Function updateScrollTop

samples/common/codehighlight/codemirror.js:3552–3558

(cm, val)

  // Sync the scrollable area and scrollbars, ensure the viewport
  // covers the visible area.
  function updateScrollTop(cm, val) {
    if (Math.abs(cm.doc.scrollTop - val) < 2) { return }
    if (!gecko) { updateDisplaySimple(cm, {top: val}); }
    setScrollTop(cm, val, true);
    if (gecko) { updateDisplaySimple(cm); }
    startWorker(cm, 100);
  }

  function setScrollTop(cm, val, forceScroll) {
    val = Math.max(0, Math.min(cm.display.scroller.scrollHeight - cm.display.scroller.clientHeight, val));