if (model->isMultiwallet()) {
297            amount = tr("%1 from wallet '%2'").arg(amount, GUIUtil::HtmlEscape(model->getWalletName()));
298        }
299
300        // generate address string
301        QString address = rcp.address;
302
303        QString recipientElement;
304
305        {
306            if(rcp.label.length() > 0) // label with address
307            {
308                recipientElement.append(tr("%1 to '%2'").arg(amount, GUIUtil::HtmlEscape(rcp.label)));
309                recipientElement.append(QString(" (%1)").arg(address));
310            }
311            else // just address
312            {
313                recipientElement.append(tr("%1 to %2").arg(amount, address));
314            }
315        }
316        formatted.append(recipientElement);
317    }
318
319    /*: Message displayed when attempting to create a transaction. Cautionary text to prompt the user to verify
320        that the displayed transaction details represent the transaction the user intends to create. */
321    question_string.append(tr("Do you want to create this transaction?"));
322    question_string.append("<br /><span style='font-size:10pt;'>");
323    if (model->wallet().privateKeysDisabled() && !model->wallet().hasExternalSigner()) {
324        /*: Text to inform a user attempting to create a transaction of their current options. At this stage,
325            a user can only create a PSBT. This string is displayed when private keys are disabled and an external
326            signer is not available. */
327        question_string.append(tr("Please, review your transaction proposal. This will produce a Partially Signed Bitcoin Transaction (PSBT) which you can save or copy and then sign with e.g. an offline %1 wallet, or a PSBT-compatible hardware wallet.").arg(CLIENT_NAME));
328    } else if (model->getOptionsModel()->getEnablePSBTControls()) {
329        /*: Text to inform a user attempting to create a transaction of their current options. At this stage,
330            a user can send their transaction or create a PSBT. This string is displayed when both private keys
331            and PSBT controls are enabled. */
332        question_string.append(tr("Please, review your transaction. You can create and send this transaction or create a Partially Signed Bitcoin Transaction (PSBT), which you can save or copy and then sign with, e.g., an offline %1 wallet, or a PSBT-compatible hardware wallet.").arg(CLIENT_NAME));
333    } else {
334        /*: Text to prompt a user to review the details of the transaction they are attempting to send. */
335        question_string.append(tr("Please, review your transaction."));
336    }
337    question_string.append("</span>%1");
338
339    if(txFee > 0)
340    {
341        // append fee string if a fee is required
342        question_string.append("<hr /><b>");
343        question_string.append(tr("Transaction fee"));
344        question_string.append("</b>");
345
346        // append transaction size
347        //: When reviewing a newly created PSBT (via Send flow), the transaction fee is shown, with "virtual size" of the transaction displayed for context
348        question_string.append(" (" + tr("%1 kvB", "PSBT transaction creation").arg((double)m_current_transaction->getTransactionSize() / 1000, 0, 'g', 3) + "): ");
349
350        // append transaction fee value
351        question_string.append("<span style='color:#aa0000; font-weight:bold;'>");
352        question_string.append(BitcoinUnits::formatHtmlWithUnit(model->getOptionsModel()->getDisplayUnit(), txFee));
353        question_string.append("</span><br />");
354    }
355
356    // append RBF message
357    question_string.append("<span style='font-size:10pt; font-weight:normal;'>");
358    question_string.append(tr("You can increase the fee later."));
359
360    // add total amount in all subdivision units
361    question_string.append("<hr />");
362    CAmount totalAmount = m_current_transaction->getTotalTransactionAmount() + txFee;
363    QStringList alternativeUnits;
364    for (const BitcoinUnit u : BitcoinUnits::availableUnits()) {
365        if(u != model->getOptionsModel()->getDisplayUnit())
366            alternativeUnits.append(BitcoinUnits::formatHtmlWithUnit(u, totalAmount));
367    }
368    question_string.append(QString("<b>%1</b>: <b>%2</b>").arg(tr("Total Amount"))
369        .arg(BitcoinUnits::formatHtmlWithUnit(model->getOptionsModel()->getDisplayUnit(), totalAmount)));
370    question_string.append(QString("<br /><span style='font-size:10pt; font-weight:normal;'>(=%1)</span>")
371        .arg(alternativeUnits.join(" " + tr("or") + " ")));
372
373    if (formatted.size() > 1) {
374        question_string = question_string.arg("");
375        informative_text = tr("To review recipient list click \"Show Details…\"");
376        detailed_text = formatted.join("\n\n");
377    } else {
378        question_string = question_string.arg("<br /><br />" + formatted.at(0));
379    }
380
381    return true;
382}
383
384void SendCoinsDialog::presentPSBT(PartiallySignedTransaction& psbtx)
385{
386    // Serialize the PSBT
387    DataStream ssTx{};
388    ssTx << psbtx;
389    GUIUtil::setClipboard(EncodeBase64(ssTx.str()).c_str());
390    QMessageBox msgBox(this);
391    //: Caption of "PSBT has been copied" messagebox
392    msgBox.setText(tr("Unsigned Transaction", "PSBT copied"));
393    msgBox.setInformativeText(tr("The PSBT has been copied to the clipboard. You can also save it."));
394    msgBox.setStandardButtons(QMessageBox::Save | QMessageBox::Discard);
395    msgBox.setDefaultButton(QMessageBox::Discard);
396    msgBox.setObjectName("psbt_copied_message");
397    switch (msgBox.exec()) {
398    case QMessageBox::Save: {
399        QString selectedFilter;
400        QString fileNameSuggestion = "";
401        bool first = true;
402        for (const SendCoinsRecipient &rcp : m_current_transaction->getRecipients()) {
403            if (!first) {
404                fileNameSuggestion.append(" - ");
405            }
406            QString labelOrAddress = rcp.label.isEmpty() ? rcp.address : rcp.label;
407            QString amount = BitcoinUnits::formatWithUnit(model->getOptionsModel()->getDisplayUnit(), rcp.amount);
408            fileNameSuggestion.append(labelOrAddress + "-" + amount);
409            first = false;
410        }
411        fileNameSuggestion.append(".psbt");
412        QString filename = GUIUtil::getSaveFileName(this,
413            tr("Save Transaction Data"), fileNameSuggestion,
414            //: Expanded name of the binary PSBT file format. See: BIP 174.
415            tr("Partially Signed Transaction (Binary)") + QLatin1String(" (*.psbt)"), &selectedFilter);
416        if (filename.isEmpty()) {
417            return;
418        }
419        std::ofstream out{filename.toLocal8Bit().data(), std::ofstream::out | std::ofstream::binary};
420        out << ssTx.str();
421        out.close();
422        //: Popup message when a PSBT has been saved to a file
423        Q_EMIT message(tr("PSBT saved"), tr("PSBT saved to disk"), CClientUIInterface::MSG_INFORMATION);
424        break;
425    }
426    case QMessageBox::Discard:
427        break;
428    default:
429        assert(false);
430    } // msgBox.exec()
431}
432
433bool SendCoinsDialog::signWithExternalSigner(PartiallySignedTransaction& psbtx, CMutableTransaction& mtx, bool& complete) {
434    std::optional<PSBTError> err;
435    try {
436        err = model->wallet().fillPSBT({.sign = true, .bip32_derivs = true}, /*n_signed=*/nullptr, psbtx, complete);
437    } catch (const std::runtime_error& e) {
438        QMessageBox::critical(nullptr, tr("Sign failed"), e.what());
439        return false;
440    }
441    if (err == PSBTError::EXTERNAL_SIGNER_NOT_FOUND) {
442        //: "External signer" means using devices such as hardware wallets.
443        const QString msg = tr("External signer not found");
444        QMessageBox::critical(nullptr, msg, msg);
445        return false;
446    }
447    if (err == PSBTError::EXTERNAL_SIGNER_FAILED) {
448        //: "External signer" means using devices such as hardware wallets.
449        const QString msg = tr("External signer failure");
450        QMessageBox::critical(nullptr, msg, msg);
451        return false;
452    }
453    if (err) {
454        qWarning() << "Failed to sign PSBT";
455        processSendCoinsReturn(WalletModel::TransactionCreationFailed);
456        return false;
457    }
458    // fillPSBT does not always properly finalize
459    complete = FinalizeAndExtractPSBT(psbtx, mtx);
460    return true;
461}
462
463void SendCoinsDialog::sendButtonClicked([[maybe_unused]] bool checked)
464{
465    if(!model || !model->getOptionsModel())
466        return;
467
468    QString question_string, informative_text, detailed_text;
469    if (!PrepareSendText(question_string, informative_text, detailed_text)) return;
470    assert(m_current_transaction);
471
472    const QString confirmation = tr("Confirm send coins");
473    const bool enable_send{!model->wallet().privateKeysDisabled() || model->wallet().hasExternalSigner()};
474    const bool always_show_unsigned{model->getOptionsModel()->getEnablePSBTControls()};
475    auto confirmationDialog = new SendConfirmationDialog(confirmation, question_string, informative_text, detailed_text, SEND_CONFIRM_DELAY, enable_send, always_show_unsigned, this);
476    confirmationDialog->setAttribute(Qt::WA_DeleteOnClose);
477    // TODO: Replace QDialog::exec() with safer QDialog::show().
478    const auto retval = static_cast<QMessageBox::StandardButton>(confirmationDialog->exec());
479
480    if(retval != QMessageBox::Yes && retval != QMessageBox::Save)
481    {
482        fNewRecipientAllowed = true;
483        return;
484    }
485
486    bool send_failure = false;
487    if (retval == QMessageBox::Save) {
488        // "Create Unsigned" clicked
489        CMutableTransaction mtx = CMutableTransaction{*(m_current_transaction->getWtx())};
490        PartiallySignedTransaction psbtx(mtx);
491        bool complete = false;
492        // Fill without signing
493        const auto err{model->wallet().fillPSBT({.sign = false, .bip32_derivs = true}, /*n_signed=*/nullptr, psbtx, complete)};
494        assert(!complete);
495        assert(!err);
496
497        // Copy PSBT to clipboard and offer to save
498        presentPSBT(psbtx);
499    } else {
500        // "Send" clicked