Function autoLayout

scripts/grid.cjs:156–236

(spec)

}

function autoLayout(spec) {
  const style = spec.style || 'single';
  const dir = spec.direction || 'horizontal';
  const padding = 2;
  const arrowLen = spec.arrowLength || 6;

  // Calculate box dimensions
  const boxes = spec.boxes.map(b => {
    const lines = b.label.split('\n');
    const maxLineLen = Math.max(...lines.map(l => l.length));
    const w = Math.max(maxLineLen + 4, 8); // min width 8
    const h = lines.length + 2;
    return { ...b, w, h, lines };
  });

  // Auto-position if no explicit coordinates
  const needsLayout = boxes.some(b => b.x === undefined || b.y === undefined);

  // Check if any arrows have labels (need extra row for label above arrow)
  const hasArrowLabels = spec.arrows && spec.arrows.some(a => a.label);

  if (needsLayout) {
    if (dir === 'horizontal') {
      let curX = 0;
      const maxH = Math.max(...boxes.map(b => b.h));
      const yOffset = hasArrowLabels ? 1 : 0; // extra row for arrow labels
      boxes.forEach(b => {
        b.x = curX;
        b.y = yOffset + Math.floor((maxH - b.h) / 2); // vertically center
        curX += b.w + arrowLen;
      });
    } else {
      let curY = 0;
      const maxW = Math.max(...boxes.map(b => b.w));
      boxes.forEach(b => {
        b.x = Math.floor((maxW - b.w) / 2); // horizontally center
        b.y = curY;
        curY += b.h + 3; // gap for arrow + label
      });
    }
  }

  // Calculate grid size
  const totalW = Math.max(...boxes.map(b => b.x + b.w)) + padding;
  const totalH = Math.max(...boxes.map(b => b.y + b.h)) + padding;
  const grid = new Grid(totalW, totalH);

  // Index boxes by ID
  const boxMap = new Map();
  boxes.forEach(b => {
    const rect = grid.box(b.x, b.y, b.w, b.h, b.label, style);
    boxMap.set(b.id, { ...rect, ...b });
  });

  // Draw arrows
  if (spec.arrows) {
    spec.arrows.forEach(a => {
      const from = boxMap.get(a.from);