build error log:

Building file: ../dialogs/MasterConfigurationDialog.cpp
Invoking: GCC C++ Compiler
g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"dialogs/MasterConfigurationDialog.d" -MT"dialogs/MasterConfigurationDialog.d" -o"dialogs/MasterConfigurationDialog.o" "../dialogs/MasterConfigurationDialog.cpp"
/usr/include/FL/Fl_Group.H: In copy constructor ‘MasterConfigurationDialog::Transformation::Transformation(const MasterConfigurationDialog::Transformation&)’:
/usr/include/FL/Fl_Group.H:47: error: ‘Fl_Group::Fl_Group(const Fl_Group&)’ is private
../dialogs/../include/MasterConfigurationDialog.h:77: error: within this context
../dialogs/MasterConfigurationDialog.cpp: In constructor ‘MasterConfigurationDialog::MasterConfigurationDialog()’:
../dialogs/MasterConfigurationDialog.cpp:55: note: synthesized method ‘MasterConfigurationDialog::Transformation::Transformation(const MasterConfigurationDialog::Transformation&)’ first required here 
make: *** [dialogs/MasterConfigurationDialog.o] Error 1
make: Target `all' not remade because of errors.

code (incomplete)

// transformation class widget
	class Transformation : public Fl_Group {
	public:
		
		// the format for fields is "<type1:|field1|field2|field3|" ... "|fieldN|><type2:|field1|field2||field3|" ... "|fieldN|>" ...
		// name must be a key; name is the currently selected key
		Transformation(int x, int y, const char* fields, bool active) : 
			Fl_Group(x, y, WIDTH - 10, 2*(DEFAULT_TEXTSIZE) + 6) {
			
			this->end();
			
			string transforms = string(fields);
			transformTypes = vector<string>();
			
			// initialize data
			format = string(fields);
			this->fields = vector<Fl_Float_Input*>();
			
			// initialize the members
			typeMenu = new Fl_Menu_Button(x + 30, y, 100, DEFAULT_TEXTSIZE + 6);
			activeButton = new Fl_Check_Button(x, y, DEFAULT_TEXTSIZE + 6, DEFAULT_TEXTSIZE + 6);
			activeButton->value(active);
			
			// find all the transformation types
			while(true) {
				// find the < and : to get the types
				string::size_type start = transforms.find("<", 0);
				string::size_type end = transforms.find(":", 0);
				
				// get the type
				string key = transforms.substr( start+1, end - (start+1) );
				
				// add the type
				transformTypes.push_back( key );
				
				// advance transforms
				transforms = transforms.substr( end+1 );
				
				// break when we run out of string 
				if(transforms.length() <= 2)
					break;
			}
			
			// build the transformation types menu
			for(vector<string>::iterator i = transformTypes.begin(); i != transformTypes.end(); i++) {
				typeMenu->add( i->c_str(), 0, this->getTransformationCallback, this);
			}
			
			// label it
			// typeMenu->label(name);
			
			// add the widgets
			this->add(typeMenu);
			this->add(activeButton);
		}
		
		virtual ~Transformation() { }
		
		// read the transformation type from the menu
		static void getTransformationCallback(Fl_Widget* w, void* data) {
			Transformation* t = (Transformation*)(data);
			Fl_Menu_Button* mb = (Fl_Menu_Button*)(w);
			t->getTransformationCallback_real(t, mb);
		}
		
		// getters
		string getTransformationType(void) { return string( typeMenu->label() ); }
		vector<string> getSupportedTransformations(void) { return transformTypes; }
		bool isActive(void) { return activeButton->value(); }
		
		// return string representation in BZW format
		string toString() {
			return string(typeMenu->label()) + "\n";
		}
		
	private:
		
		// label the menu button with the selection
		void getTransformationCallback_real(Transformation* t, Fl_Menu_Button* mb) {
			const Fl_Menu_Item* menu = mb->menu();
			mb->label(menu[mb->value()].label());
		}
		
		// change callbacks based on a new selection
		void changeFields(const char* name) {
			string transformation = string( name );
			
			// remove previous fields
			if(fields.size() != 0) {
				for(vector<Fl_Float_Input*>::iterator i = fields.begin(); i != fields.end(); i++) {
					this->remove(*i);
					delete *i;
				}	
			}
			
			// cut out the list of fields
			string::size_type startIndex = format.find("<" + transformation + ":", 0);
			startIndex = format.find("|", startIndex);
			
			string::size_type endIndex = format.find("|>", startIndex);
			
			string fieldList = format.substr(startIndex, endIndex - startIndex);
			printf("%s\n", fieldList.c_str());
			
			// find all fields and make them
			
		}
		
		// data
		vector<string> transformTypes;
		Fl_Menu_Button* typeMenu;
		Fl_Check_Button* activeButton;
		vector<Fl_Float_Input*> fields;
		string format;
	};