wallet(HD): Qt UI - Seed Phrase dialog (generate/restore/backup)

Adds HDSeedDialog (Settings > Seed Phrase) with Generate New / Reveal for Backup / Restore from Phrase, driven by new WalletModel HD methods. Restore rescans the chain. Requires wallet unlock via the standard UnlockContext.

src/CMakeLists.txt

@@ -307,6 +307,7 @@ if(BUILD_QT)
         qt/trianglesunits.cpp
         qt/qvaluecombobox.cpp
         qt/askpassphrasedialog.cpp
+        qt/hdseeddialog.cpp
         qt/notificator.cpp
         qt/qtipcserver.cpp
         qt/rpcconsole.cpp

src/qt/hdseeddialog.cpp

@@ -0,0 +1,142 @@
+// Copyright (c) 2026 The Triangles developers
+// Distributed under the MIT/X11 software license.
+#include "hdseeddialog.h"
+#include "walletmodel.h"
+
+#include <QVBoxLayout>
+#include <QHBoxLayout>
+#include <QPushButton>
+#include <QPlainTextEdit>
+#include <QLabel>
+#include <QMessageBox>
+#include <QFont>
+
+HDSeedDialog::HDSeedDialog(QWidget *parent)
+    : QDialog(parent), model(0), seedText(0), statusLabel(0)
+{
+    setWindowTitle(tr("HD Seed Phrase (BIP39)"));
+    resize(560, 360);
+
+    QVBoxLayout *layout = new QVBoxLayout(this);
+
+    QLabel *intro = new QLabel(tr(
+        "A 24-word seed phrase is a complete backup of this wallet. Anyone who has it "
+        "can spend your coins. Write it down on paper and keep it offline."), this);
+    intro->setWordWrap(true);
+    layout->addWidget(intro);
+
+    seedText = new QPlainTextEdit(this);
+    seedText->setPlaceholderText(tr(
+        "Your 24-word phrase appears here when you generate or reveal it. "
+        "To restore, paste an existing 24-word phrase here and click 'Restore from Phrase'."));
+    QFont mono("monospace");
+    mono.setStyleHint(QFont::Monospace);
+    seedText->setFont(mono);
+    layout->addWidget(seedText);
+
+    statusLabel = new QLabel(this);
+    statusLabel->setWordWrap(true);
+    layout->addWidget(statusLabel);
+
+    QHBoxLayout *btns = new QHBoxLayout();
+    QPushButton *genBtn = new QPushButton(tr("Generate New"), this);
+    QPushButton *showBtn = new QPushButton(tr("Reveal for Backup"), this);
+    QPushButton *restoreBtn = new QPushButton(tr("Restore from Phrase"), this);
+    QPushButton *closeBtn = new QPushButton(tr("Close"), this);
+    btns->addWidget(genBtn);
+    btns->addWidget(showBtn);
+    btns->addWidget(restoreBtn);
+    btns->addStretch();
+    btns->addWidget(closeBtn);
+    layout->addLayout(btns);
+
+    connect(genBtn, SIGNAL(clicked()), this, SLOT(onGenerate()));
+    connect(showBtn, SIGNAL(clicked()), this, SLOT(onShow()));
+    connect(restoreBtn, SIGNAL(clicked()), this, SLOT(onRestore()));
+    connect(closeBtn, SIGNAL(clicked()), this, SLOT(accept()));
+}
+
+void HDSeedDialog::setModel(WalletModel *modelIn)
+{
+    model = modelIn;
+    refreshStatus();
+}
+
+void HDSeedDialog::refreshStatus()
+{
+    if (!model || !statusLabel) return;
+    if (model->hdEnabled())
+        statusLabel->setText(tr("Status: HD seed is ACTIVE. Use 'Reveal for Backup' to view your phrase."));
+    else
+        statusLabel->setText(tr("Status: no HD seed yet. Use 'Generate New' to create one."));
+}
+
+void HDSeedDialog::onGenerate()
+{
+    if (!model) return;
+    if (model->hdEnabled()) {
+        QMessageBox::warning(this, tr("HD seed already set"),
+            tr("This wallet already has an HD seed. Use 'Reveal for Backup' to view it."));
+        return;
+    }
+    if (QMessageBox::question(this, tr("Generate new seed"),
+            tr("Generate a new 24-word HD seed for this wallet?"),
+            QMessageBox::Yes | QMessageBox::No) != QMessageBox::Yes)
+        return;
+
+    WalletModel::UnlockContext ctx(model->requestUnlock());
+    if (!ctx.isValid()) return;
+
+    QString mnemonic, err;
+    if (!model->hdNew(mnemonic, err)) {
+        QMessageBox::critical(this, tr("Error"), err);
+        return;
+    }
+    seedText->setPlainText(mnemonic);
+    QMessageBox::information(this, tr("Write this down"),
+        tr("Your new 24-word seed phrase is shown above. Write it on paper and store it safely "
+           "and offline. This is the only backup of this wallet."));
+    refreshStatus();
+}
+
+void HDSeedDialog::onShow()
+{
+    if (!model) return;
+    WalletModel::UnlockContext ctx(model->requestUnlock());
+    if (!ctx.isValid()) return;
+
+    QString mnemonic, err;
+    if (!model->hdShow(mnemonic, err)) {
+        QMessageBox::critical(this, tr("Error"), err);
+        return;
+    }
+    seedText->setPlainText(mnemonic);
+}
+
+void HDSeedDialog::onRestore()
+{
+    if (!model) return;
+    QString phrase = seedText->toPlainText().trimmed();
+    if (phrase.isEmpty()) {
+        QMessageBox::warning(this, tr("No phrase"),
+            tr("Paste a 24-word phrase into the box first."));
+        return;
+    }
+    if (QMessageBox::question(this, tr("Restore from phrase"),
+            tr("Restore the HD seed from the phrase in the box and rescan the chain? "
+               "This replaces the current HD seed."),
+            QMessageBox::Yes | QMessageBox::No) != QMessageBox::Yes)
+        return;
+
+    WalletModel::UnlockContext ctx(model->requestUnlock());
+    if (!ctx.isValid()) return;
+
+    QString err;
+    if (!model->hdRestore(phrase, err)) {
+        QMessageBox::critical(this, tr("Error"), err);
+        return;
+    }
+    QMessageBox::information(this, tr("Restored"),
+        tr("HD seed restored and the chain was rescanned for your funds."));
+    refreshStatus();
+}

src/qt/hdseeddialog.h

@@ -0,0 +1,34 @@
+// Copyright (c) 2026 The Triangles developers
+// Distributed under the MIT/X11 software license.
+#ifndef HDSEEDDIALOG_H
+#define HDSEEDDIALOG_H
+
+#include <QDialog>
+
+class WalletModel;
+QT_BEGIN_NAMESPACE
+class QPlainTextEdit;
+class QLabel;
+QT_END_NAMESPACE
+
+/** Generate, reveal (for backup), and restore the wallet's BIP39 HD seed phrase. */
+class HDSeedDialog : public QDialog
+{
+    Q_OBJECT
+public:
+    explicit HDSeedDialog(QWidget *parent = 0);
+    void setModel(WalletModel *model);
+
+private:
+    WalletModel *model;
+    QPlainTextEdit *seedText;
+    QLabel *statusLabel;
+    void refreshStatus();
+
+private slots:
+    void onGenerate();
+    void onShow();
+    void onRestore();
+};
+
+#endif // HDSEEDDIALOG_H

src/qt/trianglesgui.cpp

@@ -31,6 +31,7 @@
 #include "trianglesunits.h"
 #include "guiconstants.h"
 #include "askpassphrasedialog.h"
+#include "hdseeddialog.h"
 #include "notificator.h"
 #include "guiutil.h"
 #include "rpcconsole.h"
@@ -484,6 +485,8 @@ void TrianglesGUI::createActions(bool fIsTestnet)
     backupWalletAction->setStatusTip(tr("Backup wallet to another location"));
     changePassphraseAction = new QAction(QIcon(":/menu_16/passphrase"), tr("&Change Passphrase..."), this);
     changePassphraseAction->setStatusTip(tr("Change the passphrase used for wallet encryption"));
+    hdSeedAction = new QAction(QIcon(":/menu_16/passphrase"), tr("&Seed Phrase (HD Backup)..."), this);
+    hdSeedAction->setStatusTip(tr("Generate, restore, or back up your 24-word HD seed phrase"));
     unlockWalletAction = new QAction(QIcon(":/menu_16/unlock"), tr("&Unlock Wallet..."), this);
     unlockWalletAction->setStatusTip(tr("Unlock wallet"));
     unlockWalletStakingAction = new QAction(QIcon(":/menu_16/unlock"), tr("&Unlock Wallet for staking..."), this);
@@ -509,6 +512,7 @@ void TrianglesGUI::createActions(bool fIsTestnet)
     connect(encryptWalletAction, SIGNAL(triggered(bool)), this, SLOT(encryptWallet(bool)));
     connect(backupWalletAction, SIGNAL(triggered()), this, SLOT(backupWallet()));
     connect(changePassphraseAction, SIGNAL(triggered()), this, SLOT(changePassphrase()));
+    connect(hdSeedAction, SIGNAL(triggered()), this, SLOT(hdSeedManager()));
     connect(unlockWalletAction, SIGNAL(triggered()), this, SLOT(unlockWallet()));
     connect(unlockWalletStakingAction, SIGNAL(triggered()), this, SLOT(unlockWalletStaking()));
     connect(lockWalletAction, SIGNAL(triggered()), this, SLOT(lockWallet()));
@@ -538,6 +542,7 @@ void TrianglesGUI::createMenuBar()
     QMenu *settings = appMenuBar->addMenu(tr("&Settings"));
     settings->addAction(encryptWalletAction);
     settings->addAction(changePassphraseAction);
+    settings->addAction(hdSeedAction);
     settings->addAction(unlockWalletAction);
     settings->addAction(lockWalletAction);
     settings->addSeparator();
@@ -1614,6 +1619,15 @@ void TrianglesGUI::changePassphrase()
     dlg.exec();
 }
 
+void TrianglesGUI::hdSeedManager()
+{
+    if (!walletModel)
+        return;
+    HDSeedDialog dlg(this);
+    dlg.setModel(walletModel);
+    dlg.exec();
+}
+
 
 void TrianglesGUI::unlockWalletStaking()
 {

src/qt/trianglesgui.h

@@ -131,6 +131,7 @@ private:
     QAction *encryptWalletAction;
     QAction *backupWalletAction;
     QAction *changePassphraseAction;
+    QAction *hdSeedAction;
     QAction *unlockWalletAction;
     QAction *unlockWalletStakingAction;
     QAction *lockWalletAction;
@@ -243,6 +244,8 @@ private slots:
     void backupWallet();
     /** Change encrypted wallet passphrase */
     void changePassphrase();
+    /** Open the HD seed phrase (generate/restore/backup) dialog */
+    void hdSeedManager();
     /** Ask for passphrase to unlock wallet temporarily */
     void unlockWallet();
     /** Ask for passphrase to unlock wallet temporarily - FOR STAKING ONLY */

src/qt/walletmodel.cpp

@@ -676,3 +676,49 @@ void WalletModel::listLockedCoins(std::vector<COutPoint>& vOutpts)
 {
     return;
 }
+
+
+// ---- HD wallet (BIP39/BIP32) ----
+bool WalletModel::hdEnabled() const
+{
+    return wallet->IsHDEnabled();
+}
+
+bool WalletModel::hdNew(QString &mnemonicOut, QString &errorOut)
+{
+    std::string mnemonic, strError;
+    if (!wallet->SetHDSeed("", "", true, mnemonic, strError)) {
+        errorOut = QString::fromStdString(strError);
+        return false;
+    }
+    wallet->TopUpKeyPool();
+    mnemonicOut = QString::fromStdString(mnemonic);
+    return true;
+}
+
+bool WalletModel::hdRestore(const QString &mnemonic, QString &errorOut)
+{
+    std::string out, strError;
+    if (!wallet->SetHDSeed(mnemonic.toStdString(), "", false, out, strError)) {
+        errorOut = QString::fromStdString(strError);
+        return false;
+    }
+    wallet->TopUpKeyPool();
+    {
+        LOCK2(cs_main, wallet->cs_wallet);
+        wallet->ScanForWalletTransactions(pindexGenesisBlock, true);
+        wallet->ReacceptWalletTransactions();
+    }
+    return true;
+}
+
+bool WalletModel::hdShow(QString &mnemonicOut, QString &errorOut)
+{
+    std::string mnemonic;
+    if (!wallet->GetHDMnemonic(mnemonic)) {
+        errorOut = QObject::tr("Wallet has no HD seed (use 'Generate New').");
+        return false;
+    }
+    mnemonicOut = QString::fromStdString(mnemonic);
+    return true;
+}

src/qt/walletmodel.h

@@ -103,6 +103,12 @@ public:
     // Wallet backup
     bool backupWallet(const QString &filename);
 
+    // ---- HD wallet (BIP39/BIP32) ----
+    bool hdEnabled() const;
+    bool hdNew(QString &mnemonicOut, QString &errorOut);
+    bool hdRestore(const QString &mnemonic, QString &errorOut);
+    bool hdShow(QString &mnemonicOut, QString &errorOut);
+
     // RAI object for unlocking wallet, returned by requestUnlock()
     class UnlockContext
     {