Docs: Python mode in the formula bar (UI parity, functions, architecture, control protocol, roadmap)

ui-parity.md gains a Python mode row and a shortcut row for
Ctrl+Alt+Shift+P with its Mac form. function-parity.md's Python in
cells row names Python mode. architecture.md describes Python mode on
the shared editor, code_field and its stop keys, and drafts that follow
their sheet by its identity. control-protocol.md lists ui.pythonMode,
the editor's python flag in ui.inspect, and when ui.inspect leaves a
draft out.
ROADMAP.md records the progress.

docs/architecture.md

@@ -1,6 +1,6 @@
 # Architecture
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-11-01 · **Change:** minor (Python cells as data; earlier: recently used functions kept in the preferences; Function Library module; accent icons; earlier: the hidden names that hold macros) · **Target:** Microsoft Excel (Microsoft 365)
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-11-01 · **Change:** minor (Python mode in the formula bar; earlier: Python cells as data; earlier: recently used functions kept in the preferences; Function Library module; accent icons; earlier: the hidden names that hold macros) · **Target:** Microsoft Excel (Microsoft 365)
 
 How GridCraft is built today. Rules for contributors are in [`AGENTS.md`](../AGENTS.md).
 
@@ -178,6 +178,22 @@ bound what a file can make the app hold (result size, spill ranges, total rebuil
 size). This build runs no Python: `python.set` stores code, and new or changed code shows
 `#BLOCKED!`.
 
+In ui-egui, Python mode is a state of the shared cell editor (`EditState::python`) that edits in
+the formula bar only, through `code_editor::code_field`: the code editor's in-order key handling
+(`apply_in_order_until`) with stop keys for commit, cancel and leaving the mode. A locked cell on
+a protected sheet is refused before a draft exists. Committing a Python edit
+(`commit_python_edit`) runs no command when the code is unchanged (no undo step), and none when
+sheet protection locked the cell while the draft was open (the draft is dropped with the warning).
+With all code deleted it runs `cell.set` with empty input on a Python cell, which clears it, and
+nothing on any other cell. Any other commit runs `python.set`; when that refuses, the message
+shows and the edit stays open. Drafts, Python or not, follow their sheet by its runtime identity
+(`Sheet::uid`, `model::SheetUid`, found again by `EditState::sheet_in`), so a sheet inserted,
+deleted or moved while one is open never takes it. After every command the open draft is pointed
+at its sheet again, so it is drawn, pointed from and committed there, and its point-mode anchor
+(held by sheet index) is let go when the sheet order changed. A draft is dropped then, with a
+message, when its sheet is gone, or when it holds Python code (in Python mode, or begun on a Python
+cell) that sheet protection now hides, as the Python editor window closes then.
+
 ## Agent control
 
 - Desktop control channel: `gridcraft --control 7979`, JSON lines on localhost
@@ -203,6 +219,7 @@ rpm, tarball), FreeBSD, and web (WASM; WebGPU or WebGL2). Release workflows in
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-11-01 | minor | Python mode in the formula bar: Python mode on the shared editor, `code_field` and its stop keys; drafts follow their sheet by `model::SheetUid` |
 | 2026-11-01 | minor | Python cells as data: `model::PyCode`, the file forms, calc laying out kept results, the limits on open, and what copying, filling and sorting do to `xl()` references; edits that would push code past the limit are refused |
 | 2026-10-31 | minor | Recently used functions (`recent.rs`, `Prefs::recent_functions`) behind `formulas.recentlyUsed` |
 | 2026-10-31 | minor | Function Library module (`function_library.rs`); accent icons (`icons::paint_accent`, `widgets::small_button_accent`) |

docs/control-protocol.md

@@ -58,13 +58,14 @@ connection; nothing sent after it runs. Blank lines are skipped.
 | `document.inspect` | | Workbook summary: sheets, used ranges, tables, charts, names, selection, undo labels |
 | `sheet.read` | `{range?, sheet?, formulas?, formatted?}` | Values (or formulas / displayed text) of a range |
 | `cell.get` | `{cell?}` | One cell: value, formula, displayed text, style, merge, comment, link |
-| `ui.inspect` | | UI state: ribbon tab, editor, open dialog, Backstage page, message, grid rect, scroll, perf, `windows` (as `window.list`) and `activeWindow` |
+| `ui.inspect` | | UI state: ribbon tab, editor (`python` is true in Python mode; a draft in Python mode or of a Python cell has `text` null and `hidden` true while that cell's code is hidden on a protected sheet, or once the draft's sheet is gone; the sheet is found by its identity, whatever was inserted, deleted or moved before it), open dialog, Backstage page, message, grid rect, scroll, perf, `windows` (as `window.list`) and `activeWindow` |
 | `ui.click` / `ui.drag` / `ui.move` | `{x, y, toX?, toY?, button?, count?, shift?, cmd?, alt?}` | Real pointer input in window points; refused with an error if it would leave more than 10,000 synthetic events or 8 MiB of synthetic input queued (pointer, key, text and move events share this budget) |
 | `ui.cell.click` / `ui.cell.drag` | `{cell}` / `{from, to}` | Pointer input at a cell's centre (works in point mode while editing); same shared queue limits |
 | `ui.key` / `ui.text` | `{key, shift?, cmd?, alt?, ctrl?}` / `{text}` | Keyboard input (typing in the grid starts editing); same shared queue limits, and one `ui.text` string may be at most 1 MiB |
 | `ui.edit.begin` / `ui.edit.text` / `ui.edit.commit` / `ui.edit.cancel` | `{text?}` / `{move?: down\|right\|up\|left\|none}` | Drive the cell editor |
 | `ui.ribbon` | `{tab}` | Switch ribbon tab |
 | `ui.dialog` / `ui.dialog.set` / `ui.dialog.confirm` / `ui.dialog.cancel` | `{name}` / `{field, value}` | Open, fill in and confirm dialogs; `confirm` runs the dialog's command with the same parameters as its OK button |
+| `ui.pythonMode` (via `engine.execute`) | `{on?}` | Python mode on the active cell, in the formula bar (an edit in progress keeps its text); `on: false` turns it off; without `on` it switches. Opens no dialog |
 | `ui.backstage` (via `engine.execute`) | `{page?: home\|new\|open\|info\|saveAs\|print\|export\|options\|account\|close}` | Open the File tab's Backstage view on a page, or close it (`ui.inspect` reports the open page as `backstage`) |
 | `ui.screenshot` | `{path?}` | PNG of the window (base64 when no path). Animations are settled first: the picture shows the final state. On the native app it works while hidden or occluded when the platform still reports the current content size (the request asks for a hidden paint); a minimized window has no capturable size, so its request stays queued until the window is restored and otherwise reports the 8 s timeout. In a **hidden browser tab** the web runner does not implement that paint request, so the capture waits until the tab is shown again or reports the 8 s timeout. Up to 4 outstanding requests; retained images are limited to 128 MiB each and 256 MiB in total (each request reserves the largest image the ±1-pixel rounding rule can retain), one capture's transient encoding working set to 256 MiB, a base64 reply to 64 MiB, and retained images plus one capture's encoding working set to 512 MiB; a request that would exceed a budget is refused without evicting earlier ones. See [Screenshot budgets](#screenshot-budgets). A resize/DPI/zoom/visibility/occlusion change during capture is retried within the bounded retry budget or reported instead of saving stale pixels; the identity intentionally includes zoom and occlusion even though the expected physical size may be unchanged, so a capture never crosses layout generations. Every reply — success, refusal or timeout — carries the request `token` as `request` |
 | `ui.set` | `{dark?, formulaBar?, ribbonCollapsed?, animations?}` | UI preferences (`formulaBar` runs `view.formulaBar`) |

docs/function-parity.md

@@ -1,6 +1,6 @@
 # Function parity: worksheet functions and formulas
 
-> **Last reviewed:** 2026-10-31 · **Last updated:** 2026-11-01 · **Change:** minor (the Python errors `#PYTHON!`, `#BUSY!`, `#TIMEOUT!` and `#BLOCKED!`, and a Python in cells row; earlier: YEARFRAC basis 0 February-end rule, MOD quotient limit, PERCENTRANK significance; earlier: edge cases matched to Excel: base conversions, BITLSHIFT/BITRSHIFT, UNICHAR noncharacters, UPPER/LOWER/PROPER casing, FIXED/DOLLAR output, F/T/GAMMA/WEIBULL/BETA distributions, BINOM trial cap, HARMEAN; earlier: ECMA.CEILING listed with USDOLLAR as not on Microsoft's list; earlier: IMSQRT reproduces the stray real part Excel gives for negative reals) · **Target:** Microsoft Excel (Microsoft 365), Excel for Mac 16.113.4
+> **Last reviewed:** 2026-10-31 · **Last updated:** 2026-11-01 · **Change:** minor (Python cells are edited in the formula bar; earlier: the Python errors `#PYTHON!`, `#BUSY!`, `#TIMEOUT!` and `#BLOCKED!`, and a Python in cells row; earlier: YEARFRAC basis 0 February-end rule, MOD quotient limit, PERCENTRANK significance; earlier: edge cases matched to Excel: base conversions, BITLSHIFT/BITRSHIFT, UNICHAR noncharacters, UPPER/LOWER/PROPER casing, FIXED/DOLLAR output, F/T/GAMMA/WEIBULL/BETA distributions, BINOM trial cap, HARMEAN; earlier: ECMA.CEILING listed with USDOLLAR as not on Microsoft's list; earlier: IMSQRT reproduces the stray real part Excel gives for negative reals) · **Target:** Microsoft Excel (Microsoft 365), Excel for Mac 16.113.4
 
 Excel's worksheet functions, category by category, against GridCraft's function library. Part of
 [target-app-parity.md](target-app-parity.md); gaps feed [gaps.md](gaps.md).
@@ -98,7 +98,7 @@ This improves series preparation; it does not change the model-fitting or season
 | Localized function names and `;` separators | **missing** (#45); en-US only |
 | Long flat operator chains (`=A1+A2+…`, `-`, `*`, `/`, `^`, `&`, comparisons) | done: no operand limit below Excel's 8,192-character formula limit (Excel, observed: `=1+1+…` with 4,096 operands is exactly 8,192 characters with the `=` and calculates; one more character is refused). Evaluated (#484), printed (#628), stored, copied, adjusted, saved and reopened without recursing once per operand, on a 1 MiB stack (#916); written to XLSX as plain formulas, not dynamic arrays; Spanish entry accepts them |
 | Error values | the seven classic errors plus `#SPILL!`, `#CALC!`, `#GETTING_DATA`, and the Python errors `#PYTHON!`, `#BUSY!`, `#TIMEOUT!`, `#BLOCKED!` done; `#FIELD!`, `#CONNECT!`, `#UNKNOWN!` missing (minor: they come from data types and cloud features). `ERROR.TYPE` gives 11 for `#BLOCKED!` as Excel does; Microsoft documents no number for `#PYTHON!`, `#BUSY!` or `#TIMEOUT!`, and GridCraft gives them 19, 20 and 21 |
-| Python in cells | partial: Python cells are stored, edited (`python.set`), copied, moved and saved, and Excel's `_xlfn._xlws.PY` cells open with their cached results; the code doesn't run, so new or changed code shows `#BLOCKED!`. Typing `=PY(` is refused with a pointer to `python.set`, so `PY` stays counted as missing above |
+| Python in cells | partial: Python cells are stored, edited (`python.set`, and Python mode in the formula bar: Ctrl+Alt+Shift+P or `=PY` then Tab), copied, moved and saved, and Excel's `_xlfn._xlws.PY` cells open with their cached results; the code doesn't run, so new or changed code shows `#BLOCKED!`. Typing `=PY(` and Enter is refused with a pointer to `python.set`, so `PY` stays counted as missing above |
 
 ## Depth (estimated)
 
@@ -134,6 +134,7 @@ workbooks; results checked in as data, not Excel files) and fixing what it finds
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-11-01 | minor | Python in cells row: Python mode in the formula bar |
 | 2026-11-01 | minor | Python in cells (stored, not run): `#PYTHON!`, `#BUSY!`, `#TIMEOUT!` and `#BLOCKED!` done, with their `ERROR.TYPE` numbers; `PY` still counted as missing |
 | 2026-10-31 | minor | BIN2*, HEX2* and OCT2* reject surrounding spaces and tabs in source strings with `#NUM!`, matching Excel; plain unpadded values remain valid |
 | 2026-10-31 | minor | DEC2BIN, DEC2HEX and DEC2OCT validate `places` before returning negative two's-complement output, and Boolean places return `#VALUE!`, matching Excel |

docs/ui-parity.md

@@ -1,6 +1,6 @@
 # UI parity
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-31 · **Change:** minor (Formulas › Function Library as labelled buttons with category menus; Recently Used and the Insert Function categories; Esc leaves a File-page text field before closing the view; earlier: checkbox cells print as boxes; Ctrl+arrow and Ctrl+Shift+arrow while pointing a formula reference; editing a hyperlink loads its existing fields; AutoSum over a selected row puts its total to the right; ribbon catalog count 276 / 292) · **Target:** Microsoft Excel (Microsoft 365), Excel for Mac 16.113.4
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-11-01 · **Change:** minor (Python cells: Python mode in the formula bar; earlier: Formulas › Function Library as labelled buttons with category menus; Recently Used and the Insert Function categories; Esc leaves a File-page text field before closing the view; earlier: checkbox cells print as boxes; Ctrl+arrow and Ctrl+Shift+arrow while pointing a formula reference; editing a hyperlink loads its existing fields; AutoSum over a selected row puts its total to the right; ribbon catalog count 276 / 292) · **Target:** Microsoft Excel (Microsoft 365), Excel for Mac 16.113.4
 
 Interaction, controls and feel, against Excel. Part of [target-app-parity.md](target-app-parity.md).
 **UI/UX fidelity: ~55% ready, 50–80 h** (estimated). Ribbon command coverage is measured
@@ -25,6 +25,7 @@ Sources: `crates/ui-egui/src` (ribbon, grid, editor, formula bar, dialogs, panes
 | Formula bar with Name Box, expand, function hints | yes | yes; grows with its content from one to five lines (Alt+Enter, wrapped text, or viewing a multi-line cell), then scrolls with the caret in view, the Name Box and buttons staying on the first line; the chevron pins it at five; the in-cell editor shows every line | done; no drag-to-resize handle |
 | Sheet tabs: rename, reorder, colour, hide, scroll | yes | yes | Ctrl-drag (Cmd or Option on macOS) drops a copy (#971); active tab revealed on navigation and resize (#681); manual wheel/trackpad browsing preserved; rename focus bug on macOS (#145) |
 | Formula bar with Name Box, expand, function hints | yes | yes | done; dynamic-array spill children show the source formula muted and read-only, using current spill ownership |
+| Python cells: Python mode | yes | yes (11-01): Ctrl+Alt+Shift+P (Cmd+Option+Shift+P on a Mac), `=PY` then Tab, or editing a Python cell edits the code in the formula bar's code editor, with a PY badge beside fx; Enter starts a new line with the indentation, Tab and Shift+Tab indent, Ctrl+Enter (Cmd+Enter) puts the code in the cell through `python.set`, Esc cancels. Deleting all the code and committing clears a Python cell, as an empty entry clears any other cell. The formula bar shows while a Python edit is open, also when View › Formula Bar hides it. On a protected sheet, a Python cell formatted Hidden shows no code in the formula bar and starts no edit, as a hidden formula shows none | this build stores Python code and doesn't run it: new or changed code shows `#BLOCKED!`; no `xl()` pointing on the sheet yet |
 | Formulas › Error Checking arrow: Circular References | yes | yes: the button opens Error Checking and its arrow opens a menu with Error Checking… and Circular References, which lists a cell on each circular reference as `Sheet!A1`, up to 100, and selects the one picked, on its own sheet (unavailable when there are none) | done; the Error Checking… item and the limit of 100 are GridCraft's own |
 | Sheet tabs: rename, reorder, colour, hide, scroll | yes | yes | active tab revealed on navigation and resize (#681); manual wheel/trackpad browsing preserved; rename focus bug on macOS (#145) |
 | Sheet tabs: rename, reorder, colour, hide, scroll | yes | yes | active tab revealed on navigation and resize (#681); New sheet (+) right after the last tab, the strip capped at 60% of the bar (#943); manual wheel/trackpad browsing preserved; next/previous skips Hidden and VeryHidden sheets and retains the current sheet and selection when no visible destination exists; rename focus bug on macOS (#145) |
@@ -136,6 +137,7 @@ otherwise. Number-format and border keys match the physical key (Ctrl+Shift+4, w
 | Shift+F3, Ctrl+F3, Ctrl+Shift+F3 | Shift+F3, Cmd+F3 (Define Name), Cmd+Shift+F3 | Insert Function, Name Manager, Create from Selection | **added** |
 | F5, Shift+F5 (Mac), F7, Shift+F9, Ctrl+Alt+F9, F12, Ctrl+F4 | same | Go To, Find, Spelling, calculate sheet / all, Save As, close | **added** |
 | Shift+F10, Alt+Shift+F10, Ctrl+F1 | Shift+F10, Cmd+Option+R | context menu, Error Checking, ribbon | **added** |
+| Ctrl+Alt+Shift+P | Cmd+Option+Shift+P | Python mode on or off | **added** |
 | F3 | not checked | Paste Name dialog, only when the workbook has names: OK puts the name at the caret of the formula being edited (or starts `=Name`), Paste List writes each name and what it refers to from the active cell (`formulas.pasteName`) | **added** |
 | F1, F4 (repeat), F6 / Shift+F6, F8 / Shift+F8, F11, End mode | same | help, Repeat, pane cycling, extend/add mode, chart sheet | missing (no such feature yet) |
 | Ctrl+Q, Ctrl+A after a function name, Ctrl+Shift+U, Ctrl+Alt+P | same | Quick Analysis, Function Arguments, formula bar height, tooltips | missing |
@@ -196,6 +198,7 @@ scrollbar bugs 2–4 · pixel/feel pass against observed Excel 7–12.
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-11-01 | minor | Python mode edits a cell's code in the formula bar's code editor (Ctrl+Alt+Shift+P, `=PY` then Tab, editing a Python cell), with the PY badge beside fx; its keys apply in input order, also several in one frame, and Ctrl+Enter commits through `python.set` (empty code clears the cell), keeping the code and showing the command's message when the code is refused |
 | 2026-10-31 | minor | Esc in a File-page text field leaves the field and cancels editing; the next Esc returns to the sheet (#3035) |
 | 2026-10-31 | minor | Recently Used lists the functions most recently entered in a formula from any source, kept with the preferences; the Insert Function dialog is titled as in Excel, its category list (Most Recently Used, All, each category) works, and its category column follows the widest name shown |
 | 2026-10-31 | minor | Formulas › Function Library: Insert Function, the AutoSum split button and three columns of labelled small buttons with category colours; category menus end with Insert Function…; More Functions cascades; Home › Editing shares the AutoSum menu; MR key tip for Recently Used |