Function countDirtyView

static/editor.md/lib/codemirror/lib/codemirror.js:3277–3284

(cm)

  // Count the number of lines in the view whose DOM representation is
  // out of date (or nonexistent).
  function countDirtyView(cm) {
    var view = cm.display.view, dirty = 0;
    for (var i = 0; i < view.length; i++) {
      var lineView = view[i];
      if (!lineView.hidden && (!lineView.node || lineView.changes)) ++dirty;
    }
    return dirty;
  }

  // EVENT HANDLERS