qml: refactor qeinvoice.py

QEInvoice/QEInvoiceParser now properly split for mapping to Invoice type (QEInvoice)
and parsing/resolving of payment identifiers (QEInvoiceParser).
additionally, old, unused QEUserEnteredPayment was removed.

invoices are now never saved with user-entered amount if the original invoice
did not specify an amount (e.g. address-only, no-amount bip21 uri, or no-amount
lightning invoice). Furthermore, QEInvoice now adds an isSaved property so the
UI doesn't need to infer that from the existence of the invoice key.

Payments of lightning invoices are now triggered through QEInvoice.pay_lightning_invoice(),
using the internally kept Invoice instance. This replaces the old call path of
QEWallet.pay_lightning_invoice(invoice_key) which required the invoice to be saved
in the backend wallet before payment.

The LNURLpay flow arriving on InvoiceDialog implicitly triggered payment, this is
now indicated by InvoiceDialog.payImmediately property instead of inferrred from the
QEInvoiceParser isLnurlPay property.

electrum/gui/qml/components/InvoiceDialog.qml

@@ -11,7 +11,7 @@ ElDialog {
     id: dialog
 
     property Invoice invoice
-    property string invoice_key
+    property bool payImmediately: false
 
     signal doPay
     signal invoiceAmountChanged
@@ -392,13 +392,13 @@ ElDialog {
                 Layout.preferredWidth: 1
                 text: qsTr('Save')
                 icon.source: '../../icons/save.png'
-                enabled: invoice_key == '' && invoice.canSave
+                enabled: !invoice.isSaved && invoice.canSave
                 onClicked: {
-                    app.stack.push(Qt.resolvedUrl('Invoices.qml'))
                     if (invoice.amount.isEmpty) {
-                        invoice.amount = amountMax.checked ? MAX : Config.unitsToSats(amountBtc.text)
+                        invoice.amountOverride = amountMax.checked ? MAX : Config.unitsToSats(amountBtc.text)
                     }
                     invoice.save_invoice()
+                    app.stack.push(Qt.resolvedUrl('Invoices.qml'))
                     dialog.close()
                 }
             }
@@ -410,15 +410,10 @@ ElDialog {
                 enabled: invoice.invoiceType != Invoice.Invalid && invoice.canPay
                 onClicked: {
                     if (invoice.amount.isEmpty) {
-                        invoice.amount = amountMax.checked ? MAX : Config.unitsToSats(amountBtc.text)
-                        if (invoice_key != '') {
-                            // delete the existing invoice because this affects get_id()
-                            invoice.wallet.delete_invoice(invoice_key)
-                            invoice_key = ''
-                        }
+                        invoice.amountOverride = amountMax.checked ? MAX : Config.unitsToSats(amountBtc.text)
                     }
-                    if (invoice_key == '') {
-                        // save invoice if new or modified
+                    if (!invoice.isSaved) {
+                        // save invoice if newly parsed
                         invoice.save_invoice()
                     }
                     doPay() // only signal here
@@ -429,18 +424,14 @@ ElDialog {
     }
 
     Component.onCompleted: {
-        if (invoice_key != '') {
-            invoice.initFromKey(invoice_key)
-        }
         if (invoice.amount.isEmpty && !invoice.status == Invoice.Expired) {
             amountContainer.editmode = true
         } else if (invoice.amount.isMax) {
             amountMax.checked = true
         }
-        if (invoice.isLnurlPay) {
-            // we arrive from a lnurl-pay confirm dialog where the user already indicated the intent to pay.
+        if (payImmediately) {
             if (invoice.canPay) {
-                if (invoice_key == '') {
+                if (!invoice.isSaved) {
                     invoice.save_invoice()
                 }
                 doPay()

electrum/gui/qml/components/WalletMainView.qml

@@ -21,7 +21,8 @@ Item {
     property string _request_expiry
 
     function openInvoice(key) {
-        var dialog = invoiceDialog.createObject(app, { invoice: invoiceParser, invoice_key: key })
+        invoice.key = key
+        var dialog = invoiceDialog.createObject(app, { invoice: invoice })
         dialog.open()
         return dialog
     }
@@ -195,6 +196,7 @@ Item {
                     Config.userKnowsPressAndHold = true
                     Daemon.currentWallet.delete_expired_requests()
                     app.stack.push(Qt.resolvedUrl('ReceiveRequests.qml'))
+                    AppController.haptic()
                 }
             }
             FlatButton {
@@ -207,11 +209,17 @@ Item {
                 onPressAndHold: {
                     Config.userKnowsPressAndHold = true
                     app.stack.push(Qt.resolvedUrl('Invoices.qml'))
+                    AppController.haptic()
                 }
             }
         }
     }
 
+    Invoice {
+        id: invoice
+        wallet: Daemon.currentWallet
+    }
+
     InvoiceParser {
         id: invoiceParser
         wallet: Daemon.currentWallet
@@ -232,7 +240,7 @@ Item {
         }
         onValidationSuccess: {
             closeSendDialog()
-            var dialog = invoiceDialog.createObject(app, { invoice: invoiceParser })
+            var dialog = invoiceDialog.createObject(app, { invoice: invoiceParser, payImmediately: invoiceParser.isLnurlPay })
             dialog.open()
         }
         onInvoiceCreateError: console.log(code + ' ' + message)
@@ -307,10 +315,16 @@ Item {
             height: parent.height
 
             onDoPay: {
-                if (invoice.invoiceType == Invoice.OnchainInvoice || (invoice.invoiceType == Invoice.LightningInvoice && invoice.amount.satsInt > Daemon.currentWallet.lightningCanSend ) ) {
+                if (invoice.invoiceType == Invoice.OnchainInvoice
+                    || (invoice.invoiceType == Invoice.LightningInvoice
+                        && invoice.amountOverride.isEmpty
+                            ? invoice.amount.satsInt > Daemon.currentWallet.lightningCanSend
+                            : invoice.amountOverride.satsInt > Daemon.currentWallet.lightningCanSend
+                        ))
+                    {
                     var dialog = confirmPaymentDialog.createObject(mainView, {
                             address: invoice.address,
-                            satoshis: invoice.amount,
+                            satoshis: invoice.amountOverride.isEmpty ? invoice.amount : invoice.amountOverride,
                             message: invoice.message
                     })
                     var canComplete = !Daemon.currentWallet.isWatchOnly && Daemon.currentWallet.canSignWithoutCosigner
@@ -328,11 +342,7 @@ Item {
                     dialog.open()
                 } else if (invoice.invoiceType == Invoice.LightningInvoice) {
                     console.log('About to pay lightning invoice')
-                    if (invoice.key == '') {
-                        console.log('No invoice key, aborting')
-                        return
-                    }
-                    Daemon.currentWallet.pay_lightning_invoice(invoice.key)
+                    invoice.pay_lightning_invoice()
                 }
             }
 

electrum/gui/qml/qeapp.py

@@ -29,7 +29,7 @@ from .qewalletdb import QEWalletDB
 from .qebitcoin import QEBitcoin
 from .qefx import QEFX
 from .qetxfinalizer import QETxFinalizer, QETxRbfFeeBumper, QETxCpfpFeeBumper, QETxCanceller
-from .qeinvoice import QEInvoice, QEInvoiceParser, QEUserEnteredPayment
+from .qeinvoice import QEInvoice, QEInvoiceParser
 from .qerequestdetails import QERequestDetails
 from .qetypes import QEAmount
 from .qeaddressdetails import QEAddressDetails
@@ -315,7 +315,6 @@ class ElectrumQmlApplication(QGuiApplication):
         qmlRegisterType(QETxFinalizer, 'org.electrum', 1, 0, 'TxFinalizer')
         qmlRegisterType(QEInvoice, 'org.electrum', 1, 0, 'Invoice')
         qmlRegisterType(QEInvoiceParser, 'org.electrum', 1, 0, 'InvoiceParser')
-        qmlRegisterType(QEUserEnteredPayment, 'org.electrum', 1, 0, 'UserEnteredPayment')
         qmlRegisterType(QEAddressDetails, 'org.electrum', 1, 0, 'AddressDetails')
         qmlRegisterType(QETxDetails, 'org.electrum', 1, 0, 'TxDetails')
         qmlRegisterType(QEChannelOpener, 'org.electrum', 1, 0, 'ChannelOpener')

electrum/gui/qml/qeinvoice.py

@@ -26,7 +26,7 @@ from .qewallet import QEWallet
 from .util import status_update_timer_interval, QtEventListener, event_listener
 
 
-class QEInvoice(QObject):
+class QEInvoice(QObject, QtEventListener):
     class Type:
         Invalid = -1
         OnchainInvoice = 0
@@ -48,118 +48,31 @@ class QEInvoice(QObject):
 
     _logger = get_logger(__name__)
 
-    def __init__(self, parent=None):
-        super().__init__(parent)
-
-        self._wallet = None  # type: Optional[QEWallet]
-        self._canSave = False
-        self._canPay = False
-        self._key = None
-
-    walletChanged = pyqtSignal()
-    @pyqtProperty(QEWallet, notify=walletChanged)
-    def wallet(self):
-        return self._wallet
-
-    @wallet.setter
-    def wallet(self, wallet: QEWallet):
-        if self._wallet != wallet:
-            self._wallet = wallet
-            self.walletChanged.emit()
-
-    canSaveChanged = pyqtSignal()
-    @pyqtProperty(bool, notify=canSaveChanged)
-    def canSave(self):
-        return self._canSave
-
-    @canSave.setter
-    def canSave(self, canSave):
-        if self._canSave != canSave:
-            self._canSave = canSave
-            self.canSaveChanged.emit()
-
-    canPayChanged = pyqtSignal()
-    @pyqtProperty(bool, notify=canPayChanged)
-    def canPay(self):
-        return self._canPay
-
-    @canPay.setter
-    def canPay(self, canPay):
-        if self._canPay != canPay:
-            self._canPay = canPay
-            self.canPayChanged.emit()
-
-    keyChanged = pyqtSignal()
-    @pyqtProperty(str, notify=keyChanged)
-    def key(self):
-        return self._key
-
-    @key.setter
-    def key(self, key):
-        if self._key != key:
-            self._key = key
-            self.keyChanged.emit()
-
-    userinfoChanged = pyqtSignal()
-    @pyqtProperty(str, notify=userinfoChanged)
-    def userinfo(self):
-        return self._userinfo
-
-    @userinfo.setter
-    def userinfo(self, userinfo):
-        if self._userinfo != userinfo:
-            self._userinfo = userinfo
-            self.userinfoChanged.emit()
-
-    def get_max_spendable_onchain(self):
-        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() if self._wallet.wallet.lnworker else 0
-
-class QEInvoiceParser(QEInvoice, QtEventListener):
-    _logger = get_logger(__name__)
-
     invoiceChanged = pyqtSignal()
     invoiceSaved = pyqtSignal([str], arguments=['key'])
-
-    validationSuccess = pyqtSignal()
-    validationWarning = pyqtSignal([str,str], arguments=['code', 'message'])
-    validationError = pyqtSignal([str,str], arguments=['code', 'message'])
-
-    invoiceCreateError = pyqtSignal([str,str], arguments=['code', 'message'])
-
-    lnurlRetrieved = pyqtSignal()
-    lnurlError = pyqtSignal([str,str], arguments=['code', 'message'])
-
     amountOverrideChanged = pyqtSignal()
 
-    _bip70PrResolvedSignal = pyqtSignal([PaymentRequest], arguments=['pr'])
-
     def __init__(self, parent=None):
         super().__init__(parent)
 
+        self._wallet = None  # type: Optional[QEWallet]
+        self._isSaved = False
+        self._canSave = False
+        self._canPay = False
+        self._key = None
         self._invoiceType = QEInvoice.Type.Invalid
-        self._recipient = ''
         self._effectiveInvoice = None
-        self._amount = QEAmount()
         self._userinfo = ''
         self._lnprops = {}
+        self._amount = QEAmount()
+        self._amountOverride = QEAmount()
 
         self._timer = QTimer(self)
         self._timer.setSingleShot(True)
         self._timer.timeout.connect(self.updateStatusString)
 
-        self._amountOverride = QEAmount()
         self._amountOverride.valueChanged.connect(self._on_amountoverride_value_changed)
 
-        self._bip70PrResolvedSignal.connect(self._bip70_payment_request_resolved)
-
-        self.clear()
-
         self.register_callbacks()
         self.destroyed.connect(lambda: self.on_destroy())
 
@@ -188,39 +101,40 @@ class QEInvoiceParser(QEInvoice, QtEventListener):
                 self.determine_can_pay()
                 self.userinfo = _('In progress...')
 
+    walletChanged = pyqtSignal()
+    @pyqtProperty(QEWallet, notify=walletChanged)
+    def wallet(self):
+        return self._wallet
+
+    @wallet.setter
+    def wallet(self, wallet: QEWallet):
+        if self._wallet != wallet:
+            self._wallet = wallet
+            self.walletChanged.emit()
+
     @pyqtProperty(int, notify=invoiceChanged)
     def invoiceType(self):
         return self._invoiceType
 
     # not a qt setter, don't let outside set state
-    def setInvoiceType(self, invoiceType: QEInvoice.Type):
+    def setInvoiceType(self, invoiceType: Type):
         self._invoiceType = invoiceType
 
-    recipientChanged = pyqtSignal()
-    @pyqtProperty(str, notify=recipientChanged)
-    def recipient(self):
-        return self._recipient
-
-    @recipient.setter
-    def recipient(self, recipient: str):
-        self.canPay = False
-        self._recipient = recipient
-        self.amountOverride = QEAmount()
-        if recipient:
-            self.validateRecipient(recipient)
-        self.recipientChanged.emit()
+    @pyqtProperty(str, notify=invoiceChanged)
+    def message(self):
+        return self._effectiveInvoice.message if self._effectiveInvoice else ''
 
-    @pyqtProperty('QVariantMap', notify=lnurlRetrieved)
-    def lnurlData(self):
-        return self._lnurlData
+    @pyqtProperty('quint64', notify=invoiceChanged)
+    def time(self):
+        return self._effectiveInvoice.time if self._effectiveInvoice else 0
 
-    @pyqtProperty(bool, notify=lnurlRetrieved)
-    def isLnurlPay(self):
-        return self._lnurlData is not None
+    @pyqtProperty('quint64', notify=invoiceChanged)
+    def expiration(self):
+        return self._effectiveInvoice.exp if self._effectiveInvoice else 0
 
     @pyqtProperty(str, notify=invoiceChanged)
-    def message(self):
-        return self._effectiveInvoice.message if self._effectiveInvoice else ''
+    def address(self):
+        return self._effectiveInvoice.get_address() if self._effectiveInvoice else ''
 
     @pyqtProperty(QEAmount, notify=invoiceChanged)
     def amount(self):
@@ -230,16 +144,6 @@ class QEInvoiceParser(QEInvoice, QtEventListener):
         self._amount.copyFrom(QEAmount(from_invoice=self._effectiveInvoice))
         return self._amount
 
-    @amount.setter
-    def amount(self, new_amount):
-        self._logger.debug(f'set new amount {repr(new_amount)}')
-        if self._effectiveInvoice:
-            self._effectiveInvoice.amount_msat = '!' if new_amount.isMax else int(new_amount.satsInt * 1000)
-
-        self.update_userinfo()
-        self.determine_can_pay()
-        self.invoiceChanged.emit()
-
     @pyqtProperty(QEAmount, notify=amountOverrideChanged)
     def amountOverride(self):
         return self._amountOverride
@@ -255,14 +159,6 @@ class QEInvoiceParser(QEInvoice, QtEventListener):
         self.update_userinfo()
         self.determine_can_pay()
 
-    @pyqtProperty('quint64', notify=invoiceChanged)
-    def time(self):
-        return self._effectiveInvoice.time if self._effectiveInvoice else 0
-
-    @pyqtProperty('quint64', notify=invoiceChanged)
-    def expiration(self):
-        return self._effectiveInvoice.exp if self._effectiveInvoice else 0
-
     statusChanged = pyqtSignal()
     @pyqtProperty(int, notify=statusChanged)
     def status(self):
@@ -277,9 +173,59 @@ class QEInvoiceParser(QEInvoice, QtEventListener):
         status = self._wallet.wallet.get_invoice_status(self._effectiveInvoice)
         return self._effectiveInvoice.get_status_str(status)
 
-    @pyqtProperty(str, notify=invoiceChanged)
-    def address(self):
-        return self._effectiveInvoice.get_address() if self._effectiveInvoice else ''
+    isSavedChanged = pyqtSignal()
+    @pyqtProperty(bool, notify=isSavedChanged)
+    def isSaved(self):
+        return self._isSaved
+
+    canSaveChanged = pyqtSignal()
+    @pyqtProperty(bool, notify=canSaveChanged)
+    def canSave(self):
+        return self._canSave
+
+    @canSave.setter
+    def canSave(self, canSave):
+        if self._canSave != canSave:
+            self._canSave = canSave
+            self.canSaveChanged.emit()
+
+    canPayChanged = pyqtSignal()
+    @pyqtProperty(bool, notify=canPayChanged)
+    def canPay(self):
+        return self._canPay
+
+    @canPay.setter
+    def canPay(self, canPay):
+        if self._canPay != canPay:
+            self._canPay = canPay
+            self.canPayChanged.emit()
+
+    keyChanged = pyqtSignal()
+    @pyqtProperty(str, notify=keyChanged)
+    def key(self):
+        return self._key
+
+    @key.setter
+    def key(self, key):
+        if self._key != key:
+            self._key = key
+            if self._effectiveInvoice and self._effectiveInvoice.get_id() == key:
+                return
+            invoice = self._wallet.wallet.get_invoice(key)
+            self._logger.debug(f'invoice from key {key}: {repr(invoice)}')
+            self.set_effective_invoice(invoice)
+            self.keyChanged.emit()
+
+    userinfoChanged = pyqtSignal()
+    @pyqtProperty(str, notify=userinfoChanged)
+    def userinfo(self):
+        return self._userinfo
+
+    @userinfo.setter
+    def userinfo(self, userinfo):
+        if self._userinfo != userinfo:
+            self._userinfo = userinfo
+            self.userinfoChanged.emit()
 
     @pyqtProperty('QVariantMap', notify=invoiceChanged)
     def lnprops(self):
@@ -304,38 +250,19 @@ class QEInvoiceParser(QEInvoice, QtEventListener):
         }
 
     def name_for_node_id(self, node_id):
-        node_alias = self._wallet.wallet.lnworker.get_node_alias(node_id) or node_id.hex()
-        return node_alias
-
-    @pyqtSlot()
-    def clear(self):
-        self.recipient = ''
-        self.setInvoiceType(QEInvoice.Type.Invalid)
-        self._bip21 = None
-        self._lnurlData = None
-        self.canSave = False
-        self.canPay = False
-        self.userinfo = ''
-        self.invoiceChanged.emit()
-
-    # don't parse the recipient string, but init qeinvoice from an invoice key
-    # this should not emit validation signals
-    @pyqtSlot(str)
-    def initFromKey(self, key):
-        self.clear()
-        invoice = self._wallet.wallet.get_invoice(key)
-        self._logger.debug(repr(invoice))
-        if invoice:
-            self.set_effective_invoice(invoice)
-            self.key = key
+        return self._wallet.wallet.lnworker.get_node_alias(node_id) or node_id.hex()
 
     def set_effective_invoice(self, invoice: Invoice):
         self._effectiveInvoice = invoice
 
-        if invoice.is_lightning():
-            self.setInvoiceType(QEInvoice.Type.LightningInvoice)
+        if invoice is None:
+            self.setInvoiceType(QEInvoice.Type.Invalid)
         else:
-            self.setInvoiceType(QEInvoice.Type.OnchainInvoice)
+            if invoice.is_lightning():
+                self.setInvoiceType(QEInvoice.Type.LightningInvoice)
+            else:
+                self.setInvoiceType(QEInvoice.Type.OnchainInvoice)
+            self._isSaved = self._wallet.wallet.get_invoice(invoice.get_id()) is not None
 
         self.set_lnprops()
 
@@ -344,6 +271,7 @@ class QEInvoiceParser(QEInvoice, QtEventListener):
 
         self.invoiceChanged.emit()
         self.statusChanged.emit()
+        self.isSavedChanged.emit()
 
         self.set_status_timer()
 
@@ -440,6 +368,86 @@ class QEInvoiceParser(QEInvoice, QtEventListener):
                     # TODO: subtract fee?
                     self.canPay = True
 
+    @pyqtSlot()
+    def pay_lightning_invoice(self):
+        if not self.canPay:
+            raise Exception('can not pay invoice, canPay is false')
+
+        if self.invoiceType != QEInvoice.Type.LightningInvoice:
+            raise Exception('pay_lightning_invoice can only pay lightning invoices')
+
+        if self.amount.isEmpty:
+            if self.amountOverride.isEmpty:
+                raise Exception('can not pay 0 amount')
+            # TODO: is update amount_msat for overrideAmount sufficient?
+            self._effectiveInvoice.amount_msat = self.amountOverride.satsInt * 1000
+
+        self._wallet.pay_lightning_invoice(self._effectiveInvoice)
+
+    def get_max_spendable_onchain(self):
+        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() if self._wallet.wallet.lnworker else 0
+
+class QEInvoiceParser(QEInvoice):
+    _logger = get_logger(__name__)
+
+    validationSuccess = pyqtSignal()
+    validationWarning = pyqtSignal([str,str], arguments=['code', 'message'])
+    validationError = pyqtSignal([str,str], arguments=['code', 'message'])
+
+    invoiceCreateError = pyqtSignal([str,str], arguments=['code', 'message'])
+
+    lnurlRetrieved = pyqtSignal()
+    lnurlError = pyqtSignal([str,str], arguments=['code', 'message'])
+
+    _bip70PrResolvedSignal = pyqtSignal([PaymentRequest], arguments=['pr'])
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+
+        self._recipient = ''
+        self._bip70PrResolvedSignal.connect(self._bip70_payment_request_resolved)
+
+        self.clear()
+
+    recipientChanged = pyqtSignal()
+    @pyqtProperty(str, notify=recipientChanged)
+    def recipient(self):
+        return self._recipient
+
+    @recipient.setter
+    def recipient(self, recipient: str):
+        self.canPay = False
+        self._recipient = recipient
+        self.amountOverride = QEAmount()
+        if recipient:
+            self.validateRecipient(recipient)
+        self.recipientChanged.emit()
+
+    @pyqtProperty('QVariantMap', notify=lnurlRetrieved)
+    def lnurlData(self):
+        return self._lnurlData
+
+    @pyqtProperty(bool, notify=lnurlRetrieved)
+    def isLnurlPay(self):
+        return self._lnurlData is not None
+
+    @pyqtSlot()
+    def clear(self):
+        self.recipient = ''
+        self.setInvoiceType(QEInvoice.Type.Invalid)
+        self._bip21 = None
+        self._lnurlData = None
+        self.canSave = False
+        self.canPay = False
+        self.userinfo = ''
+        self.invoiceChanged.emit()
+
     def setValidOnchainInvoice(self, invoice: Invoice):
         self._logger.debug('setValidOnchainInvoice')
         if invoice.is_lightning():
@@ -641,118 +649,14 @@ class QEInvoiceParser(QEInvoice, QtEventListener):
 
     @pyqtSlot()
     def save_invoice(self):
-        self.canSave = False
         if not self._effectiveInvoice:
             return
-
-        self.key = self._effectiveInvoice.get_id()
-        if self._wallet.wallet.get_invoice(self.key):
-            self._logger.info(f'invoice {self.key} already exists')
-        else:
-            self._wallet.wallet.save_invoice(self._effectiveInvoice)
-            self._wallet.invoiceModel.addInvoice(self.key)
-            self.invoiceSaved.emit(self.key)
-
-
-class QEUserEnteredPayment(QEInvoice):
-    _logger = get_logger(__name__)
-
-    validationError = pyqtSignal([str,str], arguments=['code','message'])
-    invoiceCreateError = pyqtSignal([str,str], arguments=['code', 'message'])
-    invoiceSaved = pyqtSignal()
-
-    def __init__(self, parent=None):
-        super().__init__(parent)
-
-        self._amount = QEAmount()
-        self.clear()
-
-    recipientChanged = pyqtSignal()
-    @pyqtProperty(str, notify=recipientChanged)
-    def recipient(self):
-        return self._recipient
-
-    @recipient.setter
-    def recipient(self, recipient: str):
-        if self._recipient != recipient:
-            self._recipient = recipient
-            self.validate()
-            self.recipientChanged.emit()
-
-    messageChanged = pyqtSignal()
-    @pyqtProperty(str, notify=messageChanged)
-    def message(self):
-        return self._message
-
-    @message.setter
-    def message(self, message):
-        if self._message != message:
-            self._message = message
-            self.messageChanged.emit()
-
-    amountChanged = pyqtSignal()
-    @pyqtProperty(QEAmount, notify=amountChanged)
-    def amount(self):
-        return self._amount
-
-    @amount.setter
-    def amount(self, amount):
-        if self._amount != amount:
-            self._amount.copyFrom(amount)
-            self.validate()
-            self.amountChanged.emit()
-
-
-    def validate(self):
-        self.canPay = False
-        self.canSave = False
-        self._logger.debug('validate')
-
-        if not self._recipient:
-            self.validationError.emit('recipient', _('Recipient not specified.'))
-            return
-
-        if not bitcoin.is_address(self._recipient):
-            self.validationError.emit('recipient', _('Invalid Bitcoin address'))
-            return
-
-        self.canSave = True
-
-        if self._amount.isEmpty:
-            self.validationError.emit('amount', _('Invalid amount'))
+        if self.isSaved:
             return
 
-        if self._amount.isMax:
-            self.canPay = True
-        else:
-            if self.get_max_spendable_onchain() >= self._amount.satsInt:
-                self.canPay = True
-
-    @pyqtSlot()
-    def save_invoice(self):
-        assert self.canSave
-        assert not self._amount.isMax
-
-        self._logger.debug('saving invoice to %s, amount=%s, message=%s' % (self._recipient, repr(self._amount), self._message))
-
-        inv_amt = self._amount.satsInt
-
-        try:
-            outputs = [PartialTxOutput.from_address_and_value(self._recipient, inv_amt)]
-            self._logger.debug(repr(outputs))
-            invoice = self._wallet.wallet.create_invoice(outputs=outputs, message=self._message, pr=None, URI=None)
-        except InvoiceError as e:
-            self.invoiceCreateError.emit('fatal', _('Error creating payment') + ':\n' + str(e))
-            return
-
-        self.key = invoice.get_id()
-        self._wallet.wallet.save_invoice(invoice)
-        self.invoiceSaved.emit()
-
-    @pyqtSlot()
-    def clear(self):
-        self._recipient = None
-        self._amount.clear()
-        self._message = None
         self.canSave = False
-        self.canPay = False
+
+        self.key = self._effectiveInvoice.get_id()
+        self._wallet.wallet.save_invoice(self._effectiveInvoice)
+        self._wallet.invoiceModel.addInvoice(self.key)
+        self.invoiceSaved.emit(self.key)

electrum/gui/qml/qewallet.py

@@ -28,7 +28,7 @@ from .util import QtEventListener, qt_event_listener
 
 if TYPE_CHECKING:
     from electrum.wallet import Abstract_Wallet
-
+    from .qeinvoice import QEInvoice
 
 class QEWallet(AuthMixin, QObject, QtEventListener):
     __instances = []
@@ -587,14 +587,8 @@ class QEWallet(AuthMixin, QObject, QtEventListener):
     def ln_auth_rejected(self):
         self.paymentAuthRejected.emit()
 
-    @pyqtSlot(str)
     @auth_protect(reject='ln_auth_rejected')
-    def pay_lightning_invoice(self, invoice_key):
-        self._logger.debug('about to pay LN')
-        invoice = self.wallet.get_invoice(invoice_key)
-        assert(invoice)
-        assert(invoice.lightning_invoice)
-
+    def pay_lightning_invoice(self, invoice: 'QEInvoice'):
         amount_msat = invoice.get_amount_msat()
 
         def pay_thread():