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tdelibs/tdeparts/componentfactory.h

397 行
17 KiB

#ifndef __tdeparts_componentfactory_h__
#define __tdeparts_componentfactory_h__
#include <tdeparts/factory.h>
#include <tdeparts/part.h>
#include <ktrader.h>
#include <tqmetaobject.h>
namespace KParts
{
// this is a namespace and not a class because stupid egcs 1.1.2 doesn't grok
// static template methods in classes. !@%@#$!
/**
* Namespace for KParts components
*/
namespace ComponentFactory
{
/**
* This enum type defines the possible error cases that can happen
* when loading a component.
*
* <ul>
* <li><code>ErrNoServiceFound</code> - no service implementing the
* given mimetype and fullfilling the given constraint expression
* can be found.</li>
* <li><code>ErrServiceProvidesNoLibrary</code> - the specified service
* provides no shared library</li>
* <li><code>ErrNoLibrary</code> - the specified library could not be
* loaded. Use KLibLoader::lastErrorMessage for details.</li>
* <li><code>ErrNoFactory</code> - the library does not export a factory
* for creating components</li>
* <li><code>ErrNoComponent</code> - the factory does not support creating
* components of the specified type</li>
* </ul>
*/
enum ComponentLoadingError { ErrNoServiceFound = 1,
ErrServiceProvidesNoLibrary,
ErrNoLibrary,
ErrNoFactory,
ErrNoComponent };
/**
* This template function allows to ask the given factory to create an
* instance of the given template type.
*
* Example of usage:
* \code
* MyPlugin *plugin = KParts::ComponentFactory::createInstanceFromFactory<MyPlugin>( factory, parent );
* \endcode
*
* @param factory The factory to ask for the creation of the component
* @param parent The parent object (see TQObject constructor)
* @param name The name of the object to create (see TQObject constructor)
* @param args A list of string arguments, passed to the factory and possibly
* to the component (see KLibFactory)
* @return A pointer to the newly created object or a null pointer if the
* factory was unable to create an object of the given type.
*/
template <class T>
static T *createInstanceFromFactory( KLibFactory *factory, TQObject *parent = 0,
const char *name = 0,
const TQStringList &args = TQStringList() )
{
TQObject *object = factory->create( parent, name,
T::staticMetaObject()->className(),
args );
T *result = dynamic_cast<T *>( object );
if ( !result )
delete object;
return result;
}
/**
* This template function allows to ask the given tdeparts factory to create an
* instance of the given template type.
*
* Example of usage:
* \code
* KViewPart *doc = KParts::ComponentFactory::createPartInstanceFromFactory<KViewPart>( factory, parent );
* \endcode
*
* @param factory The factory to ask for the creation of the component
* @param parentWidget the parent widget for the part
* @param widgetName the name of the part's widget
* @param parent The parent object (see TQObject constructor)
* @param name The name of the object to create (see TQObject constructor)
* @param args A list of string arguments, passed to the factory and possibly
* to the component (see KLibFactory)
* @return A pointer to the newly created object or a null pointer if the
* factory was unable to create an object of the given type.
*/
template <class T>
static T *createPartInstanceFromFactory( KParts::Factory *factory,
TQWidget *parentWidget = 0,
const char *widgetName = 0,
TQObject *parent = 0,
const char *name = 0,
const TQStringList &args = TQStringList() )
{
KParts::Part *object = factory->createPart( parentWidget, widgetName,
parent, name,
T::staticMetaObject()->className(),
args );
T *result = dynamic_cast<T *>( object );
if ( !result )
delete object;
return result;
}
/**
* This template allows to load the specified library and ask the
* factory to create an instance of the given template type.
*
* @param libraryName The library to open
* @param parent The parent object (see TQObject constructor)
* @param name The name of the object to create (see TQObject constructor)
* @param args A list of string arguments, passed to the factory and possibly
* to the component (see KLibFactory)
* @param error
* @return A pointer to the newly created object or a null pointer if the
* factory was unable to create an object of the given type.
*/
template <class T>
static T *createInstanceFromLibrary( const char *libraryName, TQObject *parent = 0,
const char *name = 0,
const TQStringList &args = TQStringList(),
int *error = 0 )
{
KLibrary *library = KLibLoader::self()->library( libraryName );
if ( !library )
{
if ( error )
*error = ErrNoLibrary;
return 0;
}
KLibFactory *factory = library->factory();
if ( !factory )
{
library->unload();
if ( error )
*error = ErrNoFactory;
return 0;
}
T *res = createInstanceFromFactory<T>( factory, parent, name, args );
if ( !res )
{
library->unload();
if ( error )
*error = ErrNoComponent;
}
return res;
}
template <class T>
static T *createPartInstanceFromLibrary( const char *libraryName,
TQWidget *parentWidget = 0,
const char *widgetName = 0,
TQObject *parent = 0,
const char *name = 0,
const TQStringList &args = TQStringList(),
int *error = 0 )
{
KLibrary *library = KLibLoader::self()->library( libraryName );
if ( !library )
{
if ( error )
*error = ErrNoLibrary;
return 0;
}
KLibFactory *factory = library->factory();
if ( !factory )
{
library->unload();
if ( error )
*error = ErrNoFactory;
return 0;
}
KParts::Factory *partFactory = dynamic_cast<KParts::Factory *>( factory );
if ( !partFactory )
{
library->unload();
if ( error )
*error = ErrNoFactory;
return 0;
}
T *res = createPartInstanceFromFactory<T>( partFactory, parentWidget,
widgetName, parent, name, args );
if ( !res )
{
library->unload();
if ( error )
*error = ErrNoComponent;
}
return res;
}
template <class T>
static T *createInstanceFromService( const KService::Ptr &service,
TQObject *parent = 0,
const char *name = 0,
const TQStringList &args = TQStringList(),
int *error = 0 )
{
TQString library = service->library();
if ( library.isEmpty() )
{
if ( error )
*error = ErrServiceProvidesNoLibrary;
return 0;
}
return createInstanceFromLibrary<T>( library.local8Bit().data(), parent,
name, args, error );
}
template <class T>
static T *createPartInstanceFromService( const KService::Ptr &service,
TQWidget *parentWidget = 0,
const char *widgetName = 0,
TQObject *parent = 0,
const char *name = 0,
const TQStringList &args = TQStringList(),
int *error = 0 )
{
TQString library = service->library();
if ( library.isEmpty() )
{
if ( error )
*error = ErrServiceProvidesNoLibrary;
return 0;
}
return createPartInstanceFromLibrary<T>( library.local8Bit().data(), parentWidget,
widgetName, parent, name, args, error );
}
template <class T, class ServiceIterator>
static T *createInstanceFromServices( ServiceIterator begin, ServiceIterator end,
TQObject *parent = 0,
const char *name = 0,
const TQStringList &args = TQStringList(),
int *error = 0 )
{
for (; begin != end; ++begin )
{
KService::Ptr service = *begin;
if ( error )
*error = 0;
T *component = createInstanceFromService<T>( service, parent, name,
args, error );
if ( component )
return component;
}
if ( error )
*error = ErrNoServiceFound;
return 0;
}
template <class T, class ServiceIterator>
static T *createPartInstanceFromServices( ServiceIterator begin,
ServiceIterator end,
TQWidget *parentWidget = 0,
const char *widgetName = 0,
TQObject *parent = 0,
const char *name = 0,
const TQStringList &args = TQStringList(),
int *error = 0 )
{
for (; begin != end; ++begin )
{
KService::Ptr service = *begin;
if ( error )
*error = 0;
T *component = createPartInstanceFromService<T>( service, parentWidget,
widgetName, parent,
name, args, error );
if ( component )
return component;
}
if ( error )
*error = ErrNoServiceFound;
return 0;
}
/**
* This method creates and returns a plugin, from the trader query for a given serviceType.
*
* Example:
* \code
* KMyAppPlugin* plugin = KParts::ComponentFactory::createInstanceFromQuery<KMyAppPlugin>( serviceType, TQString::null, parentObject );
* if ( plugin ) {
* ....
* }
* \endcode
*
* @param serviceType the type of service for which to find a plugin
* @param constraint an optional constraint to pass to the trader (see TDEIO::TDETrader)
* @param parent the parent object for the part itself
* @param name the name that will be given to the part
* @param args A list of string arguments, passed to the factory and possibly
* to the component (see KLibFactory)
* @param error The int passed here will receive an error code in case of errors.
* (See enum #ComponentLoadingError)
* @return A pointer to the newly created object or a null pointer if the
* factory was unable to create an object of the given type.
*/
template <class T>
static T *createInstanceFromQuery( const TQString &serviceType,
const TQString &constraint = TQString::null,
TQObject *parent = 0,
const char *name = 0,
const TQStringList &args = TQStringList(),
int *error = 0 )
{
TDETrader::OfferList offers = TDETrader::self()->query( serviceType, constraint );
if ( offers.isEmpty() )
{
if ( error )
*error = ErrNoServiceFound;
return 0;
}
return createInstanceFromServices<T>( offers.begin(),
offers.end(),
parent, name, args, error );
}
/**
* This method creates and returns a KParts part from a serviceType (e.g. a mimetype).
*
* You can use this method to create a generic viewer - that can display any
* kind of file, provided that there is a ReadOnlyPart installed for it - in 5 lines:
* \code
* // Given the following: KURL url, TQWidget* parentWidget and TQObject* parentObject.
* TQString mimetype = KMimeType::findByURL( url )->name();
* KParts::ReadOnlyPart* part = KParts::ComponentFactory::createPartInstanceFromQuery<KParts::ReadOnlyPart>( mimetype, TQString::null, parentWidget, 0, parentObject, 0 );
* if ( part ) {
* part->openURL( url );
* part->widget()->show(); // also insert the widget into a layout, or simply use a TQVBox as parentWidget
* }
* \endcode
*
* @param serviceType the type of service for which to find a part, e.g. a mimetype
* @param constraint an optional constraint to pass to the trader (see TDETrader)
* @param parentWidget the parent widget, will be set as the parent of the part's widget
* @param widgetName the name that will be given to the part's widget
* @param parent the parent object for the part itself
* @param name the name that will be given to the part
* @param args A list of string arguments, passed to the factory and possibly
* to the component (see KLibFactory)
* @param error The int passed here will receive an error code in case of errors.
* (See enum #ComponentLoadingError)
* @return A pointer to the newly created object or a null pointer if the
* factory was unable to create an object of the given type.
*/
template <class T>
static T *createPartInstanceFromQuery( const TQString &serviceType,
const TQString &constraint,
TQWidget *parentWidget = 0,
const char *widgetName = 0,
TQObject *parent = 0,
const char *name = 0,
const TQStringList &args = TQStringList(),
int *error = 0 )
{
TDETrader::OfferList offers = TDETrader::self()->query( serviceType, TQString::fromLatin1("KParts/ReadOnlyPart"), constraint, TQString::null );
if ( offers.isEmpty() )
{
if ( error )
*error = ErrNoServiceFound;
return 0;
}
return createPartInstanceFromServices<T>( offers.begin(), offers.end(),
parentWidget, widgetName,
parent, name, args, error );
}
}
}
#endif