public boolean hasSingleNodeSelection() {
		ProgramDnDTree tree = getTree();
		if (tree == null) {
			return false;
		}
		return tree.getSelectionCount() == 1;
	}
A context object for the {@link ProgramTreePlugin}.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/programtree/ProgramTreeActionContext.java