取消关闭事件

我有一个Eclipse的编辑。当用户选择关闭它时,将出现一个包含多个选项的对话框。其中之一是“取消”,应该取消关闭事件。我该怎么做?

到目前为止,我得到的部分代码是:

    ...
    IEditorPart openEditor = page.openEditor(input, CS_STRINGEDITOR_ID);
    openEditor.getEditorSite().getPage()
        .addPartListener(new IPartListener() {
          public void partOpened(IWorkbenchPart part) {}
          public void partDeactivated(IWorkbenchPart part) {}

          public void partClosed(IWorkbenchPart part) {
            Shell sh = new Shell(cv.getViewSite().getShell());
            // My MessageDialog with the options, one being "cancel"
            CloseDialog closeDialog = new CloseDialog(sh);
            closeDialog.open();
            int returnCode = closeDialog.getReturnCode();
            switch (returnCode) {
            case CloseDialog.CANCEL_ID:
              // Abort the close event and keep the editor alive
              break;
            }
          }