class QgsSymbolLayerV2AbstractMetadata
{
%TypeHeaderCode
#include <qgssymbollayerv2registry.h>
%End

  public:
    QgsSymbolLayerV2AbstractMetadata( QString name, QString visibleName, QgsSymbolV2::SymbolType type );

    virtual ~QgsSymbolLayerV2AbstractMetadata();

    QString name() const;
    QString visibleName() const;
    QgsSymbolV2::SymbolType type() const;

    // create a symbol layer of this type given the map of properties.
    virtual QgsSymbolLayerV2* createSymbolLayer( const QgsStringMap& map ) = 0 /Factory/;
    // create widget for symbol layer of this type. Can return NULL if there's no GUI
    virtual QgsSymbolLayerV2Widget* createSymbolLayerWidget( const QgsVectorLayer * ) /Factory/;
    // create a symbol layer of this type given the map of properties.
    virtual QgsSymbolLayerV2* createSymbolLayerFromSld( QDomElement & ) /Factory/;
};

typedef QgsSymbolLayerV2*( *QgsSymbolLayerV2CreateFunc )( const QgsStringMap& );
typedef QgsSymbolLayerV2Widget*( *QgsSymbolLayerV2WidgetFunc )( const QgsVectorLayer* );
typedef QgsSymbolLayerV2*( *QgsSymbolLayerV2CreateFromSldFunc )( QDomElement& );

/**
 Convenience metadata class that uses static functions to create symbol layer and its widget.
 */
class QgsSymbolLayerV2Metadata : QgsSymbolLayerV2AbstractMetadata
{
%TypeHeaderCode
#include <qgssymbollayerv2registry.h>
%End

  public:
    QgsSymbolLayerV2Metadata( QString name, QString visibleName,
                              QgsSymbolV2::SymbolType type,
                              QgsSymbolLayerV2CreateFunc pfCreate,
                              QgsSymbolLayerV2WidgetFunc pfWidget = NULL );

    QgsSymbolLayerV2Metadata( QString name, QString visibleName,
                              QgsSymbolV2::SymbolType type,
                              QgsSymbolLayerV2CreateFunc pfCreate,
                              QgsSymbolLayerV2CreateFromSldFunc pfCreateFromSld,
                              QgsSymbolLayerV2WidgetFunc pfWidget = NULL );

    QgsSymbolLayerV2CreateFunc createFunction() const;
    QgsSymbolLayerV2WidgetFunc widgetFunction() const;
    QgsSymbolLayerV2CreateFromSldFunc createFromSldFunction() const;

    void setWidgetFunction( QgsSymbolLayerV2WidgetFunc f );

    virtual QgsSymbolLayerV2* createSymbolLayer( const QgsStringMap& map ) /Factory/;
    virtual QgsSymbolLayerV2Widget* createSymbolLayerWidget( const QgsVectorLayer* vl ) /Factory/;
    virtual QgsSymbolLayerV2* createSymbolLayerFromSld( QDomElement& elem ) /Factory/;
};

/**
 Registry of available symbol layer classes.
 Implemented as a singleton.
 */
class QgsSymbolLayerV2Registry
{
%TypeHeaderCode
#include <qgssymbollayerv2registry.h>
%End

  public:

    //! return the single instance of this class (instantiate it if not exists)
    static QgsSymbolLayerV2Registry* instance();

    //! return metadata for specified symbol layer. Returns NULL if not found
    QgsSymbolLayerV2AbstractMetadata* symbolLayerMetadata( QString name ) const;

    //! register a new symbol layer type. Takes ownership of the metadata instance.
    bool addSymbolLayerType( QgsSymbolLayerV2AbstractMetadata* metadata );

    //! create a new instance of symbol layer given symbol layer name and properties
    QgsSymbolLayerV2* createSymbolLayer( QString name, const QgsStringMap& properties = QgsStringMap() ) const /Factory/;

    //! create a new instance of symbol layer given symbol layer name and SLD
    QgsSymbolLayerV2* createSymbolLayerFromSld( QString name, QDomElement &element ) const;

    //! return a list of available symbol layers for a specified symbol type
    QStringList symbolLayersForType( QgsSymbolV2::SymbolType type );

    //! create a new instance of symbol layer for specified symbol type with default settings
    static QgsSymbolLayerV2* defaultSymbolLayer( QgsSymbolV2::SymbolType type ) /Factory/;

  protected:
    QgsSymbolLayerV2Registry();
    ~QgsSymbolLayerV2Registry();
};