private ClipboardData getClipboardData(ITypeRoot inputElement, int offset, int length) {
    CompilationUnit astRoot =
        SharedASTProvider.getAST(inputElement, SharedASTProvider.WAIT_ACTIVE_ONLY, null);
    if (astRoot == null) {
      return null;
    }

    // do process import if selection spans over import declaration or package
    List<ImportDeclaration> list = astRoot.imports();
    if (!list.isEmpty()) {
      if (offset < ((ASTNode) list.get(list.size() - 1)).getStartPosition()) {
        return null;
      }
    } else if (astRoot.getPackage() != null) {
      if (offset < ((ASTNode) astRoot.getPackage()).getStartPosition()) {
        return null;
      }
    }

    ArrayList<SimpleName> typeImportsRefs = new ArrayList<SimpleName>();
    ArrayList<SimpleName> staticImportsRefs = new ArrayList<SimpleName>();

    ImportReferencesCollector.collect(
        astRoot,
        inputElement.getJavaProject(),
        new Region(offset, length),
        typeImportsRefs,
        staticImportsRefs);

    if (typeImportsRefs.isEmpty() && staticImportsRefs.isEmpty()) {
      return null;
    }

    HashSet<String> namesToImport = new HashSet<String>(typeImportsRefs.size());
    for (int i = 0; i < typeImportsRefs.size(); i++) {
      Name curr = typeImportsRefs.get(i);
      IBinding binding = curr.resolveBinding();
      if (binding != null && binding.getKind() == IBinding.TYPE) {
        ITypeBinding typeBinding = (ITypeBinding) binding;
        if (typeBinding.isArray()) {
          typeBinding = typeBinding.getElementType();
        }
        if (typeBinding.isTypeVariable()
            || typeBinding.isCapture()
            || typeBinding.isWildcardType()) { // can be removed when bug 98473 is fixed
          continue;
        }

        if (typeBinding.isMember() || typeBinding.isTopLevel()) {
          String name = Bindings.getRawQualifiedName(typeBinding);
          if (name.length() > 0) {
            namesToImport.add(name);
          }
        }
      }
    }

    HashSet<String> staticsToImport = new HashSet<String>(staticImportsRefs.size());
    for (int i = 0; i < staticImportsRefs.size(); i++) {
      Name curr = staticImportsRefs.get(i);
      IBinding binding = curr.resolveBinding();
      if (binding != null) {
        StringBuffer buf = new StringBuffer(Bindings.getImportName(binding));
        if (binding.getKind() == IBinding.METHOD) {
          buf.append("()"); // $NON-NLS-1$
        }
        staticsToImport.add(buf.toString());
      }
    }

    if (namesToImport.isEmpty() && staticsToImport.isEmpty()) {
      return null;
    }

    String[] typeImports = namesToImport.toArray(new String[namesToImport.size()]);
    String[] staticImports = staticsToImport.toArray(new String[staticsToImport.size()]);
    return new ClipboardData(inputElement, typeImports, staticImports);
  }
 private CompilationUnit getASTRoot(ICompilationUnit compilationUnit) {
   return SharedASTProvider.getAST(
       compilationUnit, SharedASTProvider.WAIT_NO, new NullProgressMonitor());
 }