qml: proper check for max amount onchain. move max amount lightning to superclass

electrum/gui/qml/components/InvoiceDialog.qml

@@ -115,7 +115,7 @@ ElDialog {
 
                 Label {
                     width: parent.width
-                    text: invoice.lnprops ? invoice.lnprops.pubkey : ''
+                    text: 'pubkey' in invoice.lnprops ? invoice.lnprops.pubkey : ''
                     font.family: FixedFont
                     wrapMode: Text.Wrap
                 }

electrum/gui/qml/qeinvoice.py

@@ -107,10 +107,13 @@ class QEInvoice(QObject):
             self.userinfoChanged.emit()
 
     def get_max_spendable_onchain(self):
-        c, u, x = self._wallet.wallet.get_balance()
-        #TODO determine real max
-        return c
+        spendable = self._wallet.confirmedBalance.satsInt
+        if not self._wallet.wallet.config.get('confirmed_only', False):
+            spendable += self._wallet.unconfirmedBalance.satsInt
+        return spendable
 
+    def get_max_spendable_lightning(self):
+        return self._wallet.wallet.lnworker.num_sats_can_send()
 
 class QEInvoiceParser(QEInvoice):
 
@@ -303,9 +306,6 @@ class QEInvoiceParser(QEInvoice):
                         PR_UNKNOWN: _('Invoice has unknown status'),
                     }[self.status]
 
-    def get_max_spendable_lightning(self):
-        return self._wallet.wallet.lnworker.num_sats_can_send()
-
     def setValidOnchainInvoice(self, invoice: Invoice):
         self._logger.debug('setValidOnchainInvoice')
         if invoice.is_lightning():