ui: make color setting undoable

app/widget/nodeview/nodeview.cpp

@@ -363,9 +363,13 @@ void NodeView::Duplicate()
 
 void NodeView::SetColorLabel(int index)
 {
+  MultiUndoCommand *command = new MultiUndoCommand();
+
   for (Node* node : qAsConst(selected_nodes_)) {
-    node->SetOverrideColor(index);
+    command->add_child(new NodeOverrideColorCommand(node, index));
   }
+
+  Core::instance()->undo_stack()->push(command);
 }
 
 void NodeView::ZoomIn()

app/widget/nodeview/nodeviewundo.cpp

@@ -171,4 +171,26 @@ Project *NodeRenameCommand::GetRelevantProject() const
   return nodes_.isEmpty() ? nullptr : nodes_.first()->project();
 }
 
+NodeOverrideColorCommand::NodeOverrideColorCommand(Node *node, int index) :
+  node_(node),
+  new_index_(index)
+{
+}
+
+Project *NodeOverrideColorCommand::GetRelevantProject() const
+{
+  return node_->project();
+}
+
+void NodeOverrideColorCommand::redo()
+{
+  old_index_ = node_->GetOverrideColor();
+  node_->SetOverrideColor(new_index_);
+}
+
+void NodeOverrideColorCommand::undo()
+{
+  node_->SetOverrideColor(old_index_);
+}
+
 }

app/widget/nodeview/nodeviewundo.h

@@ -342,6 +342,27 @@ private:
 
 };
 
+class NodeOverrideColorCommand : public UndoCommand
+{
+public:
+  NodeOverrideColorCommand(Node *node, int index);
+
+  virtual Project * GetRelevantProject() const override;
+
+protected:
+  virtual void redo() override;
+
+  virtual void undo() override;
+
+private:
+  Node *node_;
+
+  int old_index_;
+
+  int new_index_;
+
+};
+
 }
 
 #endif // NODEVIEWUNDO_H

app/widget/timelinewidget/timelinewidget.cpp

@@ -720,9 +720,13 @@ void TimelineWidget::ToggleSelectedEnabled()
 
 void TimelineWidget::SetColorLabel(int index)
 {
+  MultiUndoCommand *command = new MultiUndoCommand();
+
   foreach (Block* b, selected_blocks_) {
-    b->SetOverrideColor(index);
+    command->add_child(new NodeOverrideColorCommand(b, index));
   }
+
+  Core::instance()->undo_stack()->push(command);
 }
 
 void TimelineWidget::NudgeLeft()