(async function() {
  TestRunner.addResult('Test ListControl rendering for various height items case.');

  class Delegate {
    constructor() {
    }

    createElementForItem(item) {
      TestRunner.addResult('Creating element for ' + item);
      var element = document.createElement('div');
      element.style.height = this.heightForItem(item) + 'px';
      element.textContent = item;
      return element;
    }

    heightForItem(item) {
      return 7 + item % 10;
    }

    isItemSelectable(item) {
      return (item % 5 === 0) || (item % 5 === 2);
    }

    selectedItemChanged(from, to, fromElement, toElement) {
      TestRunner.addResult('Selection changed from ' + from + ' to ' + to);
      if (fromElement)
        fromElement.classList.remove('selected');
      if (toElement)
        toElement.classList.add('selected');
    }
  }

  var delegate = new Delegate();
  var model = new UI.ListModel();
  var list = new UI.ListControl(model, delegate, UI.ListMode.VariousHeightItems);
  list.element.style.height = '73px';
  UI.inspectorView.element.appendChild(list.element);

  function dumpList()
  {
    var height = list.element.offsetHeight;
    TestRunner.addResult(`----list[length=${model.length}][height=${height}]----`);
    for (var child of list.element.children) {
      var offsetTop = child.getBoundingClientRect().top - list.element.getBoundingClientRect().top;
      var offsetBottom = child.getBoundingClientRect().bottom - list.element.getBoundingClientRect().top;
      var visible = (offsetBottom <= 0 || offsetTop >= height) ? ' ' :
          (offsetTop >= 0 && offsetBottom <= height ? '*' : '+');
      var selected = child.classList.contains('selected') ? ' (selected)' : '';
      var text = child === list._topElement ? 'top' : (child === list._bottomElement ? 'bottom' : child.textContent);
      TestRunner.addResult(`${visible}[${offsetTop}] ${text}${selected}`);
    }
    TestRunner.addResult('offsets: ' + list._variableOffsets.join(' '));
    TestRunner.addResult('');
  }

  TestRunner.addResult('Adding 0, 1, 2');
  model.replaceAll([0, 1, 2]);
  dumpList();

  TestRunner.addResult('Scrolling to 0');
  list.scrollItemIntoView(0);
  dumpList();

  TestRunner.addResult('Scrolling to 2');
  list.scrollItemIntoView(2);
  dumpList();

  TestRunner.addResult('Adding 3-20');
  model.replaceRange(3, 3, [3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]);
  dumpList();

  TestRunner.addResult('Scrolling to 11');
  list.scrollItemIntoView(11);
  dumpList();

  TestRunner.addResult('Scrolling to 19');
  list.scrollItemIntoView(19);
  dumpList();

  TestRunner.addResult('Scrolling to 16 (center)');
  list.scrollItemIntoView(16, true);
  dumpList();

  TestRunner.addResult('Scrolling to 3');
  list.scrollItemIntoView(3);
  dumpList();

  TestRunner.addResult('Replacing 0, 1 with 25-36');
  model.replaceRange(0, 2, [25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36]);
  dumpList();

  TestRunner.addResult('Scrolling to 18');
  list.scrollItemIntoView(18);
  dumpList();

  TestRunner.addResult('Replacing 25-36 with 0-1');
  model.replaceRange(0, 12, [0, 1]);
  dumpList();

  TestRunner.addResult('Replacing 16-18 with 45');
  model.replaceRange(16, 19, [45]);
  dumpList();

  TestRunner.addResult('Scrolling to 4');
  list.scrollItemIntoView(4);
  dumpList();

  TestRunner.addResult('Replacing 45 with 16-18');
  model.replaceRange(16, 17, [16, 17, 18]);
  dumpList();

  TestRunner.addResult('Resizing');
  list.element.style.height = '190px';
  list.viewportResized();
  dumpList();

  TestRunner.completeTest();
})();