QLibrary Class Reference

The QLibrary class provides a wrapper for handling shared libraries. More...

#include </home/clem/local/src/opie/library/qlibrary.h>

Inheritance diagram for QLibrary:

[legend]Collaboration diagram for QLibrary:

[legend]List of all members.

Public Types
enum	Policy { Delayed, Immediately, Manual }
Public Member Functions
	QLibrary (const QString &filename, Policy=Delayed)
	~QLibrary ()
void *	resolve (const char *)
bool	unload (bool force=FALSE)
bool	isLoaded () const
void	setPolicy (Policy pol)
Policy	policy () const
QString	library () const
QRESULT	queryInterface (const QUuid &, QUnknownInterface **)
Static Public Member Functions
static void *	resolve (const QString &filename, const char *)
Private Member Functions
bool	load ()
void	createInstanceInternal ()
Private Attributes
QLibraryPrivate *	d
QString	libfile
Policy	libPol
QUnknownInterface *	entry

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Detailed Description

The QLibrary class provides a wrapper for handling shared libraries.

This class is temporarily copied from Qt 3.0.

Definition at line 32 of file qlibrary.h.

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Member Enumeration Documentation

enum QLibrary::Policy

This enum type defines the various policies a QLibrary can have with respect to loading and unloading the shared library. The policy can be: Delayed The library get's loaded as soon as needed and unloaded in the destructor Immediately The library is loaded immediately and unloaded in the destructor Manual Like delayed, and library has to be unloaded manually Enumeration values: Delayed  Immediately  Manual  Definition at line 35 of file qlibrary.h.

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Constructor & Destructor Documentation

QLibrary::QLibrary (  const QString &  filename, Policy  pol = Delayed )

Creates a QLibrary object for the shared library filename. The library get's loaded if pol is Immediately. Note that filename does not need to include the (platform specific) file extension, so calling QLibrary lib( "mylib" ); would be equivalent to QLibrary lib( "mylib.dll" ); on Windows. But "mylib.dll" will obviously not work on other platforms. See also: setPolicy(), unload() Definition at line 154 of file qlibrary.cpp. References d, Immediately, and load().

QLibrary::~QLibrary (   )

Deletes the QLibrary object. The library will be unloaded if the policy is not Manual. See also: unload(), setPolicy() Definition at line 168 of file qlibrary.cpp. References d, entry, libPol, Manual, QUnknownInterface::release(), and unload().

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Member Function Documentation

void QLibrary::createInstanceInternal (   )  [private]

Reimplemented in QComLibrary. Definition at line 179 of file qlibrary.cpp. References d, entry, IID_QLibrary, QLibraryInterface::init(), QString::isEmpty(), QLibraryPrivate::killTimer(), libfile, QLibraryPrivate::libIface, libPol, library(), load(), Manual, QLibraryPrivate::pHnd, QUnknownInterface::queryInterface(), qWarning(), resolve(), QLibraryPrivate::startTimer(), and unload(). Referenced by queryInterface().

bool QLibrary::isLoaded (   )  const

Returns whether the library is loaded. See also: unload() Definition at line 277 of file qlibrary.cpp. References d, and QLibraryPrivate::pHnd. Referenced by QComLibrary::createInstanceInternal(), and Opie::Core::Internal::OPluginLibraryHolder::ref().

QString QLibrary::library (   )  const

Returns the filename of the shared library this QLibrary object handles, including the platform specific file extension. QLibrary lib( "mylib" ); QString str = lib.library(); will set str to "mylib.dll" on Windows, and "libmylib.so" on Linux. Definition at line 402 of file qlibrary.cpp. References QString::find(), QString::isEmpty(), and libfile. Referenced by QGPluginManager::addLibrary(), compareAppletPositions(), QComLibrary::createInstanceInternal(), createInstanceInternal(), QLibraryPrivate::loadLibrary(), QLibraryPrivate::tryUnload(), and unload().

bool QLibrary::load (   )  [private]

Loads the library. Definition at line 285 of file qlibrary.cpp. References d, and QLibraryPrivate::loadLibrary(). Referenced by QComLibrary::createInstanceInternal(), createInstanceInternal(), QLibrary(), resolve(), and setPolicy().

QLibrary::Policy QLibrary::policy (   )  const

Returns the current policy. See also: setPolicy() Definition at line 386 of file qlibrary.cpp. References libPol. Referenced by QLibraryPrivate::tryUnload().

QRESULT QLibrary::queryInterface (  const QUuid &  request, QUnknownInterface **  iface )

Forwards the query to the component and returns the result. request and iface are propagated to the component's queryInterface implementation. The library gets loaded if necessary. Reimplemented in QComLibrary. Definition at line 428 of file qlibrary.cpp. References createInstanceInternal(), entry, QE_NOINTERFACE, and QUnknownInterface::queryInterface(). Referenced by SysTray::addApplets(), calc::calc(), IrServer::IrServer(), Opie::Core::OGenericPluginLoader::load(), StartMenu::loadApplets(), QPEApplication::Private::loadImageCodecs(), InputMethods::loadInputMethods(), Network::loadPlugin(), MultiauthConfig::loadPlugins(), MediaPlayerState::loadPlugins(), FontDatabase::loadRenderers(), QPEApplication::Private::loadTextCodecs(), main(), QuickPrivate::PluginLoader::queryInterface(), and Opie::Security::Internal::runPlugins().

void * QLibrary::resolve (  const QString &  filename, const char *  symb )  [static]

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Loads the library filename and returns the address of the exported symbol symb. Note that like for the constructor, filename does not need to include the (platform specific) file extension. The library staying loaded until the process exits. The function returns a null pointer if the symbol could not be resolved or if loading the library failed. Definition at line 266 of file qlibrary.cpp. References Manual, and resolve().

void * QLibrary::resolve (  const char *  symb  )

Returns the address of the exported symbol symb. The library gets loaded if necessary. The function returns NULL if the symbol could not be resolved, or if loading the library failed. typedef int (*addProc)( int, int ); addProc add = (addProc) library->resolve( "add" ); if ( add ) return add( 5, 8 ); else return 5 + 8; See also: queryInterface() Definition at line 238 of file qlibrary.cpp. References d, load(), QLibraryPrivate::pHnd, qWarning(), and QLibraryPrivate::resolveSymbol(). Referenced by QComLibrary::createInstanceInternal(), createInstanceInternal(), MainWindowImp::loadPlugin(), QSettingsPrivate::QSettingsPrivate(), and resolve().

void QLibrary::setPolicy (  Policy  pol  )

Sets the current policy to pol. The library is loaded if pol is set to Immediately. Definition at line 373 of file qlibrary.cpp. References d, Immediately, libPol, load(), and QLibraryPrivate::pHnd.

bool QLibrary::unload (  bool  force = FALSE  )

Releases the component and unloads the library when successful. Returns TRUE if the library could be unloaded, otherwise FALSE. If the component implements the QLibraryInterface, the cleanup() function of this interface will be called. The unloading will be cancelled if the subsequent call to canUnload() returns FALSE. This function gets called automatically in the destructor if the policy is not Manual. Warning: If force is set to TRUE, the library gets unloaded at any cost, which is in most cases a segmentation fault, so you should know what you're doing! See also: queryInterface(), resolve() Definition at line 307 of file qlibrary.cpp. References QUnknownInterface::addRef(), QLibraryInterface::canUnload(), QLibraryInterface::cleanup(), d, entry, FALSE, QLibraryPrivate::freeLibrary(), QLibraryPrivate::killTimer(), QLibraryPrivate::libIface, library(), QLibraryPrivate::pHnd, qWarning(), QUnknownInterface::release(), and TRUE. Referenced by StartMenu::clearApplets(), createInstanceInternal(), QPEApplication::Private::loadImageCodecs(), QPEApplication::Private::loadTextCodecs(), InputMethod::releaseInterface(), QLibraryPrivate::tryUnload(), QComLibrary::unload(), and ~QLibrary().

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Member Data Documentation

QLibraryPrivate* QLibrary::d [private]

Definition at line 62 of file qlibrary.h. Referenced by createInstanceInternal(), isLoaded(), load(), QLibrary(), resolve(), setPolicy(), unload(), and ~QLibrary().

QUnknownInterface* QLibrary::entry [private]

Reimplemented in QComLibrary. Definition at line 66 of file qlibrary.h. Referenced by createInstanceInternal(), queryInterface(), unload(), and ~QLibrary().

QString QLibrary::libfile [private]

Definition at line 64 of file qlibrary.h. Referenced by createInstanceInternal(), and library().

Policy QLibrary::libPol [private]

Definition at line 65 of file qlibrary.h. Referenced by createInstanceInternal(), policy(), setPolicy(), and ~QLibrary().

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The documentation for this class was generated from the following files:

• library/qlibrary.h
• library/qlibrary.cpp
• qmake/tools/qlibrary.cpp

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