Custom PopupMenu file selector

Question

Lately I come across what I think not uninteresting problem which is a good exercise for the usage of Dynamic. Assume you have files in a directory structure (a tree) like the one you find in the AddOns/Packages subdirectory. Here a snip of it

Packages/BarCharts
|-- Charts.m
|-- Charts3D.m
|-- Kernel
|   `-- init.m
|-- PacletInfo.m
`-- Usage.m
Packages/Benchmarking
|-- Benchmarking.m
|-- Kernel
|   `-- init.m
`-- PacletInfo.m
Packages/BlackBodyRadiation
|-- BlackBodyRadiation.m
|-- Kernel
|   `-- init.m
`-- PacletInfo.m

What I would like to have is a dynamically updating row of PopupMenu's which let's me select a file or directory like this

There should be a possibility to select directories (like the Benchmarking/Kernel) directory as well. Note that not all PopupMenu's are always visible. Their number depend on the depth of the selected file/directory. For instance consider this case

What I tried so far is to extract all files with FileNames and use Gather and replacement rules to convert them into a tree-structure. In this tree structure you can access then different levels and update the PopupMenu's in dependence of each other.

I'm really keen to see nice* ideas of others.

*short, interesting, intuitive, mind-boggling

Answer 1

My solution is only prototype but I'll update it later. It differs from Yours approach becouse my function is blind. A priori it does not know the structure of file's tree.

And there is also ActionMenu not PopupMenu. :(

This version is not very elegant but I'm going to improve this.

Lets start and set main directory and create function for each menu:

dir = {SetDirectory[$InstallationDirectory]}; 

current = 1;
MENU[j_] := Module[{k},

SetDirectory[StringJoin@Riffle[dir[[ ;; j]], "\\"]];
ActionMenu[
Dynamic@dir[[ j]],
Table[
 With[{f = FileNames[][[ i]]},
  f :> (
   current = j + 1;
   k = f;
   If[StringCount[f, "."] == 0, 
    dir = PadRight[dir[[ ;; j]], j + 1, ""]; dir[[ j + 1]] = k]
   )],
{i, Length@FileNames[]}]
 ]
 ]

now we can try:

Dynamic@Row@Table[MENU[j], {j, current}]

Basic description - we are extending path by clicking at last MENU. If You set one of previous then "current" value is changing and cutting path to the point You set. It works only for directories now by looking for "." in name. I'm going to deal with generalization later.

Ask if there are any questions.

Answer 2

A rough straightforward implementation is to find all of the subpaths in your path, and generate a button that allows setting a new path at that level for each such subpath. Here's an implementation that generates the list of files/folders when you press the menu to ensure it's up to date.

pathParts[path_] := FileNameJoin/@Rest@FoldList[Append,{},FileNameSplit[path]]

pathPartsAlternatives[path_]:= FileNames[FileNameJoin[Append[Most@FileNameSplit[path], "*"]]]

pathPartButton[Dynamic[var_],path_] :=
DynamicModule[{subpaths={}},
    EventHandler[
        Dynamic@ActionMenu[Last@FileNameSplit[path],subpaths]
    ,"MouseDown":>
    (subpaths=(RuleDelayed[Last@FileNameSplit@#,(var=FileNameJoin[{#, If[DirectoryQ[#], ".", ""]}])]&/@pathPartsAlternatives[path])),
    PassEventsDown->True]
]

pathPartsRow[Dynamic[var_]] := 
  pathPartButton[Dynamic[var], #] & /@ pathParts[var] // Row // Dynamic