Lightning: Show sending and receiving capacity. Fixes #5967

electrum/gui/kivy/uix/dialogs/lightning_channels.py

@@ -52,11 +52,20 @@ Builder.load_string(r'''
 <LightningChannelsDialog@Popup>:
     name: 'lightning_channels'
     title: _('Lightning channels.')
+    can_send: ''
+    can_receive: ''
     id: popup
     BoxLayout:
         id: box
         orientation: 'vertical'
-        spacing: '1dp'
+        spacing: '2dp'
+        padding: '12dp'
+        BoxLabel:
+            text: _('Can send') + ':'
+            value: root.can_send
+        BoxLabel:
+            text: _('Can receive') + ':'
+            value: root.can_receive
         ScrollView:
             GridLayout:
                 cols: 1
@@ -64,11 +73,16 @@ Builder.load_string(r'''
                 size_hint: 1, None
                 height: self.minimum_height
                 spacing: '2dp'
-                padding: '12dp'
-        Button:
+        BoxLayout:
             size_hint: 1, None
             height: '48dp'
-            text: _('New channel...')
+            Widget:
+                size_hint: 0.7, None
+                height: '48dp'
+            Button:
+                size_hint: 0.3, None
+                height: '48dp'
+                text: _('New...')
                 on_press: popup.app.popup_dialog('lightning_open_channel_dialog')
 
 <ChannelDetailsList@RecycleView>:
@@ -147,6 +161,7 @@ class ChannelDetailsPopup(Popup):
             _('Remote CTN'): chan.get_latest_ctn(REMOTE),
             _('Capacity'): self.app.format_amount_and_units(chan.constraints.capacity),
             _('Can send'): self.app.format_amount_and_units(chan.available_to_spend(LOCAL) // 1000),
+            _('Can receive'): self.app.format_amount_and_units(chan.available_to_spend(REMOTE) // 1000),
             _('Current feerate'): str(chan.get_latest_feerate(LOCAL)),
             _('Node ID'): bh2u(chan.node_id),
             _('Channel ID'): bh2u(chan.channel_id),
@@ -202,6 +217,7 @@ class LightningChannelsDialog(Factory.Popup):
         super(LightningChannelsDialog, self).__init__()
         self.clocks = []
         self.app = app
+        self.can_send = ''
         self.update()
 
     def show_item(self, obj):
@@ -231,6 +247,7 @@ class LightningChannelsDialog(Factory.Popup):
         l, r = self.format_fields(chan)
         item.local_balance = _('Local') + ':' + l
         item.remote_balance = _('Remote') + ': ' + r
+        self.update_can_send()
 
     def update(self):
         channel_cards = self.ids.lightning_channels_container
@@ -245,3 +262,9 @@ class LightningChannelsDialog(Factory.Popup):
             item._chan = i
             self.update_item(item)
             channel_cards.add_widget(item)
+        self.update_can_send()
+
+    def update_can_send(self):
+        lnworker = self.app.wallet.lnworker
+        self.can_send = self.app.format_amount_and_units(lnworker.can_send())
+        self.can_receive = self.app.format_amount_and_units(lnworker.can_receive())

electrum/gui/qt/channels_list.py

@@ -130,6 +130,7 @@ class ChannelsList(MyTreeView):
             if item.data(ROLE_CHANNEL_ID) == chan.channel_id:
                 for column, v in enumerate(self.format_fields(chan)):
                     self.model().item(row, column).setData(v, QtCore.Qt.DisplayRole)
+        self.update_can_send(self.parent.wallet.lnworker)
 
     @QtCore.pyqtSlot(Abstract_Wallet)
     def do_update_rows(self, wallet):
@@ -138,6 +139,7 @@ class ChannelsList(MyTreeView):
         lnworker = self.parent.wallet.lnworker
         if not lnworker:
             return
+        self.update_can_send(lnworker)
         self.model().clear()
         self.update_headers(self.headers)
         for chan in lnworker.channels.values():
@@ -149,8 +151,17 @@ class ChannelsList(MyTreeView):
             items[self.Columns.REMOTE_BALANCE].setFont(QFont(MONOSPACE_FONT))
             self.model().insertRow(0, items)
 
+    def update_can_send(self, lnworker):
+        msg = _('Can send') + ' ' + self.parent.format_amount(lnworker.can_send())\
+              + ' ' + self.parent.base_unit() + '; '\
+              + _('can receive') + ' ' + self.parent.format_amount(lnworker.can_receive())\
+              + ' ' + self.parent.base_unit()
+        self.can_send_label.setText(msg)
+
     def get_toolbar(self):
         h = QHBoxLayout()
+        self.can_send_label = QLabel('')
+        h.addWidget(self.can_send_label)
         h.addStretch()
         h.addWidget(EnterButton(_('Open Channel'), self.new_channel_dialog))
         return h

electrum/lnchannel.py

@@ -298,6 +298,9 @@ class Channel(Logger):
     def get_state(self):
         return self._state
 
+    def is_open(self):
+        return self.get_state() == channel_states.OPEN
+
     def is_closing(self):
         return self.get_state() in [channel_states.CLOSING, channel_states.FORCE_CLOSING]
 

electrum/lnworker.py

@@ -1163,6 +1163,14 @@ class LNWallet(LNWorker):
         with self.lock:
             return Decimal(sum(chan.balance(LOCAL) if not chan.is_closed() else 0 for chan in self.channels.values()))/1000
 
+    def can_send(self):
+        with self.lock:
+            return Decimal(max(chan.available_to_spend(LOCAL) if chan.is_open() else 0 for chan in self.channels.values()))/1000
+
+    def can_receive(self):
+        with self.lock:
+            return Decimal(max(chan.available_to_spend(REMOTE) if chan.is_open() else 0 for chan in self.channels.values()))/1000
+
     def list_channels(self):
         encoder = MyEncoder()
         with self.lock: