Merge bitcoin-core#403: refactor: Make paths to update Encryption and HD wallet statuses simpler

b8aa84b qt, refactor: Replace `if` check with `assert` (Hennadii Stepanov)
fcdc8b0 qt, refactor: Drop redundant signalling in WalletView::setWalletModel (Hennadii Stepanov)
37dcf16 qt, refactor: Emit WalletView::encryptionStatusChanged signal directly (Hennadii Stepanov)
7d0d4c0 qt: Add WalletFrame::currentWalletSet signal (Hennadii Stepanov)

Pull request description:

  This PR makes signal-slot paths to reach `setHDStatus` and `setEncryptionStatus` functions shorter and easier to reason about them.

  Required to simplify bitcoin-core#398 (see bitcoin-core#398 (comment)).

  ---

  **Note for reviewers.** Please verify that "Encrypt Wallet..." menu item, and the following icons

  ![DeepinScreenshot_select-area_20210811202120](https://user-images.githubusercontent.com/32963518/129074601-13fa998a-ac47-4ad2-be00-ba400b12c18a.png)

  and updated properly in each and every possible scenario.

ACKs for top commit:
  jarolrod:
    tACK b8aa84b
  Talkless:
    Code review ACK b8aa84b. Did build on Debian Sid with Qt 5.15.2 but no actual testing performed.
  ryanofsky:
    Code review ACK b8aa84b. Only change since last review was rebase

Tree-SHA512: 275737cdba02baff71049df41bc24089e916f96326dd2dea26ec607c7949cb3aae368eeabbe3ad5a0a27651503a1d65536873726de854c5f6af259bcc29727e7

Author: hebasto

src/qt/bitcoingui.cpp

@@ -113,6 +113,7 @@ BitcoinGUI::BitcoinGUI(interfaces::Node& node, const PlatformStyle *_platformSty
         connect(walletFrame, &WalletFrame::message, [this](const QString& title, const QString& message, unsigned int style) {
             this->message(title, message, style);
         });
+        connect(walletFrame, &WalletFrame::currentWalletSet, [this] { updateWalletStatus(); });
         setCentralWidget(walletFrame);
     } else
 #endif // ENABLE_WALLET
@@ -694,7 +695,6 @@ void BitcoinGUI::addWallet(WalletModel* walletModel)
     });
     connect(wallet_view, &WalletView::encryptionStatusChanged, this, &BitcoinGUI::updateWalletStatus);
     connect(wallet_view, &WalletView::incomingTransaction, this, &BitcoinGUI::incomingTransaction);
-    connect(wallet_view, &WalletView::hdEnabledStatusChanged, this, &BitcoinGUI::updateWalletStatus);
     connect(this, &BitcoinGUI::setPrivacy, wallet_view, &WalletView::setPrivacy);
     wallet_view->setPrivacy(isPrivacyModeActivated());
     const QString display_name = walletModel->getDisplayName();
@@ -1340,9 +1340,8 @@ void BitcoinGUI::setEncryptionStatus(int status)
 
 void BitcoinGUI::updateWalletStatus()
 {
-    if (!walletFrame) {
-        return;
-    }
+    assert(walletFrame);
+
     WalletView * const walletView = walletFrame->currentWalletView();
     if (!walletView) {
         return;

src/qt/walletframe.cpp

@@ -109,7 +109,8 @@ void WalletFrame::setCurrentWallet(WalletModel* wallet_model)
     walletView->updateGeometry();
 
     walletStack->setCurrentWidget(walletView);
-    walletView->updateEncryptionStatus();
+
+    Q_EMIT currentWalletSet();
 }
 
 void WalletFrame::removeWallet(WalletModel* wallet_model)

src/qt/walletframe.h

@@ -49,6 +49,7 @@ class WalletFrame : public QFrame
 Q_SIGNALS:
     void createWalletButtonClicked();
     void message(const QString& title, const QString& message, unsigned int style);
+    void currentWalletSet();
 
 private:
     QStackedWidget *walletStack;

src/qt/walletview.cpp

@@ -118,10 +118,6 @@ void WalletView::setWalletModel(WalletModel *_walletModel)
 
         // Handle changes in encryption status
         connect(_walletModel, &WalletModel::encryptionStatusChanged, this, &WalletView::encryptionStatusChanged);
-        updateEncryptionStatus();
-
-        // update HD status
-        Q_EMIT hdEnabledStatusChanged();
 
         // Balloon pop-up for new transaction
         connect(_walletModel->getTransactionTableModel(), &TransactionTableModel::rowsInserted, this, &WalletView::processNewTransaction);
@@ -211,11 +207,6 @@ void WalletView::showOutOfSyncWarning(bool fShow)
     overviewPage->showOutOfSyncWarning(fShow);
 }
 
-void WalletView::updateEncryptionStatus()
-{
-    Q_EMIT encryptionStatusChanged();
-}
-
 void WalletView::encryptWallet()
 {
     if(!walletModel)
@@ -224,7 +215,7 @@ void WalletView::encryptWallet()
     dlg.setModel(walletModel);
     dlg.exec();
 
-    updateEncryptionStatus();
+    Q_EMIT encryptionStatusChanged();
 }
 
 void WalletView::backupWallet()

src/qt/walletview.h

@@ -103,9 +103,6 @@ public Q_SLOTS:
     /** Show used receiving addresses */
     void usedReceivingAddresses();
 
-    /** Re-emit encryption status signal */
-    void updateEncryptionStatus();
-
     /** Show progress dialog e.g. for rescan */
     void showProgress(const QString &title, int nProgress);
 
@@ -117,8 +114,6 @@ public Q_SLOTS:
     void message(const QString &title, const QString &message, unsigned int style);
     /** Encryption status of wallet changed */
     void encryptionStatusChanged();
-    /** HD-Enabled status of wallet changed (only possible during startup) */
-    void hdEnabledStatusChanged();
     /** Notify that a new transaction appeared */
     void incomingTransaction(const QString& date, int unit, const CAmount& amount, const QString& type, const QString& address, const QString& label, const QString& walletName);
     /** Notify that the out of sync warning icon has been pressed */