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+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+ \example webkit/domtraversal
+ \title DOM Traversal Example
+
+ The DOM Traversal example shows how to use the QWebElement class to access
+ the structure of a Web page.
+
+ \image webkit-domtraversal.png
+
+ The QWebElement class provides an API that can be used to examine the structure
+ and content of a Web page via a Document Object Model (DOM) interface. It can be
+ used for basic traversal of the document structure, to search for particular
+ elements (see the \l{Simple Selector Example}), and to modify content in-place.
+
+ This example uses a QWebView widget to display the Web page, and a dock widget
+ holds the QTreeWidget that shows the document structure. These widgets are
+ placed in an instance of the \c Window class, which we describe below.
+
+ \section1 Window Class Definition
+
+ The \c Window class is derived from QMainWindow and its user interface is created
+ using \l{Qt Designer}. As a result, the class is also derived from the user
+ interface class created by \l uic:
+
+ \snippet examples/webkit/domtraversal/window.h Window class definition
+
+ Two important functions to note are the \c on_webView_loadFinished() slot and
+ the \c examineChildElements() function. The former is automatically called
+ when the QWebView widget finishes loading a page \mdash see the
+ \l{#Further Reading}{Further Reading} section for more information on this
+ mechanism.
+
+ The \c examineChildElements() function is used to traverse the document structure
+ and add items to the QTreeWidget.
+
+ \section1 Window Class Implementation
+
+ In the \c Window class constructor, we call the \l{QWidget::}{setupUi()} function
+ to set up the user interface described in the \c{window.ui} file:
+
+ \snippet examples/webkit/domtraversal/window.cpp Window constructor
+
+ When the Web page is loaded, the \c on_webView_loadFinished() slot is called. Here,
+ we clear the tree widget and begin inspection of the document by obtaining the
+ document element from the page's main frame:
+
+ \snippet examples/webkit/domtraversal/window.cpp begin document inspection
+
+ At this point, we call the \c examineChildElements() function to traverse the
+ document, starting with the child elements of the document element for which we
+ will create top level items in the tree widget.
+
+ The \c examineChildElements() function accepts a parent element and a parent item.
+ Starting with the first child element, which we obtain with the element's
+ \l{QWebElement::}{firstChild()} function, we examine each child element of the
+ parent item. For each valid (non-null) element, which we check by calling its
+ \l{QWebElement::}{isNull()} function, we create a new QTreeWidgetItem instance with
+ the element name and add it to the parent item.
+
+ \snippet examples/webkit/domtraversal/window.cpp traverse document
+
+ We recursively examine the child elements for each element by calling
+ \c examineChildElements() with the current child element and the newly-created item.
+ To obtain the next element at the same level in the document, we call its
+ \l{QWebElement::}{nextSibling()} function.
+
+ This recursive approach to reading the document makes it easy to create a simple
+ representation of the document structure in a tree widget.
+
+ For completeness, we show the \c setUrl() function, which is provided to allow the
+ document URL to be set from the example's \c main() function.
+
+ \snippet examples/webkit/domtraversal/window.cpp set URL
+
+ \section1 Starting the Example
+
+ We set up the application, create
+ a \c Window instance, set its URL, and show it:
+
+ \snippet examples/webkit/simpleselector/main.cpp main program
+
+ When the application's event loop is run, the Qt home page will load, and the
+ tree widget will be updated to show the document structure. Navigating to another
+ page will cause the tree widget to be updated to show the document structure of
+ the new page.
+
+ \section1 Further Reading
+
+ The QWebElement documentation contains more information about DOM access for the
+ QtWebKit classes.
+
+ In this example, we take advantage of Qt's
+ \l{Using a Designer UI File in Your Application#Automatic Connections}{auto-connection}
+ feature to avoid explicitly connecting signals to slots. The user interface
+ contains a QWebView widget called \c webView whose \l{QWebView::}{loadFinished()}
+ signal is automatically connected to the \c on_webView_loadFinished() slot when
+ we call \l{QWidget::}{setupUi()} in the \c Window constructor.
+*/