protected JTree getSourceTree() {
if (sourceTree == null) {
DirectoryDescriptor[] results = fileRenamer.getResult()
.getFileSystemRoots();
DefaultTreeModel model = new DefaultTreeModel(results,
new DefaultFilter(true), LangageManager
.getProperty("tagrename.sourcetree"));
this.sourceTree = new JTree(model);
this.sourceTree.getSelectionModel().setSelectionMode(
TreeSelectionModel.SINGLE_TREE_SELECTION);
this.sourceTree.setCellRenderer(new SourceTreeCellRenderer());