public void setPackagePresentation(String command, boolean update) {

    if (command.contains("flat")) {
      patternsTreeViewer.setContentProvider(flatCP);
      patternsTreeViewer.setLabelProvider(flatLP);
    } else {
      patternsTreeViewer.setContentProvider(hierarchicalCP);
      patternsTreeViewer.setLabelProvider(hierarchicalLP);
    }

    if (update) {
      patternsViewerInput.getGeneratedPatternsRoot().updateSelection(patternsTreeViewer);
      patternsViewerInput.getGenericPatternsRoot().updateSelection(patternsTreeViewer);
    }
  }