improved sequence creation

app/node/graph.cpp

@@ -59,6 +59,11 @@ void NodeGraph::TakeNode(Node *node, QObject* new_parent)
     return;
   }
 
+  if (!node->CanBeDeleted()) {
+    qWarning() << "Tried to delete a Node that's been flagged as not deletable";
+    return;
+  }
+
   node->DisconnectAll();
 
   disconnect(node, SIGNAL(EdgeAdded(NodeEdgePtr)), this, SIGNAL(EdgeAdded(NodeEdgePtr)));

app/node/node.cpp

@@ -25,7 +25,8 @@
 #include "common/qobjectlistcast.h"
 
 Node::Node() :
-  last_processed_time_(-1)
+  last_processed_time_(-1),
+  can_be_deleted_(true)
 {
 }
 
@@ -132,6 +133,16 @@ void Node::CopyInputs(Node *source, Node *destination)
   }
 }
 
+bool Node::CanBeDeleted()
+{
+  return can_be_deleted_;
+}
+
+void Node::SetCanBeDeleted(bool s)
+{
+  can_be_deleted_ = s;
+}
+
 rational Node::LastProcessedTime()
 {
   rational t;

app/node/node.h

@@ -222,6 +222,16 @@ public:
    */
   static void CopyInputs(Node* source, Node* destination);
 
+  /**
+   * @brief Return whether this Node can be deleted or not
+   */
+  bool CanBeDeleted();
+
+  /**
+   * @brief Set whether
+   */
+  void SetCanBeDeleted(bool s);
+
 protected:
   /**
    * @brief Add a parameter to this node
@@ -317,6 +327,11 @@ private:
    */
   QMutex run_lock_;
 
+  /**
+   * @brief Internal variable for whether this Node can be deleted or not
+   */
+  bool can_be_deleted_;
+
 private slots:
   void InputChanged(rational start, rational end);
 

app/node/processor/renderer/renderer.cpp

@@ -131,6 +131,10 @@ void RendererProcessor::InvalidateCache(const rational &start_range, const ratio
 {
   Q_UNUSED(from)
 
+  if (timebase_.isNull()) {
+    return;
+  }
+
   //ClearCachedValuesInParameters(start_range, end_range);
   texture_input_->ClearCachedValue();
   length_input_->ClearCachedValue();