Contents

• Public Types
• Public Functions
• Static Public Members
• Detailed Description
• Enabling Plugins
• Web Application Support

Detailed Description

TheQWebSettings class provides an object to store the settings used byQWebPage andQWebFrame.

EachQWebPage object has its ownQWebSettings 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 usingglobalSettings().

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 thesetAttribute() function. TheWebAttribute enum further describes each attribute.

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

Enabling Plugins

Support for browser plugins can enabled by setting thePluginsEnabled attribute. For many applications, this attribute is enabled for all pages by setting it on theglobal settings object.QtWebKit will always ignore this setting when processing Qt plugins. The decision to allow a Qt plugin is made by the client in its reimplementation ofQWebPage::createPlugin().

Web Application Support

WebKit provides support for features specified inHTML 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 thesetOfflineStoragePath() with an appropriate file path, and can limit the quota for each application by callingsetOfflineStorageDefaultQuota().

Member Type Documentation

enum QWebSettings::FontFamily

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

enum QWebSettings::FontSize

This enum describes the font sizes configurable throughQWebSettings.

enum QWebSettings::WebAttribute

This enum describes various attributes that are configurable throughQWebSettings.

enum QWebSettings::WebGraphic

This enums describes the standard graphical elements used in webpages.

Member Function Documentation

[static]void QWebSettings::clearIconDatabase()

Clears the icon database.

[static]void QWebSettings::clearMemoryCaches()

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 alsosetDefaultTextEncoding().

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

EnablesWebKit data persistence and sets the path topath. Ifpath is empty, the user-specific data location specified byDataLocation will be used instead.

This method will simultaneously set and enable theiconDatabasePath(),localStoragePath(),offlineStoragePath() andofflineWebApplicationCachePath().

This function was introduced in Qt 4.6.

See alsolocalStoragePath().

QString QWebSettings::fontFamily(FontFamily which) const

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

See alsosetFontFamily().

int QWebSettings::fontSize(FontSize type) const

Returns the default font size fortype.

See alsosetFontSize().

[static]QWebSettings * QWebSettings::globalSettings()

Returns the global settings object.

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

[static]QString QWebSettings::iconDatabasePath()

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

See alsosetIconDatabasePath() andclearIconDatabase().

[static]QIcon QWebSettings::iconForUrl(constQUrl & url)

Returns the web site's icon forurl.

If the web site does not specify an iconOR if the icon is not in the database, a nullQIcon is returned.

Note:The returned icon's size is arbitrary.

See alsosetIconDatabasePath().

QString QWebSettings::localStoragePath() const

Returns the path for HTML5 local storage.

This function was introduced in Qt 4.6.

See alsosetLocalStoragePath().

[static]int QWebSettings::maximumPagesInCache()

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

See alsosetMaximumPagesInCache().

[static]qint64 QWebSettings::offlineStorageDefaultQuota()

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

This function was introduced in Qt 4.5.

See alsosetOfflineStorageDefaultQuota().

[static]QString QWebSettings::offlineStoragePath()

Returns the path of the HTML5 client-side database storage or an empty string if the feature is disabled.

This function was introduced in Qt 4.5.

See alsosetOfflineStoragePath().

[static]QString QWebSettings::offlineWebApplicationCachePath()

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 alsosetOfflineWebApplicationCachePath().

[static]qint64 QWebSettings::offlineWebApplicationCacheQuota()

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

This function was introduced in Qt 4.6.

See alsosetOfflineWebApplicationCacheQuota().

void QWebSettings::resetAttribute(WebAttribute attribute)

Resets the setting ofattribute to the value specified in the globalQWebSettings instance.

This function has no effect on the globalQWebSettings instance.

See alsoglobalSettings().

void QWebSettings::resetFontFamily(FontFamily which)

Resets the actual font family specified bywhich to the one set in the globalQWebSettings instance.

This function has no effect on the globalQWebSettings instance.

void QWebSettings::resetFontSize(FontSize type)

Resets the font size fortype to the size specified in the global settings object.

This function has no effect on the globalQWebSettings instance.

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

Enables or disables the specifiedattribute feature depending on the value ofon.

void QWebSettings::setDefaultTextEncoding(constQString & encoding)

Specifies the default text encoding system.

Theencoding, 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 seeQTextCodec

This function was introduced in Qt 4.6.

See alsodefaultTextEncoding().

void QWebSettings::setFontFamily(FontFamily which, constQString & family)

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

See alsofontFamily().

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

Sets the font size fortype tosize.

See alsofontSize().

[static]void QWebSettings::setIconDatabasePath(constQString & path)

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

path must point to an existing directory.

Setting an empty path disables the icon database.

See alsoiconDatabasePath() andclearIconDatabase().

void QWebSettings::setLocalStoragePath(constQString & path)

Sets the path for HTML5 local storage topath.

For more information on HTML5 local storage see theWeb Storage standard.

Support for local storage can enabled by setting theLocalStorageEnabled attribute.

This function was introduced in Qt 4.6.

See alsolocalStoragePath().

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

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

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 topages.

For more information about the feature, please refer to:

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

See alsomaximumPagesInCache().

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

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

ThecacheMinDeadCapacity specifies theminimum number of bytes that dead objects should consume when the cache is under pressure.

cacheMaxDead is themaximum number of bytes that dead objects should consume when the cache isnot under pressure.

totalCapacity specifies themaximum number of bytes that the cache should consumeoverall.

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

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

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

This function was introduced in Qt 4.5.

See alsoofflineStorageDefaultQuota().

[static]void QWebSettings::setOfflineStoragePath(constQString & path)

Setspath as the save location for HTML5 client-side database storage data.

path must point to an existing directory.

Setting an empty path disables the feature.

Support for client-side databases can enabled by setting theOfflineStorageDatabaseEnabled attribute.

This function was introduced in Qt 4.5.

See alsoofflineStoragePath().

[static]void QWebSettings::setOfflineWebApplicationCachePath(constQString & path)

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

An application cache acts like an HTTP cache in some sense. For documents that use the application cache via JavaScript, the loader engine 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.

Setting an empty path disables the feature.

Support for offline web application cache storage can enabled by setting theOfflineWebApplicationCacheEnabled attribute.

This function was introduced in Qt 4.6.

See alsoofflineWebApplicationCachePath().

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

Sets the value of the quota for the offline web application cache tomaximumSize.

This function was introduced in Qt 4.6.

See alsoofflineWebApplicationCacheQuota().

void QWebSettings::setUserStyleSheetUrl(constQUrl & location)

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

Thelocation 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=="

Note:If the base64 data is not valid, the style will not be applied.

See alsouserStyleSheetUrl().

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

Setsgraphic to be drawn whenQtWebKit needs to draw an image of the giventype.

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

See alsowebGraphic().

bool QWebSettings::testAttribute(WebAttribute attribute) const

Returns true ifattribute is enabled; otherwise returns false.

QUrl QWebSettings::userStyleSheetUrl() const

Returns the location of the user stylesheet.

See alsosetUserStyleSheetUrl().

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

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

See alsosetWebGraphic().