docs: function (name, data) {
              switch (name) {
                  case 'pageavailable':
                      if (data.page === index + 1 || data.upto > index || data.all === true) {
                          if (status === PAGE_STATUS_CONVERTING) {
                              status = PAGE_STATUS_NOT_LOADED;
                          }
                      }
                      break;
                  case 'textenabledchange':
                      if (data.enabled === true) {
                          this.enableTextSelection();
                      } else {
                          this.disableTextSelection();
                      }
                      break;
                  case 'pagefocus':
                      // falls through
                  case 'zoom':
                      isVisible = pageNum === data.page || (util.inArray(pageNum, data.visiblePages) > -1);
                      break;
  
                  // no default
              }
          }