function mousedown(e) {
    if (isMiddleOrRightButtonOnMouseUpDown(e)
        || (e.target && e.target.draggable)
    ) {
        return;
    }

    var x = e.offsetX;
    var y = e.offsetY;

    // Only check on mosedown, but not mousemove.
    // Mouse can be out of target when mouse moving.
    if (this.pointerChecker && this.pointerChecker(e, x, y)) {
        this._x = x;
        this._y = y;
        this._dragging = true;
    }
}
@public
@param {module:echarts/ExtensionAPI} api
@param {Object} dataZoomInfo
@param {string} dataZoomInfo.coordId
@param {Function} dataZoomInfo.containsPoint
@param {Array.<string>} dataZoomInfo.allCoordIds
@param {string} dataZoomInfo.dataZoomId
@param {Object} dataZoomInfo.getRange
@param {Function} dataZoomInfo.getRange.pan
@param {Function} dataZoomInfo.getRange.zoom
@param {Function} dataZoomInfo.getRange.scrollMove
@param {boolean} dataZoomInfo.dataZoomModel