qml: add max amount option in invoice dialog and show in invoice delegate

electrum/gui/qml/components/InvoiceDialog.qml

@@ -26,6 +26,8 @@ ElDialog {
         color: "#aa000000"
     }
 
+    property bool _canMax: invoice.invoiceType == Invoice.OnchainInvoice
+
     ColumnLayout {
         width: parent.width
         height: parent.height
@@ -172,6 +174,16 @@ ElDialog {
                         columns: 2
 
                         Label {
+                            visible: invoice.amount.isMax
+                            Layout.columnSpan: 2
+                            font.pixelSize: constants.fontSizeXLarge
+                            font.bold: true
+                            Layout.fillWidth: true
+                            text: qsTr('All on-chain funds')
+                        }
+
+                        Label {
+                            visible: !invoice.amount.isMax
                             font.pixelSize: constants.fontSizeXLarge
                             font.family: FixedFont
                             font.bold: true
@@ -179,6 +191,7 @@ ElDialog {
                         }
 
                         Label {
+                            visible: !invoice.amount.isMax
                             Layout.fillWidth: true
                             text: Config.baseUnit
                             color: Material.accentColor
@@ -187,14 +200,14 @@ ElDialog {
 
                         Label {
                             id: fiatValue
-                            visible: Daemon.fx.enabled
+                            visible: Daemon.fx.enabled && !invoice.amount.isMax
                             text: Daemon.fx.fiatValue(invoice.amount, false)
                             font.pixelSize: constants.fontSizeMedium
                             color: constants.mutedForeground
                         }
 
                         Label {
-                            visible: Daemon.fx.enabled
+                            visible: Daemon.fx.enabled && !invoice.amount.isMax
                             Layout.fillWidth: true
                             text: Daemon.fx.fiatCurrency
                             font.pixelSize: constants.fontSizeMedium
@@ -209,6 +222,7 @@ ElDialog {
                         icon.color: 'transparent'
                         onClicked: {
                             amountBtc.text = invoice.amount.satsInt == 0 ? '' : Config.formatSats(invoice.amount)
+                            amountMax.checked = invoice.amount.isMax
                             amountContainer.editmode = true
                             amountBtc.focus = true
                         }
@@ -216,26 +230,42 @@ ElDialog {
                     GridLayout {
                         visible: amountContainer.editmode
                         Layout.fillWidth: true
-                        columns: 2
+                        columns: 3
                         BtcField {
                             id: amountBtc
                             fiatfield: amountFiat
+                            enabled: !amountMax.checked
                         }
 
                         Label {
                             text: Config.baseUnit
                             color: Material.accentColor
+                            Layout.fillWidth: amountMax.visible ? false : true
+                            Layout.columnSpan: amountMax.visible ? 1 : 2
+                        }
+                        Switch {
+                            id: amountMax
+                            text: qsTr('Max')
+                            visible: _canMax
                             Layout.fillWidth: true
+                            checked: invoice.amount.isMax
+                            onCheckedChanged: {
+                                if (activeFocus) {
+                                    invoice.amount.isMax = checked
+                                }
+                            }
                         }
 
                         FiatField {
                             id: amountFiat
                             btcfield: amountBtc
-                            visible: Daemon.fx.enabled
+                            visible: Daemon.fx.enabled && !amountMax.checked
+                            enabled: !amountMax.checked
                         }
 
                         Label {
-                            visible: Daemon.fx.enabled
+                            Layout.columnSpan: 2
+                            visible: Daemon.fx.enabled && !amountMax.checked
                             text: Daemon.fx.fiatCurrency
                             color: Material.accentColor
                         }
@@ -247,7 +277,7 @@ ElDialog {
                         icon.color: 'transparent'
                         onClicked: {
                             amountContainer.editmode = false
-                            invoice.amount = Config.unitsToSats(amountBtc.text)
+                            invoice.amount = amountMax.checked ? MAX : Config.unitsToSats(amountBtc.text)
                         }
                     }
                     ToolButton {
@@ -315,7 +345,7 @@ ElDialog {
         if (invoice_key != '') {
             invoice.initFromKey(invoice_key)
         }
-        if (invoice.amount.satsInt == 0)
+        if (invoice.amount.isEmpty)
             amountContainer.editmode = true
     }
 }

electrum/gui/qml/components/controls/InvoiceDelegate.qml

@@ -67,13 +67,17 @@ ItemDelegate {
 
             Label {
                 id: amount
-                text: model.amount.isEmpty ? '' : Config.formatSats(model.amount)
+                text: model.amount.isEmpty
+                    ? ''
+                    : model.amount.isMax
+                        ? 'MAX'
+                        : Config.formatSats(model.amount)
                 font.pixelSize: constants.fontSizeMedium
                 font.family: FixedFont
             }
 
             Label {
-                text: model.amount.isEmpty ? '' : Config.baseUnit
+                text: model.amount.isEmpty || model.amount.isMax ? '' : Config.baseUnit
                 font.pixelSize: constants.fontSizeMedium
                 color: Material.accentColor
             }
@@ -105,14 +109,14 @@ ItemDelegate {
             }
             Label {
                 id: fiatValue
-                visible: Daemon.fx.enabled
+                visible: Daemon.fx.enabled && !model.amount.isMax
                 Layout.alignment: Qt.AlignRight
                 text: model.amount.isEmpty ? '' : Daemon.fx.fiatValue(model.amount, false)
                 font.family: FixedFont
                 font.pixelSize: constants.fontSizeSmall
             }
             Label {
-                visible: Daemon.fx.enabled
+                visible: Daemon.fx.enabled && !model.amount.isMax
                 Layout.alignment: Qt.AlignRight
                 text: model.amount.isEmpty ? '' : Daemon.fx.fiatCurrency
                 font.pixelSize: constants.fontSizeSmall

electrum/gui/qml/qeinvoice.py

@@ -182,7 +182,7 @@ class QEInvoiceParser(QEInvoice):
     def amount(self, new_amount):
         self._logger.debug(f'set new amount {repr(new_amount)}')
         if self._effectiveInvoice:
-            self._effectiveInvoice.amount_msat = int(new_amount.satsInt * 1000)
+            self._effectiveInvoice.amount_msat = '!' if new_amount.isMax else int(new_amount.satsInt * 1000)
 
         self.determine_can_pay()
         self.invoiceChanged.emit()