Add UI update signal

examples/calculator/LongProcessingRandomNumber.hpp

@@ -1,7 +1,6 @@
 #pragma once
 
 #include <QtNodes/NodeDelegateModel>
-#include <QtNodes/BasicGraphicsScene>
 #include <QTimer>
 #include <QtCore/QObject>
 #include <QtWidgets/QLabel>
@@ -18,20 +17,17 @@ class RandomNumberModel : public MathOperationDataModel
 public:
     RandomNumberModel() {
         QObject::connect(this, &NodeDelegateModel::computingStarted, this, [this]() {
-            //auto n1 = _number1.lock()->number();
-            //auto n2 = _number2.lock()->number();
-
-            //if (n1 > n2) {
-            //    this->setNodeProcessingStatus(
-            //        NodeDelegateModel::NodeProcessingStatus::Status::Failed);
-            //} else {
-                this->setNodeProcessingStatus(
+            this->setNodeProcessingStatus(
                     NodeDelegateModel::NodeProcessingStatus::Status::Processing);
-            //}
+
+            emit requestNodeUpdate();
+
         });
         QObject::connect(this, &NodeDelegateModel::computingFinished, this, [this]() {
             this->setNodeProcessingStatus(
                 NodeDelegateModel::NodeProcessingStatus::Status::Updated);
+
+            emit requestNodeUpdate();
         });
     }
     virtual ~RandomNumberModel() {}
@@ -60,8 +56,11 @@ class RandomNumberModel : public MathOperationDataModel
                     double a = n1->number();
                     double b = n2->number();
 
-                    if (a > b)
-                        std::swap(a, b);
+                    if (a > b) {
+                        this->setNodeProcessingStatus(NodeDelegateModel::NodeProcessingStatus::Status::Failed);
+                        emit requestNodeUpdate();
+                        return;
+                    }
 
                     double upper = std::nextafter(b, std::numeric_limits<double>::max());
                     double randomValue = QRandomGenerator::global()->generateDouble() * (upper - a) + a;

examples/calculator/MathOperationDataModel.cpp

@@ -38,20 +38,5 @@ void MathOperationDataModel::setInData(std::shared_ptr<NodeData> data, PortIndex
         _number2 = numberData;
     }
 
-    /*
-    Q_EMIT computingStarted();
-
-    QTimer *timer = new QTimer(this);
-    timer->start(1000);
-    int secondsRemaining = 10;
-    connect(timer, &QTimer::timeout, this, [=]() mutable {
-        if (--secondsRemaining <= 0) {
-            timer->stop();
-            compute();
-            Q_EMIT computingFinished();
-        }
-    });
-    */
-
     compute();
 }

include/QtNodes/internal/NodeDelegateModel.hpp

@@ -152,6 +152,14 @@ public Q_SLOTS:
 
     void embeddedWidgetSizeUpdated();
 
+    /// Request an update of the node's UI.
+    /**
+     * Emit this signal whenever some internal state change requires
+     * the node to be repainted. The containing graph model will
+     * propagate the update to the scene.
+     */
+    void requestNodeUpdate();
+
     /// Call this function before deleting the data associated with ports.
     /**
    * The function notifies the Graph Model and makes it remove and recompute the

src/DataFlowGraphModel.cpp

@@ -93,6 +93,10 @@ NodeId DataFlowGraphModel::addNode(QString const nodeType)
                 this,
                 &DataFlowGraphModel::portsInserted);
 
+        connect(model.get(), &NodeDelegateModel::requestNodeUpdate, this, [newId, this]() {
+            Q_EMIT nodeUpdated(newId);
+        });
+
         _models[newId] = std::move(model);
 
         Q_EMIT nodeCreated(newId);
@@ -528,6 +532,9 @@ void DataFlowGraphModel::loadNode(QJsonObject const &nodeJson)
                 &NodeDelegateModel::portsInserted,
                 this,
                 &DataFlowGraphModel::portsInserted);
+        connect(model.get(), &NodeDelegateModel::requestNodeUpdate, this, [restoredNodeId, this]() {
+            Q_EMIT nodeUpdated(restoredNodeId);
+        });
 
         _models[restoredNodeId] = std::move(model);