qml: show experimental warning before opening first lightning channel. closes #8564

electrum/gui/qml/components/Channels.qml

@@ -136,8 +136,22 @@ Pane {
                 enabled: Daemon.currentWallet.confirmedBalance.satsInt > 0
                 text: qsTr('Open Channel')
                 onClicked: {
-                    var dialog = openChannelDialog.createObject(root)
-                    dialog.open()
+                    if (Daemon.currentWallet.channelModel.count == 0) {
+                        var txt = Daemon.currentWallet.channelModel.lightningWarningMessage() + '\n\n' +
+                            qsTr('Do you want to create your first channel?')
+                        var confirmdialog = app.messageDialog.createObject(root, {
+                            text: txt,
+                            yesno: true
+                        })
+                        confirmdialog.accepted.connect(function () {
+                            var dialog = openChannelDialog.createObject(root)
+                            dialog.open()
+                        })
+                        confirmdialog.open()
+                    } else {
+                        var dialog = openChannelDialog.createObject(root)
+                        dialog.open()
+                    }
                 }
                 icon.source: '../../icons/lightning.png'
             }

electrum/gui/qml/qechannellistmodel.py

@@ -5,11 +5,13 @@ from electrum.lnchannel import ChannelState
 from electrum.lnutil import LOCAL, REMOTE
 from electrum.logging import get_logger
 from electrum.util import Satoshis
+from electrum.gui import messages
 
 from .qetypes import QEAmount
 from .util import QtEventListener, qt_event_listener
 from .qemodelfilter import QEFilterProxyModel
 
+
 class QEChannelListModel(QAbstractListModel, QtEventListener):
     _logger = get_logger(__name__)
 
@@ -195,3 +197,6 @@ class QEChannelListModel(QAbstractListModel, QtEventListener):
         self._fm_nobackups = self.filterModel('is_backup', False)
         return self._fm_nobackups
 
+    @pyqtSlot(result=str)
+    def lightningWarningMessage(self):
+        return messages.MSG_LIGHTNING_WARNING