ref: dfab56b94698b9ebb5291931a9f67c6cebac8881
dir: opossum/domino-lib/TreeWalker.js
"use strict";
module.exports = TreeWalker;
var Node = require('./Node');
var NodeFilter = require('./NodeFilter');
var NodeTraversal = require('./NodeTraversal');
var utils = require('./utils');
var mapChild = {
first: 'firstChild',
last: 'lastChild',
next: 'firstChild',
previous: 'lastChild'
};
var mapSibling = {
first: 'nextSibling',
last: 'previousSibling',
next: 'nextSibling',
previous: 'previousSibling'
};
/* Private methods and helpers */
/**
* @spec https://dom.spec.whatwg.org/#concept-traverse-children
* @method
* @access private
* @param {TreeWalker} tw
* @param {string} type One of 'first' or 'last'.
* @return {Node|null}
*/
function traverseChildren(tw, type) {
var child, node, parent, result, sibling;
node = tw._currentNode[mapChild[type]];
while (node !== null) {
result = tw._internalFilter(node);
if (result === NodeFilter.FILTER_ACCEPT) {
tw._currentNode = node;
return node;
}
if (result === NodeFilter.FILTER_SKIP) {
child = node[mapChild[type]];
if (child !== null) {
node = child;
continue;
}
}
while (node !== null) {
sibling = node[mapSibling[type]];
if (sibling !== null) {
node = sibling;
break;
}
parent = node.parentNode;
if (parent === null || parent === tw.root || parent === tw._currentNode) {
return null;
} else {
node = parent;
}
}
}
return null;
}
/**
* @spec https://dom.spec.whatwg.org/#concept-traverse-siblings
* @method
* @access private
* @param {TreeWalker} tw
* @param {TreeWalker} type One of 'next' or 'previous'.
* @return {Node|nul}
*/
function traverseSiblings(tw, type) {
var node, result, sibling;
node = tw._currentNode;
if (node === tw.root) {
return null;
}
while (true) {
sibling = node[mapSibling[type]];
while (sibling !== null) {
node = sibling;
result = tw._internalFilter(node);
if (result === NodeFilter.FILTER_ACCEPT) {
tw._currentNode = node;
return node;
}
sibling = node[mapChild[type]];
if (result === NodeFilter.FILTER_REJECT || sibling === null) {
sibling = node[mapSibling[type]];
}
}
node = node.parentNode;
if (node === null || node === tw.root) {
return null;
}
if (tw._internalFilter(node) === NodeFilter.FILTER_ACCEPT) {
return null;
}
}
}
/* Public API */
/**
* Latest version: https://dom.spec.whatwg.org/#treewalker
*
* @constructor
* @param {Node} root
* @param {number} whatToShow [optional]
* @param {Function|NodeFilter} filter [optional]
* @throws Error
*/
function TreeWalker(root, whatToShow, filter) {
if (!root || !root.nodeType) {
utils.NotSupportedError();
}
// Read-only properties
this._root = root;
this._whatToShow = Number(whatToShow) || 0;
this._filter = filter || null;
this._active = false;
// Read-write property
this._currentNode = root;
}
Object.defineProperties(TreeWalker.prototype, {
root: { get: function() { return this._root; } },
whatToShow: { get: function() { return this._whatToShow; } },
filter: { get: function() { return this._filter; } },
currentNode: {
get: function currentNode() {
return this._currentNode;
},
set: function setCurrentNode(v) {
if (!(v instanceof Node)) {
throw new TypeError("Not a Node"); // `null` is also not a node
}
this._currentNode = v;
},
},
/**
* @method
* @param {Node} node
* @return {Number} Constant NodeFilter.FILTER_ACCEPT,
* NodeFilter.FILTER_REJECT or NodeFilter.FILTER_SKIP.
*/
_internalFilter: { value: function _internalFilter(node) {
/* jshint bitwise: false */
var result, filter;
if (this._active) {
utils.InvalidStateError();
}
// Maps nodeType to whatToShow
if (!(((1 << (node.nodeType - 1)) & this._whatToShow))) {
return NodeFilter.FILTER_SKIP;
}
filter = this._filter;
if (filter === null) {
result = NodeFilter.FILTER_ACCEPT;
} else {
this._active = true;
try {
if (typeof filter === 'function') {
result = filter(node);
} else {
result = filter.acceptNode(node);
}
} finally {
this._active = false;
}
}
// Note that coercing to a number means that
// `true` becomes `1` (which is NodeFilter.FILTER_ACCEPT)
// `false` becomes `0` (neither accept, reject, or skip)
return (+result);
}},
/**
* @spec https://dom.spec.whatwg.org/#dom-treewalker-parentnode
* @based on WebKit's TreeWalker::parentNode
* https://trac.webkit.org/browser/webkit/trunk/Source/WebCore/dom/TreeWalker.cpp?rev=220453#L50
* @method
* @return {Node|null}
*/
parentNode: { value: function parentNode() {
var node = this._currentNode;
while (node !== this.root) {
node = node.parentNode;
if (node === null) {
return null;
}
if (this._internalFilter(node) === NodeFilter.FILTER_ACCEPT) {
this._currentNode = node;
return node;
}
}
return null;
}},
/**
* @spec https://dom.spec.whatwg.org/#dom-treewalker-firstchild
* @method
* @return {Node|null}
*/
firstChild: { value: function firstChild() {
return traverseChildren(this, 'first');
}},
/**
* @spec https://dom.spec.whatwg.org/#dom-treewalker-lastchild
* @method
* @return {Node|null}
*/
lastChild: { value: function lastChild() {
return traverseChildren(this, 'last');
}},
/**
* @spec http://www.w3.org/TR/dom/#dom-treewalker-previoussibling
* @method
* @return {Node|null}
*/
previousSibling: { value: function previousSibling() {
return traverseSiblings(this, 'previous');
}},
/**
* @spec http://www.w3.org/TR/dom/#dom-treewalker-nextsibling
* @method
* @return {Node|null}
*/
nextSibling: { value: function nextSibling() {
return traverseSiblings(this, 'next');
}},
/**
* @spec https://dom.spec.whatwg.org/#dom-treewalker-previousnode
* @based on WebKit's TreeWalker::previousNode
* https://trac.webkit.org/browser/webkit/trunk/Source/WebCore/dom/TreeWalker.cpp?rev=220453#L181
* @method
* @return {Node|null}
*/
previousNode: { value: function previousNode() {
var node, result, previousSibling, lastChild;
node = this._currentNode;
while (node !== this._root) {
for (previousSibling = node.previousSibling;
previousSibling;
previousSibling = node.previousSibling) {
node = previousSibling;
result = this._internalFilter(node);
if (result === NodeFilter.FILTER_REJECT) {
continue;
}
for (lastChild = node.lastChild;
lastChild;
lastChild = node.lastChild) {
node = lastChild;
result = this._internalFilter(node);
if (result === NodeFilter.FILTER_REJECT) {
break;
}
}
if (result === NodeFilter.FILTER_ACCEPT) {
this._currentNode = node;
return node;
}
}
if (node === this.root || node.parentNode === null) {
return null;
}
node = node.parentNode;
if (this._internalFilter(node) === NodeFilter.FILTER_ACCEPT) {
this._currentNode = node;
return node;
}
}
return null;
}},
/**
* @spec https://dom.spec.whatwg.org/#dom-treewalker-nextnode
* @based on WebKit's TreeWalker::nextNode
* https://trac.webkit.org/browser/webkit/trunk/Source/WebCore/dom/TreeWalker.cpp?rev=220453#L228
* @method
* @return {Node|null}
*/
nextNode: { value: function nextNode() {
var node, result, firstChild, nextSibling;
node = this._currentNode;
result = NodeFilter.FILTER_ACCEPT;
CHILDREN:
while (true) {
for (firstChild = node.firstChild;
firstChild;
firstChild = node.firstChild) {
node = firstChild;
result = this._internalFilter(node);
if (result === NodeFilter.FILTER_ACCEPT) {
this._currentNode = node;
return node;
} else if (result === NodeFilter.FILTER_REJECT) {
break;
}
}
for (nextSibling = NodeTraversal.nextSkippingChildren(node, this.root);
nextSibling;
nextSibling = NodeTraversal.nextSkippingChildren(node, this.root)) {
node = nextSibling;
result = this._internalFilter(node);
if (result === NodeFilter.FILTER_ACCEPT) {
this._currentNode = node;
return node;
} else if (result === NodeFilter.FILTER_SKIP) {
continue CHILDREN;
}
}
return null;
}
}},
/** For compatibility with web-platform-tests. */
toString: { value: function toString() {
return "[object TreeWalker]";
}},
});