Merge #257: refactor: Use template function qOverload in signal-slot connections

cdbc2bd qt: Use template function qOverload in signal-slot connections (Hennadii Stepanov)

Pull request description:

  A nice template function [`qOverload`](https://doc.qt.io/qt-5/qtglobal.html#qOverload) is available for us now (bitcoin/bitcoin#20413, bitcoin/bitcoin#21286).

  Its usage makes code much more readable.

  This PR does not change behavior.

ACKs for top commit:
  Talkless:
    utACK cdbc2bd.
  promag:
    Code review ACK cdbc2bd.

Tree-SHA512: 72002aa646b1a79bab62d498825b3f245dc7ebdc189280f8bd3b4076e1bb50be8802c02bc872ff6f70c1ea81faec66d3bec36471119dd98c9e70d87b990396ae

Author: hebasto

src/qt/bitcoinamountfield.cpp

@@ -239,7 +239,7 @@ BitcoinAmountField::BitcoinAmountField(QWidget *parent) :
 
     // If one if the widgets changes, the combined content changes as well
     connect(amount, &AmountSpinBox::valueChanged, this, &BitcoinAmountField::valueChanged);
-    connect(unit, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &BitcoinAmountField::unitChanged);
+    connect(unit, qOverload<int>(&QComboBox::currentIndexChanged), this, &BitcoinAmountField::unitChanged);
 
     // Set default based on configuration
     unitChanged(unit->currentIndex());

src/qt/bitcoingui.cpp

@@ -561,7 +561,7 @@ void BitcoinGUI::createToolBars()
 
         m_wallet_selector = new QComboBox();
         m_wallet_selector->setSizeAdjustPolicy(QComboBox::AdjustToContents);
-        connect(m_wallet_selector, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &BitcoinGUI::setCurrentWalletBySelectorIndex);
+        connect(m_wallet_selector, qOverload<int>(&QComboBox::currentIndexChanged), this, &BitcoinGUI::setCurrentWalletBySelectorIndex);
 
         m_wallet_selector_label = new QLabel();
         m_wallet_selector_label->setText(tr("Wallet:") + " ");

src/qt/intro.cpp

@@ -155,7 +155,7 @@ Intro::Intro(QWidget *parent, int64_t blockchain_size_gb, int64_t chain_state_si
         UpdatePruneLabels(prune_checked);
         UpdateFreeSpaceLabel();
     });
-    connect(ui->pruneGB, QOverload<int>::of(&QSpinBox::valueChanged), [this](int prune_GB) {
+    connect(ui->pruneGB, qOverload<int>(&QSpinBox::valueChanged), [this](int prune_GB) {
         m_prune_target_gb = prune_GB;
         UpdatePruneLabels(ui->prune->isChecked());
         UpdateFreeSpaceLabel();

src/qt/optionsdialog.cpp

@@ -197,17 +197,17 @@ void OptionsDialog::setModel(OptionsModel *_model)
     /* Main */
     connect(ui->prune, &QCheckBox::clicked, this, &OptionsDialog::showRestartWarning);
     connect(ui->prune, &QCheckBox::clicked, this, &OptionsDialog::togglePruneWarning);
-    connect(ui->pruneSize, static_cast<void (QSpinBox::*)(int)>(&QSpinBox::valueChanged), this, &OptionsDialog::showRestartWarning);
-    connect(ui->databaseCache, static_cast<void (QSpinBox::*)(int)>(&QSpinBox::valueChanged), this, &OptionsDialog::showRestartWarning);
-    connect(ui->threadsScriptVerif, static_cast<void (QSpinBox::*)(int)>(&QSpinBox::valueChanged), this, &OptionsDialog::showRestartWarning);
+    connect(ui->pruneSize, qOverload<int>(&QSpinBox::valueChanged), this, &OptionsDialog::showRestartWarning);
+    connect(ui->databaseCache, qOverload<int>(&QSpinBox::valueChanged), this, &OptionsDialog::showRestartWarning);
+    connect(ui->threadsScriptVerif, qOverload<int>(&QSpinBox::valueChanged), this, &OptionsDialog::showRestartWarning);
     /* Wallet */
     connect(ui->spendZeroConfChange, &QCheckBox::clicked, this, &OptionsDialog::showRestartWarning);
     /* Network */
     connect(ui->allowIncoming, &QCheckBox::clicked, this, &OptionsDialog::showRestartWarning);
     connect(ui->connectSocks, &QCheckBox::clicked, this, &OptionsDialog::showRestartWarning);
     connect(ui->connectSocksTor, &QCheckBox::clicked, this, &OptionsDialog::showRestartWarning);
     /* Display */
-    connect(ui->lang, static_cast<void (QValueComboBox::*)()>(&QValueComboBox::valueChanged), [this]{ showRestartWarning(); });
+    connect(ui->lang, qOverload<>(&QValueComboBox::valueChanged), [this]{ showRestartWarning(); });
     connect(ui->thirdPartyTxUrls, &QLineEdit::textChanged, [this]{ showRestartWarning(); });
 }
 

src/qt/qvaluecombobox.cpp

@@ -7,7 +7,7 @@
 QValueComboBox::QValueComboBox(QWidget *parent) :
         QComboBox(parent), role(Qt::UserRole)
 {
-    connect(this, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &QValueComboBox::handleSelectionChanged);
+    connect(this, qOverload<int>(&QComboBox::currentIndexChanged), this, &QValueComboBox::handleSelectionChanged);
 }
 
 QVariant QValueComboBox::value() const

src/qt/rpcconsole.cpp

@@ -959,7 +959,7 @@ void RPCConsole::startExecutor()
     executor->moveToThread(&thread);
 
     // Replies from executor object must go to this object
-    connect(executor, &RPCExecutor::reply, this, static_cast<void (RPCConsole::*)(int, const QString&)>(&RPCConsole::message));
+    connect(executor, &RPCExecutor::reply, this, qOverload<int, const QString&>(&RPCConsole::message));
 
     // Requests from this object must go to executor
     connect(this, &RPCConsole::cmdRequest, executor, &RPCExecutor::request);

src/qt/sendcoinsdialog.cpp

@@ -173,15 +173,15 @@ void SendCoinsDialog::setModel(WalletModel *_model)
         for (const int n : confTargets) {
             ui->confTargetSelector->addItem(tr("%1 (%2 blocks)").arg(GUIUtil::formatNiceTimeOffset(n*Params().GetConsensus().nPowTargetSpacing)).arg(n));
         }
-        connect(ui->confTargetSelector, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &SendCoinsDialog::updateSmartFeeLabel);
-        connect(ui->confTargetSelector, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this, &SendCoinsDialog::coinControlUpdateLabels);
+        connect(ui->confTargetSelector, qOverload<int>(&QComboBox::currentIndexChanged), this, &SendCoinsDialog::updateSmartFeeLabel);
+        connect(ui->confTargetSelector, qOverload<int>(&QComboBox::currentIndexChanged), this, &SendCoinsDialog::coinControlUpdateLabels);
 
 #if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
         connect(ui->groupFee, &QButtonGroup::idClicked, this, &SendCoinsDialog::updateFeeSectionControls);
         connect(ui->groupFee, &QButtonGroup::idClicked, this, &SendCoinsDialog::coinControlUpdateLabels);
 #else
-        connect(ui->groupFee, static_cast<void (QButtonGroup::*)(int)>(&QButtonGroup::buttonClicked), this, &SendCoinsDialog::updateFeeSectionControls);
-        connect(ui->groupFee, static_cast<void (QButtonGroup::*)(int)>(&QButtonGroup::buttonClicked), this, &SendCoinsDialog::coinControlUpdateLabels);
+        connect(ui->groupFee, qOverload<int>(&QButtonGroup::buttonClicked), this, &SendCoinsDialog::updateFeeSectionControls);
+        connect(ui->groupFee, qOverload<int>(&QButtonGroup::buttonClicked), this, &SendCoinsDialog::coinControlUpdateLabels);
 #endif
 
         connect(ui->customFee, &BitcoinAmountField::valueChanged, this, &SendCoinsDialog::coinControlUpdateLabels);

src/qt/transactionview.cpp

@@ -177,12 +177,12 @@ TransactionView::TransactionView(const PlatformStyle *platformStyle, QWidget *pa
     abandonAction = contextMenu->addAction(tr("Abandon transaction"), this, &TransactionView::abandonTx);
     contextMenu->addAction(tr("Edit address label"), this, &TransactionView::editLabel);
 
-    connect(dateWidget, static_cast<void (QComboBox::*)(int)>(&QComboBox::activated), this, &TransactionView::chooseDate);
-    connect(typeWidget, static_cast<void (QComboBox::*)(int)>(&QComboBox::activated), this, &TransactionView::chooseType);
-    connect(watchOnlyWidget, static_cast<void (QComboBox::*)(int)>(&QComboBox::activated), this, &TransactionView::chooseWatchonly);
-    connect(amountWidget, &QLineEdit::textChanged, amount_typing_delay, static_cast<void (QTimer::*)()>(&QTimer::start));
+    connect(dateWidget, qOverload<int>(&QComboBox::activated), this, &TransactionView::chooseDate);
+    connect(typeWidget, qOverload<int>(&QComboBox::activated), this, &TransactionView::chooseType);
+    connect(watchOnlyWidget, qOverload<int>(&QComboBox::activated), this, &TransactionView::chooseWatchonly);
+    connect(amountWidget, &QLineEdit::textChanged, amount_typing_delay, qOverload<>(&QTimer::start));
     connect(amount_typing_delay, &QTimer::timeout, this, &TransactionView::changedAmount);
-    connect(search_widget, &QLineEdit::textChanged, prefix_typing_delay, static_cast<void (QTimer::*)()>(&QTimer::start));
+    connect(search_widget, &QLineEdit::textChanged, prefix_typing_delay, qOverload<>(&QTimer::start));
     connect(prefix_typing_delay, &QTimer::timeout, this, &TransactionView::changedSearch);
 
     connect(transactionView, &QTableView::doubleClicked, this, &TransactionView::doubleClicked);

src/qt/walletview.cpp

@@ -71,13 +71,13 @@ WalletView::WalletView(const PlatformStyle *_platformStyle, QWidget *parent):
 
     connect(overviewPage, &OverviewPage::transactionClicked, this, &WalletView::transactionClicked);
     // Clicking on a transaction on the overview pre-selects the transaction on the transaction history page
-    connect(overviewPage, &OverviewPage::transactionClicked, transactionView, static_cast<void (TransactionView::*)(const QModelIndex&)>(&TransactionView::focusTransaction));
+    connect(overviewPage, &OverviewPage::transactionClicked, transactionView, qOverload<const QModelIndex&>(&TransactionView::focusTransaction));
 
     connect(overviewPage, &OverviewPage::outOfSyncWarningClicked, this, &WalletView::requestedSyncWarningInfo);
 
     connect(sendCoinsPage, &SendCoinsDialog::coinsSent, this, &WalletView::coinsSent);
     // Highlight transaction after send
-    connect(sendCoinsPage, &SendCoinsDialog::coinsSent, transactionView, static_cast<void (TransactionView::*)(const uint256&)>(&TransactionView::focusTransaction));
+    connect(sendCoinsPage, &SendCoinsDialog::coinsSent, transactionView, qOverload<const uint256&>(&TransactionView::focusTransaction));
 
     // Clicking on "Export" allows to export the transaction list
     connect(exportButton, &QPushButton::clicked, transactionView, &TransactionView::exportClicked);