QWebView Class Reference
[QtWebKit module]

Detailed Description

The QWebView class provides a widget that is used to view and edit web documents.

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

The image below shows QWebView previewed in Qt Designer with a Nokia website.

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

     QWebView *view = new QWebView(parent);
     view->load(QUrl("http://qt.nokia.com/"));
     view->show();

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 true or false - indicates load success or failure.

The page() function returns a pointer to the web page object. See Elements of QWebView for an explanation of how the web page is related to the view. To modify your web view's settings, you can access the QWebSettings object with the settings() function. With QWebSettings, 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 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. QWebView maintains the state of the returned actions but allows modification of action properties such as text or icon.

A QWebView can be printed onto a QPrinter using the print() function. This function is marked as a slot and can be conveniently connected to QPrintPreviewDialog's 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 QWebView and reimplement the createWindow() function.

Elements of QWebView

QWebView consists of other objects such as QWebFrame and QWebPage. The flowchart below shows these elements are related.

Note: It is possible to use QWebPage and QWebFrame, without using QWebView, if you do not require QWidget attributes. Nevertheless, QtWebKit depends on QtGui, so you should use a QApplication instead of QCoreApplication.

See also Previewer Example, Web Browser, Form Extractor Example, Google Chat Example, and Fancy Browser Example.

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Property Documentation

icon : const QIcon

This property holds the icon associated with the web page currently viewed.

By default, this property contains a null icon.

Access functions:

QIcon

icon () const

See also iconChanged() and QWebSettings::iconForUrl().

modified : const bool

This property holds whether the document was modified by the user.

Parts of HTML documents can be editable for example through the contenteditable attribute on HTML elements.

By default, this property is false.

Access functions:

bool	isModified () const

renderHints : QPainter::RenderHints

This property holds the default render hints for the view.

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

QPainter::TextAntialiasing is enabled by default.

Note: This property is not available on Symbian. However, the getter and setter functions can still be used directly.

This property was introduced in Qt 4.6.

Access functions:

QPainter::RenderHints	renderHints () const
void	setRenderHints ( QPainter::RenderHints hints )

See also QPainter::renderHints().

selectedText : const QString

This property holds the text currently selected.

By default, this property contains an empty string.

Access functions:

QString

selectedText () const

See also findText() and selectionChanged().

title : const QString

This property holds the title of the web page currently viewed.

By default, this property contains an empty string.

Access functions:

QString

title () const

See also titleChanged().

url : QUrl

This property holds 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.

Access functions:

QUrl	url () const
void	setUrl ( const QUrl & url )

See also load() and urlChanged().

zoomFactor : qreal

This property holds the zoom factor for the view.

This property was introduced in Qt 4.5.

Access functions:

qreal	zoomFactor () const
void	setZoomFactor ( qreal factor )

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Member Function Documentation

QWebView::QWebView ( QWidget * parent = 0 )

Constructs an empty QWebView with parent parent.

See also load().

QWebView::~QWebView ()   [virtual]

Destroys the web view.

void QWebView::back ()   [slot]

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

     view->page()->triggerPageAction(QWebPage::GoBack);

See also forward() and pageAction().

void QWebView::changeEvent ( QEvent * e )   [virtual protected]

Reimplemented from QWidget::changeEvent().

void QWebView::contextMenuEvent ( QContextMenuEvent * ev )   [virtual protected]

Reimplemented from QWidget::contextMenuEvent().

QWebView * QWebView::createWindow ( QWebPage::WebWindowType type )   [virtual protected]

This function is called from the createWindow() method of the associated QWebPage, each time the page wants to create a new window of the given 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.

See also QWebPage::createWindow().

void QWebView::dragEnterEvent ( QDragEnterEvent * ev )   [virtual protected]

Reimplemented from QWidget::dragEnterEvent().

void QWebView::dragLeaveEvent ( QDragLeaveEvent * ev )   [virtual protected]

Reimplemented from QWidget::dragLeaveEvent().

void QWebView::dragMoveEvent ( QDragMoveEvent * ev )   [virtual protected]

Reimplemented from QWidget::dragMoveEvent().

void QWebView::dropEvent ( QDropEvent * ev )   [virtual protected]

Reimplemented from QWidget::dropEvent().

bool QWebView::event ( QEvent * e )   [virtual]

Reimplemented from QObject::event().

bool QWebView::findText ( const QString & subString, QWebPage::FindFlags options = 0 )

Finds the specified string, subString, in the page, using the given 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 subString was found; otherwise returns false.

See also selectedText() and selectionChanged().

void QWebView::focusInEvent ( QFocusEvent * ev )   [virtual protected]

Reimplemented from QWidget::focusInEvent().

bool QWebView::focusNextPrevChild ( bool next )   [virtual protected]

Reimplemented from QWidget::focusNextPrevChild().

void QWebView::focusOutEvent ( QFocusEvent * ev )   [virtual protected]

Reimplemented from QWidget::focusOutEvent().

void QWebView::forward ()   [slot]

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

     view->page()->triggerPageAction(QWebPage::GoForward);

See also back() and pageAction().

QWebHistory * QWebView::history () const

Returns a pointer to the view's history of navigated web pages.

It is equivalent to

     view->page()->history();

void QWebView::iconChanged ()   [signal]

This signal is emitted whenever the icon of the page is loaded or changes.

In order for icons to be loaded, you will need to set an icon database path using QWebSettings::setIconDatabasePath().

See also icon() and QWebSettings::setIconDatabasePath().

void QWebView::inputMethodEvent ( QInputMethodEvent * e )   [virtual protected]

Reimplemented from QWidget::inputMethodEvent().

QVariant QWebView::inputMethodQuery ( Qt::InputMethodQuery property ) const   [virtual]

Reimplemented from QWidget::inputMethodQuery().

void QWebView::keyPressEvent ( QKeyEvent * ev )   [virtual protected]

Reimplemented from QWidget::keyPressEvent().

void QWebView::keyReleaseEvent ( QKeyEvent * ev )   [virtual protected]

Reimplemented from QWidget::keyReleaseEvent().

void QWebView::linkClicked ( const QUrl & url )   [signal]

This signal is emitted whenever the user clicks on a link and the page's linkDelegationPolicy property is set to delegate the link handling for the specified url.

See also QWebPage::linkDelegationPolicy().

void QWebView::load ( const QUrl & url )

Loads the specified url and displays it.

Note: The view remains the same until enough data has arrived to display the new url.

See also setUrl(), url(), urlChanged(), and QUrl::fromUserInput().

void QWebView::load ( const QNetworkRequest & request, QNetworkAccessManager::Operation operation = QNetworkAccessManager::GetOperation, const QByteArray & body = QByteArray() )

Loads a network request, request, using the method specified in operation.

body is optional and is only used for POST operations.

Note: The view remains the same until enough data has arrived to display the new url.

See also url() and urlChanged().

void QWebView::loadFinished ( bool ok )   [signal]

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

See also loadStarted().

void QWebView::loadProgress ( int progress )   [signal]

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 progress and scales from 0 to 100, which is the default range of QProgressBar.

See also loadStarted() and loadFinished().

void QWebView::loadStarted ()   [signal]

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

See also loadProgress() and loadFinished().

void QWebView::mouseDoubleClickEvent ( QMouseEvent * ev )   [virtual protected]

Reimplemented from QWidget::mouseDoubleClickEvent().

void QWebView::mouseMoveEvent ( QMouseEvent * ev )   [virtual protected]

Reimplemented from QWidget::mouseMoveEvent().

void QWebView::mousePressEvent ( QMouseEvent * ev )   [virtual protected]

Reimplemented from QWidget::mousePressEvent().

void QWebView::mouseReleaseEvent ( QMouseEvent * ev )   [virtual protected]

Reimplemented from QWidget::mouseReleaseEvent().

QWebPage * QWebView::page () const

Returns a pointer to the underlying web page.

See also setPage().

QAction * QWebView::pageAction ( QWebPage::WebAction action ) const

Returns a pointer to a QAction that encapsulates the specified web action action.

void QWebView::paintEvent ( QPaintEvent * ev )   [virtual protected]

Reimplemented from QWidget::paintEvent().

void QWebView::print ( QPrinter * printer ) const   [slot]

Prints the main frame to the given printer.

See also QWebFrame::print() and QPrintPreviewDialog.

void QWebView::reload ()   [slot]

Reloads the current document.

See also stop(), pageAction(), and loadStarted().

void QWebView::resizeEvent ( QResizeEvent * e )   [virtual protected]

Reimplemented from QWidget::resizeEvent().

void QWebView::selectionChanged ()   [signal]

This signal is emitted whenever the selection changes.

See also selectedText().

void QWebView::setContent ( const QByteArray & data, const QString & mimeType = QString(), const QUrl & baseUrl = QUrl() )

Sets the content of the web view to the specified content data. If the 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 baseUrl.

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

See also load(), setHtml(), and QWebFrame::toHtml().

void QWebView::setHtml ( const QString & html, const QUrl & baseUrl = QUrl() )

Sets the content of the web view to the specified html.

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

The 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.

See also load(), setContent(), and QWebFrame::toHtml().

void QWebView::setPage ( QWebPage * page )

Makes 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 document is a child of the web view, it will be deleted.

See also page().

void QWebView::setRenderHint ( QPainter::RenderHint hint, bool enabled = true )

If enabled is true, enables the specified render hint; otherwise disables it.

This function was introduced in Qt 4.6.

See also renderHints and QPainter::renderHints().

void QWebView::setTextSizeMultiplier ( qreal factor )

Sets the value of the multiplier used to scale the text in a Web page to the factor specified.

See also textSizeMultiplier().

QWebSettings * QWebView::settings () const

Returns a pointer to the view/page specific settings object.

It is equivalent to

     view->page()->settings();

See also QWebSettings::globalSettings().

QSize QWebView::sizeHint () const   [virtual]

Reimplemented from QWidget::sizeHint().

void QWebView::statusBarMessage ( const QString & text )   [signal]

This signal is emitted when the status bar text is changed by the page.

void QWebView::stop ()   [slot]

Convenience slot that stops loading the document.

It is equivalent to

     view->page()->triggerPageAction(QWebPage::Stop);

See also reload(), pageAction(), and loadFinished().

qreal QWebView::textSizeMultiplier () const

Returns the value of the multiplier used to scale the text in a Web page.

See also setTextSizeMultiplier().

void QWebView::titleChanged ( const QString & title )   [signal]

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

See also title().

void QWebView::triggerPageAction ( QWebPage::WebAction action, bool checked = false )

Triggers the specified action. If it is a checkable action the specified checked state is assumed.

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

     view->triggerAction(QWebPage::Copy);

See also pageAction().

void QWebView::urlChanged ( const QUrl & url )   [signal]

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

See also url() and load().

void QWebView::wheelEvent ( QWheelEvent * ev )   [virtual protected]

Reimplemented from QWidget::wheelEvent().