/**
 * Copyright 2013 Facebook, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * @providesModule getUnboundedScrollPosition
 * @typechecks
 */

"use strict";

/**
 * Gets the scroll position of the supplied element or window.
 *
 * The return values are unbounded, unlike `getScrollPosition`. This means they
 * may be negative or exceed the element boundaries (which is possible using
 * inertial scrolling).
 *
 * @param {DOMWindow|DOMElement} scrollable
 * @return {object} Map with `x` and `y` keys.
 */
function getUnboundedScrollPosition(scrollable) {
  if (scrollable === window) {
    return {
      x: document.documentElement.scrollLeft || document.body.scrollLeft,
      y: document.documentElement.scrollTop  || document.body.scrollTop
    };
  }
  return {
    x: scrollable.scrollLeft,
    y: scrollable.scrollTop
  };
}

module.exports = getUnboundedScrollPosition;

/**
 * Copyright 2013 Facebook, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * @providesModule getUnboundedScrollPosition
 * @typechecks
 */

"use strict";

/**
 * Gets the scroll position of the supplied element or window.
 *
 * The return values are unbounded, unlike `getScrollPosition`. This means they
 * may be negative or exceed the element boundaries (which is possible using
 * inertial scrolling).
 *
 * @param {DOMWindow|DOMElement} scrollable
 * @return {object} Map with `x` and `y` keys.
 */
function getUnboundedScrollPosition(scrollable) {
  if (scrollable === window) {
    return {
      x: window.pageXOffset || document.documentElement.scrollLeft,
      y: window.pageYOffset || document.documentElement.scrollTop
    };
  }
  return {
    x: scrollable.scrollLeft,
    y: scrollable.scrollTop
  };
}

module.exports = getUnboundedScrollPosition;

Fix scrollLeft/scrollTop warning in latest Chrome
Fix scrollLeft/scrollTop warning in latest Chrome

Chrome gives the warnings

```
body.scrollLeft is deprecated in strict mode. Please use 'documentElement.scrollLeft' if in strict mode and 'body.scrollLeft' only if in quirks mode.
body.scrollTop is deprecated in strict mode. Please use 'documentElement.scrollTop' if in strict mode and 'body.scrollTop' only if in quirks mode.
```

the first time getUnboundedScrollPosition is invoked. This fixes it. (All modern browsers support `pageYOffset`; IE 8 doesn't but works properly with `document.documentElement.scrollTop` except in quirks mode which React doesn't support.)
