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If you develop a library that is to be loaded dynamically at runtime, then you should return a pointer to your factory. The K_EXPORT_COMPONENT_FACTORY macro is provided for this purpose:
K_EXPORT_COMPONENT_FACTORY( libkspread, KSpreadFactory ) |
The first macro argument is the name of your library, the second specifies the name of your factory.
In the constructor of your factory you should create an instance of KInstance like this:
s_global = new KInstance( "kspread" );
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This KInstance is comparable to KGlobal used by normal applications. It allows you to find resource files (images, XML, sound etc.) belonging to the library.
If you want to load a library, use KLibLoader. You can query KLibLoader directly for a pointer to the libraries factory by using the KLibLoader::factory() function.
The KLibFactory is used to create the components, the library has to offer. The factory of KSpread for example will create instances of KSpreadDoc, while the Konqueror factory will create KonqView widgets. All objects created by the factory must be derived from QObject, since QObject offers type safe casting.
KLibFactory is an abstract class. Reimplement the createObject() method to give it functionality.
| KLibFactory ( QObject* parent = 0, const char* name = 0 )
| KLibFactory |
Create a new factory.
Parameters:
| parent | the parent of the QObject, 0 for no parent |
| name | the name of the QObject, 0 for no name |
| ~KLibFactory ()
| ~KLibFactory |
[virtual]
| QObject* create ( QObject* parent = 0, const char* name = 0, const char* classname = "QObject", const QStringList &args = QStringList() )
| create |
Creates a new object. The returned object has to be derived from the requested classname.
It is valid behavior to create different kinds of objects
depending on the requested classname. For example a koffice
library may usually return a pointer to KoDocument. But
if asked for a "QWidget", it could create a wrapper widget,
that encapsulates the Koffice specific features.
create() automatically emits a signal objectCreated to tell the library about its newly created object. This is very important for reference counting, and allows unloading the library automatically once all its objects have been destroyed.
Parameters:
| parent | the parent of the QObject, 0 for no parent |
| name | the name of the QObject, 0 for no name |
| classname | the name of the class |
| args | a list of arguments |
| void objectCreated ( QObject *obj )
| objectCreated |
[signal]
Emitted in #create
Parameters:
| obj | the new object |
| QObject* createObject ( QObject* parent = 0, const char* name = 0, const char* classname = "QObject", const QStringList &args = QStringList() )
| createObject |
[protected pure virtual]
Creates a new object. The returned object has to be derived from the requested classname.
It is valid behavior to create different kinds of objects
depending on the requested classname. For example a koffice
library may usually return a pointer to KoDocument. But
if asked for a "QWidget", it could create a wrapper widget,
that encapsulates the Koffice specific features.
This function is called by #create()
Parameters:
| parent | the parent of the QObject, 0 for no parent |
| name | the name of the QObject, 0 for no name |
| classname | the name of the class |
| args | a list of arguments |
| void virtual_hook ( int id, void* data )
| virtual_hook |
[protected virtual]