gistfile1.dart

#import('dart:html');

List<Element> remaining;
int gameInterval = null, position = 0, points = 0;
Element selectedEl = null, pointsTally = null;

void main() {
  remaining = new List<Element>();
  TableElement table = createTable(3, 4);
  pointsTally = query("#points-tally");
  document.body.insertAdjacentElement('afterbegin', table);
  
  table.on.click.add(cellClick);
  
  gameInterval = window.setInterval(play, 1000);
}

TableElement createTable(int rows, int cols) {
  TableElement table = new TableElement();
  TableRowElement row;
  TableCellElement col;
  
  for (int i = 0; i < rows; i++) {
    row = new TableRowElement();
    for (int j = 0; j < cols; j++) {
      col = new TableCellElement();
      row.insertAdjacentElement('beforeend', col);
      remaining.add(col);
    }
    table.insertAdjacentElement('beforeend', row);
  }
  
  return table;
}

void cellClick (Event evt) {
  Element target = evt.srcElement;
  if (!target.classes.contains('highlight')) return;
  selectedEl.classes.add('whacked');
  remaining.removeRange(position, 1);
  if (remaining.length === 0) window.clearInterval(gameInterval);
  pointsTally.text = (points += 10).toString();
}

void play () {
  position = (Math.random() * remaining.length).toInt();
  if (selectedEl !== null) selectedEl.classes.remove('highlight');
  selectedEl = remaining[position];
  selectedEl.classes.add('highlight');
}