如何改变具有弯曲边缘的森林的目录树的生长方向

Question

我正在使用此代码来显示目录树，效果很好：

\definecolor{treelines}{RGB}{40, 63, 100}
\definecolor{treefirst}{RGB}{40, 63, 100}
\definecolor{treesec}{RGB}{55, 84, 136}

\begin{forest}
    for tree={
    text=white,
    text width=2.3cm,
    minimum height=0.75cm,
    if level=0
       {fill=treefirst}
       {fill=treesec},
    rounded corners=4pt,
    grow'=0,
    child anchor=west,
    parent anchor=south,
    anchor=west,
    calign=first,
    edge={treelines,rounded corners,line width=1pt},
    edge path={
        \noexpand\path [draw, \forestoption{edge}]
        (!u.south west) +(7.5pt,0) |- (.child anchor)\forestoption{edge label};
    },
    before typesetting nodes={
    if n=1
        {insert before={[,phantom]}}
        {}
    },
    fit=band,
    s sep=15pt,
    before computing xy={l=15pt},
 }
[Project
    [item1]
    [item2]
    [item3
        [sitem1]
        [sitem2]
        [sitem3]
        [sitem4]
    ]
 ]
 \end{forest}

输出结果如下：

现在我想让 item3 向东延伸，如下所示：

我无法让它工作。使用 calign = center 至少可以为子树生成正确的格式，但边缘仍然全部错误。

Answer 1

如果需要半自动解决方案...

请注意，下面使用库folder中的样式edges而不是自己的样式。

\documentclass[tikz,border=10pt]{standalone}
\usepackage[edges]{forest}
\definecolor{treelines}{RGB}{40, 63, 100}
\definecolor{treefirst}{RGB}{40, 63, 100}
\definecolor{treesec}{RGB}{55, 84, 136}
\forestset{% ateb: https://tex.stackexchange.com/a/705018/ addaswyd o gwestiwn flewz: https://tex.stackexchange.com/q/531154/
  dir down/.style={%
    for tree={%
      folder,
      grow'=0,
    },
  },
  dir switch/.style={%
    delay={%
      prepend={%
        [,
          grow'/.option=!r.grow,
          folder,
          no edge,
          china,
          delay n=2{%
            coordinate,
            for nodewalk={%
              while nodewalk valid={next}{append=!next,do dynamics}%
            }{},
          },
          before typesetting nodes={%
            if={%
              > Ow+P  {n children}{isodd(##1)}
            }{%
              for nodewalk={fake=first,until={ > Ow+n O= {!u.n children}{(##1+1)/2}{n} }{fake=next},current}{calign with current edge,edge+={rounded corners=false}}
            }{%
              for nodewalk={fake=first,until={ > Ow+n O= {!u.n children}{(##1)/2}{n} }{fake=next},current}{%
                insert after={%
                  [, phantom,calign with current,coordinate,edge+={rounded corners=false}]
                },
              },
            },
            for children={edge path'={(!uu.parent anchor) -- ++(\foresteregister{folder indent},0pt) |- (.child anchor)}},
          },
        ]%
      },
    },
    before typesetting nodes={
      grow'=#1,
      parent anchor/.option=!r.grow,
      l sep'=0pt,
      s sep'=0pt,
    },
  },
  china/.style={%
    for tree={%
      text=white,
      text width=2.3cm,
      minimum height=0.75cm,
      if level=0{%
        fill=treefirst,
      }{%
        fill=treesec,
      },
      rounded corners=4pt,
      edge={treelines,rounded corners,line width=1pt},
    },
  },
}
\begin{document}

\begin{forest}
  dir down,
  china,
  [Project
    [item1]
    [item2]
    [item3, dir switch=90
      [sitem1]
      [sitem2]
      [sitem3]
      [sitem4]
    ]
  ]
\end{forest}
\end{document}