gridcraft/docs/chart-parity.md

Chart parity

Last reviewed: 2026-10-18 · Last updated: 2026-10-29 · Change: minor (selected chart source outlines stay beneath floating objects) · Target: Microsoft Excel (Microsoft 365), Excel for Mac 16.113.4

Excel's chart types and chart elements against GridCraft. Part of target-app-parity.md. Breadth ~50%, ready ~30%, 40–60 h (estimated).

Sources: crates/model/src/features.rs (ChartKind, Chart, Series), crates/chart/src (layout and rendering), crates/xlsx/src/chart.rs (DrawingML chart parts), merged PRs #62, #116, #158 and #161, and issue #190.

Chart types

Excel type	Excel subtypes	GridCraft	Notes
Column	clustered, stacked, 100% stacked, 3-D clustered/stacked/100%, 3-D column	3 of 7	no 3-D
Bar	clustered, stacked, 100%, 3-D ×3	3 of 6	no 3-D
Line	line, stacked, 100% stacked, with markers ×3, 3-D line	3 of 7 (line, with markers, stacked)	no 100% stacked; smoothed lines landed (#62)
Pie	pie, 3-D pie, pie of pie, bar of pie, doughnut	2 of 5 (pie, doughnut)	no exploded, pie of pie, bar of pie
Area	area, stacked, 100%, 3-D ×3	3 of 6	no 3-D; 100% stacked drawn as shares of each category's total and kept as percentStacked in XLSX
X Y (scatter)	markers, smooth lines (±markers), straight lines (±markers)	2 of 5	no smooth lines
Bubble	bubble, 3-D bubble	1 of 2
Stock	high-low-close, open-high-low-close, volume-HLC, volume-OHLC	1 kind
Surface	3-D surface, wireframe, contour, wireframe contour	0 of 4
Radar	radar, with markers, filled	1 of 3
Treemap, Sunburst	1 each	2 of 2
Histogram, Pareto	2	1 of 2	no Pareto
Box & Whisker	1	1 of 1	exclusive (default) and inclusive quartiles per series; XLSX round-trip; chart.set {quartiles} changes all series
Waterfall, Funnel	2	2 of 2	lose their kind in XLSX (PR #161)
Box & Whisker	1	1 of 1
Waterfall, Funnel	2	2 of 2
Filled map	1	0	needs geographic boundary data (licensing decision)
Combo	custom combinations, secondary axis	yes (line on secondary axis)
Total	~60 subtypes	26 (~43%)	usage-weighted breadth higher (~65%): column, bar, line, pie and scatter dominate

Chart elements and formatting

Element	Excel	GridCraft
Move and resize the chart object	yes	yes (corner handle, Format Chart Area Size fields)
Selected chart source-data outline	visible on uncovered cells, beneath floating objects	painted above cells and below charts, shapes, pictures and slicers; retains pane clipping and right-to-left cell geometry (#2861)
Chart title, axis titles	text, linked to cells, full formatting	text only
Legend	position, overlay, formatting, per-entry delete	position only
Data labels	value, category, series, percentage, from cells, callouts, position	one on/off flag
Gridlines	major/minor per axis, formatting	one on/off flag
Axis options	min/max/units, log scale, reverse order, crossing point, display units, date axis, number format	missing (auto only)
Multi-level category axis (a category range two or more columns wide beside the values: year beside month)	the outer levels grouped under the labels with separators	read (multiLvlStrRef), drawn (rows under the labels; columns beside them in bar charts; up to three outer levels), written back with Excel's level caches
Secondary axis	any series	line series in combo charts
Trendlines	linear, exponential, logarithmic, polynomial, power, moving average, equation and R²	all six types, several per series, name, forward/backward forecast, set intercept, equation and R² label, line colour/width/dash; read, written and drawn on 2-D column, bar, line, area, scatter and bubble series; chart.addElement trendline adds/removes them. No Format Trendline pane, label position/number format not kept
Error bars	fixed, %, standard deviation/error, custom	missing
Up/down bars, high-low lines, drop lines, series lines	yes	missing
Data table under the chart	yes	missing
Per-series / per-point fill, line, marker, effects	Format pane for every element	series colour only; Format Chart pane covers chart-level options
Chart styles and colour palettes	~16 styles × colour sets	style number stored, own palettes
Chart sheets	yes	kept, not editable: not shown, and written back unchanged in their place on save (#727); left out when a sheet they plot is deleted or renamed. No F11 / Move Chart > New sheet
Chart templates (.crtx)	yes	missing
Recommended Charts	yes	dialog with recommendations from the data's shape (own heuristic) and an All Charts list, live previews (#215)
Switch Row/Column, Select Data	yes	yes (Switch on charts read from files landed in #116)
Recommended Charts	yes	partial (Insert ▸ Recommended)
Switch Row/Column, Select Data	yes	yes (Switch on charts read from files landed in #116); Select Data dialog: data range, remove series, Horizontal (Category) Axis Labels (#287). No series add/edit or hidden/empty cell options
Sparklines (line, column, win/loss, markers, axis)	yes	line, column, win/loss
PivotCharts	yes	Insert ▸ PivotChart (insert.pivotChart): bound to a PivotTable's report, rebuilt on refresh and layout changes, c:pivotSource round trip; no field buttons, innermost category level only
Animation on data change	yes (Windows)	no

XLSX round-trip

Charts are read from and written to DrawingML chart parts, but only the fields the model holds survive: anything else (axis scaling, label options, error bars, per-point formats, chartex extensions) is lost when GridCraft saves a workbook it opened. That is the main reason charts are ~30% ready: a user who opens an Excel workbook with charts and saves it gets simpler charts back.

Series data, categories and names may refer to defined names, as dynamic (OFFSET) ranges do: Excel writes a workbook-scoped name as [0]!Name in <c:f>. GridCraft reads it as the bare name and writes it back with [0]!; a sheet-scoped name is written Sheet!Name. Excel needs the qualifier: with a bare name in <c:f> it draws the whole chart blank, without a repair prompt (observed in Excel for Windows, Microsoft 365). External books ([1]Sheet1!…) are kept as they are (#1686). Such series get no numCache/strCache on save (#1690).

Work (40–60 h)

1. Chart resizing (#190): 1–2 h.
2. Preserve unmodelled chart XML on round-trip (keep the original part, patch only edited fields): 6–10 h.
3. Axis options, label options, gridlines per axis, legend formatting: 10–15 h.
4. Error bars; Format Trendline pane (trendlines landed): 4–6 h.
5. Per-element Format pane parity, smoothed lines, exploded pie, pie/bar of pie, 100% variants: 8–12 h.
6. 3-D column/bar/pie/area, surface and contour, Pareto: 8–12 h.
7. Chart sheets, templates and PivotChart field buttons: 5–8 h. Filled map: owner decision on boundary data.

Revision history

Date	Change	Summary
2026-10-29	minor	Selected charts highlight their source cells beneath floating objects, so the blue outline no longer crosses the chart; uncovered source cells remain highlighted (#2861)
2026-10-24	minor	100% Stacked Area: inserted from the ribbon and All Charts, drawn as shares of each category's total, read and written as percentStacked
2026-10-18	trivial	Stale notes: stock/combo, treemap/sunburst, box and waterfall kinds survive XLSX round-trip (PRs #158, #161)
2026-10-16	trivial	Series that refer to defined names ([0]!Name, Sheet!Name) resolve instead of showing #NAME?, and are saved qualified, as Excel needs (#1686)
2026-10-16	minor	Box & whisker quartiles default to exclusive, honor each series on draw and XLSX round-trip; chart.set {quartiles} changes the method (#1453)
2026-10-13	minor	Multi-level category axes: read, drawn (outer levels under or beside the labels), written back with level caches
2026-10-12	trivial	chart sheets are kept on save, still not editable (#727)
2026-10-11	minor	Trendlines: all six types modelled, round-tripped through c:trendline, drawn with forecast and equation/R² labels; chart.addElement trendline
2026-10-11	minor	PivotCharts (insert.pivotChart)
2026-10-11	minor	Recommended Charts dialog with previews (#215)
2026-10-11	minor	Select Data dialog with category axis labels; a blank top-left cell makes the first column the categories (#287)
2026-10-10	minor	Smooth lines (#62) and Switch Row/Column on file charts (#116) landed; chart resize bug (#190)
2026-10-10	major	Created from a source audit: 25 kinds (25 of ~60 subtypes), element gaps, round-trip loss