@Override
  protected ContentAssistRequest computeCompletionProposals(
      String matchString,
      ITextRegion completionRegion,
      IDOMNode treeNode,
      IDOMNode xmlnode,
      CompletionProposalInvocationContext context) {
    ContentAssistRequest contentAssistRequest =
        super.computeCompletionProposals(matchString, completionRegion, treeNode, xmlnode, context);
    if (contentAssistRequest != null) return contentAssistRequest;

    String regionType = completionRegion.getType();
    if (DOMRegionContext.XML_CDATA_TEXT.equals(regionType)) {
      Node parentNode = xmlnode.getParentNode();
      Node statementNode = MybatipseXmlUtil.findEnclosingStatementNode(parentNode);
      if (statementNode == null) return null;

      int offset = context.getInvocationOffset();
      ITextViewer viewer = context.getViewer();
      contentAssistRequest =
          new ContentAssistRequest(
              xmlnode,
              parentNode,
              ContentAssistUtils.getStructuredDocumentRegion(viewer, offset),
              completionRegion,
              offset,
              0,
              matchString);
      proposeStatementText(contentAssistRequest, statementNode);
    }
    return contentAssistRequest;
  }
  protected void addAttributeValueProposals(
      ContentAssistRequest contentAssistRequest, CompletionProposalInvocationContext context) {
    IDOMNode node = (IDOMNode) contentAssistRequest.getNode();
    String tagName = node.getNodeName();
    IStructuredDocumentRegion open = node.getFirstStructuredDocumentRegion();
    ITextRegionList openRegions = open.getRegions();
    int i = openRegions.indexOf(contentAssistRequest.getRegion());
    if (i < 0) return;
    ITextRegion nameRegion = null;
    while (i >= 0) {
      nameRegion = openRegions.get(i--);
      if (nameRegion.getType() == DOMRegionContext.XML_TAG_ATTRIBUTE_NAME) break;
    }

    // get the attribute in question (first attr name to the left of the cursor)
    String attributeName = null;
    if (nameRegion != null) attributeName = open.getText(nameRegion);

    ProposalType proposalType = resolveProposalType(tagName, attributeName);
    if (ProposalType.None.equals(proposalType)) {
      return;
    }

    String currentValue = null;
    if (contentAssistRequest.getRegion().getType() == DOMRegionContext.XML_TAG_ATTRIBUTE_VALUE)
      currentValue = contentAssistRequest.getText();
    else currentValue = "";

    String matchString = null;
    int matchStrLen = contentAssistRequest.getMatchString().length();
    int start = contentAssistRequest.getReplacementBeginPosition();
    int length = contentAssistRequest.getReplacementLength();
    if (currentValue.length() > StringUtils.strip(currentValue).length()
        && (currentValue.startsWith("\"") || currentValue.startsWith("'"))
        && matchStrLen > 0) {
      // Value is surrounded by (double) quotes.
      matchString = currentValue.substring(1, matchStrLen);
      start++;
      length = currentValue.length() - 2;
      currentValue = currentValue.substring(1, length + 1);
    } else {
      matchString = currentValue.substring(0, matchStrLen);
    }

    IJavaProject project = getJavaProject(contentAssistRequest);
    try {
      switch (proposalType) {
        case Package:
          proposePackage(contentAssistRequest, project, matchString, start, length);
          break;
        case TypeAlias:
          addProposals(
              contentAssistRequest,
              ProposalComputorHelper.proposeJavaType(project, start, length, false, matchString));
          break;
        case ResultType:
          addProposals(
              contentAssistRequest,
              ProposalComputorHelper.proposeJavaType(project, start, length, true, matchString));
          break;
        case ResultProperty:
          proposeProperty(contentAssistRequest, matchString, start, length, node);
          break;
        case TypeHandlerType:
          addProposals(
              contentAssistRequest,
              ProposalComputorHelper.proposeTypeHandler(project, start, length, matchString));
          break;
        case CacheType:
          addProposals(
              contentAssistRequest,
              ProposalComputorHelper.proposeCacheType(project, start, length, matchString));
          break;
        case SettingName:
          addProposals(
              contentAssistRequest,
              ProposalComputorHelper.proposeSettingName(start, length, matchString));
          break;
        case ObjectFactory:
          addProposals(
              contentAssistRequest,
              ProposalComputorHelper.proposeObjectFactory(project, start, length, matchString));
          break;
        case ObjectWrapperFactory:
          addProposals(
              contentAssistRequest,
              ProposalComputorHelper.proposeObjectWrapperFactory(
                  project, start, length, matchString));
          break;
        case StatementId:
          proposeStatementId(contentAssistRequest, project, matchString, start, length, node);
          break;
        case MapperNamespace:
          proposeMapperNamespace(contentAssistRequest, project, start, length);
          break;
        case ResultMap:
          String ownId =
              "resultMap".equals(tagName) && "extends".equals(attributeName)
                  ? XpathUtil.xpathString(node, "@id")
                  : null;
          addProposals(
              contentAssistRequest,
              proposeResultMapReference(
                  project,
                  node.getOwnerDocument(),
                  start,
                  currentValue,
                  matchString.length(),
                  ownId));
          break;
        case Include:
          addProposals(
              contentAssistRequest,
              ProposalComputorHelper.proposeReference(
                  project, node.getOwnerDocument(), matchString, start, length, "sql", null));
          break;
        case SelectId:
          // TODO: include mapper methods with @Select.
          addProposals(
              contentAssistRequest,
              ProposalComputorHelper.proposeReference(
                  project, node.getOwnerDocument(), matchString, start, length, "select", null));
          break;
        case KeyProperty:
          String nodeName = node.getNodeName();
          Node statementNode =
              "update".equals(nodeName) || "insert".equals(nodeName)
                  ? node
                  : MybatipseXmlUtil.findEnclosingStatementNode(node.getParentNode());
          addProposals(
              contentAssistRequest,
              proposeParameter(project, start, length, statementNode, false, matchString));
          break;
        case ParamProperty:
          addProposals(
              contentAssistRequest,
              proposeParameter(
                  project,
                  start,
                  length,
                  MybatipseXmlUtil.findEnclosingStatementNode(node),
                  true,
                  matchString));
          break;
        case ParamPropertyPartial:
          AttrTextParser parser = new AttrTextParser(currentValue, matchString.length());
          addProposals(
              contentAssistRequest,
              proposeParameter(
                  project,
                  start + parser.getMatchStringStart(),
                  parser.getReplacementLength(),
                  MybatipseXmlUtil.findEnclosingStatementNode(node.getParentNode()),
                  true,
                  parser.getMatchString()));
          break;
        default:
          break;
      }
    } catch (Exception e) {
      Activator.log(Status.ERROR, e.getMessage(), e);
    }
  }