path: root/src/webenginewidgets/doc/src/qwebengineview_lgpl.qdoc

/*
    Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
    Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
    Copyright (C) 2008 Holger Hans Peter Freyther
    Copyright (C) 2009 Girish Ramakrishnan <girish@forwardbias.in>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

// The documentation in this file was imported from QtWebKit and is thus constrained
// by its LGPL license. Documentation written from scratch for new methods should be
// placed inline in the code as usual.

/*!
    \class QWebEngineView
    \since 4.4
    \brief The QWebEngineView class provides a widget that is used to view and edit
    web documents.
    \ingroup advanced

    \inmodule QtWebEngine

    QWebEngineView is the main widget component of the Qt WebKit web browsing module.
    It can be used in various applications to display web content live from the
    Internet.

    A web site can be loaded onto QWebEngineView with the load() function. Like all
    Qt widgets, the show() function must be invoked in order to display
    QWebEngineView. The snippet below illustrates this:

    \snippet snippets/simple/main.cpp Using QWebEngineView

    Alternatively, setUrl() can also be used to load a web site. If you have
    the HTML content readily available, you can use setHtml() instead.

    The loadStarted() signal is emitted when the view begins loading. The
    loadProgress() signal, on the other hand, is emitted whenever an element of
    the web view completes loading, such as an embedded image, a script, etc.
    Finally, the loadFinished() signal is emitted when the view has loaded
    completely. It's argument - either \c true or \c false - indicates
    load success or failure.

    The page() function returns a pointer to the web page object. See
    \l{Elements of QWebEngineView} for an explanation of how the web page
    is related to the view. To modify your web view's settings, you can access
    the QWebEngineSettings object with the settings() function. With QWebEngineSettings,
    you can change the default fonts, enable or disable features such as
    JavaScript and plugins.

    The title of an HTML document can be accessed with the title() property.
    Additionally, a web site may also specify an icon, which can be accessed
    using the icon() property. If the title or the icon changes, the corresponding
    titleChanged() and iconChanged() signals will be emitted. The
    textSizeMultiplier() property can be used to change the overall size of
    the text displayed in the web view.

    If you require a custom context menu, you can implement it by reimplementing
    \l{QWidget::}{contextMenuEvent()} and populating your QMenu with the actions
    obtained from pageAction(). More functionality such as reloading the view,
    copying selected text to the clipboard, or pasting into the view, is also
    encapsulated within the QAction objects returned by pageAction(). These
    actions can be programmatically triggered using triggerPageAction().
    Alternatively, the actions can be added to a toolbar or a menu directly.
    QWebEngineView maintains the state of the returned actions but allows
    modification of action properties such as \l{QAction::}{text} or
    \l{QAction::}{icon}.

    A QWebEngineView can be printed onto a QPrinter using the print() function.
    This function is marked as a slot and can be conveniently connected to
    \l{QPrintPreviewDialog}'s \l{QPrintPreviewDialog::}{paintRequested()}
    signal.

    If you want to provide support for web sites that allow the user to open
    new windows, such as pop-up windows, you can subclass QWebEngineView and
    reimplement the createWindow() function.

    \section1 Elements of QWebEngineView

    QWebEngineView also consists of a QWebEnginePage.
    It is possible to use QWebEnginePage without using QWebEngineView,
    if you do not require QWidget attributes. Nevertheless, Qt WebKit depends
    on QtGui, so you should use a QApplication instead of QCoreApplication.

    \sa {Previewer Example}, {WebEngine Tab Browser Example}, {Form Extractor Example},
    {Google Chat Example}, {WebEngine Fancy Browser Example}
*/


/*!
    \fn QWebEngineView::QWebEngineView(QWidget *parent)
    Constructs an empty QWebEngineView with parent \a parent.

    \sa load()
*/

/*!
    \fn QWebEngineView::~QWebEngineView()
    Destroys the web view.
*/

/*!
    \fn QWebEnginePage *QWebEngineView::page() const
    Returns a pointer to the underlying web page.

    \sa setPage()
*/

/*!
    \fn void QWebEngineView::setPage(QWebEnginePage* page)
    Makes \a page the new web page of the web view.

    The parent QObject of the provided page remains the owner
    of the object. If the current page is a child of the web
    view, it will be deleted.

    \sa page()
*/

/*!
    \fn void QWebEngineView::load(const QUrl &url)
    Loads the specified \a url and displays it.

    \note The view remains the same until enough data has arrived to display the new \a url.

    \sa setUrl(), url(), urlChanged(), QUrl::fromUserInput()
*/

/*!
    \fn void QWebEngineView::setHtml(const QString &html, const QUrl &baseUrl)
    Sets the content of the web view to the specified \a html.

    External objects such as stylesheets or images referenced in the HTML
    document are located relative to \a baseUrl.

    The \a html is loaded immediately; external objects are loaded asynchronously.

    When using this method, WebKit assumes that external resources such as
    JavaScript programs or style sheets are encoded in UTF-8 unless otherwise
    specified. For example, the encoding of an external script can be specified
    through the charset attribute of the HTML script tag. Alternatively, the
    encoding can also be specified by the web server.

    This is a convenience function equivalent to setContent(html, "text/html", baseUrl).

    \warning This function works only for HTML, for other mime types (i.e. XHTML, SVG)
    setContent() should be used instead.

    \sa load(), setContent(), QWebEnginePage::toHtml(), QWebEnginePage::setContent()
*/

/*!
    \fn void QWebEngineView::setContent(const QByteArray &data, const QString &mimeType, const QUrl &baseUrl)
    Sets the content of the web view to the specified content \a data. If the \a mimeType argument
    is empty it is currently assumed that the content is HTML but in future versions we may introduce
    auto-detection.

    External objects referenced in the content are located relative to \a baseUrl.

    The \a data is loaded immediately; external objects are loaded asynchronously.

    \sa load(), setHtml(), QWebEnginePage::toHtml()
*/

/*!
    \fn QWebEngineHistory *QWebEngineView::history() const
    Returns a pointer to the view's history of navigated web pages.

    It is equivalent to

    \snippet snippets/qtwebengine_qwebengineview_snippet.cpp 0
*/

/*!
    \property QWebEngineView::title
    \brief the title of the web page currently viewed

    By default, this property contains an empty string.

    \sa titleChanged()
*/

/*!
    \property QWebEngineView::url
    \brief the url of the web page currently viewed

    Setting this property clears the view and loads the URL.

    By default, this property contains an empty, invalid URL.

    \sa load(), urlChanged()
*/

/*!
    \property QWebEngineView::hasSelection
    \brief whether this page contains selected content or not.

    By default, this property is false.

    \sa selectionChanged()
*/

/*!
    \property QWebEngineView::selectedText
    \brief the text currently selected

    By default, this property contains an empty string.

    \sa findText(), selectionChanged()
*/

/*!
    \fn QAction *QWebEngineView::pageAction(QWebEnginePage::WebAction action) const
    Returns a pointer to a QAction that encapsulates the specified web action \a action.
*/

/*!
    \fn void QWebEngineView::triggerPageAction(QWebEnginePage::WebAction action, bool checked)
    Triggers the specified \a action. If it is a checkable action the specified
    \a checked state is assumed.

    The following example triggers the copy action and therefore copies any
    selected text to the clipboard.

    \snippet snippets/qtwebengine_qwebengineview_snippet.cpp 2

    \sa pageAction()
*/

/*
    \property QWebEngineView::textInteractionFlags
    \brief how the view should handle user input

    Specifies how the user can interact with the text on the page.
*/


/*!
    \property QWebEngineView::zoomFactor
    \since 4.5
    \brief the zoom factor for the view
*/

/*!
    \property QWebEngineView::renderHints
    \since 4.6
    \brief the default render hints for the view

    These hints are used to initialize QPainter before painting the Web page.

    QPainter::TextAntialiasing and QPainter::SmoothPixmapTransform are enabled by default.

    \sa QPainter::renderHints()
*/

/*!
    \fn bool QWebEngineView::findText(const QString &subString, QWebEnginePage::FindFlags options)
    Finds the specified string, \a subString, in the page, using the given \a options.

    If the HighlightAllOccurrences flag is passed, the function will highlight all occurrences
    that exist in the page. All subsequent calls will extend the highlight, rather than
    replace it, with occurrences of the new string.

    If the HighlightAllOccurrences flag is not passed, the function will select an occurrence
    and all subsequent calls will replace the current occurrence with the next one.

    To clear the selection, just pass an empty string.

    Returns true if \a subString was found; otherwise returns false.

    \sa selectedText(), selectionChanged()
*/

/*!
    \fn void QWebEngineView::stop()
    Convenience slot that stops loading the document.

    It is equivalent to

    \snippet snippets/qtwebengine_qwebengineview_snippet.cpp 3

    \sa reload(), pageAction(), loadFinished()
*/

/*!
    \fn void QWebEngineView::back()
    Convenience slot that loads the previous document in the list of documents
    built by navigating links. Does nothing if there is no previous document.

    It is equivalent to

    \snippet snippets/qtwebengine_qwebengineview_snippet.cpp 4

    \sa forward(), pageAction()
*/

/*!
    \fn void QWebEngineView::forward()
    Convenience slot that loads the next document in the list of documents
    built by navigating links. Does nothing if there is no next document.

    It is equivalent to

    \snippet snippets/qtwebengine_qwebengineview_snippet.cpp 5

    \sa back(), pageAction()
*/

/*!
    \fn void QWebEngineView::reload()
    Reloads the current document.

    \sa stop(), pageAction(), loadStarted()
*/

/*!
    \fn QWebEngineView *QWebEngineView::createWindow(QWebEnginePage::WebWindowType type)
    This function is called from the createWindow() method of the associated QWebEnginePage,
    each time the page wants to create a new window of the given \a type. This might
    be the result, for example, of a JavaScript request to open a document in a new window.

    \note If the createWindow() method of the associated page is reimplemented, this
    method is not called, unless explicitly done so in the reimplementation.

    \note In the cases when the window creation is being triggered by JavaScript, apart from
    reimplementing this method application must also set the JavaScriptCanOpenWindows attribute
    of QWebEngineSettings to true in order for it to get called.

    \sa QWebEnginePage::createWindow()
*/

/*!
    \fn void QWebEngineView::titleChanged(const QString &title)

    This signal is emitted whenever the \a title of the main frame changes.

    \sa title()
*/

/*!
    \fn void QWebEngineView::urlChanged(const QUrl &url)

    This signal is emitted when the \a url of the view changes.

    \sa url(), load()
*/

/*!
    \fn void QWebEngineView::statusBarMessage(const QString& text)

    This signal is emitted when the status bar \a text is changed by the page.
*/

/*!
    \fn void QWebEngineView::loadStarted()

    This signal is emitted when a new load of the page is started.

    \sa loadProgress(), loadFinished()
*/

/*!
    \fn void QWebEngineView::loadFinished(bool ok)

    This signal is emitted when a load of the page is finished.
    \a ok will indicate whether the load was successful or any error occurred.

    \sa loadStarted()
*/

/*!
    \fn void QWebEngineView::selectionChanged()

    This signal is emitted whenever the selection changes.

    \sa selectedText()
*/

/*!
    \fn void QWebEngineView::loadProgress(int progress)

    This signal is emitted every time an element in the web page
    completes loading and the overall loading progress advances.

    This signal tracks the progress of all child frames.

    The current value is provided by \a progress and scales from 0 to 100,
    which is the default range of QProgressBar.

    \sa loadStarted(), loadFinished()
*/