Function maybeScrollWindow

samples/common/codehighlight/codemirror.js:3410–3422

(cm, rect)

  // If an editor sits on the top or bottom of the window, partially
  // scrolled out of view, this ensures that the cursor is visible.
  function maybeScrollWindow(cm, rect) {
    if (signalDOMEvent(cm, "scrollCursorIntoView")) { return }

    var display = cm.display, box = display.sizer.getBoundingClientRect(), doScroll = null;
    if (rect.top + box.top < 0) { doScroll = true; }
    else if (rect.bottom + box.top > (window.innerHeight || document.documentElement.clientHeight)) { doScroll = false; }
    if (doScroll != null && !phantom) {
      var scrollNode = elt("div", "\u200b", null, ("position: absolute;\n                         top: " + (rect.top - display.viewOffset - paddingTop(cm.display)) + "px;\n                         height: " + (rect.bottom - rect.top + scrollGap(cm) + display.barHeight) + "px;\n                         left: " + (rect.left) + "px; width: " + (Math.max(2, rect.right - rect.left)) + "px;"));
      cm.display.lineSpace.appendChild(scrollNode);
      scrollNode.scrollIntoView(doScroll);
      cm.display.lineSpace.removeChild(scrollNode);
    }
  }

  // Scroll a given position into view (immediately), verifying that
  // it actually became visible (as line heights are accurately