support for MAX amounts

electrum/gui/qml/components/ConfirmTxDialog.qml

@@ -35,6 +35,13 @@ Dialog {
         color: "#aa000000"
     }
 
+    function updateAmountText() {
+        btcValue.text = Config.formatSats(finalizer.effectiveAmount, false)
+        fiatValue.text = Daemon.fx.enabled
+            ? '(' + Daemon.fx.fiatValue(finalizer.effectiveAmount, false) + ' ' + Daemon.fx.fiatCurrency + ')'
+            : ''
+    }
+
     GridLayout {
         id: layout
         width: parent.width
@@ -56,8 +63,8 @@ Dialog {
         RowLayout {
             Layout.fillWidth: true
             Label {
+                id: btcValue
                 font.bold: true
-                text: Config.formatSats(satoshis, false)
             }
 
             Label {
@@ -68,11 +75,16 @@ Dialog {
             Label {
                 id: fiatValue
                 Layout.fillWidth: true
-                text: Daemon.fx.enabled
-                        ? '(' + Daemon.fx.fiatValue(satoshis, false) + ' ' + Daemon.fx.fiatCurrency + ')'
-                        : ''
                 font.pixelSize: constants.fontSizeMedium
             }
+
+            Component.onCompleted: updateAmountText()
+            Connections {
+                target: finalizer
+                function onEffectiveAmountChanged() {
+                    updateAmountText()
+                }
+            }
         }
 
         Label {

electrum/gui/qml/components/Send.qml

@@ -79,6 +79,7 @@ Pane {
         BtcField {
             id: amount
             fiatfield: amountFiat
+            enabled: !is_max.checked
             Layout.preferredWidth: parent.width /3
             onTextChanged: {
                 userEnteredPayment.amount = is_max.checked ? MAX : Config.unitsToSats(amount.text)
@@ -107,6 +108,7 @@ Pane {
             id: amountFiat
             btcfield: amount
             visible: Daemon.fx.enabled
+            enabled: !is_max.checked
             Layout.preferredWidth: parent.width /3
         }
 
@@ -243,7 +245,6 @@ Pane {
             title: qsTr('Confirm Payment')
             finalizer: TxFinalizer {
                 wallet: Daemon.currentWallet
-                onAmountChanged: console.log(amount.satsInt)
             }
         }
     }

electrum/gui/qml/qechannelopener.py

@@ -127,17 +127,20 @@ class QEChannelOpener(QObject):
             return
 
         amount = '!' if self._amount.isMax else self._amount.satsInt
+        self._logger.debug('amount = %s' % str(amount))
+
         coins = self._wallet.wallet.get_spendable_coins(None, nonlocal_only=True)
 
-        mktx = lambda: lnworker.mktx_for_open_channel(
+        mktx = lambda amt: lnworker.mktx_for_open_channel(
             coins=coins,
-            funding_sat=amount,
+            funding_sat=amt,
             node_id=self._peer.pubkey,
             fee_est=None)
 
         acpt = lambda tx: self.do_open_channel(tx, str(self._peer), None)
 
         self._finalizer = QETxFinalizer(self, make_tx=mktx, accept=acpt)
+        self._finalizer.amount = self._amount
         self._finalizer.wallet = self._wallet
         self.finalizerChanged.emit()
 

electrum/gui/qml/qetxfinalizer.py

@@ -21,6 +21,7 @@ class QETxFinalizer(QObject):
 
     _address = ''
     _amount = QEAmount()
+    _effectiveAmount = QEAmount()
     _fee = QEAmount()
     _feeRate = ''
     _wallet = None
@@ -75,6 +76,11 @@ class QETxFinalizer(QObject):
             self._amount = amount
             self.amountChanged.emit()
 
+    effectiveAmountChanged = pyqtSignal()
+    @pyqtProperty(QEAmount, notify=effectiveAmountChanged)
+    def effectiveAmount(self):
+        return self._effectiveAmount
+
     feeChanged = pyqtSignal()
     @pyqtProperty(QEAmount, notify=feeChanged)
     def fee(self):
@@ -208,28 +214,34 @@ class QETxFinalizer(QObject):
         self.update()
 
     @profiler
-    def make_tx(self):
-        if self.f_make_tx:
-            tx = self.f_make_tx()
-            return tx
+    def make_tx(self, amount):
+        self._logger.debug('make_tx amount = %s' % str(amount))
+
+        if self.f_make_tx:
+            tx = self.f_make_tx(amount)
+        else:
+            # default impl
+            coins = self._wallet.wallet.get_spendable_coins(None)
+            outputs = [PartialTxOutput.from_address_and_value(self.address, amount)]
+            tx = self._wallet.wallet.make_unsigned_transaction(coins=coins,outputs=outputs, fee=None,rbf=self._rbf)
 
-        # default impl
-        coins = self._wallet.wallet.get_spendable_coins(None)
-        outputs = [PartialTxOutput.from_address_and_value(self.address, self._amount.satsInt)]
-        tx = self._wallet.wallet.make_unsigned_transaction(coins=coins,outputs=outputs, fee=None,rbf=self._rbf)
         self._logger.debug('fee: %d, inputs: %d, outputs: %d' % (tx.get_fee(), len(tx.inputs()), len(tx.outputs())))
-        self._logger.debug(repr(tx.outputs()))
+
         outputs = []
         for o in tx.outputs():
-            outputs.append(o.to_json())
+            outputs.append({
+                'address': o.get_ui_address_str(),
+                'value_sats': o.value
+            })
         self.outputs = outputs
+
         return tx
 
     @pyqtSlot()
     def update(self):
         try:
             # make unsigned transaction
-            tx = self.make_tx()
+            tx = self.make_tx(amount = '!' if self._amount.isMax else self._amount.satsInt)
         except NotEnoughFunds:
             self.warning = _("Not enough funds")
             self._valid = False
@@ -246,6 +258,9 @@ class QETxFinalizer(QObject):
 
         amount = self._amount.satsInt if not self._amount.isMax else tx.output_value()
 
+        self._effectiveAmount = QEAmount(amount_sat=amount)
+        self.effectiveAmountChanged.emit()
+
         tx_size = tx.estimated_size()
         fee = tx.get_fee()
         feerate = Decimal(fee) / tx_size  # sat/byte