Function computePanelSizes

packages/core/src/widgets/splitPane.ts:93–129

(
  percentages: readonly number[],
  available: number,
  dividerSize: number = DEFAULT_DIVIDER_SIZE,
  minSizes?: readonly number[],
  maxSizes?: readonly number[],
)

 * @returns Computed panel sizes and divider positions
 */
export function computePanelSizes(
  percentages: readonly number[],
  available: number,
  dividerSize: number = DEFAULT_DIVIDER_SIZE,
  minSizes?: readonly number[],
  maxSizes?: readonly number[],
): PanelSizes {
  const panelCount = percentages.length;
  if (panelCount === 0) {
    return Object.freeze({ sizes: Object.freeze([]), dividerPositions: Object.freeze([]) });
  }

  const totalDividerSpace = Math.max(0, panelCount - 1) * dividerSize;
  const availableForPanels = Math.max(0, available - totalDividerSpace);

  // First pass: compute ideal sizes with deterministic integer remainder handling.
  const weights = percentages.map((p) =>
    Number.isFinite(p) && (p as number) > 0 ? (p as number) : 0,
  );
  const sizes = distributeInteger(availableForPanels, weights);

  normalizePanelCellSizes(sizes, availableForPanels, minSizes, maxSizes);

  // Compute divider positions
  const dividerPositions: number[] = [];
  let position = 0;
  for (let j = 0; j < sizes.length - 1; j++) {
    position += sizes[j] ?? 0;
    dividerPositions.push(position);
    position += dividerSize;
  }

  return Object.freeze({
    sizes: Object.freeze(sizes),
    dividerPositions: Object.freeze(dividerPositions),
  });
}

/**
 * Compute panel sizes in cells for both percent and absolute sizing modes.