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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
loader.lazyRequireGetter(
this,
"nodeFilterConstants",
"resource://devtools/shared/dom-node-filter-constants.js"
);
loader.lazyRequireGetter(
this,
"standardTreeWalkerFilter",
"resource://devtools/server/actors/inspector/utils.js",
true
);
// SKIP_TO_* arguments are used with the DocumentWalker, driving the strategy to use if
// the starting node is incompatible with the filter function of the walker.
const SKIP_TO_PARENT = "SKIP_TO_PARENT";
const SKIP_TO_SIBLING = "SKIP_TO_SIBLING";
class DocumentWalker {
/**
* Wrapper for inDeepTreeWalker. Adds filtering to the traversal methods.
* See inDeepTreeWalker for more information about the methods.
*
* @param {DOMNode} node
* @param {Window} rootWin
* @param {Object}
* - {Function} filter
* A custom filter function Taking in a DOMNode and returning an Int. See
* WalkerActor.nodeFilter for an example.
* - {String} skipTo
* Either SKIP_TO_PARENT or SKIP_TO_SIBLING. If the provided node is not
* compatible with the filter function for this walker, try to find a compatible
* one either in the parents or in the siblings of the node.
* - {Boolean} showAnonymousContent
* Pass true to let the walker return and traverse anonymous content.
* When navigating host elements to which shadow DOM is attached, the light tree
* will be visible only to a walker with showAnonymousContent=false. The shadow
* tree will only be visible to a walker with showAnonymousContent=true.
*/
constructor(
node,
rootWin,
{
filter = standardTreeWalkerFilter,
skipTo = SKIP_TO_PARENT,
showAnonymousContent = true,
} = {}
) {
if (Cu.isDeadWrapper(rootWin) || !rootWin.location) {
throw new Error("Got an invalid root window in DocumentWalker");
}
this.walker = Cc[
"@mozilla.org/inspector/deep-tree-walker;1"
].createInstance(Ci.inIDeepTreeWalker);
this.walker.showAnonymousContent = showAnonymousContent;
this.walker.showSubDocuments = true;
this.walker.showDocumentsAsNodes = true;
this.walker.init(rootWin.document);
this.filter = filter;
// Make sure that the walker knows about the initial node (which could
// be skipped due to a filter).
this.walker.currentNode = this.getStartingNode(node, skipTo);
}
get currentNode() {
return this.walker.currentNode;
}
set currentNode(val) {
this.walker.currentNode = val;
}
parentNode() {
return this.walker.parentNode();
}
nextNode() {
const node = this.walker.currentNode;
if (!node) {
return null;
}
let nextNode = this.walker.nextNode();
while (nextNode && this.isSkippedNode(nextNode)) {
nextNode = this.walker.nextNode();
}
return nextNode;
}
firstChild() {
if (!this.walker.currentNode) {
return null;
}
let firstChild = this.walker.firstChild();
while (firstChild && this.isSkippedNode(firstChild)) {
firstChild = this.walker.nextSibling();
}
return firstChild;
}
lastChild() {
if (!this.walker.currentNode) {
return null;
}
let lastChild = this.walker.lastChild();
while (lastChild && this.isSkippedNode(lastChild)) {
lastChild = this.walker.previousSibling();
}
return lastChild;
}
previousSibling() {
let node = this.walker.previousSibling();
while (node && this.isSkippedNode(node)) {
node = this.walker.previousSibling();
}
return node;
}
nextSibling() {
let node = this.walker.nextSibling();
while (node && this.isSkippedNode(node)) {
node = this.walker.nextSibling();
}
return node;
}
getStartingNode(node, skipTo) {
// Keep a reference on the starting node in case we can't find a node compatible with
// the filter.
const startingNode = node;
if (skipTo === SKIP_TO_PARENT) {
while (node && this.isSkippedNode(node)) {
node = node.parentNode;
}
} else if (skipTo === SKIP_TO_SIBLING) {
node = this.getClosestAcceptedSibling(node);
}
return node || startingNode;
}
/**
* Loop on all of the provided node siblings until finding one that is compliant with
* the filter function.
*/
getClosestAcceptedSibling(node) {
if (this.filter(node) === nodeFilterConstants.FILTER_ACCEPT) {
// node is already valid, return immediately.
return node;
}
// Loop on starting node siblings.
let previous = node;
let next = node;
while (previous || next) {
previous = previous?.previousSibling;
next = next?.nextSibling;
if (
previous &&
this.filter(previous) === nodeFilterConstants.FILTER_ACCEPT
) {
// A valid node was found in the previous siblings of the node.
return previous;
}
if (next && this.filter(next) === nodeFilterConstants.FILTER_ACCEPT) {
// A valid node was found in the next siblings of the node.
return next;
}
}
return null;
}
isSkippedNode(node) {
return this.filter(node) === nodeFilterConstants.FILTER_SKIP;
}
}
exports.DocumentWalker = DocumentWalker;
exports.SKIP_TO_PARENT = SKIP_TO_PARENT;
exports.SKIP_TO_SIBLING = SKIP_TO_SIBLING;
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