qgpluginmanager.cpp

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

/*!
  \fn QRESULT QPluginManager::queryInterface(const QString& feature, Type** iface) const

  Sets \a iface to point to the interface providing \a feature.

  \sa featureList(), library()
*/



#include <qptrlist.h>

QGPluginManager::QGPluginManager( const QUuid& id, const QStringList& paths, const QString &suffix, bool cs )
    : interfaceId( id ), plugDict( 17, cs ), casesens( cs ), autounload( TRUE )
{
    // Every QLibrary object is destroyed on destruction of the manager
    libDict.setAutoDelete( TRUE );
    for ( QStringList::ConstIterator it = paths.begin(); it != paths.end(); ++it ) {
	QString path = *it;
	addLibraryPath( path + suffix );
    }
}

QGPluginManager::~QGPluginManager()
{
    if ( !autounload ) {
	QDictIterator<QLibrary> it( libDict );
	while ( it.current() ) {
	    QLibrary *lib = it.current();
	    ++it;
	    lib->setAutoUnload( FALSE );
	}
    }
}

void QGPluginManager::addLibraryPath( const QString& path )
{
    if ( !enabled() || !QDir( path ).exists( ".", TRUE ) )
	return;

#if defined(Q_OS_WIN32)
    QString filter = "*.dll";
#elif defined(Q_OS_MACX)
    QString filter = "*.dylib; *.so";
#elif defined(Q_OS_HPUX)
    QString filter = "*.sl";
#elif defined(Q_OS_UNIX)
    QString filter = "*.so";
#endif

    QStringList plugins = QDir(path).entryList( filter );
    for ( QStringList::Iterator p = plugins.begin(); p != plugins.end(); ++p ) {
	QString lib = QDir::cleanDirPath( path + "/" + *p );
	if ( libList.contains( lib ) )
	    continue;
	libList.append( lib );
    }
}

const QLibrary* QGPluginManager::library( const QString& feature ) const
{
    if ( !enabled() || feature.isEmpty() )
	return 0;

    // We already have a QLibrary object for this feature
    QLibrary *library = 0;
    if ( ( library = plugDict[feature] ) )
	return library;

    // Find the filename that matches the feature request best
    QMap<int, QStringList> map;
    QStringList::ConstIterator it = libList.begin();
    int best = 0;
    int worst = 15;
    while ( it != libList.end() ) {
	if ( (*it).isEmpty() || libDict[*it] ) {
	    ++it;
	    continue;
	}
	QString basename = QFileInfo(*it).baseName();
	int s = similarity( feature, basename );
	if ( s < worst )
	    worst = s;
	if ( s > best )
	    best = s;
	map[s].append( basename + QChar(0xfffd) + *it );
	++it;
    }

    if ( map.isEmpty() )
	return 0; // no libraries to add

    // Start with the best match to get the library object
    QGPluginManager *that = (QGPluginManager*)this;
    for ( int s = best; s >= worst; --s ) {
	QStringList group = map[s];
	group.sort(); // sort according to the base name
	QStringList::ConstIterator git = group.begin();
	while ( git != group.end() ) {
	    QString lib = (*git).mid( (*git).find( QChar(0xfffd) ) + 1 );
	    QString basename = (*git).left( (*git).find( QChar(0xfffd) ) );
	    ++git;

	    QStringList sameBasename;
	    while( git != group.end() &&
		   basename == (*git).left( (*git).find( QChar(0xfffd) ) )  ) {
		sameBasename << (*git).mid( (*git).find( QChar(0xfffd) ) + 1 );
		++git;
	    }

	    if ( sameBasename.isEmpty() ) {
		that->addLibrary( new QComLibrary( lib ) );
	    } else {
		QPtrList<QComLibrary> same;
		same.setAutoDelete( TRUE );
		for ( QStringList::ConstIterator bit = sameBasename.begin();
		      bit != sameBasename.end(); ++bit )
		    same.append( new QComLibrary( *bit ) );
		QComLibrary* bestMatch = 0;
		for ( QComLibrary* candidate = same.first(); candidate; candidate = same.next() )
		    if ( candidate->qtVersion() && candidate->qtVersion() <= QT_VERSION
			 && ( !bestMatch || candidate->qtVersion() > bestMatch->qtVersion() ) )
			bestMatch = candidate;
		if ( bestMatch ) {
		    same.find( bestMatch );
		    that->addLibrary( same.take() );
		}
	    }

	    if ( ( library = that->plugDict[feature] ) )
		return library;
	}
    }
    return 0;
}

QStringList QGPluginManager::featureList() const
{
    QStringList features;

    if ( !enabled() )
	return features;

    QGPluginManager *that = (QGPluginManager*)this;
    QStringList theLibs = libList;
    QStringList phase2Libs;
    QStringList phase2Deny;

    /* In order to get the feature list we need to add all interesting
      libraries. If there are libraries with the same base name, we
      prioritze the one that fits our Qt version number and ignore the
      others  */
    QStringList::Iterator it;
    for ( it = theLibs.begin(); it != theLibs.end(); ++it  ) {
	if ( (*it).isEmpty() || libDict[*it] )
	    continue;
	QComLibrary* library = new QComLibrary( *it );
	if ( library->qtVersion() == QT_VERSION ) {
	    that->addLibrary( library );
	    phase2Deny << QFileInfo( *it ).baseName();
	} else {
	    delete library;
	    phase2Libs << *it;
	}
    }
    for ( it = phase2Libs.begin(); it != phase2Libs.end(); ++it  )
	if ( !phase2Deny.contains( QFileInfo( *it ).baseName() ) )
	    that->addLibrary( new QComLibrary( *it ) );

    for ( QDictIterator<QLibrary> pit( plugDict ); pit.current(); ++pit )
	features << pit.currentKey();

    return features;
}

bool QGPluginManager::addLibrary( QLibrary* lib )
{
    if ( !enabled() || !lib )
	return FALSE;

    QComLibrary* plugin = (QComLibrary*)lib;
    bool useful = FALSE;

    QUnknownInterface* iFace = 0;
    plugin->queryInterface( interfaceId, &iFace );
    if ( iFace ) {
	QFeatureListInterface *fliFace = 0;
	QComponentInformationInterface *cpiFace = 0;
	iFace->queryInterface( IID_QFeatureList, (QUnknownInterface**)&fliFace );
	if ( !fliFace )
	    plugin->queryInterface( IID_QFeatureList, (QUnknownInterface**)&fliFace );
	if ( !fliFace ) {
	    iFace->queryInterface( IID_QComponentInformation, (QUnknownInterface**)&cpiFace );
	    if ( !cpiFace )
		plugin->queryInterface( IID_QComponentInformation, (QUnknownInterface**)&cpiFace );
	}
	QStringList fl;
	if ( fliFace )
	    // Map all found features to the library
	    fl = fliFace->featureList();
	else if ( cpiFace )
	    fl << cpiFace->name();

	for ( QStringList::Iterator f = fl.begin(); f != fl.end(); ++f ) {
	    QLibrary *old = plugDict[*f];
	    if ( !old ) {
		useful = TRUE;
		plugDict.replace( *f, plugin );
	    } else {
		// we have old *and* plugin, which one to pick?
		QComLibrary* first = (QComLibrary*)old;
		QComLibrary* second = (QComLibrary*)plugin;
		bool takeFirst = TRUE;
		if ( first->qtVersion() != QT_VERSION ) {
		    if ( second->qtVersion() == QT_VERSION )
			takeFirst = FALSE;
		    else if ( second->qtVersion() < QT_VERSION &&
			      first->qtVersion() > QT_VERSION )
			takeFirst = FALSE;
		}
		if ( !takeFirst ) {
		    useful = TRUE;
		    plugDict.replace( *f, plugin );
		    qWarning("%s: Discarding feature %s in %s!",
			     (const char*) QFile::encodeName( plugin->library()),
			     (*f).latin1(),
			     (const char*) QFile::encodeName( old->library() ) );
		} else {
		    qWarning("%s: Feature %s already defined in %s!",
			     (const char*) QFile::encodeName( old->library() ),
			     (*f).latin1(),
			     (const char*) QFile::encodeName( plugin->library() ) );
		}
	    }
	}
	if ( fliFace )
	    fliFace->release();
	if ( cpiFace )
	    cpiFace->release();
	iFace->release();
    }

    if ( useful ) {
	libDict.replace( plugin->library(), plugin );
	if ( !libList.contains( plugin->library() ) )
	    libList.append( plugin->library() );
	return TRUE;
    }
    delete plugin;
    return FALSE;
}


bool QGPluginManager::enabled() const
{
#ifdef QT_SHARED
    return TRUE;
#else
    return FALSE;
#endif
}

QRESULT QGPluginManager::queryUnknownInterface(const QString& feature, QUnknownInterface** iface) const
{
    QComLibrary* plugin = 0;
    plugin = (QComLibrary*)library( feature );
    return plugin ? plugin->queryInterface( interfaceId, (QUnknownInterface**)iface ) : QE_NOINTERFACE;
}

#endif //QT_NO_COMPONENT