public DomainFile getSelectedDomainFile() {
		GTreeNode node = tree.getLastSelectedPathComponent();
		if (node instanceof DomainFileNode) {
			return ((DomainFileNode) node).getDomainFile();
		}
		return null;
	}
Get the last selected domain file.
@return null if no domain file is selected.
Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/ProjectDataTreePanel.java