goog.provide('ol.dom');


/**
 * Create an html canvas element and returns its 2d context.
 * @param {number=} opt_width Canvas width.
 * @param {number=} opt_height Canvas height.
 * @return {CanvasRenderingContext2D} The context.
 */
ol.dom.createCanvasContext2D = function(opt_width, opt_height) {
  var canvas = document.createElement('CANVAS');
  if (opt_width) {
    canvas.width = opt_width;
  }
  if (opt_height) {
    canvas.height = opt_height;
  }
  return canvas.getContext('2d');
};


/**
 * Get the current computed width for the given element including margin,
 * padding and border.
 * Equivalent to jQuery's `$(el).outerWidth(true)`.
 * @param {!Element} element Element.
 * @return {number} The width.
 */
ol.dom.outerWidth = function(element) {
  var width = element.offsetWidth;
  var style = element.currentStyle || getComputedStyle(element);
  width += parseInt(style.marginLeft, 10) + parseInt(style.marginRight, 10);

  return width;
};


/**
 * Get the current computed height for the given element including margin,
 * padding and border.
 * Equivalent to jQuery's `$(el).outerHeight(true)`.
 * @param {!Element} element Element.
 * @return {number} The height.
 */
ol.dom.outerHeight = function(element) {
  var height = element.offsetHeight;
  var style = element.currentStyle || getComputedStyle(element);
  height += parseInt(style.marginTop, 10) + parseInt(style.marginBottom, 10);

  return height;
};

/**
 * @param {Node} newNode Node to replace old node
 * @param {Node} oldNode The node to be replaced
 */
ol.dom.replaceNode = function(newNode, oldNode) {
  var parent = oldNode.parentNode;
  if (parent) {
    parent.replaceChild(newNode, oldNode);
  }
};

/**
 * @param {Node} node The node to remove.
 * @returns {Node} The node that was removed or null.
 */
ol.dom.removeNode = function(node) {
  return node && node.parentNode ? node.parentNode.removeChild(node) : null;
};

/**
 * @param {Node} node The node to remove the children from.
 */
ol.dom.removeChildren = function(node) {
  while (node.lastChild) {
    node.removeChild(node.lastChild);
  }
};
