#7 Dynamic ports nodes

* send adding/removing signal by port index.
* shift ports when middle port is removed.
* dynamic load and save of the ports.
* added MinModel and MaxModel in calculator example.
* added method hasDynamicPorts(PortType) to NodeDataModel.
* added a .flow sample for calculator.

examples/calculator/MaxModel.cpp

@@ -0,0 +1,162 @@
+#include "MaxModel.hpp"
+
+
+unsigned int
+MaxModel::
+nPorts(QtNodes::PortType portType) const
+{
+   if (portType == PortType::In)
+      return _numberList.size()+1;
+   else
+      return 1;
+}
+
+bool
+MaxModel::
+hasDynamicPorts(QtNodes::PortType portType) const
+{
+  if(portType == PortType::In)
+    return true;
+
+  return false;
+}
+
+QtNodes::NodeDataType
+MaxModel::
+dataType(QtNodes::PortType, QtNodes::PortIndex) const
+{
+  return DecimalData().type();
+}
+
+std::shared_ptr<QtNodes::NodeData>
+MaxModel::
+outData(QtNodes::PortIndex)
+{
+  return _result;
+}
+
+void
+MaxModel::
+setInData(std::shared_ptr<QtNodes::NodeData> data, QtNodes::PortIndex portIndex)
+{
+  if (auto numberData = std::dynamic_pointer_cast<DecimalData>(data))
+  {
+    if (portIndex == static_cast<int>(_numberList.size()))
+    {
+      _numberList.push_back(numberData);
+      Q_EMIT portAdded(PortType::In, _numberList.size());
+    }
+    else
+    {
+      _numberList[portIndex] = numberData;
+    }
+  }
+  else
+  {
+      if(portIndex < static_cast<int>(_numberList.size()))
+     {
+       _numberList.erase(_numberList.begin() + portIndex);
+       Q_EMIT portRemoved(PortType::In, portIndex);
+     }
+  }
+
+  compute();
+}
+
+QString
+MaxModel::
+caption() const
+{
+  return QStringLiteral("Max");
+}
+
+bool
+MaxModel::
+portCaptionVisible(QtNodes::PortType, QtNodes::PortIndex) const
+{
+  return true;
+}
+
+QString
+MaxModel::
+portCaption(QtNodes::PortType portType, QtNodes::PortIndex) const
+{
+  switch (portType)
+  {
+    case PortType::In:
+      return QStringLiteral("Decimal");
+
+    case PortType::Out:
+      return QStringLiteral("Result");
+
+    default:
+      break;
+  }
+  return QString();
+}
+
+QString
+MaxModel::
+name() const
+{
+  return QStringLiteral("Max");
+}
+
+QtNodes::NodeValidationState
+MaxModel::
+validationState() const
+{
+  return _modelValidationState;
+}
+
+QString
+MaxModel::
+validationMessage() const
+{
+  return _modelValidationError;
+}
+
+void
+MaxModel::
+compute()
+{
+  if(_numberList.size() > 0)
+  {
+    _modelValidationState = NodeValidationState::Valid;
+    _modelValidationError = "";
+  }
+  else
+  {
+    _modelValidationState = NodeValidationState::Warning;
+    _modelValidationError = QString("Missing or incorrect inputs");
+  }
+
+  std::vector<double> numbers;
+  numbers.reserve(_numberList.size());
+
+  for (auto& portData : _numberList)
+  {
+    auto num = portData.lock();
+    if (num && num->isValid())
+    {
+      numbers.emplace_back(num->number());
+    }
+  }
+
+  if(!numbers.empty())
+    _result = std::make_shared<DecimalData>(*std::max_element(numbers.begin(), numbers.end()));
+  else
+    _result = std::make_shared<DecimalData>();
+
+  Q_EMIT dataUpdated(0);
+}
+
+void MaxModel::restore(const QJsonObject& obj)
+{
+   int in = obj["dynamic_inputs"].toInt();
+   if(in > 0){
+     // since when node is saved port's number is size+1 with an empty port
+     // to restore the correct size of the array it has to be input-1
+      _numberList.resize(in-1);
+   }
+}

examples/calculator/MaxModel.hpp

@@ -0,0 +1,75 @@
+#pragma once
+
+#include <nodes/NodeDataModel>
+
+#include "DecimalData.hpp"
+
+using QtNodes::PortType;
+using QtNodes::PortIndex;
+using QtNodes::NodeData;
+using QtNodes::NodeDataType;
+using QtNodes::NodeDataModel;
+using QtNodes::NodeValidationState;
+
+class MaxModel : public NodeDataModel
+{
+   Q_OBJECT
+
+public:
+
+  unsigned int
+  nPorts(PortType portType) const override;
+
+  bool
+  hasDynamicPorts(PortType portType) const override;
+
+  NodeDataType
+  dataType(PortType portType, PortIndex portIndex) const override;
+
+  std::shared_ptr<NodeData>
+  outData(PortIndex port) override;
+
+  void
+  setInData(std::shared_ptr<NodeData> data, PortIndex portIndex) override;
+
+public:
+
+  QString
+  caption() const override;
+
+  bool
+  portCaptionVisible(PortType portType, PortIndex portIndex) const override;
+
+  QString
+  portCaption(PortType portType, PortIndex portIndex) const override;
+
+  QString
+  name() const override;
+
+public:
+
+  QWidget *
+  embeddedWidget() override { return nullptr; }
+
+  NodeValidationState
+  validationState() const override;
+
+  QString
+  validationMessage() const override;
+
+private:
+
+  void
+  restore(const QJsonObject& obj) override;
+
+  void
+  compute();
+
+private:
+
+   std::vector<std::weak_ptr<DecimalData>> _numberList;
+   std::shared_ptr<DecimalData> _result;
+
+   NodeValidationState _modelValidationState = NodeValidationState::Warning;
+   QString _modelValidationError = QString("Missing or incorrect inputs");
+};