code: function _onResize () {
          _width = window.innerWidth;
          _height = window.innerHeight;
          var
              orientation,
              orientationChanged = false,
              toRemove = [],
              toAdd = [];
          if (_width > _height) {
              orientation = "gpf-landscape";
          } else {
              orientation = "gpf-portrait";
          }
          if (_orientation !== orientation) {
              toRemove.push(_orientation);
              _orientation = orientation;
              toAdd.push(orientation);
              orientationChanged = true;
          }
          gpf.html.alterClass(document.body, toAdd, toRemove);
          _broadcaster.broadcastEvent("resize", {
              width: _width,
              height: _height
          });
          if (orientationChanged) {
              _broadcaster.broadcastEvent("rotate", {
                  orientation: orientation
              });
          }
      }
docs: HTML Event "resize" listener
  
  @private