62 lines
1.7 KiB
JavaScript
62 lines
1.7 KiB
JavaScript
'use strict';
|
|
|
|
/**
|
|
* Copyright (c) 2013-present, Facebook, Inc.
|
|
*
|
|
* This source code is licensed under the MIT license found in the
|
|
* LICENSE file in the root directory of this source tree.
|
|
*
|
|
* @typechecks
|
|
*/
|
|
|
|
var getStyleProperty = require('./getStyleProperty');
|
|
|
|
/**
|
|
* @param {DOMNode} element [description]
|
|
* @param {string} name Overflow style property name.
|
|
* @return {boolean} True if the supplied ndoe is scrollable.
|
|
*/
|
|
function _isNodeScrollable(element, name) {
|
|
var overflow = Style.get(element, name);
|
|
return overflow === 'auto' || overflow === 'scroll';
|
|
}
|
|
|
|
/**
|
|
* Utilities for querying and mutating style properties.
|
|
*/
|
|
var Style = {
|
|
/**
|
|
* Gets the style property for the supplied node. This will return either the
|
|
* computed style, if available, or the declared style.
|
|
*
|
|
* @param {DOMNode} node
|
|
* @param {string} name Style property name.
|
|
* @return {?string} Style property value.
|
|
*/
|
|
get: getStyleProperty,
|
|
|
|
/**
|
|
* Determines the nearest ancestor of a node that is scrollable.
|
|
*
|
|
* NOTE: This can be expensive if used repeatedly or on a node nested deeply.
|
|
*
|
|
* @param {?DOMNode} node Node from which to start searching.
|
|
* @return {?DOMWindow|DOMElement} Scroll parent of the supplied node.
|
|
*/
|
|
getScrollParent: function getScrollParent(node) {
|
|
if (!node) {
|
|
return null;
|
|
}
|
|
var ownerDocument = node.ownerDocument;
|
|
while (node && node !== ownerDocument.body) {
|
|
if (_isNodeScrollable(node, 'overflow') || _isNodeScrollable(node, 'overflowY') || _isNodeScrollable(node, 'overflowX')) {
|
|
return node;
|
|
}
|
|
node = node.parentNode;
|
|
}
|
|
return ownerDocument.defaultView || ownerDocument.parentWindow;
|
|
}
|
|
|
|
};
|
|
|
|
module.exports = Style; |