Function measureCharPrepared

docs/themes/htx/source/js/codemirror.js:3330–3357

(cm, prepared, ch, bias, varHeight)

  // Given a prepared measurement object, measures the position of an
  // actual character (or fetches it from the cache).
  function measureCharPrepared(cm, prepared, ch, bias, varHeight) {
    if (prepared.before) {
      ch = -1;
    }
    var key = ch + (bias || ""),
      found;
    if (prepared.cache.hasOwnProperty(key)) {
      found = prepared.cache[key];
    } else {
      if (!prepared.rect) {
        prepared.rect = prepared.view.text.getBoundingClientRect();
      }
      if (!prepared.hasHeights) {
        ensureLineHeights(cm, prepared.view, prepared.rect);
        prepared.hasHeights = true;
      }
      found = measureCharInner(cm, prepared, ch, bias);
      if (!found.bogus) {
        prepared.cache[key] = found;
      }
    }
    return {
      left: found.left,
      right: found.right,
      top: varHeight ? found.rtop : found.top,
      bottom: varHeight ? found.rbottom : found.bottom,
    };
  }

  var nullRect = { left: 0, right: 0, top: 0, bottom: 0 };