Only allow resizing points for now (no size or opacity)

Author: alxvth

src/ScatterplotPlugin.cpp

@@ -183,12 +183,14 @@ ScatterplotPlugin::ScatterplotPlugin(const PluginFactory* factory) :
                     /*else*/ false;
 
                 if (sameNumPoints || sameNumPointsAsFull) {
-
                     // Offer the option to use the points dataset as source for points colors
                     dropRegions << new DropWidget::DropRegion(this, "Point color", QString("Colorize %1 points with %2").arg(_positionDataset->text(), candidateDataset->text()), "palette", true, [this, candidateDataset]() {
                         _settingsAction.getColoringAction().setCurrentColorDataset(candidateDataset);   // calls addColorDataset internally
                         });
 
+                }
+
+                if (sameNumPoints) {
                     // Offer the option to use the points dataset as source for points size
                     dropRegions << new DropWidget::DropRegion(this, "Point size", QString("Size %1 points with %2").arg(_positionDataset->text(), candidateDataset->text()), "ruler-horizontal", true, [this, candidateDataset]() {
                         _settingsAction.getPlotAction().getPointPlotAction().setCurrentPointSizeDataset(candidateDataset);