Changelog

[0.1.2] - 2026-10-01

Added

• The feature documentation, thirteen pages under docs/ with a screenshot each. It is written as the IDE behaves rather than as it was assembled: what a panel shows, which backend a file gets, what is remembered between runs. The two editors that had become one are described as one, and the pages that used to carry the story of a bug now carry the behaviour and leave the story to the commit that found it.

Changed

• The project configuration is JSON. It was TOML, and TOML it no longer is: .undoProject/project.json, .undoProject/plcs.json, .undoProject/tasks.json, undoLogic/<plc>/exports.json and one file per task under undoCore/tasks/. Nothing reads the old format and nothing migrates it, so a project written against it has to be rewritten once. strictness in the semantics block is a boolean now rather than a string. JSON was already the language of the rest of the tree — every diagnostic, every build descriptor — and a project described in a second one was the only file the IDE could not read as itself.
• One editor panel, for every kind of file. A .st, a .json, a .cpp and a configuration file all open in the same Editor panel above the same tab bar. The Structured Text editor used to be a panel of its own, which meant two bars of open files over one set of files and a shipped layout arranging a panel that no longer exists; and every backend drew its own ImGui window inside the panel it was dispatched from, so a .json came to be shown in a floating window titled with its own filename while the Editor panel behind it drew the same backend again. The panel owns the window and a backend draws its contents; the ST document is drawn by EditorApp calling three functions in the order the panel calls them, because the keyboard and the unsaved prompt belong to the panel while the signature help and the completion lists are separate windows drawn after the document.
• A project's own .json opens as text, and can be looked at as a tree instead. Which one a .json gets is the file's role and not its extension, answered from the open project: the configuration is the file the user is told to edit by hand, and a tree has nothing to type into. "Open as Text" and "Open as Tree" are both in the tree's context menu for any .json, they replace the tab rather than adding a second one, and a .json outside any project is a tree as it always was.

Fixed

• A FUNCTION could not be parsed at all, new or edited. The generated header wrote the name and a colon and stopped, so the type after it was empty: FUNCTION Foo :, which st2cpp rejects before it reaches a single line of the body. The POU type and the return type are two fields, and the second one had nowhere to go — it was asked for in the add-METHOD dialog and dropped afterwards, so a method added to a FUNCTION lost its type too. The return type is now written into the header, read back when the file is opened rather than carried in memory across the two, and editable next to the POU type for a file that was generated before this, which is what the ones on disk are. A diagnostic that falls outside every editor's own lines says so in those words and names the generated line, because "see the Output panel" pointed at a file the user had never opened.
• A backend could open a file behind the tab bar's back. The JSON viewer had an "Open File" button of its own, which loaded straight into the viewer: the bar then answered "nothing is open" for a document that was on screen and could not be reached again. Every route goes through EditorApp::openFile now.
• The text and C++ editors each opened a window titled with the name of the file they were editing, which floated away from the panel it was dispatched from.
• A release could publish without its archive. The upload of the tarball was refused with a 403 while the 103-byte checksum beside it went through, the two having been sent concurrently, and the job did not try again: v0.1.2 was published with a checksum for a file nobody could download. The files are sent one at a time and retried, and the job fails if the release does not end up carrying both, because a release that looks finished and is not is worse than a failed run. The same job now keeps a compilation cache between releases, which is most of what made it take ten minutes.

[0.1.1] - 2026-10-01

Added

• The editor has tabs. OpenDocuments holds the set of open files, which one is on screen, and which of them are permanent, and it is the only thing that answers those questions: the backends behind it know about one file each, and none of them knows that a second .st is open somewhere. A click in the tree opens a file and keeps it, the tab bar scrolls sideways rather than squeezing, each tab carries a dot while it has changes that are not on disk and a close button, and the panel is sized from what it holds rather than by a zero that ImGui reads as "all of it" (a bar of that kind grew to the height of the whole ST Editor panel and pushed the editor it sat above out of sight).
• A file that is open and not on screen is held whole, per backend: STDocument for the ST panes, the text and its path for the others. A tab that comes back shows what was in it, at the cursor and the pane division it was left at. The AST, the semantic analysis and the source map are not kept: they are derived, and a snapshot of them is stale the moment a character is typed.
• The files that were opened are remembered between runs, under File > Open Recent Files or Ctrl+P. The list is persistent, newest first, and it is fed by every route into the editor rather than by the menu: a file is remembered however it was reached. It shares one length with the recent projects list ([recent] max), because one remembered-things-too-many is enough, and a rename or a move rewrites the entry in place rather than leaving an entry for a file that is no longer there. A file deleted outside the IDE stays in the list and is shown as missing, so that an entry disappearing is never a mistake.
• What the IDE is handed is opened: a file or a project on the command line, and files dropped onto the window. OpenTarget decides which of the two a path is and leaves a request, because the undoApp that can act on it is a plugin and the core cannot call into one. The desktop entry gained F and the JSON and plain-text MIME types, so a .st file can be opened from the file manager.
• The ST Output panel can be filtered. The generated ST was dumped into the same list as the diagnostics, so for any file of size the two errors worth reading arrived somewhere under hundreds of lines of it. undoAppSTOutput.hpp holds the decisions, apart from the panel that draws them, because what is counted is what is hidden: a panel that says "0 errors" while hiding them is worse than one that says nothing. The switches persist per workspace, and a search field filters what is left.
• The terminal has one tab per shell, each with its own close button. Every session is pumped rather than only the one on screen: a shell left in a background tab is a process that is still running, and its output was sitting in the kernel buffer until the user came back and then arrived all at once.
• Three suites, all headless and all runnable on a machine with no display: 11 core tests, 23 editor tests and 1 terminal test. Each one has found a real bug; the ones that found one are named below.

Changed

• A single click in the tree keeps its file in a tab. It used to open a preview that the next click replaced, so the file being read was gone from the bar the moment another was opened, and holding on to one meant double clicking, which is a rule nobody can see — and ImGui only counts a double click when both clicks land within a few pixels of each other. The preview slot survives in the model for a caller that means "I am looking through these" and asks for it explicitly, and browsing past a preview that holds edits pins it.
• A rename or a move is followed. Four things file an open document under its path: the tab (which is its ImGui id), the key its stashed text is held under, the path the editor is told to save to, and the entry in the recent files list. A rename that moved three of the four was not a stale label but a second file: Ctrl+S wrote a copy where the original used to be, and the file the stash held came back with the old path inside it. A folder carries every file inside it, so renaming one moves their tabs too, and deleting a file or a folder closes the tabs that pointed at it rather than leaving rows that offer to open something that is gone.
• The unsaved mark is read from the editors once a frame and nowhere else. It used to be set when a tab was left, which answered a different question with the same answer: "keep this tab" and "this has changes" are not the same thing, so every tab that had been looked at twice carried an asterisk that nothing took off, because no save path cleared it either. Ctrl+S now reaches .st, .cpp and text files from any panel, and clears the mark only after the file opened for writing.
• "Open as Text" on a .json gives the file a tab of its own. It used to close the editors and load the text behind their backs, so the file had no name in the bar, nothing in the list to ask for it again, and one file could be open in two backends at once. It is one file, so it is one row, and the row is the text one.
• The ST editor panel lost its File: <name> row and its (unsaved changes) text: the tab bar drawn a few lines above already says both. The tooltip switch moved onto the button row, where a per-editor setting belongs. The POU type stayed, because it is the only place that writes down whether the file declares a PROGRAM, a FUNCTION_BLOCK or a FUNCTION, and a FUNCTION's return type hangs off it.
• The recent projects list is loaded the first time it is asked for. Loading it only happened on the calls that open or forget a project, so a run in which nobody opened anything showed an empty list while the entries sat in the state file, which reads as a lost history.
• The editor suite compiles the sources the tests share once into an archive instead of once per test. It used to be the whole cost of the suite: each of the tests recompiled the plugin and the st2cpp sources around it, in sequence.
• The shipped layout no longer carries the default Debug window, so a first run does not open a panel with nothing in it.

Fixed

• A row of a recent-files list could not be picked when another row had the same file name in a different folder. PushID covered the button and stopped before the Selectable, so both rows were drawn and submitted under the label alone. Both popups had it, and it looked right: the rows rendered, in order, with the right name on them, and the first pick worked.
• The recent-files popup was measured on the frame it opened, which is the size asked for rather than the size of its contents: a list of two rows reported itself as one row high. ImGui only learns how tall a window's content is once it has laid it out, so a popup is drawn for a few frames before it is read.
• Escape did nothing after asking for a workspace folder. The fallback dialog called OpenPopup with no Begin anywhere to match it, so the entry stayed on ImGui's open stack for the rest of the session and swallowed every Escape pressed afterwards.
• A file list row is not found by its fill colour while the cursor is on it: ImGui draws a button under the cursor in the hovered colour, and the row that had just been clicked moved out from under the pointer anyway. The tests park the mouse before measuring, which is also the only way to say why.
• Switching tabs marked the file being left as edited, and nothing ever took the mark off, because stashActiveDocument was asked to do two things at once. Reading it once a frame from the editors is the fix, and a save that failed leaves the mark alone, because it is the last thing standing between an edit and losing it.
• Closing a project left the previous project's files in the tab bar. The bar is what a user looks at to see what is open, so it was claiming files that the editors were not holding and that could not be opened.
• The recent projects and recent files lists could be emptied by a limit of zero read back from a hand-edited state file, with nothing to say why. The limit is clamped on the way out as well as on the way in, and the two lists are trimmed to it on the next load.
• The second and later terminal tabs were folded into the first. Every tab is titled "Terminal" until the shell renames it, and ImGui derives a tab's id from its label alone, so the shells ran and could not be seen or closed. Selecting a tab that was appended behind ImGui's back needed ImGuiTabItemFlags_SetSelected on the item: ImGuiTabBarFlags_AutoSelectNewTabs only selects when the bar has nothing selected, which is why the + button left the old tab on screen.

Known issues

• "Open as Text" and "Open as Tree" are only offered on .json, which is the only backend that cannot show its file as text.
• A terminal tab cannot be reordered by dragging. ImGui would move the tab and the panel would keep drawing the shell it thinks is there, so it is not offered rather than offered and wrong.
• Opening a text file and saving it without editing it adds a newline at the end. The editor normalises the text it holds, and the save writes what it holds.
• The editor suite is the slow one: it compiles the plugin and st2cpp before it runs anything. The archive took the per-test cost out of it; what is left is the cost of building the thing once.