gui: address type dropdown, add bech32m

Co-authored-by: João Barbosa <joao.paulo.barbosa@gmail.com>

doc/release-notes-gui-459.md

@@ -0,0 +1,4 @@
+GUI changes
+-----------
+
+- The Bech32 checkbox has been replaced with a dropdown for all address types, including the new Bech32m (BIP-350) standard for Taproot enabled wallets.

src/qt/forms/receivecoinsdialog.ui

@@ -195,7 +195,7 @@
            </widget>
           </item>
           <item>
-           <widget class="QCheckBox" name="useBech32">
+           <widget class="QComboBox" name="addressType">
             <property name="sizePolicy">
              <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
               <horstretch>0</horstretch>
@@ -211,12 +211,6 @@
             <property name="focusPolicy">
              <enum>Qt::StrongFocus</enum>
             </property>
-            <property name="toolTip">
-             <string>Native segwit addresses (aka Bech32 or BIP-173) reduce your transaction fees later on and offer better protection against typos, but old wallets don't support them. When unchecked, an address compatible with older wallets will be created instead.</string>
-            </property>
-            <property name="text">
-             <string>Generate native segwit (Bech32) address</string>
-            </property>
            </widget>
           </item>
           <item>
@@ -366,7 +360,7 @@
  <tabstops>
   <tabstop>reqLabel</tabstop>
   <tabstop>reqAmount</tabstop>
-  <tabstop>useBech32</tabstop>
+  <tabstop>addressType</tabstop>
   <tabstop>reqMessage</tabstop>
   <tabstop>receiveButton</tabstop>
   <tabstop>clearButton</tabstop>

src/qt/receivecoinsdialog.cpp

@@ -87,10 +87,18 @@ void ReceiveCoinsDialog::setModel(WalletModel *_model)
             &QItemSelectionModel::selectionChanged, this,
             &ReceiveCoinsDialog::recentRequestsView_selectionChanged);
 
-        if (model->wallet().getDefaultAddressType() == OutputType::BECH32) {
-            ui->useBech32->setCheckState(Qt::Checked);
-        } else {
-            ui->useBech32->setCheckState(Qt::Unchecked);
+        // Populate address type dropdown and select default
+        auto add_address_type = [&](OutputType type, const QString& text, const QString& tooltip) {
+            const auto index = ui->addressType->count();
+            ui->addressType->addItem(text, (int) type);
+            ui->addressType->setItemData(index, tooltip, Qt::ToolTipRole);
+            if (model->wallet().getDefaultAddressType() == type) ui->addressType->setCurrentIndex(index);
+        };
+        add_address_type(OutputType::LEGACY, "Base58 (Legacy)", "Not recommended due to higher fees and less protection against typos.");
+        add_address_type(OutputType::P2SH_SEGWIT, "Base58 (P2SH-SegWit)", "Generates an address compatible with older wallets.");
+        add_address_type(OutputType::BECH32, "Bech32 (SegWit)", "Generates a native segwit address (BIP-173). Some old wallets don't support it.");
+        if (model->wallet().taprootEnabled()) {
+            add_address_type(OutputType::BECH32M, "Bech32m (Taproot)", "Bech32m (BIP-350) is an upgrade to Bech32, wallet support is still limited.");
         }
 
         // Set the button to be enabled or disabled based on whether the wallet can give out new addresses.
@@ -144,15 +152,7 @@ void ReceiveCoinsDialog::on_receiveButton_clicked()
     QString address;
     QString label = ui->reqLabel->text();
     /* Generate new receiving address */
-    OutputType address_type;
-    if (ui->useBech32->isChecked()) {
-        address_type = OutputType::BECH32;
-    } else {
-        address_type = model->wallet().getDefaultAddressType();
-        if (address_type == OutputType::BECH32) {
-            address_type = OutputType::P2SH_SEGWIT;
-        }
-    }
+    const OutputType address_type = (OutputType)ui->addressType->currentData().toInt();
     address = model->getAddressTableModel()->addRow(AddressTableModel::Receive, label, "", address_type);
 
     switch(model->getAddressTableModel()->getEditStatus())