docs: function(evt) {
          var propagate = true;
          this.pinching = false;
          if (OpenLayers.Event.isMultiTouch(evt)) {
              this.started = true;
              this.last = this.start = {
                  distance: this.getDistance(evt.touches),
                  delta: 0,
                  scale: 1
              };
              this.callback("start", [evt, this.start]);
              propagate = !this.stopDown;
          } else if (this.started) {
              // Some webkit versions send fake single-touch events during
              // multitouch, which cause the drag handler to trigger
              return false;
          } else {
              this.started = false;
              this.start = null;
              this.last = null;
          }
          // prevent document dragging
          OpenLayers.Event.preventDefault(evt);
          return propagate;
      }