Closes #22

core/tree_node.cpp

@@ -10,6 +10,7 @@
  */
 
 #include "tree_node.h"
+#include <stdexcept>
 
 TreeNode::TreeNode()
     : m_type(NodeType::Root), m_name("dbc") {
@@ -23,8 +24,14 @@ TreeNode::TreeNode(const SignalInfo &signal)
     : m_type(NodeType::Signal), m_name(signal.name), m_signal(std::make_unique<SignalInfo>(signal)) {
 }
 
-void TreeNode::AddChild(std::unique_ptr<TreeNode> child) {
+void TreeNode::AddChild(std::unique_ptr<TreeNode> &&child) {
     if (child) {
+        for (const TreeNode *ancestor = this; ancestor; ancestor = ancestor->m_parent) {
+            if (ancestor == child.get())
+                throw std::invalid_argument("Cannot insert a node into its own subtree");
+        }
+        if (child->m_parent)
+            throw std::invalid_argument("Child is already attached");
         m_children.push_back(std::move(child));
         m_children.back()->m_parent = this;
         m_children.back()->m_row = m_children.size() - 1U;
@@ -72,3 +79,18 @@ const TreeNode *TreeNode::GetParent() const {
 std::size_t TreeNode::GetRow() const {
     return m_row;
 }
+
+std::optional<FrameKey> TreeNode::GetFrameKey() const {
+    if (m_frame)
+        return FrameKey(m_frame->canId, m_frame->isExtended);
+    if (m_signal && m_parent && m_parent->GetType() == NodeType::Frame)
+        return m_parent->GetFrameKey();
+    return std::nullopt;
+}
+
+std::optional<SignalKey> TreeNode::GetSignalKey() const {
+    const std::optional<FrameKey> frame = GetFrameKey();
+    if (m_signal && frame)
+        return SignalKey(*frame, m_signal->name);
+    return std::nullopt;
+}