Function htmlBuilder

static/katex/katex.mjs:7368–7523

(grp, options)

// NOTE: Unlike most `htmlBuilder`s, this one handles not only "accent", but
const htmlBuilder = (grp, options) => {
  // Accents are handled in the TeXbook pg. 443, rule 12.
  let base;
  let group;
  const supSub = checkNodeType(grp, "supsub");
  let supSubGroup;

  if (supSub) {
    // If our base is a character box, and we have superscripts and
    // subscripts, the supsub will defer to us. In particular, we want
    // to attach the superscripts and subscripts to the inner body (so
    // that the position of the superscripts and subscripts won't be
    // affected by the height of the accent). We accomplish this by
    // sticking the base of the accent into the base of the supsub, and
    // rendering that, while keeping track of where the accent is.
    // The real accent group is the base of the supsub group
    group = assertNodeType(supSub.base, "accent"); // The character box is the base of the accent group

    base = group.base; // Stick the character box into the base of the supsub group

    supSub.base = base; // Rerender the supsub group with its new base, and store that
    // result.

    supSubGroup = assertSpan(buildGroup(supSub, options)); // reset original base

    supSub.base = group;
  } else {
    group = assertNodeType(grp, "accent");
    base = group.base;
  } // Build the base group


  const body = buildGroup(base, options.havingCrampedStyle()); // Does the accent need to shift for the skew of a character?

  const mustShift = group.isShifty && utils.isCharacterBox(base); // Calculate the skew of the accent. This is based on the line "If the
  // nucleus is not a single character, let s = 0; otherwise set s to the
  // kern amount for the nucleus followed by the \skewchar of its font."
  // Note that our skew metrics are just the kern between each character
  // and the skewchar.

  let skew = 0;

  if (mustShift) {
    // If the base is a character box, then we want the skew of the
    // innermost character. To do that, we find the innermost character:
    const baseChar = utils.getBaseElem(base); // Then, we render its group to get the symbol inside it

    const baseGroup = buildGroup(baseChar, options.havingCrampedStyle()); // Finally, we pull the skew off of the symbol.

    skew = assertSymbolDomNode(baseGroup).skew; // Note that we now throw away baseGroup, because the layers we
    // removed with getBaseElem might contain things like \color which
    // we can't get rid of.
    // TODO(emily): Find a better way to get the skew
  } // calculate the amount of space between the body and the accent


  let clearance = Math.min(body.height, options.fontMetrics().xHeight); // Build the accent