Cache current dataset and handle dataChanged

Add a _currentDataset member to ScalarAction and wire up its dataChanged signal when a new source is selected. Previously connections could accumulate; the code now disconnects any existing dataset signal before connecting the new one and forwards updates via a lambda that calls sourceDataChanged(getCurrentDataset()).

Also update several parameter names in comments for clarity (variantMap, sourceSelectionIndex, offset).

Author: ThomasKroes

src/ScalarAction.cpp

@@ -33,6 +33,14 @@ ScalarAction::ScalarAction(QObject* parent, const QString& title, const float& m
                     scatterplotPlugin->addNotification(QString("The number of points in the scalar source dataset does not match the number of points in the position dataset. (numPositions=%1, numScalars:%2)").arg(QString::number(numPositions), QString::number(numScalars)));
                 }
             }
+
+            if (_currentDataset.isValid()) {
+                disconnect(&_currentDataset, &Dataset<>::dataChanged, this, nullptr);
+            }
+
+            connect(&_currentDataset, &Dataset<>::dataChanged, this, [this]() -> void {
+                sourceDataChanged(getCurrentDataset());
+            });
         }
 
         if (emitSourceSelectionChanged)

src/ScalarAction.h

@@ -81,7 +81,7 @@ class ScalarAction : 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;
 
@@ -100,7 +100,7 @@ class ScalarAction : public GroupAction
 
     /**
      * Signals that the source selection changed
-     * @param sourceIndex Index of the selected source (0 is constant, 1 is selection, above is a dataset)
+     * @param sourceSelectionIndex Index of the selected source (0 is constant, 1 is selection, above is a dataset)
      */
     void sourceSelectionChanged(const std::uint32_t& sourceSelectionIndex);
 
@@ -125,13 +125,14 @@ class ScalarAction : public GroupAction
 
     /**
      * Signals that the scalar offset changed
-     * @param magnitude Scalar magnitude
+     * @param offset Scalar offset
      */
     void offsetChanged(const float& offset);
 
 private:
     DecimalAction           _magnitudeAction;   /** Scalar magnitude action */
     ScalarSourceAction      _sourceAction;      /** Scalar source action */
+    Dataset<>               _currentDataset;    /** Cached current dataset (if any) */
 
     friend class mv::AbstractActionsManager;
 };