function isLabelVisible()

in packages/ketcher-core/src/application/render/restruct/reatom.ts [766:816]

• 43 lines of code
• 24 McCabe index (conditional complexity)

function isLabelVisible(restruct, options, atom: ReAtom) {
  const isAttachmentPointAtom = Boolean(atom.a.attachmentPoints);
  const isCarbon = atom.a.label.toLowerCase() === 'c';
  const visibleTerminal =
    options.showHydrogenLabels !== ShowHydrogenLabels.Off &&
    options.showHydrogenLabels !== ShowHydrogenLabels.Hetero;

  const neighborsLength =
    atom.a.neighbors.length === 0 ||
    (atom.a.neighbors.length < 2 && visibleTerminal);

  if (isAttachmentPointAtom && isCarbon) {
    return false;
  }

  const shouldBeVisible =
    neighborsLength ||
    options.carbonExplicitly ||
    options.showHydrogenLabels === ShowHydrogenLabels.On ||
    atom.a.alias ||
    atom.a.isotope !== null ||
    atom.a.radical !== 0 ||
    atom.a.charge !== null ||
    atom.a.explicitValence >= 0 ||
    atom.a.atomList !== null ||
    atom.a.rglabel !== null ||
    (atom.a.badConn && options.showValenceWarnings) ||
    atom.a.label.toLowerCase() !== 'c';

  if (shouldBeVisible) return true;

  if (atom.a.neighbors.length === 2) {
    const nei1 = atom.a.neighbors[0];
    const nei2 = atom.a.neighbors[1];
    const hb1 = restruct.molecule.halfBonds.get(nei1);
    const hb2 = restruct.molecule.halfBonds.get(nei2);
    const bond1 = restruct.bonds.get(hb1.bid);
    const bond2 = restruct.bonds.get(hb2.bid);

    const sameNotStereo =
      bond1.b.type === bond2.b.type &&
      bond1.b.stereo === Bond.PATTERN.STEREO.NONE &&
      bond2.b.stereo === Bond.PATTERN.STEREO.NONE;

    if (sameNotStereo && Math.abs(Vec2.cross(hb1.dir, hb2.dir)) < 0.2) {
      return true;
    }
  }

  return false;
}