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QWebSettings Class Reference
[QtWebKit module]

The QWebSettings class provides an object to store the settings used by QWebPage and QWebFrame. More...

 #include <QWebSettings>

This class is not part of the Qt GUI Framework Edition.

This class was introduced in Qt 4.4.

• List of all members, including inherited members

Public Types

Public Functions

Static Public Members

Related Non-Members

Detailed Description

The QWebSettings class provides an object to store the settings used by QWebPage and QWebFrame.

Each QWebPage object has its own QWebSettings object, which configures the settings for that page. If a setting is not configured, then it is looked up in the global settings object, which can be accessed using globalSettings().

QWebSettings allows configuration of browser properties, such as font sizes and families, the location of a custom style sheet, and generic attributes like JavaScript and plugins. Individual attributes are set using the setAttribute() function. The WebAttribute enum further describes each attribute.

QWebSettings also configures global properties such as the Web page memory cache and the Web page icon database, local database storage and offline applications storage.

Enabling Plugins

Support for browser plugins can enabled by setting the PluginsEnabled attribute. For many applications, this attribute is enabled for all pages by setting it on the global settings object.

Web Application Support

WebKit provides support for features specified in HTML 5 that improve the performance and capabilities of Web applications. These include client-side (offline) storage and the use of a Web application cache.

Client-side (offline) storage is an improvement over the use of cookies to store persistent data in Web applications. Applications can configure and enable the use of an offline storage database by calling the setOfflineStoragePath() with an appropriate file path, and can limit the quota for each application by calling setOfflineStorageDefaultQuota().

See also QWebPage::settings(), QWebView::settings(), and Web Browser.

Member Type Documentation

enum QWebSettings::FontFamily

This enum describes the generic font families defined by CSS 2. For more information see the CSS standard.

enum QWebSettings::FontSize

This enum describes the font sizes configurable through QWebSettings.

enum QWebSettings::WebAttribute

This enum describes various attributes that are configurable through QWebSettings.

enum QWebSettings::WebGraphic

This enums describes the standard graphical elements used in webpages.

Member Function Documentation

void QWebSettings::clearIconDatabase ()   [static]

Clears the icon database.

void QWebSettings::clearMemoryCaches ()   [static]

Frees up as much memory as possible by cleaning all memory caches such as page, object and font cache.

This function was introduced in Qt 4.6.

QString QWebSettings::defaultTextEncoding () const

Returns the default text encoding.

This function was introduced in Qt 4.6.

See also setDefaultTextEncoding().

void QWebSettings::enablePersistentStorage ( const QString & path = QString() )   [static]

Enables WebKit persistent data and sets the path to path. If the path is empty the path for persistent data is set to the user-specific data location specified by DataLocation.

This function was introduced in Qt 4.6.

See also localStoragePath().

QString QWebSettings::fontFamily ( FontFamily which ) const

Returns the actual font family for the specified generic font family, which.

See also setFontFamily().

int QWebSettings::fontSize ( FontSize type ) const

Returns the default font size for type.

See also setFontSize().

QWebSettings * QWebSettings::globalSettings ()   [static]

Returns the global settings object.

Any setting changed on the default object is automatically applied to all QWebPage instances where the particular setting is not overriden already.

QString QWebSettings::iconDatabasePath ()   [static]

Returns the path of the icon database or an empty string if the icon database is disabled.

See also setIconDatabasePath() and clearIconDatabase().

QIcon QWebSettings::iconForUrl ( const QUrl & url )   [static]

Returns the web site's icon for url.

If the web site does not specify an icon, or the icon is not in the database, a null QIcon is returned.

Note: The returned icon's size is arbitrary.

See also setIconDatabasePath().

QString QWebSettings::localStoragePath () const

Returns the path for HTML5 local storage.

This function was introduced in Qt 4.6.

See also setLocalStoragePath().

int QWebSettings::maximumPagesInCache ()   [static]

Returns the maximum number of web pages that are kept in the memory cache.

See also setMaximumPagesInCache().

qint64 QWebSettings::offlineStorageDefaultQuota ()   [static]

Returns the value of the default quota for new offline storage databases.

This function was introduced in Qt 4.5.

See also setOfflineStorageDefaultQuota().

QString QWebSettings::offlineStoragePath ()   [static]

Returns the path of the HTML5 offline storage or an empty string if the feature is disabled.

This function was introduced in Qt 4.5.

See also setOfflineStoragePath().

QString QWebSettings::offlineWebApplicationCachePath ()   [static]

Returns the path of the HTML5 offline web application cache storage or an empty string if the feature is disabled.

This function was introduced in Qt 4.6.

See also setOfflineWebApplicationCachePath().

qint64 QWebSettings::offlineWebApplicationCacheQuota ()   [static]

Returns the value of the quota for the offline web application cache.

This function was introduced in Qt 4.6.

See also setOfflineWebApplicationCacheQuota().

void QWebSettings::resetAttribute ( WebAttribute attribute )

Resets the setting of attribute. This function has no effect on the global QWebSettings instance.

See also globalSettings().

void QWebSettings::resetFontFamily ( FontFamily which )

Resets the actual font family to the default font family, specified by which.

This function has no effect on the global QWebSettings instance.

void QWebSettings::resetFontSize ( FontSize type )

Resets the font size for type to the size specified in the global settings object.

This function has no effect on the global QWebSettings instance.

void QWebSettings::setAttribute ( WebAttribute attribute, bool on )

Enables or disables the specified attribute feature depending on the value of on.

void QWebSettings::setDefaultTextEncoding ( const QString & encoding )

Specifies the default text encoding system.

The encoding, must be a string describing an encoding such as "utf-8", "iso-8859-1", etc. If left empty a default value will be used. For a more extensive list of encoding names see QTextCodec

This function was introduced in Qt 4.6.

See also defaultTextEncoding().

void QWebSettings::setFontFamily ( FontFamily which, const QString & family )

Sets the actual font family to family for the specified generic family, which.

See also fontFamily().

void QWebSettings::setFontSize ( FontSize type, int size )

Sets the font size for type to size.

See also fontSize().

void QWebSettings::setIconDatabasePath ( const QString & path )   [static]

Sets the path of the icon database to path. The icon database is used to store "favicons" associated with web sites.

path must point to an existing directory where the icons are stored.

Setting an empty path disables the icon database.

See also iconDatabasePath().

void QWebSettings::setLocalStoragePath ( const QString & path )

Sets the path for HTML5 local storage to path.

For more information on HTML5 local storage see the Web Storage standard.

Support for local storage can enabled by setting the LocalStorageEnabled attribute.

This function was introduced in Qt 4.6.

See also localStoragePath().

void QWebSettings::setMaximumPagesInCache ( int pages )   [static]

Sets the maximum number of pages to hold in the memory page cache to pages.

The Page Cache allows for a nicer user experience when navigating forth or back to pages in the forward/back history, by pausing and resuming up to pages per page group.

For more information about the feature, please refer to:

http://webkit.org/blog/427/webkit-page-cache-i-the-basics/

See also maximumPagesInCache().

void QWebSettings::setObjectCacheCapacities ( int cacheMinDeadCapacity, int cacheMaxDead, int totalCapacity )   [static]

Specifies the capacities for the memory cache for dead objects such as stylesheets or scripts.

The cacheMinDeadCapacity specifies the minimum number of bytes that dead objects should consume when the cache is under pressure.

cacheMaxDead is the maximum number of bytes that dead objects should consume when the cache is not under pressure.

totalCapacity specifies the maximum number of bytes that the cache should consume overall.

The cache is enabled by default. Calling setObjectCacheCapacities(0, 0, 0) will disable the cache. Calling it with one non-zero enables it again.

void QWebSettings::setOfflineStorageDefaultQuota ( qint64 maximumSize )   [static]

Sets the value of the default quota for new offline storage databases to maximumSize.

This function was introduced in Qt 4.5.

See also offlineStorageDefaultQuota().

void QWebSettings::setOfflineStoragePath ( const QString & path )   [static]

Sets the path for HTML5 offline storage to path.

path must point to an existing directory where the databases are stored.

Setting an empty path disables the feature.

This function was introduced in Qt 4.5.

See also offlineStoragePath().

void QWebSettings::setOfflineWebApplicationCachePath ( const QString & path )   [static]

Sets the path for HTML5 offline web application cache storage to path.

An application cache acts like an HTTP cache in some sense. For documents that use the application cache via JavaScript, the loader mechinery will first ask the application cache for the contents, before hitting the network.

The feature is described in details at: http://dev.w3.org/html5/spec/Overview.html#appcache

path must point to an existing directory where the cache is stored.

Setting an empty path disables the feature.

This function was introduced in Qt 4.6.

See also offlineWebApplicationCachePath().

void QWebSettings::setOfflineWebApplicationCacheQuota ( qint64 maximumSize )   [static]

Sets the value of the quota for the offline web application cache to maximumSize.

This function was introduced in Qt 4.6.

See also offlineWebApplicationCacheQuota().

void QWebSettings::setUserStyleSheetUrl ( const QUrl & location )

Specifies the location of a user stylesheet to load with every web page.

The location must be either a path on the local filesystem, or a data URL with UTF-8 and Base64 encoded data, such as:

"data:text/css;charset=utf-8;base64,cCB7IGJhY2tncm91bmQtY29sb3I6IHJlZCB9Ow==;"

See also userStyleSheetUrl().

void QWebSettings::setWebGraphic ( WebGraphic type, const QPixmap & graphic )   [static]

Sets graphic to be drawn when QtWebKit needs to draw an image of the given type.

For example, when an image cannot be loaded the pixmap specified by MissingImageGraphic is drawn instead.

See also webGraphic().

bool QWebSettings::testAttribute ( WebAttribute attribute ) const

Returns true if attribute is enabled; otherwise returns false.

QUrl QWebSettings::userStyleSheetUrl () const

Returns the location of the user stylesheet.

See also setUserStyleSheetUrl().

QPixmap QWebSettings::webGraphic ( WebGraphic type )   [static]

Returns a previously set pixmap used to draw replacement graphics of the specified type.

For example, when an image cannot be loaded the pixmap specified by MissingImageGraphic is drawn instead.

See also setWebGraphic().

Related Non-Members

void QWebSettings::enablePersistentStorage ( const QString & path = QString() )   [static]

Enables WebKit persistent data and sets the path to path. If the path is empty the path for persistent data is set to the user-specific data location specified by DataLocation.

This function was introduced in Qt 4.6.

See also localStoragePath().

QString QWebSettings::localStoragePath () const

Returns the path for HTML5 local storage.

This function was introduced in Qt 4.6.

See also setLocalStoragePath().

QString QWebSettings::offlineWebApplicationCachePath ()   [static]

Returns the path of the HTML5 offline web application cache storage or an empty string if the feature is disabled.

This function was introduced in Qt 4.6.

See also setOfflineWebApplicationCachePath().

void QWebSettings::setLocalStoragePath ( const QString & path )

Sets the path for HTML5 local storage to path.

For more information on HTML5 local storage see the Web Storage standard.

Support for local storage can enabled by setting the LocalStorageEnabled attribute.

This function was introduced in Qt 4.6.

See also localStoragePath().

void QWebSettings::setOfflineWebApplicationCachePath ( const QString & path )   [static]

Sets the path for HTML5 offline web application cache storage to path.

An application cache acts like an HTTP cache in some sense. For documents that use the application cache via JavaScript, the loader mechinery will first ask the application cache for the contents, before hitting the network.

The feature is described in details at: http://dev.w3.org/html5/spec/Overview.html#appcache

path must point to an existing directory where the cache is stored.

Setting an empty path disables the feature.

This function was introduced in Qt 4.6.

See also offlineWebApplicationCachePath().