timeline/project: block serializations to and from xml now include links

Fixes issue where blocks would become unlinked after copy/paste or save/load.

app/node/block/block.cpp

@@ -198,6 +198,22 @@ rational Block::MediaToSequenceTime(const rational &media_time) const
   return (media_time - media_in()) / speed() + in();
 }
 
+void Block::LoadInternal(QXmlStreamReader *reader, XMLNodeData &xml_node_data)
+{
+  if (reader->name() == QStringLiteral("link")) {
+    xml_node_data.block_links.append({this, reader->readElementText().toULongLong()});
+  } else {
+    Node::LoadInternal(reader, xml_node_data);
+  }
+}
+
+void Block::SaveInternal(QXmlStreamWriter *writer) const
+{
+  foreach (Block* link, linked_clips_) {
+    writer->writeTextElement(QStringLiteral("link"), QString::number(reinterpret_cast<quintptr>(link)));
+  }
+}
+
 void Block::LengthInputChanged()
 {
   emit LengthChanged(length());

app/node/block/block.h

@@ -113,6 +113,10 @@ protected:
 
   rational MediaToSequenceTime(const rational& media_time) const;
 
+  virtual void LoadInternal(QXmlStreamReader* reader, XMLNodeData& xml_node_data) override;
+
+  virtual void SaveInternal(QXmlStreamWriter* writer) const override;
+
   Block* previous_;
   Block* next_;
 

app/node/node.cpp

@@ -82,7 +82,7 @@ void Node::Load(QXmlStreamReader *reader, XMLNodeData& xml_node_data, const QAto
 
       param->Load(reader, xml_node_data, cancelled);
     } else {
-      reader->skipCurrentElement();
+      LoadInternal(reader, xml_node_data);
     }
   }
 }
@@ -99,6 +99,8 @@ void Node::Save(QXmlStreamWriter *writer, const QString &custom_name) const
     param->Save(writer);
   }
 
+  SaveInternal(writer);
+
   writer->writeEndElement(); // node
 }
 
@@ -219,6 +221,15 @@ void Node::DependentEdgeChanged(NodeInput *from)
   }
 }
 
+void Node::LoadInternal(QXmlStreamReader *reader, XMLNodeData &)
+{
+  reader->skipCurrentElement();
+}
+
+void Node::SaveInternal(QXmlStreamWriter *) const
+{
+}
+
 QString Node::ReadFileAsString(const QString &filename)
 {
   QFile f(filename);

app/node/node.h

@@ -345,6 +345,10 @@ protected:
 
   virtual void DependentEdgeChanged(NodeInput* from);
 
+  virtual void LoadInternal(QXmlStreamReader* reader, XMLNodeData& xml_node_data);
+
+  virtual void SaveInternal(QXmlStreamWriter* writer) const;
+
 public slots:
 
 signals: