public class DWAdapterFactoryContentProvider extends AdapterFactoryContentProvider {

	public DWAdapterFactoryContentProvider(AdapterFactory adapterFactory) {
		super(adapterFactory);
	}
	
	@Override
	protected IPropertySource createPropertySource(Object object, IItemPropertySource itemPropertySource) {
		return new PropertySource(object, itemPropertySource) {
			@Override
			 protected IPropertyDescriptor createPropertyDescriptor(IItemPropertyDescriptor itemPropertyDescriptor)
			  {
			    return new PropertyDescriptor(object, itemPropertyDescriptor) {
			    	@Override
			    	public CellEditor createPropertyEditor(Composite composite) {
			    		Object genericFeature = itemPropertyDescriptor.getFeature(object);
			    		if ( genericFeature instanceof EStructuralFeature )
			    	    {
			    	      final EStructuralFeature feature = (EStructuralFeature)genericFeature;
			    	      if ( feature == DynamicWarehousePackage.eINSTANCE.getLevelReference_Role() ||
			    	    	   feature == DynamicWarehousePackage.eINSTANCE.getDimensionReference_Role() ) {
			    	    	  return new ExtendedComboBoxCellEditor( composite, 
			    	    			  new ArrayList<Object>( itemPropertyDescriptor.getChoiceOfValues(object) ), 
			    	    			  getEditLabelProvider(), true, SWT.NONE ) {
			    	    		  
			    	    		  CCombo control;
			    	    		  
			    	    		  @Override
			    	    		  protected Control createControl(Composite parent) {
			    	    			 control = (CCombo) super.createControl(parent); 
			    	    			 return control;
			    	    		  }
			    	    		  
			    	    		  @Override
			    	    		  public Object doGetValue() {
			    	    			  String newValue = control.getText();
			    	    			  Object selectedValue = super.doGetValue();
			    	    			  if ( selectedValue == null && newValue != null ) {
			    	    				  String[] list = new String[getItems().length + 1];
			    	    				  list[0] = newValue;
			    	    				  for ( int i = 0; i < getItems().length; i++ ) {
			    	    					  list[i + 1] = getItems()[i];
			    	    				  }
			    	    				  setItems( list );
			    	    				  return super.doGetValue();
			    	    			  }
			    	    			  return selectedValue;
			    	    		  }
			    	    	  };
			    	      }
			    	    }
			    		
			    		return super.createPropertyEditor(composite);
			    	}
			    };
			  }
		};
	}

}