Merge bitcoin-core/gui#471: Add Wallet Restore in the GUI

bc13ec888c doc: Add a release note about the "restore wallet" menu item (w0xlt)
e7a3f698b5 gui: Add Wallet Restore in the GUI (w0xlt)

Pull request description:

  This PR adds a menu item to restore a wallet from a backup file in the GUI.
  Currently this option exists only in RPC interface.

  Motivation: It makes easier for non-technical users to restore backups.

  Master | PR |
  --- | ---
  <img width="307" alt="master" src="https://user-images.githubusercontent.com/94266259/141673349-0bf8a237-ecec-42e4-a0d7-1d5863940036.png"> | <img width="307" alt="pr" src="https://user-images.githubusercontent.com/94266259/141673350-972dea23-ae56-4283-a365-819da62b7067.png"> |

ACKs for top commit:
  w0xlt:
    Added a release note in a new commit (bc13ec888c) to not invalidate the ACKs for the previous one.
  furszy:
    utACK bc13ec8
  shaavan:
    ACK bc13ec888c
  hebasto:
    ACK bc13ec888c

Tree-SHA512: edc3675484238857b77e74382a4041dd5d2cbcda1e2d5bfe52c83d9d7bb7be8a243ecd97e25e994d8c30ab6d7c59ead5a1c953a46dce173666b137eeffc3c94f

doc/release-notes/release-notes-471.md

@@ -0,0 +1,4 @@
+GUI changes
+--------
+
+- A new menu item to restore a wallet from a backup file has been added (#471).

src/qt/bitcoingui.cpp

@@ -47,6 +47,7 @@
 #include <QCursor>
 #include <QDateTime>
 #include <QDragEnterEvent>
+#include <QInputDialog>
 #include <QKeySequence>
 #include <QListWidget>
 #include <QMenu>
@@ -348,6 +349,12 @@ void BitcoinGUI::createActions()
     m_create_wallet_action->setEnabled(false);
     m_create_wallet_action->setStatusTip(tr("Create a new wallet"));
 
+    //: Name of the menu item that restores wallet from a backup file.
+    m_restore_wallet_action = new QAction(tr("Restore Wallet…"), this);
+    m_restore_wallet_action->setEnabled(false);
+    //: Status tip for Restore Wallet menu item
+    m_restore_wallet_action->setStatusTip(tr("Restore a wallet from a backup file"));
+
     m_close_all_wallets_action = new QAction(tr("Close All Wallets…"), this);
     m_close_all_wallets_action->setStatusTip(tr("Close all wallets"));
 
@@ -412,6 +419,27 @@ void BitcoinGUI::createActions()
                 action->setEnabled(false);
             }
         });
+        connect(m_restore_wallet_action, &QAction::triggered, [this] {
+            //: Name of the wallet data file format.
+            QString name_data_file = tr("Wallet Data");
+
+            //: The title for Restore Wallet File Windows
+            QString title_windows = tr("Load Wallet Backup");
+
+            QString backup_file = GUIUtil::getOpenFileName(this, title_windows, QString(), name_data_file + QLatin1String(" (*.dat)"), nullptr);
+            if (backup_file.isEmpty()) return;
+
+            bool wallet_name_ok;
+            //: Title of the Restore Wallet input dialog (where the wallet name is entered)
+            QString wallet_name = QInputDialog::getText(this, tr("Restore Name"), tr("Wallet Name:"), QLineEdit::Normal, "", &wallet_name_ok);
+            if (!wallet_name_ok || wallet_name.isEmpty()) return;
+
+            auto activity = new RestoreWalletActivity(m_wallet_controller, this);
+            connect(activity, &RestoreWalletActivity::restored, this, &BitcoinGUI::setCurrentWallet, Qt::QueuedConnection);
+
+            auto backup_file_path = fs::PathFromString(backup_file.toStdString());
+            activity->restore(backup_file_path, wallet_name.toStdString());
+        });
         connect(m_close_wallet_action, &QAction::triggered, [this] {
             m_wallet_controller->closeWallet(walletFrame->currentWalletModel(), this);
         });
@@ -450,8 +478,10 @@ void BitcoinGUI::createMenuBar()
         file->addAction(m_close_wallet_action);
         file->addAction(m_close_all_wallets_action);
         file->addSeparator();
-        file->addAction(openAction);
         file->addAction(backupWalletAction);
+        file->addAction(m_restore_wallet_action);
+        file->addSeparator();
+        file->addAction(openAction);
         file->addAction(signMessageAction);
         file->addAction(verifyMessageAction);
         file->addAction(m_load_psbt_action);
@@ -642,6 +672,7 @@ void BitcoinGUI::setWalletController(WalletController* wallet_controller)
     m_create_wallet_action->setEnabled(true);
     m_open_wallet_action->setEnabled(true);
     m_open_wallet_action->setMenu(m_open_wallet_menu);
+    m_restore_wallet_action->setEnabled(true);
 
     GUIUtil::ExceptionSafeConnect(wallet_controller, &WalletController::walletAdded, this, &BitcoinGUI::addWallet);
     connect(wallet_controller, &WalletController::walletRemoved, this, &BitcoinGUI::removeWallet);

src/qt/bitcoingui.h

@@ -157,6 +157,7 @@ private:
     QAction* m_create_wallet_action{nullptr};
     QAction* m_open_wallet_action{nullptr};
     QMenu* m_open_wallet_menu{nullptr};
+    QAction* m_restore_wallet_action{nullptr};
     QAction* m_close_wallet_action{nullptr};
     QAction* m_close_all_wallets_action{nullptr};
     QAction* m_wallet_selector_label_action = nullptr;

src/qt/walletcontroller.cpp

@@ -373,3 +373,46 @@ void LoadWalletsActivity::load()
         QTimer::singleShot(0, this, [this] { Q_EMIT finished(); });
     });
 }
+
+RestoreWalletActivity::RestoreWalletActivity(WalletController* wallet_controller, QWidget* parent_widget)
+    : WalletControllerActivity(wallet_controller, parent_widget)
+{
+}
+
+void RestoreWalletActivity::restore(const fs::path& backup_file, const std::string& wallet_name)
+{
+    QString name = QString::fromStdString(wallet_name);
+
+    showProgressDialog(
+        //: Title of progress window which is displayed when wallets are being restored.
+        tr("Restore Wallet"),
+        /*: Descriptive text of the restore wallets progress window which indicates to
+            the user that wallets are currently being restored.*/
+        tr("Restoring Wallet <b>%1</b>…").arg(name.toHtmlEscaped()));
+
+    QTimer::singleShot(0, worker(), [this, backup_file, wallet_name] {
+        std::unique_ptr<interfaces::Wallet> wallet = node().walletLoader().restoreWallet(backup_file, wallet_name, m_error_message, m_warning_message);
+
+        if (wallet) m_wallet_model = m_wallet_controller->getOrCreateWallet(std::move(wallet));
+
+        QTimer::singleShot(0, this, &RestoreWalletActivity::finish);
+    });
+}
+
+void RestoreWalletActivity::finish()
+{
+    if (!m_error_message.empty()) {
+        //: Title of message box which is displayed when the wallet could not be restored.
+        QMessageBox::critical(m_parent_widget, tr("Restore wallet failed"), QString::fromStdString(m_error_message.translated));
+    } else if (!m_warning_message.empty()) {
+        //: Title of message box which is displayed when the wallet is restored with some warning.
+        QMessageBox::warning(m_parent_widget, tr("Restore wallet warning"), QString::fromStdString(Join(m_warning_message, Untranslated("\n")).translated));
+    } else {
+        //: Title of message box which is displayed when the wallet is successfully restored.
+        QMessageBox::information(m_parent_widget, tr("Restore wallet message"), QString::fromStdString(Untranslated("Wallet restored successfully \n").translated));
+    }
+
+    if (m_wallet_model) Q_EMIT restored(m_wallet_model);
+
+    Q_EMIT finished();
+}

src/qt/walletcontroller.h

@@ -33,6 +33,10 @@ class Node;
 class Wallet;
 } // namespace interfaces
 
+namespace fs {
+class path;
+}
+
 class AskPassphraseDialog;
 class CreateWalletActivity;
 class CreateWalletDialog;
@@ -155,4 +159,20 @@ public:
     void load();
 };
 
+class RestoreWalletActivity : public WalletControllerActivity
+{
+    Q_OBJECT
+
+public:
+    RestoreWalletActivity(WalletController* wallet_controller, QWidget* parent_widget);
+
+    void restore(const fs::path& backup_file, const std::string& wallet_name);
+
+Q_SIGNALS:
+    void restored(WalletModel* wallet_model);
+
+private:
+    void finish();
+};
+
 #endif // BITCOIN_QT_WALLETCONTROLLER_H