<!DOCTYPE html>
<body>
<script src="../resources/runner.js"></script>
<script src="resources/paint.js"></script>
<style>
  div {
    /* To ensure consistent line wrapping behavior about empty spans across
       browsers. */
    white-space: pre;
  }
  span {
    padding: 1px;
  }
  .changeColor {
    background-color: green;
  }
</style>
<script>
// This test measures the lifecycle update performance of changing background
// colors in large trees.

function buildTree(parent, depth, arity, createElementCallback) {
  for (var child = 0; child < arity; child++) {
    var element = createElementCallback(depth);
    parent.appendChild(element);
    createElementCallback(element, depth);
    if (depth > 1)
      buildTree(element, depth - 1, arity, createElementCallback);
  }
}

// Build a tall tree that is skinny. A middle layer of
// the tree should have the changeColor class.
buildTree(document.body, 15, 2,
  function(depth) {
    // Use divs at upper levels to avoid too much layout time.
    var element = document.createElement(depth > 9 ? 'div' : 'span');
    element.style.backgroundColor = 'green';
    if (depth == 5)
      element.classList.add('changeColor');
    // Insert new lines to break long lines.
    if (depth == 12)
      element.textContent = '\n';
    return element;
  }
);

// Build a short tree that is fat. A middle layer of
// the tree should have the changeColor class.
buildTree(document.body, 6, 7,
  function(depth) {
    // Use divs at upper levels to avoid too much layout time.
    var element = document.createElement(depth > 4 ? 'div' : 'span');
    element.style.backgroundColor = 'orange';
    if (depth == 3)
      element.classList.add('changeColor');
    // Insert new lines to break long lines.
    if (depth == 6)
      element.textContent = '\n';
    return element;
  }
);

var runCount = 0;
var elementsToChange = document.getElementsByClassName('changeColor');
var colors = [
 "rgb(128, 18, 237)",
 "rgb(191, 1, 191)",
 "rgb(237, 18, 128)",
 "rgb(255, 64, 64)",
 "rgb(237, 127, 18)",
 "rgb(191, 191, 1)",
 "rgb(128, 237, 18)",
 "rgb(64, 255, 64)",
 "rgb(18, 237, 127)",
 "rgb(1, 191, 191)",
 "rgb(18, 128, 237)",
 "rgb(64, 64, 255)"
];
measurePaint({
  run: function() {
    runCount++;
    var newColor = colors[runCount % colors.length];
    for (var index = 0; index < elementsToChange.length; index++)
      elementsToChange[index].style.backgroundColor = newColor;
  },
});
</script>
</body>