pptx-gslides-manager/src/utils/recalcParagraphAndRunIndices.js

Node.js library for uploading PPTX files to Google Slides, extracting slide shapes and tables, and managing slide decks.

/**
 * recalcParagraphAndRunIndices
 * 
 * Given a shapeData or cellData with `paragraphs: [...]`,
 * we recalculate all paragraphs’ start/end, and each run’s start/end,
 * based on the updated text. For each paragraph, runs are laid out
 * consecutively, possibly ending with a newline if you want to
 * preserve paragraph boundaries.
 *
 * @param {Object} shapeOrCellData - Object that has a `paragraphs` array
 */
function recalcParagraphAndRunIndices(shapeOrCellData) {
  if (!Array.isArray(shapeOrCellData.paragraphs)) return;

  let runningIndex = 0;
  for (const paragraph of shapeOrCellData.paragraphs) {
    paragraph.startIndex = runningIndex;

    for (const run of paragraph.runs) {
      // Set run’s startIndex
      run.startIndex = runningIndex;
      // endIndex = startIndex + length of the run's text
      run.endIndex = run.startIndex + (run.text?.length || 0);
      runningIndex = run.endIndex;
    }

    paragraph.endIndex = runningIndex;
    // Optionally, if you want each paragraph to always end in a `\n`
    // you might do something like:
    // runningIndex += 1; // account for a newline
    // paragraph.endIndex = runningIndex;
  }
}

module.exports = recalcParagraphAndRunIndices;