Adds validation state feedback to nodes

.gitignore

@@ -4,4 +4,6 @@ CMakeLists.txt.user
 build*/
 .vscode/
 
+qt-build
+
 tags

examples/calculator/DivisionModel.hpp

@@ -55,17 +55,27 @@ class DivisionModel : public MathOperationDataModel
         auto n1 = _number1.lock();
         auto n2 = _number2.lock();
 
+        QtNodes::NodeValidationState state;
         if (n2 && (n2->number() == 0.0)) {
-            //modelValidationState = NodeValidationState::Error;
-            //modelValidationError = QStringLiteral("Division by zero error");
+            state._state = QtNodes::NodeValidationState::State::Error;
+            state._stateMessage = QStringLiteral("Division by zero error");
+            setValidatonState(state);
             _result.reset();
+        } else if ( n2 && (n2->number() < 1e-5)) {
+            state._state = QtNodes::NodeValidationState::State::Warning;
+            state._stateMessage = QStringLiteral("Very small divident. Result might overflow");
+            setValidatonState(state);
+            if (n1) {
+                _result = std::make_shared<DecimalData>(n1->number() / n2->number());
+            } else {
+                _result.reset();
+            }
         } else if (n1 && n2) {
-            //modelValidationState = NodeValidationState::Valid;
-            //modelValidationError = QString();
+            setValidatonState(state);
             _result = std::make_shared<DecimalData>(n1->number() / n2->number());
         } else {
-            //modelValidationState = NodeValidationState::Warning;
-            //modelValidationError = QStringLiteral("Missing or incorrect inputs");
+            QtNodes::NodeValidationState state;
+            setValidatonState(state);
             _result.reset();
         }
 

include/QtNodes/internal/DefaultNodePainter.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <QIcon>
 #include <QtGui/QPainter>
 
 #include "AbstractNodePainter.hpp"
@@ -30,5 +31,10 @@ class NODE_EDITOR_PUBLIC DefaultNodePainter : public AbstractNodePainter
     void drawEntryLabels(QPainter *painter, NodeGraphicsObject &ngo) const;
 
     void drawResizeRect(QPainter *painter, NodeGraphicsObject &ngo) const;
+
+    void drawValidationIcon(QPainter *painter, NodeGraphicsObject &ngo) const;
+
+private:
+    QIcon _toolTipIcon{"://info-tooltip.svg"};
 };
 } // namespace QtNodes

include/QtNodes/internal/Definitions.hpp

@@ -18,21 +18,22 @@ NODE_EDITOR_PUBLIC Q_NAMESPACE
 Q_NAMESPACE_EXPORT(NODE_EDITOR_PUBLIC)
 #endif
 
-    /**
+/**
  * Constants used for fetching QVariant data from GraphModel.
  */
-    enum class NodeRole {
-        Type = 0,           ///< Type of the current node, usually a string.
-        Position = 1,       ///< `QPointF` positon of the node on the scene.
-        Size = 2,           ///< `QSize` for resizable nodes.
-        CaptionVisible = 3, ///< `bool` for caption visibility.
-        Caption = 4,        ///< `QString` for node caption.
-        Style = 5,          ///< Custom NodeStyle as QJsonDocument
-        InternalData = 6,   ///< Node-stecific user data as QJsonObject
-        InPortCount = 7,    ///< `unsigned int`
-        OutPortCount = 9,   ///< `unsigned int`
-        Widget = 10,        ///< Optional `QWidget*` or `nullptr`
-    };
+enum class NodeRole {
+    Type = 0,             ///< Type of the current node, usually a string.
+    Position = 1,         ///< `QPointF` positon of the node on the scene.
+    Size = 2,             ///< `QSize` for resizable nodes.
+    CaptionVisible = 3,   ///< `bool` for caption visibility.
+    Caption = 4,          ///< `QString` for node caption.
+    Style = 5,            ///< Custom NodeStyle as QJsonDocument
+    InternalData = 6,     ///< Node-stecific user data as QJsonObject
+    InPortCount = 7,      ///< `unsigned int`
+    OutPortCount = 9,     ///< `unsigned int`
+    Widget = 10,          ///< Optional `QWidget*` or `nullptr`
+    ValidationState = 11, ///< Enum NodeValidationState of the node
+};
 Q_ENUM_NS(NodeRole)
 
 /**

include/QtNodes/internal/NodeDelegateModel.hpp

@@ -1,18 +1,36 @@
 #pragma once
 
+#include <memory>
+
+#include <QMetaType>
+#include <QtWidgets/QWidget>
+
 #include "Definitions.hpp"
 #include "Export.hpp"
 #include "NodeData.hpp"
 #include "NodeStyle.hpp"
 #include "Serializable.hpp"
 
-#include <QtWidgets/QWidget>
-
-#include <memory>
-
-
 namespace QtNodes {
 
+/**
+ * Describes whether a node configuration is usable and defines a description message
+ */
+struct NodeValidationState
+{
+    enum class State : int {
+        Valid = 0,      ///< All required inputs are present and correct.
+        Warning = 1,    ///< Some inputs are missing or questionable, processing may be unreliable.
+        Error = 2,      ///< Inputs or settings are invalid, preventing successful computation.
+    };
+    bool isValid() { return _state == State::Valid; };
+    QString const message() { return _stateMessage; }
+    State state() { return _state; }
+
+    State _state{State::Valid};
+    QString _stateMessage{""};
+};
+
 class StyleCollection;
 
 /**
@@ -45,9 +63,16 @@ class NODE_EDITOR_PUBLIC NodeDelegateModel : public QObject, public Serializable
     /// It is possible to hide port caption in GUI
     virtual bool portCaptionVisible(PortType, PortIndex) const { return false; }
 
+    /// Validation State will default to Valid, but you can manipulate it by overriding in an inherited class
+    virtual NodeValidationState validationState() const { return _nodeValidationState; }
+
+public:
     QJsonObject save() const override;
+
     void load(QJsonObject const &) override;
 
+    void setValidatonState(const NodeValidationState &validationState);
+
     virtual unsigned int nPorts(PortType portType) const = 0;
 
     virtual NodeDataType dataType(PortType portType, PortIndex portIndex) const = 0;
@@ -117,6 +142,10 @@ public Q_SLOTS:
 
 private:
     NodeStyle _nodeStyle;
+
+    NodeValidationState _nodeValidationState;
 };
 
 } // namespace QtNodes
+
+Q_DECLARE_METATYPE(QtNodes::NodeValidationState)

include/QtNodes/internal/NodeStyle.hpp

@@ -43,6 +43,7 @@ class NODE_EDITOR_PUBLIC NodeStyle : public Style
 
     QColor WarningColor;
     QColor ErrorColor;
+    QColor ToolTipIconColor;
 
     float PenWidth;
     float HoveredPenWidth;

resources/DefaultStyle.json

@@ -17,8 +17,9 @@
     "FontColorFaded" : "gray",
     "ConnectionPointColor": [169, 169, 169],
     "FilledConnectionPointColor": "cyan",
-    "ErrorColor": "red",
-    "WarningColor": [128, 128, 0],
+    "ErrorColor": [211, 47, 47],
+    "WarningColor": [255, 179, 0],
+    "ToolTipIconColor": "white",
 
     "PenWidth": 1.0,
     "HoveredPenWidth": 1.5,

resources/resources.qrc

@@ -1,5 +1,6 @@
-<RCC version="1.0">
-    <qresource>
+<RCC>
+    <qresource prefix="/">
         <file>DefaultStyle.json</file>
+        <file>info-tooltip.svg</file>
     </qresource>
 </RCC>

src/DataFlowGraphModel.cpp

@@ -8,7 +8,6 @@
 #include <stack>
 #include <stdexcept>
 
-
 namespace QtNodes {
 
 DataFlowGraphModel::DataFlowGraphModel(std::shared_ptr<NodeDelegateModelRegistry> registry)
@@ -117,12 +116,10 @@ bool DataFlowGraphModel::connectionPossible(ConnectionId const connectionId) con
     // Check port bounds, i.e. that we do not connect non-existing port numbers
     auto checkPortBounds = [&](PortType const portType) {
         NodeId const nodeId = getNodeId(portType, connectionId);
-        auto portCountRole = (portType == PortType::Out) ?
-                             NodeRole::OutPortCount :
-                             NodeRole::InPortCount;
+        auto portCountRole = (portType == PortType::Out) ? NodeRole::OutPortCount
+                                                         : NodeRole::InPortCount;
 
-        std::size_t const portCount =
-          nodeData(nodeId, portCountRole).toUInt();
+        std::size_t const portCount = nodeData(nodeId, portCountRole).toUInt();
 
         return getPortIndex(portType, connectionId) < portCount;
     };
@@ -146,12 +143,9 @@ bool DataFlowGraphModel::connectionPossible(ConnectionId const connectionId) con
         return connected.empty() || (policy == ConnectionPolicy::Many);
     };
 
-    bool const basicChecks =
-           getDataType(PortType::Out).id == getDataType(PortType::In).id
-           && portVacant(PortType::Out)
-           && portVacant(PortType::In)
-           && checkPortBounds(PortType::Out)
-           && checkPortBounds(PortType::In);
+    bool const basicChecks = getDataType(PortType::Out).id == getDataType(PortType::In).id
+                             && portVacant(PortType::Out) && portVacant(PortType::In)
+                             && checkPortBounds(PortType::Out) && checkPortBounds(PortType::In);
 
     // In data-flow mode (this class) it's important to forbid graph loops.
     // We perform depth-first graph traversal starting from the "Input" port of
@@ -161,17 +155,16 @@ bool DataFlowGraphModel::connectionPossible(ConnectionId const connectionId) con
         std::stack<NodeId> filo;
         filo.push(connectionId.inNodeId);
 
-        while (!filo.empty())
-        {
-            auto id = filo.top(); filo.pop();
+        while (!filo.empty()) {
+            auto id = filo.top();
+            filo.pop();
 
             if (id == connectionId.outNodeId) { // LOOP!
-                  return true;
+                return true;
             }
 
             // Add out-connections to continue interations
-            std::size_t const nOutPorts =
-                nodeData(id, NodeRole::OutPortCount).toUInt();
+            std::size_t const nOutPorts = nodeData(id, NodeRole::OutPortCount).toUInt();
 
             for (PortIndex index = 0; index < nOutPorts; ++index) {
                 auto const &outConnectionIds = connections(id, PortType::Out, index);
@@ -188,7 +181,6 @@ bool DataFlowGraphModel::connectionPossible(ConnectionId const connectionId) con
     return basicChecks && (loopsEnabled() || !hasLoops());
 }
 
-
 void DataFlowGraphModel::addConnection(ConnectionId const connectionId)
 {
     _connectivity.insert(connectionId);
@@ -294,9 +286,14 @@ QVariant DataFlowGraphModel::nodeData(NodeId nodeId, NodeRole role) const
         break;
 
     case NodeRole::Widget: {
-        auto w = model->embeddedWidget();
+        auto *w = model->embeddedWidget();
         result = QVariant::fromValue(w);
     } break;
+
+    case NodeRole::ValidationState: {
+        auto validationState = model->validationState();
+        result = QVariant::fromValue(validationState);
+    } break;
     }
 
     return result;
@@ -356,6 +353,16 @@ bool DataFlowGraphModel::setNodeData(NodeId nodeId, NodeRole role, QVariant valu
 
     case NodeRole::Widget:
         break;
+
+    case NodeRole::ValidationState: {
+        if (value.canConvert<NodeValidationState>()) {
+            auto state = value.value<NodeValidationState>();
+            if (auto node = delegateModel<NodeDelegateModel>(nodeId); node != nullptr) {
+                node->setValidatonState(state);
+            }
+        }
+        Q_EMIT nodeUpdated(nodeId);
+    } break;
     }
 
     return result;
@@ -538,7 +545,8 @@ void DataFlowGraphModel::loadNode(QJsonObject const &nodeJson)
         connect(model.get(),
                 &NodeDelegateModel::portsAboutToBeDeleted,
                 this,
-                [restoredNodeId, this](PortType const portType, PortIndex const first, PortIndex const last) {
+                [restoredNodeId,
+                 this](PortType const portType, PortIndex const first, PortIndex const last) {
                     portsAboutToBeDeleted(restoredNodeId, portType, first, last);
                 });
 
@@ -550,7 +558,8 @@ void DataFlowGraphModel::loadNode(QJsonObject const &nodeJson)
         connect(model.get(),
                 &NodeDelegateModel::portsAboutToBeInserted,
                 this,
-                [restoredNodeId, this](PortType const portType, PortIndex const first, PortIndex const last) {
+                [restoredNodeId,
+                 this](PortType const portType, PortIndex const first, PortIndex const last) {
                     portsAboutToBeInserted(restoredNodeId, portType, first, last);
                 });