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/** |
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* Pure, WP-free structural model for the native table's span-aware |
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* operations. The block tree is reduced to anchors-only rows; every plan |
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* function returns instructions for the dispatcher in table-ops.ts. |
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* |
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* Positions: row = row-block index, col = visual grid column. A cell with |
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* rowSpan/colSpan occupies a rectangle anchored at its position; covered |
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* positions hold no cell. |
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*/ |
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|
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export interface GridCell { |
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id: string; |
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rowSpan: number; |
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colSpan: number; |
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} |
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|
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export type GridRow = GridCell[]; |
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|
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export interface CellPosition { |
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row: number; |
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col: number; |
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} |
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|
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export interface Occupancy { |
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/** occupancy[row][col] = id of the cell covering that position. */ |
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matrix: string[][]; |
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/** Anchor position for each cell id. */ |
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anchors: Map<string, CellPosition>; |
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cols: number; |
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} |
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|
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export function buildOccupancy(rows: GridRow[]): Occupancy { |
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const matrix: string[][] = rows.map(() => []); |
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const anchors = new Map<string, CellPosition>(); |
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let cols = 0; |
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|
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rows.forEach((row, r) => { |
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let c = 0; |
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for (const cell of row) { |
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while (matrix[r][c] !== undefined) { |
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c++; |
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} |
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|
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anchors.set(cell.id, { row: r, col: c }); |
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|
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for (let dr = 0; dr < cell.rowSpan; dr++) { |
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for (let dc = 0; dc < cell.colSpan; dc++) { |
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if (matrix[r + dr]) { |
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matrix[r + dr][c + dc] = cell.id; |
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} |
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} |
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} |
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|
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c += cell.colSpan; |
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if (c > cols) { |
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cols = c; |
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} |
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} |
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|
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// Trailing covered positions widen the grid too. |
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while (matrix[r][c] !== undefined) { |
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c++; |
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if (c > cols) { |
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cols = c; |
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} |
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} |
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}); |
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|
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return { matrix, anchors, cols }; |
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} |
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|
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export interface InsertRowPlan { |
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/** Cells whose rowSpan grows by one (they cross the insertion line). */ |
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growSpans: string[]; |
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/** Number of fresh cells the new row block needs. */ |
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newCellCount: number; |
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} |
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|
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/** |
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* Plan inserting a row so the new row sits at `index` (0..rows.length). |
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* A span crosses the line when its anchor row < index and it extends to |
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* index or beyond. |
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*/ |
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export function planInsertRow(rows: GridRow[], index: number): InsertRowPlan { |
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const { anchors, cols } = buildOccupancy(rows); |
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|
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const growSpans: string[] = []; |
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let coveredCols = 0; |
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|
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for (const row of rows) { |
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for (const cell of row) { |
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const pos = anchors.get(cell.id)!; |
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if (pos.row < index && pos.row + cell.rowSpan > index) { |
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growSpans.push(cell.id); |
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coveredCols += cell.colSpan; |
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} |
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} |
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} |
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|
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return { growSpans, newCellCount: Math.max(0, cols - coveredCols) }; |
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} |
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|
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export interface DeleteRowPlan { |
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/** Cells whose rowSpan shrinks by one (they cross the deleted row). */ |
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shrinkSpans: string[]; |
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/** |
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* Cells anchored IN the deleted row that span further down: they must be |
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* re-anchored into the next row. `insertIndex` is the cell-array index in |
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* the next row block where the replacement belongs. |
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*/ |
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reanchor: Array<{ |
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id: string; |
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insertIndex: number; |
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rowSpan: number; |
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colSpan: number; |
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}>; |
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} |
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|
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export function planDeleteRow(rows: GridRow[], index: number): DeleteRowPlan { |
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const { matrix, anchors } = buildOccupancy(rows); |
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|
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const shrinkSpans: string[] = []; |
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const reanchor: DeleteRowPlan["reanchor"] = []; |
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|
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for (const row of rows) { |
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for (const cell of row) { |
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const pos = anchors.get(cell.id)!; |
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const crosses = |
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pos.row < index && pos.row + cell.rowSpan > index; |
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if (crosses) { |
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shrinkSpans.push(cell.id); |
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} |
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} |
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} |
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|
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const nextRow = rows[index + 1]; |
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if (nextRow) { |
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for (const cell of rows[index]) { |
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const pos = anchors.get(cell.id)!; |
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if (cell.rowSpan <= 1) { |
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continue; |
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} |
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|
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// Where in the next row's cell array does this column fall? |
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// Count next-row anchors whose column is left of ours. |
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let insertIndex = 0; |
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for (const nextCell of nextRow) { |
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const nextPos = anchors.get(nextCell.id)!; |
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if (nextPos.col < pos.col) { |
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insertIndex++; |
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} |
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} |
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|
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reanchor.push({ |
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id: cell.id, |
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insertIndex, |
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rowSpan: cell.rowSpan - 1, |
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colSpan: cell.colSpan, |
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}); |
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} |
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} |
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|
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return { shrinkSpans, reanchor }; |
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} |
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|
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export type ColumnRowAction = |
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| { type: "insert"; rowIndex: number; insertIndex: number } |
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| { type: "grow"; rowIndex: number; id: string } |
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| { type: "skip"; rowIndex: number }; |
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|
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/** |
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* Plan inserting a column so the new column sits at grid column `index` |
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* (0..cols). Per row: insert a fresh cell before the anchor at/after the |
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* position, or grow a span that crosses the line, or skip rows covered by a |
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* multi-row span already grown at its anchor row. |
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*/ |
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export function planInsertColumn( |
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rows: GridRow[], |
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index: number |
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): ColumnRowAction[] { |
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const { matrix, anchors, cols } = buildOccupancy(rows); |
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const actions: ColumnRowAction[] = []; |
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const grown = new Set<string>(); |
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|
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rows.forEach((row, r) => { |
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// Inserting at the far edges never splits a span. |
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if (index < cols) { |
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const coveringId = matrix[r][index]; |
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if (coveringId !== undefined) { |
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const pos = anchors.get(coveringId)!; |
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// The line between index-1 and index runs through this cell |
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// when its anchor starts left of index. |
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if (pos.col < index) { |
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if (pos.row === r) { |
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actions.push({ type: "grow", rowIndex: r, id: coveringId }); |
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grown.add(coveringId); |
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} else { |
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// Covered by a span anchored in an earlier row. |
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actions.push({ type: "skip", rowIndex: r }); |
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} |
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return; |
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} |
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} |
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} |
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|
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// Fresh cell: its array position = number of anchors in this row |
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// whose column is left of the target column. |
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let insertIndex = 0; |
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for (const cell of row) { |
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const pos = anchors.get(cell.id)!; |
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if (pos.col < index) { |
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insertIndex++; |
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} |
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} |
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|
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actions.push({ type: "insert", rowIndex: r, insertIndex }); |
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}); |
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|
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return actions; |
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} |
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|
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export type DeleteColumnRowAction = |
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| { type: "remove"; rowIndex: number; id: string } |
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| { type: "shrink"; rowIndex: number; id: string } |
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| { type: "skip"; rowIndex: number }; |
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|
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/** Plan deleting grid column `index`. */ |
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export function planDeleteColumn( |
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rows: GridRow[], |
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index: number |
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): DeleteColumnRowAction[] { |
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const { matrix, anchors } = buildOccupancy(rows); |
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const actions: DeleteColumnRowAction[] = []; |
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const handled = new Set<string>(); |
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|
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rows.forEach((row, r) => { |
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const id = matrix[r][index]; |
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if (id === undefined) { |
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actions.push({ type: "skip", rowIndex: r }); |
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return; |
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} |
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|
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const pos = anchors.get(id)!; |
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if (pos.row !== r) { |
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// Covered by a span anchored above; handled at its anchor row. |
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actions.push({ type: "skip", rowIndex: r }); |
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return; |
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} |
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|
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if (handled.has(id)) { |
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actions.push({ type: "skip", rowIndex: r }); |
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return; |
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} |
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handled.add(id); |
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|
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const cell = findCell(rows, id)!; |
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if (cell.colSpan > 1) { |
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actions.push({ type: "shrink", rowIndex: r, id }); |
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} else { |
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actions.push({ type: "remove", rowIndex: r, id }); |
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} |
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}); |
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|
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return actions; |
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} |
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|
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export interface MergePlan { |
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anchorId: string; |
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rowSpan: number; |
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colSpan: number; |
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absorbedIds: string[]; |
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} |
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|
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/** |
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* Plan merging the given cells. Valid only when the cells' combined |
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* rectangles exactly tile a rectangle. Returns null when invalid. |
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*/ |
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export function planMerge(rows: GridRow[], ids: string[]): MergePlan | null { |
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if (ids.length < 2) { |
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return null; |
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} |
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|
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const { anchors } = buildOccupancy(rows); |
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|
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let minRow = Infinity; |
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let minCol = Infinity; |
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let maxRow = -1; |
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let maxCol = -1; |
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let area = 0; |
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|
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for (const id of ids) { |
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const pos = anchors.get(id); |
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const cell = findCell(rows, id); |
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if (!pos || !cell) { |
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return null; |
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} |
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|
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minRow = Math.min(minRow, pos.row); |
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minCol = Math.min(minCol, pos.col); |
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maxRow = Math.max(maxRow, pos.row + cell.rowSpan - 1); |
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maxCol = Math.max(maxCol, pos.col + cell.colSpan - 1); |
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area += cell.rowSpan * cell.colSpan; |
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} |
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|
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const rectArea = (maxRow - minRow + 1) * (maxCol - minCol + 1); |
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if (area !== rectArea) { |
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return null; |
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} |
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|
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// The anchor is the top-left cell; it must sit exactly at the rect corner. |
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let anchorId: string | null = null; |
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for (const id of ids) { |
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const pos = anchors.get(id)!; |
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if (pos.row === minRow && pos.col === minCol) { |
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anchorId = id; |
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break; |
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} |
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} |
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if (!anchorId) { |
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return null; |
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} |
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|
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return { |
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anchorId, |
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rowSpan: maxRow - minRow + 1, |
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colSpan: maxCol - minCol + 1, |
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absorbedIds: ids.filter(id => id !== anchorId), |
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}; |
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} |
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|
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export interface SplitPlan { |
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/** Fresh 1x1 cells to insert: per row, the cell-array insertion index. */ |
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inserts: Array<{ rowIndex: number; insertIndex: number; count: number }>; |
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} |
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|
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/** Plan splitting a merged cell back into 1x1 cells. */ |
| 337 |
export function planSplit(rows: GridRow[], id: string): SplitPlan | null { |
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const { anchors } = buildOccupancy(rows); |
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const pos = anchors.get(id); |
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const cell = findCell(rows, id); |
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if (!pos || !cell || (cell.rowSpan === 1 && cell.colSpan === 1)) { |
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return null; |
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} |
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|
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const inserts: SplitPlan["inserts"] = []; |
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|
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for (let dr = 0; dr < cell.rowSpan; dr++) { |
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const r = pos.row + dr; |
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const row = rows[r]; |
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if (!row) { |
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continue; |
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} |
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|
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// In the anchor's own row the anchor keeps the first position, so |
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// colSpan-1 fresh cells go right after it. In covered rows all |
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// colSpan positions need fresh cells. |
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const count = dr === 0 ? cell.colSpan - 1 : cell.colSpan; |
| 358 |
if (count === 0) { |
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continue; |
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} |
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|
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let insertIndex = 0; |
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for (const rowCell of row) { |
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const rowPos = anchors.get(rowCell.id)!; |
| 365 |
if ( |
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rowPos.col < pos.col || |
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(dr === 0 && rowCell.id === id) |
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) { |
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insertIndex++; |
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} |
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} |
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|
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inserts.push({ rowIndex: r, insertIndex, count }); |
| 374 |
} |
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|
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return { inserts }; |
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} |
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|
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export function findCell(rows: GridRow[], id: string): GridCell | null { |
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for (const row of rows) { |
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for (const cell of row) { |
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if (cell.id === id) { |
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return cell; |
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} |
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} |
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} |
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return null; |
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} |
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|
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/** Grid column of a cell (for toolbar labels / column ops entry points). */ |
| 391 |
export function cellColumn(rows: GridRow[], id: string): number | null { |
| 392 |
const { anchors } = buildOccupancy(rows); |
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return anchors.get(id)?.col ?? null; |
| 394 |
} |
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|
