gecko-dev/browser/devtools/shared/DOMHelpers.jsm

157 строки
4.6 KiB
JavaScript

/* 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/. */
const Ci = Components.interfaces;
const Cu = Components.utils;
Cu.import("resource://gre/modules/Services.jsm");
this.EXPORTED_SYMBOLS = ["DOMHelpers"];
/**
* DOMHelpers
* Makes DOM traversal easier. Goes through iframes.
*
* @constructor
* @param nsIDOMWindow aWindow
* The content window, owning the document to traverse.
*/
this.DOMHelpers = function DOMHelpers(aWindow) {
if (!aWindow) {
throw new Error("window can't be null or undefined");
}
this.window = aWindow;
};
DOMHelpers.prototype = {
getParentObject: function Helpers_getParentObject(node)
{
let parentNode = node ? node.parentNode : null;
if (!parentNode) {
// Documents have no parentNode; Attr, Document, DocumentFragment, Entity,
// and Notation. top level windows have no parentNode
if (node && node == this.window.Node.DOCUMENT_NODE) {
// document type
if (node.defaultView) {
let embeddingFrame = node.defaultView.frameElement;
if (embeddingFrame)
return embeddingFrame.parentNode;
}
}
// a Document object without a parentNode or window
return null; // top level has no parent
}
if (parentNode.nodeType == this.window.Node.DOCUMENT_NODE) {
if (parentNode.defaultView) {
return parentNode.defaultView.frameElement;
}
// parent is document element, but no window at defaultView.
return null;
}
if (!parentNode.localName)
return null;
return parentNode;
},
getChildObject: function Helpers_getChildObject(node, index, previousSibling,
showTextNodesWithWhitespace)
{
if (!node)
return null;
if (node.contentDocument) {
// then the node is a frame
if (index == 0) {
return node.contentDocument.documentElement; // the node's HTMLElement
}
return null;
}
if (node.getSVGDocument) {
let svgDocument = node.getSVGDocument();
if (svgDocument) {
// then the node is a frame
if (index == 0) {
return svgDocument.documentElement; // the node's SVGElement
}
return null;
}
}
let child = null;
if (previousSibling) // then we are walking
child = this.getNextSibling(previousSibling);
else
child = this.getFirstChild(node);
if (showTextNodesWithWhitespace)
return child;
for (; child; child = this.getNextSibling(child)) {
if (!this.isWhitespaceText(child))
return child;
}
return null; // we have no children worth showing.
},
getFirstChild: function Helpers_getFirstChild(node)
{
let SHOW_ALL = Components.interfaces.nsIDOMNodeFilter.SHOW_ALL;
this.treeWalker = node.ownerDocument.createTreeWalker(node,
SHOW_ALL, null);
return this.treeWalker.firstChild();
},
getNextSibling: function Helpers_getNextSibling(node)
{
let next = this.treeWalker.nextSibling();
if (!next)
delete this.treeWalker;
return next;
},
isWhitespaceText: function Helpers_isWhitespaceText(node)
{
return node.nodeType == this.window.Node.TEXT_NODE &&
!/[^\s]/.exec(node.nodeValue);
},
destroy: function Helpers_destroy()
{
delete this.window;
delete this.treeWalker;
},
/**
* A simple way to be notified (once) when a window becomes
* interactive (DOMContentLoaded).
*
* It is based on the chromeEventHandler. This is useful when
* chrome iframes are loaded in content docshells (in Firefox
* tabs for example).
*/
onceDOMReady: function Helpers_onLocationChange(callback) {
let window = this.window;
let docShell = window.QueryInterface(Ci.nsIInterfaceRequestor)
.getInterface(Ci.nsIWebNavigation)
.QueryInterface(Ci.nsIDocShell);
let onReady = function(event) {
if (event.target == window.document) {
docShell.chromeEventHandler.removeEventListener("DOMContentLoaded", onReady, false);
// If in `callback` the URL of the window is changed and a listener to DOMContentLoaded
// is attached, the event we just received will be also be caught by the new listener.
// We want to avoid that so we execute the callback in the next queue.
Services.tm.mainThread.dispatch(callback, 0);
}
}
docShell.chromeEventHandler.addEventListener("DOMContentLoaded", onReady, false);
}
};