public void validatePage() {

    StatusInfo si = new StatusInfo(StatusInfo.OK, "");

    if (patternText != null) {
      String patternName = patternText.getText();
      if (patternName == null || patternName.length() == 0) {
        if (parameterSet) {
          si.setError(PATTERN_NAME_MUST_BE_SPECIFIED);
        } else {
          si.setWarning(PATTERN_NAME_SHOULD_BE_SPECIFIED);
        }
      }
    }

    if (si.getSeverity() == IStatus.OK) {
      si.setInfo("");
    }

    updateStatus(si);

    if (si.isError()) {
      setErrorMessage(si.getMessage());
    }
  }
  protected void checkIfPatternValid() {
    String pattern = fExclusionPatternDialog.getText().trim();
    if (pattern.length() == 0) {
      fExclusionPatternStatus.setError(NewWizardMessages.ExclusionInclusionEntryDialog_error_empty);
      return;
    }
    IPath path = new Path(pattern);
    if (path.isAbsolute() || path.getDevice() != null) {
      fExclusionPatternStatus.setError(
          NewWizardMessages.ExclusionInclusionEntryDialog_error_notrelative);
      return;
    }
    if (fExistingPatterns.contains(pattern)) {
      fExclusionPatternStatus.setError(
          NewWizardMessages.ExclusionInclusionEntryDialog_error_exists);
      return;
    }

    fExclusionPattern = pattern;
    fExclusionPatternStatus.setOK();
  }
  @Override
  public void setVisible(boolean visible) {
    super.setVisible(visible);
    pageVisible = visible;

    // Wizards are not allowed to start up with an error message
    if (visible) {
      setFocus();

      if (pageStatus.matches(IStatus.ERROR)) {
        StatusInfo status = new StatusInfo();
        status.setError("");
        pageStatus = status;
      }
    }
  }
  /**
   * This method is a hook which gets called after the source folder's text input field has changed.
   * This default implementation updates the model and returns an error status. The underlying model
   * is only valid if the returned status is OK.
   *
   * @return the model's error status
   */
  protected IStatus containerChanged() {
    StatusInfo status = new StatusInfo();

    fCurrRoot = null;
    String str = getPackageFragmentRootText();
    if (str.length() == 0) {
      status.setError(NewWizardMessages.NewContainerWizardPage_error_EnterContainerName);
      return status;
    }
    IPath path = new Path(str);
    IResource res = fWorkspaceRoot.findMember(path);
    if (res != null) {
      int resType = res.getType();
      if (resType == IResource.PROJECT || resType == IResource.FOLDER) {
        IProject proj = res.getProject();
        if (!proj.isOpen()) {
          status.setError(
              Messages.format(
                  NewWizardMessages.NewContainerWizardPage_error_ProjectClosed,
                  BasicElementLabels.getPathLabel(proj.getFullPath(), false)));
          return status;
        }
        IJavaProject jproject = JavaCore.create(proj);
        fCurrRoot = jproject.getPackageFragmentRoot(res);
        if (res.exists()) {
          if (res.isVirtual()) {
            status.setError(NewWizardMessages.NewContainerWizardPage_error_FolderIsVirtual);
            return status;
          }
          try {
            if (!proj.hasNature(JavaCore.NATURE_ID)) {
              if (resType == IResource.PROJECT) {
                status.setError(NewWizardMessages.NewContainerWizardPage_warning_NotAJavaProject);
              } else {
                status.setWarning(
                    NewWizardMessages.NewContainerWizardPage_warning_NotInAJavaProject);
              }
              return status;
            }
            if (fCurrRoot.isArchive()) {
              status.setError(
                  Messages.format(
                      NewWizardMessages.NewContainerWizardPage_error_ContainerIsBinary,
                      BasicElementLabels.getPathLabel(path, false)));
              return status;
            }
            if (fCurrRoot.getKind() == IPackageFragmentRoot.K_BINARY) {
              status.setWarning(
                  Messages.format(
                      NewWizardMessages.NewContainerWizardPage_warning_inside_classfolder,
                      BasicElementLabels.getPathLabel(path, false)));
            } else if (!jproject.isOnClasspath(fCurrRoot)) {
              status.setWarning(
                  Messages.format(
                      NewWizardMessages.NewContainerWizardPage_warning_NotOnClassPath,
                      BasicElementLabels.getPathLabel(path, false)));
            }
          } catch (JavaModelException e) {
            status.setWarning(NewWizardMessages.NewContainerWizardPage_warning_NotOnClassPath);
          } catch (CoreException e) {
            status.setWarning(NewWizardMessages.NewContainerWizardPage_warning_NotAJavaProject);
          }
        }
        return status;
      } else {
        status.setError(
            Messages.format(
                NewWizardMessages.NewContainerWizardPage_error_NotAFolder,
                BasicElementLabels.getPathLabel(path, false)));
        return status;
      }
    } else {
      status.setError(
          Messages.format(
              NewWizardMessages.NewContainerWizardPage_error_ContainerDoesNotExist,
              BasicElementLabels.getPathLabel(path, false)));
      return status;
    }
  }