Move read volumes logic to dataloadermodule and dir-is-read

modules/dataloader/dataloadermodule.cpp

@@ -35,9 +35,42 @@ namespace {
     constexpr const char* _loggerCat = "DataLoaderModule";
 }
 
+namespace {
+    static const openspace::properties::Property::PropertyInfo ShowInternalVolumesInfo = {
+        "ShowInternalVolumesTrigger",
+        "Trigger load volume data files",
+        "If this property is triggered it will call the function to load and show volume data"
+    };
+
+    static const openspace::properties::Property::PropertyInfo VolumesInfo = {
+        "Volumes",
+        "List of volume items stored internally and ready to load",
+        "This list contains names of volume data files converted from the CDF format"
+    };
+
+    static const openspace::properties::Property::PropertyInfo FieldlinesInfo = {
+        "Fieldlines",
+        "List of fieldline items stored internally and ready to load",
+        "This list contains names of fieldline data files converted from the CDF format"
+    };
+}
+
 namespace openspace {
 
-DataLoaderModule::DataLoaderModule() : OpenSpaceModule(Name) {}
+DataLoaderModule::DataLoaderModule() 
+    : OpenSpaceModule(Name)
+    , _showInternalVolumesTrigger(ShowInternalVolumesInfo)
+    , _volumeDataItems(VolumesInfo)
+{
+    _showInternalVolumesTrigger.onChange([this](){
+        // showInternalDataType(DataTypes.volume);
+        validateDataDirectory();
+        _loader->createInternalDataItemProperties();
+    });
+
+    addProperty(_volumeDataItems);
+    addProperty(_showInternalVolumesTrigger);
+}
 
 DataLoaderModule::~DataLoaderModule() {}
 
@@ -56,7 +89,9 @@ void DataLoaderModule::setDataDirectoryRead(bool isRead) {
 }
 
 void DataLoaderModule::validateDataDirectory() {
-    if(!_dataDirectoryIsRead) {
+    if(_dataDirectoryIsRead == false) {
+
+        // TODO: generalize
         _reader->readVolumeDataItems();
     }
 }