Check scalar source dataset point count

When the source picker index points to a dataset, verify that the selected scalar source dataset has the same number of points as the ScatterplotPlugin's position dataset. If the counts differ, suppress emitting sourceSelectionChanged and add a user notification explaining the mismatch to prevent invalid selection. Also fix a parameter name in ScalarSourceAction.h's doc comment (variantMap).

Author: ThomasKroes

src/ScalarAction.cpp

@@ -18,7 +18,23 @@ ScalarAction::ScalarAction(QObject* parent, const QString& title, const float& m
     addAction(&_sourceAction);
 
     connect(&_sourceAction.getPickerAction(), &OptionAction::currentIndexChanged, this, [this](const std::uint32_t& currentIndex) {
-        emit sourceSelectionChanged(currentIndex);
+        bool emitSourceSelectionChanged = true;
+
+        if (currentIndex >= ScalarSourceModel::DefaultRow::DatasetStart) {
+            if (auto scatterplotPlugin = dynamic_cast<ScatterplotPlugin*>(findPluginAncestor())) {
+                auto positionDataset            = scatterplotPlugin->getPositionDataset();
+                auto scalarSourcePointsDataset  = Dataset<Points>(getCurrentDataset());
+
+                if (scalarSourcePointsDataset->getNumPoints() != positionDataset->getNumPoints()) {
+                    emitSourceSelectionChanged = false;
+
+                    scatterplotPlugin->addNotification("The number of points in the scalar source dataset does not match the number of points in the position dataset.");
+                }
+            }
+        }
+
+        if (emitSourceSelectionChanged)
+            emit sourceSelectionChanged(currentIndex);
     });
 
     connect(&_magnitudeAction, &DecimalAction::valueChanged, this, [this](const float& value) {

src/ScalarSourceAction.h

@@ -54,7 +54,7 @@ class ScalarSourceAction : public GroupAction
 
     /**
      * Load widget action from variant map
-     * @param Variant map representation of the widget action
+     * @param variantMap Variant map representation of the widget action
      */
     void fromVariantMap(const QVariantMap& variantMap) override;