A project is a directory with a .undoProject/ descriptor in it. Opening one changes what the Workspace tree shows and what a .json opens as.

a project open, its name and the Save/Close buttons in the Workspace toolbar

Creating one

New Project in the Workspace toolbar asks for a name, a parent directory and an author, then writes the descriptor. Open Project picks a directory that already has one; the dialog is a folder chooser, and it falls back to zenity when tinyfiledialogs is not compiled in.

With a project open the header names it in green, with Save and Close beside it. Save writes the descriptor back; Close drops back to the plain workspace and clears the tab bar.

The two toolbars

The Workspace panel has a toolbar above the tree and a second one below it.

	Without a project	With a project
Above	New Project, Open Project, Select Workspace, Refresh	the project name, Save, Close, Select Workspace, Refresh
Below	+ POU, + Folder, + File	+ PLC, + Task

Select Workspace is the folder-without-a-project case: the tree is flat and the folder is where files are opened from.

What a project is on disk

myProject/
|-- .undoProject/
|   |-- project.json          name, version, author, target, semantics
|   |-- plcs.json             the PLCs
|   `-- tasks.json            the task list
|-- undoCore/
|   |-- tasks/                one JSON file per task
|   `-- ...                   the core sources
|-- undoLogic/
|   `-- <plc>/
|       `-- exports.json      the PROGRAM order of that PLC
`-- ...

All of it is JSON, and nothing reads or migrates the old TOML format, so a project written against it has to be rewritten once. See json.md for the two backends a .json can get.

Without a project

A folder can be opened as a workspace with no project in it. The tree is flat rather than role-aware, the folder context menu offers the generic New POU / New File / New Folder, and every .json in it is a tree rather than configuration.

The tree knows the roles

With a project open, the tree is built from the roles in plcs.json and the shape of the directory rather than from names alone: undoLogic/<plc>/exports.json is the PLC's exports file because the PLC is in the list, not because of what it is called. A project with no plcs.json has no PLC, and its exports file is an ordinary .json.

Recent projects

A project that has been open is remembered between runs: recent.md.