keep graph channel style after reset

libshvvisu/src/timeline/graph.cpp

@@ -147,6 +147,11 @@ void Graph::createChannelsFromModel(shv::visu::timeline::Graph::SortChannels sor
 		QColor("orange"),
 		QColor(0x6d, 0xa1, 0x3a), // green
 	};
+	QMap<QString, GraphChannel::Style> orig_styles;
+	for (int i = 0; i < channelCount(); ++i) {
+		auto *ch = channelAt(i);
+		orig_styles[ch->shvPath()] = ch->style();
+	}
 	clearChannels();
 	if(!m_model)
 		return;
@@ -168,9 +173,14 @@ void Graph::createChannelsFromModel(shv::visu::timeline::Graph::SortChannels sor
 	for(auto model_ix : model_ixs) {
 		GraphChannel *ch = appendChannel(model_ix);
 		auto channel_ix = channelCount() - 1;
-		GraphChannel::Style style = ch->style();
-		style.setColor(colors.value(channel_ix % colors.count()));
-		ch->setStyle(style);
+		if (orig_styles.contains(ch->shvPath())) {
+			ch->setStyle(orig_styles[ch->shvPath()]);
+		}
+		else {
+			GraphChannel::Style style = ch->style();
+			style.setColor(colors.value(channel_ix % colors.count()));
+			ch->setStyle(style);
+		}
 	}
 	resetChannelsRanges();
 }

libshvvisu/src/timeline/graphwidget.cpp

@@ -759,12 +759,7 @@ void GraphWidget::showGraphContextMenu(const QPoint &mouse_pos)
 	menu.addAction(tr("Hide channels without changes"), this, [this]() {
 		m_graph->hideFlatChannels();
 	});
-	menu.addAction(tr("Reset channels to defaults"), this, [this]() {
-		m_graph->createChannelsFromModel();
-		auto graph_filter = m_graph->channelFilter();
-		graph_filter.setMatchingPaths(m_graph->channelPaths());
-		m_graph->setChannelFilter(graph_filter);
-	});
+	menu.addAction(tr("Reset channels to defaults"), m_graph, &Graph::reset);
 	if (m_graph->isYAxisVisible()) {
 		menu.addAction(tr("Hide Y axis"), this, [this]() {
 			m_graph->setYAxisVisible(false);