https://github.com/lue-bird/elm-rosetree-path

navigate rosetrees and forests
https://github.com/lue-bird/elm-rosetree-path

elm forest multiway-tree navigation path rosetree tree tree-path

Last synced: 26 days ago
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navigate rosetrees and forests

• Host: GitHub
• URL: https://github.com/lue-bird/elm-rosetree-path
• Owner: lue-bird
• License: mit
• Created: 2021-06-28T19:51:45.000Z (over 3 years ago)
• Default Branch: master
• Last Pushed: 2023-07-26T08:41:38.000Z (over 1 year ago)
• Last Synced: 2024-12-09T18:02:08.613Z (about 1 month ago)
• Topics: elm, forest, multiway-tree, navigation, path, rosetree, tree, tree-path
• Language: Elm
• Homepage: https://package.elm-lang.org/packages/lue-bird/elm-rosetree-path/latest/
• Size: 123 KB
• Stars: 0
• Watchers: 1
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: changes.md
  • License: LICENSE

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README

        
# rosetree-path

A path is the location of a branch in a tree (or forest).

With this package you can use paths to navigate and alter

a [zwilias/elm-rosetree](https://package.elm-lang.org/packages/zwilias/elm-rosetree/latest/) or a list of them, also called a "forest".

An alternative way of

keeping track of one focus is a [`Tree.Zipper`](https://package.elm-lang.org/packages/zwilias/elm-rosetree/latest/Tree-Zipper).

However! Paths are nice if you want to

- keep track of many different locations

- easily deal with _potentially_ focussed nodes etc.

- don't want to pollute `Msg`es with potentially large, changing tree content

Example: A big tree on the screen where subtrees can be moved and deleted.

```elm

import Tree.Path exposing (TreePath)

import Tree.Navigate

type alias Model =

    { tree : Tree { translate : ( Float, Float ) }

    , dragged : Maybe TreePath

    }

type Msg =

    = RightClickedOn ForestPath

    | MouseMoved ( Float, Float )

  --| ...

viewTree =

    Tree.Navigate.restructure

        (\sub ->

            (...

                |> onMouseDown (PressedOn sub.path)

                |> (case sub.path |> Tree.Path.step of

                        Just childPath ->

                            onRightClick (RightClickedOn childPath)

                        Nothing ->

                            -- top level node should not be removable

                            identity

                   )

            )

                :: sub.children

                |> group

                |> shift sub.label.translate

        )

update msg model =

    case msg of

        RightClickedOn path ->

            { model

              | tree =

                  model.tree

                    |> Tree.mapChildren

                        (Forest.Navigate.remove path)

            }

        

        MouseMoved mousePosition ->

            case model.dragged of

                Just path ->

                    { model

                      | tree =

                          model.tree

                            |> Tree.Navigate.alter path

                                (Tree.mapLabel

                                    (\l -> { l | translate = ... })

                                )

                    }

                Nothing ->

                    model

        

      --...

```

Complete implementation in [example/](https://github.com/lue-bird/rosetree-path/tree/master/example/).