export channel backup from kivy gui

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

@@ -180,6 +180,11 @@ Builder.load_string(r'''
         BoxLayout:
             size_hint: 1, None
             height: '48dp'
+            Button:
+                size_hint: 0.5, None
+                height: '48dp'
+                text: _('Backup')
+                on_release: root.export_backup()
             Button:
                 size_hint: 0.5, None
                 height: '48dp'
@@ -284,6 +289,9 @@ class ChannelBackupPopup(Popup):
         super(ChannelBackupPopup,self).__init__(**kwargs)
         self.chan = chan
         self.app = app
+        self.short_id = format_short_channel_id(chan.short_channel_id)
+        self.state = chan.get_state_for_GUI()
+        self.title = _('Channel Backup')
 
     def request_force_close(self):
         msg = _('Request force close?')
@@ -363,6 +371,10 @@ class ChannelDetailsPopup(Popup):
         self.app._trigger_update_history()
         self.dismiss()
 
+    def export_backup(self):
+        text = self.app.wallet.lnworker.export_channel_backup(self.chan.channel_id)
+        self.app.qr_dialog(_("Channel Backup " + self.chan.short_id_for_GUI()), 'channel_backup:'+text)
+
     def force_close(self):
         Question(_('Force-close channel?'), self._force_close).open()
 

electrum/lnchannel.py

@@ -146,6 +146,8 @@ class AbstractChannel(Logger):
         self.logger.debug(f'Setting channel state: {old_state.name} -> {state.name}')
         self._state = state
         self.storage['state'] = self._state.name
+        if self.lnworker:
+            self.lnworker.channel_state_changed(self)
 
     def get_state(self) -> channel_states:
         return self._state
@@ -567,12 +569,6 @@ class Channel(AbstractChannel):
             self.hm.channel_open_finished()
             self.peer_state = peer_states.GOOD
 
-    def set_state(self, state: channel_states) -> None:
-        super().set_state(state)
-        if self.lnworker:
-            self.lnworker.save_channel(self)
-            self.lnworker.network.trigger_callback('channel', self)
-
     def get_state_for_GUI(self):
         # status displayed in the GUI
         cs = self.get_state()

electrum/lnworker.py

@@ -657,6 +657,10 @@ class LNWallet(LNWorker):
         with self.lock:
             return {x: y for (x, y) in self.channels.items() if y.node_id == node_id}
 
+    def channel_state_changed(self, chan):
+        self.save_channel(chan)
+        self.network.trigger_callback('channel', chan)
+
     def save_channel(self, chan):
         assert type(chan) is Channel
         if chan.config[REMOTE].next_per_commitment_point == chan.config[REMOTE].current_per_commitment_point:
@@ -1367,6 +1371,9 @@ class LNBackups(Logger):
         for channel_id, cb in self.db.get_dict("channel_backups").items():
             self.channel_backups[bfh(channel_id)] = ChannelBackup(cb, sweep_address=self.sweep_address, lnworker=self)
 
+    def channel_state_changed(self, chan):
+        self.network.trigger_callback('channel', chan)
+
     def peer_closed(self, chan):
         pass
 
@@ -1390,16 +1397,17 @@ class LNBackups(Logger):
 
     def import_channel_backup(self, encrypted):
         xpub = self.wallet.get_fingerprint()
-        x = pw_decode_bytes(encrypted, xpub, version=PW_HASH_VERSION_LATEST)
-        cb = ChannelBackupStorage.from_bytes(x)
-        channel_id = cb.channel_id().hex()
+        decrypted = pw_decode_bytes(encrypted, xpub, version=PW_HASH_VERSION_LATEST)
+        cb_storage = ChannelBackupStorage.from_bytes(decrypted)
+        channel_id = cb_storage.channel_id().hex()
         d = self.db.get_dict("channel_backups")
         if channel_id in d:
             raise Exception('Channel already in wallet')
-        d[channel_id] = cb
-        self.channel_backups[bfh(channel_id)] = ChannelBackup(cb, sweep_address=self.sweep_address, lnworker=self)
+        d[channel_id] = cb_storage
+        self.channel_backups[bfh(channel_id)] = cb = ChannelBackup(cb_storage, sweep_address=self.sweep_address, lnworker=self)
         self.wallet.save_db()
         self.network.trigger_callback('channels_updated', self.wallet)
+        self.lnwatcher.add_channel(cb.funding_outpoint.to_str(), cb.get_funding_address())
 
     def remove_channel_backup(self, channel_id):
         d = self.db.get_dict("channel_backups")

electrum/tests/test_lnpeer.py

@@ -124,6 +124,9 @@ class MockLNWallet(Logger):
                 if chan.short_channel_id == short_channel_id:
                     return chan
 
+    def channel_state_changed(self, chan):
+        pass
+
     def save_channel(self, chan):
         print("Ignoring channel save")