V2: Hide "Add Question" button on page if allowEdit set to false onElementAllowOperations event

[andrewtelnov]

The following code should remove buttons: "Delete", "Duplicate" and "Add Question" on the first page in Creator surface. Right now we do not remove "Add Question" buttons.

  creator.onElementAllowOperations.add((sender, options) => {
    if(options.obj.isPage) {
      const isFirstPage = sender.survey.pages.indexOf(options.obj) === 0;
      if(isFirstPage) {
        options.allowDelete = false;
        options.allowEdit = false;
        options.allowCopy = false;
      }
    }
  });