feat(sheet): extract form control checkboxes

[tomsideguide]

Form control checkboxes are drawing objects floating over the grid, so every spreadsheet reader dropped them (#115).

Each checkbox now lands in the cell its anchor starts in, as [x] / [ ] plus its caption: xlsx/xlsm/xlsb read the worksheet's VML drawing, xls reads MSODRAWING + OBJ + TXO, ods reads office:forms controls anchored in a cell. Hidden controls, and controls in hidden rows or columns, are omitted like any hidden content.

Stacked on #122. Watch: the mixed state and ODS controls anchored to the page (coordinates only) are not placed; the new Excel 365 cell checkboxes still come out as TRUE/FALSE.

---

Summary by cubic

Extracts form control checkboxes and renders them inline in their anchor cell. Previously these shapes were dropped; now cells show “[x]” or “[ ]” plus the caption so user-visible data survives.

• Behavior and coverage

  • Appends checkboxes after existing cell text; supports multiple per cell. Hidden controls and mixed state are omitted. Controls in hidden rows/columns do not render. ODS controls anchored to the page are not placed. Excel 365 native cell checkboxes still render as TRUE/FALSE.
  • OOXML (.xlsx/.xlsm/.xlsb): reads legacy VML checkboxes via worksheet .rels to vmlDrawing*.vml; ignores non-checkbox shapes and visibility:hidden.
  • BIFF8 .xls: takes anchor from MSODRAWING client anchors, checked state from OBJ (mixed ignored), caption from TXO.
  • ODS: expands office:forms form:checkbox referenced by draw:control in a cell; uses form:label and form:(current-)state.

• Notes (review and API)

  • New sheet::controls; checkboxes flow through SheetContent.checkboxes and are merged in build_table.
  • Adds XML namespaces FORM and X_VML.
  • Renderers must handle Inline::Checkbox(checked) tokens.

^{Written for commit 6066677. Summary will update on new commits.}

[tomsideguide]

@cubic-dev-ai review

[cubic-dev-ai]

2 issues found and verified against the latest diff

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="src/formats/sheet/xlsx.rs">

<violation number="1" location="src/formats/sheet/xlsx.rs:411">
P2: When a checkbox is anchored at the hidden origin of a merged range, the merge relocation moves it into the first visible row or column. Filter controls anchored in hidden coordinates before merging so hidden controls remain omitted.</violation>
</file>

<file name="src/formats/odf/table.rs">

<violation number="1" location="src/formats/odf/table.rs:28">
P1: Standard ODS places `office:forms` under `office:spreadsheet`, alongside `table:table`. Because `parse_table` receives only the table, `read_checkboxes(elem)` misses those forms and drops every anchored control. Collect forms at spreadsheet scope and pass them into each table parser.</violation>
</file>

<sub>Reply with feedback, questions, or to request a fix.

Fix all with cubic | Re-trigger cubic</sub>

[cubic-dev-ai]

P1: Standard ODS places office:forms under office:spreadsheet, alongside table:table. Because parse_table receives only the table, read_checkboxes(elem) misses those forms and drops every anchored control. Collect forms at spreadsheet scope and pass them into each table parser.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At src/formats/odf/table.rs, line 28:

<comment>Standard ODS places `office:forms` under `office:spreadsheet`, alongside `table:table`. Because `parse_table` receives only the table, `read_checkboxes(elem)` misses those forms and drops every anchored control. Collect forms at spreadsheet scope and pass them into each table parser.</comment>

<file context>
@@ -23,6 +25,7 @@ pub fn parse_table(elem: &Element, ctx: &Ctx) -> Result<Vec<Block>, ConvertError
         pending_rows: 0,
         header_rows: 0,
         rows_emitted: 0,
+        checkboxes: read_checkboxes(elem),
     };
     walk_rows(elem, ctx, &mut state, true)?;
</file context>

[cubic-dev-ai]

P2: When a checkbox is anchored at the hidden origin of a merged range, the merge relocation moves it into the first visible row or column. Filter controls anchored in hidden coordinates before merging so hidden controls remain omitted.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At src/formats/sheet/xlsx.rs, line 411:

<comment>When a checkbox is anchored at the hidden origin of a merged range, the merge relocation moves it into the first visible row or column. Filter controls anchored in hidden coordinates before merging so hidden controls remain omitted.</comment>

<file context>
@@ -400,10 +404,20 @@ pub(super) fn build_table(
+    // the assembly no longer cares which was which.
+    let mut cells: HashMap<(u32, u32), Vec<Inline>> = HashMap::new();
+    for (at, boxes) in sheet.checkboxes.drain() {
+        if at.0 < MAX_ROWS && at.1 < MAX_COLS {
+            cells.insert(at, cell_inlines(sheet.cells.remove(&at), &boxes));
+        }
</file context>

Suggested change

	if at.0 < MAX_ROWS && at.1 < MAX_COLS {
	if at.0 < MAX_ROWS && at.1 < MAX_COLS && !hidden_row(at.0) && !hidden_col(at.1) {

[cubic-dev-ai]

@cubic-dev-ai review

@tomsideguide I have started the AI code review. It will take a few minutes to complete.

[tomsideguide]

@cubic-dev-ai review

[cubic-dev-ai]

@cubic-dev-ai review

@tomsideguide I have started the AI code review. It will take a few minutes to complete.

[cubic-dev-ai]

All reported issues were addressed across 8 files

<sub>Reply with feedback, questions, or to request a fix.

Fix all with cubic | Re-trigger cubic</sub>

[tomsideguide]

@cubic-dev-ai review

[cubic-dev-ai]

@cubic-dev-ai review

@tomsideguide I have started the AI code review. It will take a few minutes to complete.

[cubic-dev-ai]

No issues found across 8 files

_{Re-trigger cubic}