Function getZLevelTop

packages/designer/src/document/node/node.ts:1406–1419

(child: INode, zLevel: number)

}

export function getZLevelTop(child: INode, zLevel: number): INode | null {
  let l = child.zLevel;
  if (l < zLevel || zLevel < 0) {
    return null;
  }
  if (l === zLevel) {
    return child;
  }
  let r: any = child;
  while (r && l-- > zLevel) {
    r = r.parent;
  }
  return r;
}

/**
 * 测试两个节点是否为包含关系