qt: Handle peer addition/removal in a right way

This change fixes a bug when a multiple rows selection gets inconsistent
after a peer addition/removal.

src/qt/peertablemodel.cpp

@@ -148,7 +148,30 @@ void PeerTableModel::refresh()
  new_peers_data.append(stats);
  }
 
- Q_EMIT layoutAboutToBeChanged();
- m_peers_data.swap(new_peers_data);
- Q_EMIT layoutChanged();
+ // Handle a new peer addition or an old peer in a right way. See:
+ // - https://doc.qt.io/qt-5/model-view-programming.html#inserting-and-removing-rows
+ // - https://doc.qt.io/qt-5/model-view-programming.html#resizable-models
+ // We use the fact that interfaces::Node::getNodesStats
+ // returns std::vector naturally sorted by nodeid.
+ for (int i = 0; i < m_peers_data.size();) {
+ if (i < new_peers_data.size() && m_peers_data.at(i).nodeStats.nodeid == new_peers_data.at(i).nodeStats.nodeid) {
+ ++i;
+ continue;
+ }
+ // A peer has been removed from the table.
+ beginRemoveRows(QModelIndex(), i, i);
+ m_peers_data.erase(m_peers_data.begin() + i);
+ endRemoveRows();
+ }
+
+ if (m_peers_data.size() < new_peers_data.size()) {
+ // Some peers have been added to the end of the table.
+ beginInsertRows(QModelIndex(), m_peers_data.size(), new_peers_data.size() - 1);
+ m_peers_data.swap(new_peers_data);
+ endInsertRows();
+ } else {
+ m_peers_data.swap(new_peers_data);
+ }
+
+ Q_EMIT changed();
 }

src/qt/peertablemodel.h

@@ -72,6 +72,9 @@ class PeerTableModel : public QAbstractTableModel
 public Q_SLOTS:
  void refresh();
 
+Q_SIGNALS:
+ void changed();
+
 private:
  //! Internal peer data structure.
  QList<CNodeCombinedStats> m_peers_data{};

src/qt/rpcconsole.cpp

@@ -639,7 +639,7 @@ void RPCConsole::setClientModel(ClientModel *model, int bestblock_height, int64_
 
  // peer table signal handling - update peer details when selecting new node
  connect(ui->peerWidget->selectionModel(), &QItemSelectionModel::selectionChanged, this, &RPCConsole::updateDetailWidget);
- connect(model->getPeerTableModel(), &PeerTableModel::layoutChanged, this, &RPCConsole::updateDetailWidget);
+ connect(model->getPeerTableModel(), &PeerTableModel::changed, this, &RPCConsole::updateDetailWidget);
 
  // set up ban table
  ui->banlistWidget->setModel(model->getBanTableModel());