QContentPlugin Class Reference
[QtBaseModule]

Detailed Description

The QContentPlugin class provides an interface for the Qt Extended Document System to discover detailed information about a file.

Content plug-ins are used by the document system to read meta-data from files that may be used to index the content or better describe it to the user. When a new file is first discovered by the document system its extension is used to identify possible plug-ins that may be able to identify the file. If any such plug-in is found the plug-in's installContent() method is called with the file name and the destination QContent as arguments. The document system will keep trying potential content plug-ins until one is found that identifies itself as having successfully processed the file by returning true.

The content plug-ins are also invoked when a content record is found to be out of date, but in this case the updateContent() method of the plug-in is called. A content record is determined to be out of date when the backing file's last modified date is more recent than the content records last update date.

Member Function Documentation

QContentPlugin::~QContentPlugin ()   [virtual]

Destroys a QContentPlugin.

bool QContentPlugin::installContent ( const QString & fileName, QContent * content )   [pure virtual]

Populates content with data from the file with the file name fileName. Returns true if the content plug-in successfully populated the QContent.

Installation is only performed when the content is first identified by the content system, if the file changes after installation updateContent() will be called to ensure the content data is up to date; otherwise returns false

QStringList QContentPlugin::keys () const   [pure virtual]

Returns a list of the file extensions the QContentPlugin instance can report on.

void QContentPlugin::preloadPlugins ()   [static]

Initializes the content plug-in manager.

This should not normally not be necessary as the plug-in manager is loaded on demand.

bool QContentPlugin::updateContent ( QContent * content )   [virtual]

Refreshes the content data of content following a change to the file it references.

Returns true if the content data has been ensured to be up to date; otherwise returns false.