Implement runtime validation and error reporting (paceholder#46)

* Node validation and error display implemented

* Added option to iterate through nodes in the scene. (Useful to read out data from all the nodes, makes code generation based on the graphs easier.)

* Visual error fix for nodes that change size depending on input, plus minor styling and logic fixes in the example, based on the comments of @russelltg

* Validation extended to handle warnings, based on the idea of @RusselTG ; Error display colors now come from the style system;  Additional bugfixes

* DefaultStyle.json identation fix

* FlowScene.cpp identation fix

* Travis build test fix

Author: LandonJerre

.travis.yml

@@ -32,7 +32,7 @@ matrix:
 
 before_install:
   #- if [ "$QT_BASE" = "54" ]; then sudo add-apt-repository ppa:beineri/opt-qt542-trusty -y; fi
-  - if [ "$QT_BASE" = "57" ]; then sudo add-apt-repository ppa:beineri/opt-qt57-trusty -y; fi
+  - if [ "$QT_BASE" = "57" ]; then sudo add-apt-repository ppa:beineri/opt-qt571-trusty -y; fi
   - sudo apt-get update -qq
 
 install:

examples/calculator/AdditionModel.hpp

@@ -52,11 +52,15 @@ class AdditionModel : public MathOperationDataModel
 
     if (n1 && n2)
     {
+      modelValidationState = NodeValidationState::Valid;
+      modelValidationError = QString("");
       _result = std::make_shared<NumberData>(n1->number() +
                                              n2->number());
     }
     else
     {
+      modelValidationState = NodeValidationState::Warning;
+      modelValidationError = QString("Missing or incorrect inputs");
       _result.reset();
     }
 

examples/calculator/DivisionModel.hpp

@@ -45,7 +45,7 @@ class DivisionModel : public MathOperationDataModel
       default:
         break;
     }
-	return QString("");
+    return QString("");
   }
 
   QString
@@ -74,16 +74,26 @@ class DivisionModel : public MathOperationDataModel
     auto n1 = _number1.lock();
     auto n2 = _number2.lock();
 
-    if (n1 && n2 && (n2->number() != 0.0))
+    if (n2 && (n2->number() == 0.0))
     {
+      modelValidationState = NodeValidationState::Error;
+      modelValidationError = QString("Division by zero error");
+      _result.reset();
+    }
+    else if (n1 && n2)
+    {
+      modelValidationState = NodeValidationState::Valid;
+      modelValidationError = QString("");
       _result = std::make_shared<NumberData>(n1->number() /
-                                             n2->number());
+        n2->number());
     }
     else
     {
+      modelValidationState = NodeValidationState::Warning;
+      modelValidationError = QString("Missing or incorrect inputs");
       _result.reset();
     }
-
+    
     emit dataUpdated(outPortIndex);
   }
 };

examples/calculator/MathOperationDataModel.cpp

@@ -53,3 +53,17 @@ setInData(std::shared_ptr<NodeData> data, PortIndex portIndex)
 }
 
 
+NodeValidationState
+MathOperationDataModel::
+validationState() const
+{
+  return modelValidationState;
+}
+
+
+QString
+MathOperationDataModel::
+validationMessage() const
+{
+  return modelValidationError;
+}

examples/calculator/MathOperationDataModel.hpp

@@ -32,6 +32,10 @@ class MathOperationDataModel : public NodeDataModel
 
   QWidget * embeddedWidget() override { return nullptr; }
 
+  NodeValidationState validationState() const override;
+
+  QString validationMessage() const override;
+
 protected:
 
   virtual void compute() = 0;
@@ -42,4 +46,7 @@ class MathOperationDataModel : public NodeDataModel
   std::weak_ptr<NumberData> _number2;
 
   std::shared_ptr<NumberData> _result;
+
+  NodeValidationState modelValidationState = NodeValidationState::Warning;
+  QString modelValidationError = QString("Missing or incorrect inputs");
 };

examples/calculator/MultiplicationModel.hpp

@@ -52,11 +52,15 @@ class MultiplicationModel : public MathOperationDataModel
 
     if (n1 && n2)
     {
+      modelValidationState = NodeValidationState::Valid;
+      modelValidationError = QString("");
       _result = std::make_shared<NumberData>(n1->number() *
                                              n2->number());
     }
     else
     {
+      modelValidationState = NodeValidationState::Warning;
+      modelValidationError = QString("Missing or incorrect inputs");
       _result.reset();
     }
 

examples/calculator/NumberDisplayDataModel.cpp

@@ -58,12 +58,32 @@ setInData(std::shared_ptr<NodeData> data, int)
 
   if (numberData)
   {
+    modelValidationState = NodeValidationState::Valid;
+    modelValidationError = QString("");
     _label->setText(numberData->numberAsText());
   }
   else
   {
+    modelValidationState = NodeValidationState::Warning;
+    modelValidationError = QString("Missing or incorrect inputs");
     _label->clear();
   }
 
   _label->adjustSize();
 }
+
+
+NodeValidationState
+NumberDisplayDataModel::
+validationState() const
+{
+  return modelValidationState;
+}
+
+
+QString
+NumberDisplayDataModel::
+validationMessage() const
+{
+  return modelValidationError;
+}

examples/calculator/NumberDisplayDataModel.hpp

@@ -63,7 +63,16 @@ class NumberDisplayDataModel : public NodeDataModel
   QWidget *
   embeddedWidget() override { return _label; }
 
+  NodeValidationState 
+  validationState() const override;
+
+  QString 
+  validationMessage() const override;
+
 private:
 
+  NodeValidationState modelValidationState = NodeValidationState::Warning;
+  QString modelValidationError = QString("Missing or incorrect inputs");
+
   QLabel * _label;
 };

examples/calculator/SubtractionModel.hpp

@@ -77,11 +77,15 @@ class SubtractionModel : public MathOperationDataModel
 
     if (n1 && n2)
     {
+      modelValidationState = NodeValidationState::Valid;
+      modelValidationError = QString("");
       _result = std::make_shared<NumberData>(n1->number() -
                                              n2->number());
     }
     else
     {
+      modelValidationState = NodeValidationState::Warning;
+      modelValidationError = QString("Missing or incorrect inputs");
       _result.reset();
     }
 

resources/DefaultStyle.json

@@ -16,6 +16,8 @@
     "FontColorFaded" : "gray",
     "ConnectionPointColor": [169, 169, 169],
     "FilledConnectionPointColor": "cyan",
+    "ErrorColor": "red",
+    "WarningColor": [128, 128, 0],
 
     "PenWidth": 1.0,
     "HoveredPenWidth": 1.5,

src/FlowScene.cpp

@@ -215,6 +215,17 @@ setRegistry(std::shared_ptr<DataModelRegistry> registry)
 }
 
 
+void
+FlowScene::
+iterateOverNodes(std::function<void(Node*)> visitor)
+{
+  for (const auto& _node : _nodes)
+  {
+    visitor(_node.second.get());
+  }
+}
+
+
 //------------------------------------------------------------------------------
 
 void

src/FlowScene.hpp

@@ -6,6 +6,7 @@
 #include <unordered_map>
 #include <tuple>
 #include <memory>
+#include <functional>
 
 #include "Connection.hpp"
 #include "Export.hpp"
@@ -64,6 +65,9 @@ class NODE_EDITOR_PUBLIC FlowScene
   void
   setRegistry(std::shared_ptr<DataModelRegistry> registry);
 
+  void
+  iterateOverNodes(std::function<void(Node*)> visitor);
+
 public:
 
   void

src/Node.cpp

@@ -176,7 +176,12 @@ propagateData(std::shared_ptr<NodeData> nodeData,
               PortIndex inPortIndex) const
 {
   _nodeDataModel->setInData(nodeData, inPortIndex);
-
+  
+  //Recalculate the nodes visuals. A data change can result in the node taking more space than before, so this forces a recalculate+repaint on the affected node
+  _nodeGraphicsObject->setGeometryChanged();
+  _nodeGeometry.recalculateSize();
+  _nodeGraphicsObject->update();
+  _nodeGraphicsObject->moveConnections();
 }
 
 

src/NodeDataModel.hpp

@@ -10,6 +10,13 @@
 
 #include "Export.hpp"
 
+enum class NodeValidationState
+{
+  Valid,
+  Warning,
+  Error
+};
+
 class NODE_EDITOR_PUBLIC NodeDataModel
   : public QObject
   , public Serializable
@@ -74,6 +81,14 @@ class NODE_EDITOR_PUBLIC NodeDataModel
   virtual
   bool
   resizable() const { return false; }
+  
+  virtual
+  NodeValidationState
+  validationState() const { return NodeValidationState::Valid; }
+
+  virtual
+  QString
+  validationMessage() const { return QString(""); }
 
 signals:
 

src/NodeGeometry.cpp

@@ -89,6 +89,12 @@ recalculateSize() const
   }
 
   _width = std::max(_width, captionWidth());
+
+  if (_dataModel->validationState() != NodeValidationState::Valid)
+  {
+    _width = std::max(_width, validationWidth());
+    _height += validationHeight() + _spacing;
+  }
 }
 
 
@@ -213,7 +219,11 @@ widgetPosition() const
 {
   if (auto w = _dataModel->embeddedWidget())
   {
-
+    if (_dataModel->validationState() != NodeValidationState::Valid)
+    {
+      return QPointF(_spacing + portWidth(PortType::In),
+                     (captionHeight() + _height - validationHeight() - _spacing - w->height()) / 2.0);
+    }
     return QPointF(_spacing + portWidth(PortType::In),
                    (captionHeight() + _height - w->height()) / 2.0);
   }
@@ -248,6 +258,26 @@ captionWidth() const
 }
 
 
+unsigned int
+NodeGeometry::
+validationHeight() const
+{
+  QString msg = _dataModel->validationMessage();
+
+  return _boldFontMetrics.boundingRect(msg).height();
+}
+
+
+unsigned int
+NodeGeometry::
+validationWidth() const
+{
+  QString msg = _dataModel->validationMessage();
+
+  return _boldFontMetrics.boundingRect(msg).width();
+}
+
+
 unsigned int
 NodeGeometry::
 portWidth(PortType portType) const
@@ -259,9 +289,13 @@ portWidth(PortType portType) const
     QString name;
 
     if (_dataModel->portCaptionVisible(portType, i))
+    {
       name = _dataModel->portCaption(portType, i);
+    }
     else
+    {
       name = _dataModel->dataType(portType, i).name;
+    }
 
     width = std::max(unsigned(_fontMetrics.width(name)),
                      width);

src/NodeGeometry.hpp

@@ -102,6 +102,12 @@ class NodeGeometry
   QPointF
   widgetPosition() const;
 
+  unsigned int
+  validationHeight() const;
+
+  unsigned int
+  validationWidth() const;
+
 private:
 
   unsigned int