superdoc-dev
diff --git a/‎packages/layout-engine/contracts/src/index.ts‎
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diff --git a/‎packages/layout-engine/contracts/src/resolved-layout.ts‎
Lines changed: 16 additions & 0 deletions b/‎packages/layout-engine/contracts/src/resolved-layout.ts‎
Lines changed: 16 additions & 0 deletions
diff --git a/‎packages/layout-engine/contracts/src/run-helpers.test.ts‎
Lines changed: 139 additions & 0 deletions b/‎packages/layout-engine/contracts/src/run-helpers.test.ts‎
Lines changed: 139 additions & 0 deletions
diff --git a/‎packages/layout-engine/contracts/src/run-helpers.ts‎
Lines changed: 109 additions & 0 deletions b/‎packages/layout-engine/contracts/src/run-helpers.ts‎
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diff --git a/‎packages/layout-engine/layout-bridge/src/index.ts‎
Lines changed: 2 additions & 1 deletion b/‎packages/layout-engine/layout-bridge/src/index.ts‎
Lines changed: 2 additions & 1 deletion
@@ -2065,4 +2065,8 @@ export type {
 } from './resolved-layout.js';
 export { isResolvedTableItem, isResolvedImageItem, isResolvedDrawingItem } from './resolved-layout.js';
 
+// Pure transformations on inline-run shapes (used by pm-adapter, layout-bridge,
+// and painter-dom). Located in contracts to avoid reverse stage dependencies.
+export { expandRunsForInlineNewlines, sliceRunsForLine } from './run-helpers.js';
+
 export * as Engines from './engines/index.js';
@@ -1,4 +1,6 @@
 import type {
+  ColumnLayout,
+  ColumnRegion,
   DrawingBlock,
   FlowMode,
   Fragment,
@@ -66,6 +68,10 @@ export type ResolvedPage = {
   };
   /** Page orientation. */
   orientation?: 'portrait' | 'landscape';
+  /** Column layout configuration for this page (reflects page-start config). */
+  columns?: ColumnLayout;
+  /** Vertical column regions when continuous section breaks change column layout mid-page. */
+  columnRegions?: ColumnRegion[];
 };
 
 /** Union of all resolved paint item kinds. */
@@ -111,6 +117,10 @@ export type ResolvedFragmentItem = {
   zIndex?: number;
   /** Source fragment kind — used by the painter for wrapper style decisions. */
   fragmentKind: Fragment['kind'];
+  /** Source fragment back-pointer. Lets the painter iterate resolved items
+   *  and pass the underlying fragment to render helpers without indexing
+   *  back into the legacy `page.fragments` array. */
+  fragment: Fragment;
   /** Block ID. Written to data-block-id. */
   blockId: string;
   /**
@@ -257,6 +267,8 @@ export type ResolvedTableItem = {
    * promote this to a permanent API surface.
    */
   fragmentIndex: number;
+  /** Source TableFragment back-pointer (see ResolvedFragmentItem.fragment). */
+  fragment: Fragment;
   /** ProseMirror start position for click-to-position mapping. */
   pmStart?: number;
   /** ProseMirror end position for click-to-position mapping. */
@@ -318,6 +330,8 @@ export type ResolvedImageItem = {
    * promote this to a permanent API surface.
    */
   fragmentIndex: number;
+  /** Source ImageFragment back-pointer (see ResolvedFragmentItem.fragment). */
+  fragment: Fragment;
   /** ProseMirror start position for click-to-position mapping. */
   pmStart?: number;
   /** ProseMirror end position for click-to-position mapping. */
@@ -371,6 +385,8 @@ export type ResolvedDrawingItem = {
    * promote this to a permanent API surface.
    */
   fragmentIndex: number;
+  /** Source DrawingFragment back-pointer (see ResolvedFragmentItem.fragment). */
+  fragment: Fragment;
   /** ProseMirror start position for click-to-position mapping. */
   pmStart?: number;
   /** ProseMirror end position for click-to-position mapping. */
 
@@ -0,0 +1,139 @@
+import { describe, it, expect } from 'vitest';
+import type { FlowBlock, Line, ParagraphBlock, Run, TabRun, TextRun, TrackedChangeMeta } from './index.js';
+import { expandRunsForInlineNewlines, sliceRunsForLine } from './run-helpers.js';
+
+describe('expandRunsForInlineNewlines', () => {
+  const makeRun = (text: string, pmStart = 0): TextRun => ({
+    text,
+    fontFamily: 'Arial',
+    fontSize: 12,
+    pmStart,
+    pmEnd: pmStart + text.length,
+  });
+
+  it('returns runs without inline newlines unchanged', () => {
+    const runs: Run[] = [makeRun('hello')];
+    expect(expandRunsForInlineNewlines(runs)).toEqual(runs);
+  });
+
+  it('splits a text run at a single inline newline', () => {
+    const result = expandRunsForInlineNewlines([makeRun('foo\nbar')]);
+    expect(result).toHaveLength(3);
+    expect(result[0]).toMatchObject({ text: 'foo', pmStart: 0, pmEnd: 3 });
+    expect(result[1]).toMatchObject({ kind: 'break', pmStart: 3, pmEnd: 4 });
+    expect(result[2]).toMatchObject({ text: 'bar', pmStart: 4, pmEnd: 7 });
+  });
+
+  it('keeps the break and advances the cursor for a leading newline', () => {
+    const result = expandRunsForInlineNewlines([makeRun('\nfoo')]);
+    expect(result).toHaveLength(2);
+    expect(result[0]).toMatchObject({ kind: 'break', pmStart: 0, pmEnd: 1 });
+    expect(result[1]).toMatchObject({ text: 'foo', pmStart: 1, pmEnd: 4 });
+  });
+
+  it('keeps both breaks when a run contains consecutive inline newlines', () => {
+    const result = expandRunsForInlineNewlines([makeRun('a\n\nb')]);
+    expect(result).toHaveLength(4);
+    expect(result[0]).toMatchObject({ text: 'a', pmStart: 0, pmEnd: 1 });
+    expect(result[1]).toMatchObject({ kind: 'break', pmStart: 1, pmEnd: 2 });
+    expect(result[2]).toMatchObject({ kind: 'break', pmStart: 2, pmEnd: 3 });
+    expect(result[3]).toMatchObject({ text: 'b', pmStart: 3, pmEnd: 4 });
+  });
+
+  it('does not emit an empty trailing text run for a trailing newline', () => {
+    const result = expandRunsForInlineNewlines([makeRun('foo\n')]);
+    expect(result).toHaveLength(2);
+    expect(result[0]).toMatchObject({ text: 'foo', pmStart: 0, pmEnd: 3 });
+    expect(result[1]).toMatchObject({ kind: 'break', pmStart: 3, pmEnd: 4 });
+  });
+
+  it('propagates trackedChange metadata onto emitted break runs', () => {
+    const trackedChange: TrackedChangeMeta = {
+      id: 'change-1',
+      kind: 'insert',
+      author: 'alice',
+      date: '2024-01-01T00:00:00Z',
+    };
+    const run: TextRun = { ...makeRun('foo\nbar'), trackedChange };
+    const result = expandRunsForInlineNewlines([run]);
+    expect(result[1]).toMatchObject({ kind: 'break', trackedChange });
+  });
+});
+
+describe('sliceRunsForLine', () => {
+  const makeTextRun = (text: string, pmStart = 0): TextRun => ({
+    text,
+    fontFamily: 'Arial',
+    fontSize: 12,
+    pmStart,
+    pmEnd: pmStart + text.length,
+  });
+
+  const makeParagraph = (runs: Run[]): ParagraphBlock => ({
+    kind: 'paragraph',
+    id: 'p-1',
+    runs,
+  });
+
+  const makeLine = (overrides: Partial<Line> = {}): Line => ({
+    fromRun: 0,
+    fromChar: 0,
+    toRun: 0,
+    toChar: 0,
+    width: 0,
+    ascent: 12,
+    descent: 4,
+    lineHeight: 16,
+    ...overrides,
+  });
+
+  it('returns an empty array for non-paragraph blocks', () => {
+    const block: FlowBlock = {
+      kind: 'image',
+      id: 'i-1',
+      attrs: { src: 'about:blank', alt: '' },
+    } as unknown as FlowBlock;
+    expect(sliceRunsForLine(block, makeLine())).toEqual([]);
+  });
+
+  it('passes tab runs through unchanged', () => {
+    const tab: TabRun = { kind: 'tab', text: '\t', pmStart: 0, pmEnd: 1 };
+    const block = makeParagraph([tab]);
+    const line = makeLine({ toRun: 0, fromChar: 0, toChar: 1 });
+    expect(sliceRunsForLine(block, line)).toEqual([tab]);
+  });
+
+  it('passes line-break runs through unchanged', () => {
+    const lineBreak: Run = { kind: 'lineBreak', pmStart: 0, pmEnd: 1 } as Run;
+    const block = makeParagraph([lineBreak]);
+    const line = makeLine({ toRun: 0, fromChar: 0, toChar: 1 });
+    expect(sliceRunsForLine(block, line)).toEqual([lineBreak]);
+  });
+
+  it('slices text on the first/last run and adjusts pmStart/pmEnd', () => {
+    const run = makeTextRun('hello world', 100);
+    const block = makeParagraph([run]);
+    const line = makeLine({ fromRun: 0, fromChar: 0, toRun: 0, toChar: 5 });
+    const result = sliceRunsForLine(block, line);
+    expect(result).toHaveLength(1);
+    expect(result[0]).toMatchObject({ text: 'hello', pmStart: 100, pmEnd: 105 });
+  });
+
+  it('passes middle text runs through unchanged when the line spans multiple runs', () => {
+    const first = makeTextRun('foo', 0);
+    const middle = makeTextRun('bar', 3);
+    const last = makeTextRun('baz', 6);
+    const block = makeParagraph([first, middle, last]);
+    const line = makeLine({ fromRun: 0, fromChar: 0, toRun: 2, toChar: 3 });
+    const result = sliceRunsForLine(block, line);
+    expect(result).toHaveLength(3);
+    expect(result[1]).toBe(middle);
+  });
+
+  it('drops empty slices when the requested range produces no characters', () => {
+    const run = makeTextRun('abc', 0);
+    const block = makeParagraph([run]);
+    const line = makeLine({ fromRun: 0, fromChar: 2, toRun: 0, toChar: 2 });
+    expect(sliceRunsForLine(block, line)).toEqual([]);
+  });
+});
@@ -0,0 +1,109 @@
+/**
+ * Pure transformations on inline-run shapes.
+ *
+ * These helpers operate on `Run[]` shapes defined in this contracts package.
+ * They have no upstream dependencies (no pm-adapter, no layout-bridge, no
+ * style-engine), so any stage can consume them without creating a reverse
+ * dependency back into a downstream package.
+ */
+
+import type { FlowBlock, Line, Run, TextRun } from './index.js';
+
+/**
+ * Expands text runs that contain inline newlines into multiple runs.
+ *
+ * @param {Run[]} runs - The runs to expand
+ * @returns {Run[]} The expanded runs
+ */
+export function expandRunsForInlineNewlines(runs: Run[]): Run[] {
+  const result: Run[] = [];
+  for (const run of runs) {
+    const textRun = run as TextRun;
+    if ('text' in run && typeof textRun.text === 'string' && textRun.text.includes('\n')) {
+      const segments = textRun.text.split('\n');
+      let cursor = textRun.pmStart ?? 0;
+      segments.forEach((segment, idx) => {
+        if (segment.length > 0) {
+          result.push({ ...textRun, text: segment, pmStart: cursor, pmEnd: cursor + segment.length });
+          cursor += segment.length;
+        }
+        if (idx !== segments.length - 1) {
+          result.push({
+            kind: 'break',
+            breakType: 'line',
+            pmStart: cursor,
+            pmEnd: cursor + 1,
+            sdt: textRun.sdt,
+            trackedChange: textRun.trackedChange,
+          });
+          cursor += 1;
+        }
+      });
+    } else {
+      result.push(run);
+    }
+  }
+  return result;
+}
+
+/**
+ * Extracts the subset of runs that appear in a specific line.
+ * Handles partial runs that span multiple lines.
+ *
+ * @param block - The paragraph block containing the runs
+ * @param line - The line to extract runs for
+ * @returns Array of runs present in the line
+ */
+export function sliceRunsForLine(block: FlowBlock, line: Line): Run[] {
+  const result: Run[] = [];
+  if (block.kind !== 'paragraph') return result;
+
+  for (let runIndex = line.fromRun; runIndex <= line.toRun; runIndex += 1) {
+    const run = block.runs[runIndex];
+    if (!run) continue;
+
+    if (run.kind === 'tab') {
+      result.push(run);
+      continue;
+    }
+
+    // Images, line breaks, breaks, field annotations, and math runs are atomic
+    // units. They occupy a single character of the run sequence and are passed
+    // through to the result without slicing.
+    if (
+      'src' in run ||
+      run.kind === 'lineBreak' ||
+      run.kind === 'break' ||
+      run.kind === 'fieldAnnotation' ||
+      run.kind === 'math'
+    ) {
+      result.push(run);
+      continue;
+    }
+
+    const text = run.text ?? '';
+    const isFirstRun = runIndex === line.fromRun;
+    const isLastRun = runIndex === line.toRun;
+
+    if (isFirstRun || isLastRun) {
+      const start = isFirstRun ? line.fromChar : 0;
+      const end = isLastRun ? line.toChar : text.length;
+      const slice = text.slice(start, end);
+      if (!slice) continue;
+      const pmStart =
+        run.pmStart != null ? run.pmStart + start : run.pmEnd != null ? run.pmEnd - (text.length - start) : undefined;
+      const pmEnd =
+        run.pmStart != null ? run.pmStart + end : run.pmEnd != null ? run.pmEnd - (text.length - end) : undefined;
+      result.push({
+        ...run,
+        text: slice,
+        pmStart,
+        pmEnd,
+      });
+    } else {
+      result.push(run);
+    }
+  }
+
+  return result;
+}
@@ -74,7 +74,8 @@ export type { HeaderFooterLayoutResult, IncrementalLayoutResult } from './increm
 export { computeDisplayPageNumber } from '@superdoc/layout-engine';
 export type { DisplayPageInfo, HeaderFooterConstraints } from '@superdoc/layout-engine';
 export { remeasureParagraph } from './remeasure';
-export { measureCharacterX, sliceRunsForLine } from './text-measurement';
+export { measureCharacterX } from './text-measurement';
+export { sliceRunsForLine } from '@superdoc/contracts';
 export { clickToPositionDom, findPageElement } from './dom-mapping';
 export { isListItem, getWordLayoutConfig, calculateTextStartIndent, extractParagraphIndent } from './list-indent-utils';
 export type { TextIndentCalculationParams } from './list-indent-utils';