Don't offer non-vector layer providers as options for virtual layer source layers

python/core/auto_generated/providers/qgsprovidermetadata.sip.in

@@ -201,6 +201,47 @@ Returns the provider's capabilities.
 .. versionadded:: 3.18.1
 %End
 
+    SIP_PYOBJECT supportedLayerTypes() const /TypeHint="List[QgsMapLayerType]"/;
+%Docstring
+Returns a list of the map layer types supported by the provider.
+
+.. versionadded:: 3.26
+%End
+%MethodCode
+    // adapted from the qpymultimedia_qlist.sip file from the PyQt6 sources
+
+    const QList< QgsMapLayerType > cppRes = sipCpp->supportedLayerTypes();
+
+    PyObject *l = PyList_New( cppRes.size() );
+
+    if ( !l )
+      sipIsErr = 1;
+    else
+    {
+      for ( int i = 0; i < cppRes.size(); ++i )
+      {
+        PyObject *eobj = sipConvertFromEnum( static_cast<int>( cppRes.at( i ) ),
+                                             sipType_QgsMapLayerType );
+
+        if ( !eobj )
+        {
+          sipIsErr = 1;
+        }
+
+        PyList_SetItem( l, i, eobj );
+      }
+
+      if ( !sipIsErr )
+      {
+        sipRes = l;
+      }
+      else
+      {
+        Py_DECREF( l );
+      }
+    }
+%End
+
  QString library() const /Deprecated/;
 %Docstring
 This returns the library file name

python/core/auto_generated/providers/qgsproviderregistry.sip.in

@@ -318,6 +318,14 @@ Returns list of available providers by their keys
     QgsProviderMetadata *providerMetadata( const QString &providerKey ) const;
 %Docstring
 Returns metadata of the provider or ``None`` if not found
+%End
+
+    QSet< QString > providersForLayerType( QgsMapLayerType type ) const;
+%Docstring
+Returns a list of the provider keys for available providers which handle the specified
+layer ``type``.
+
+.. versionadded:: 3.26
 %End
 
     class ProviderCandidateDetails

src/core/providers/copc/qgscopcprovider.cpp

@@ -194,6 +194,11 @@ QgsProviderMetadata::ProviderCapabilities QgsCopcProviderMetadata::providerCapab
   return FileBasedUris;
 }
 
+QList<QgsMapLayerType> QgsCopcProviderMetadata::supportedLayerTypes() const
+{
+  return { QgsMapLayerType::PointCloudLayer };
+}
+
 QString QgsCopcProviderMetadata::encodeUri( const QVariantMap &parts ) const
 {
   const QString path = parts.value( QStringLiteral( "path" ) ).toString();

src/core/providers/copc/qgscopcprovider.h

@@ -77,6 +77,7 @@ class QgsCopcProviderMetadata : public QgsProviderMetadata
     QVariantMap decodeUri( const QString &uri ) const override;
     QString filters( FilterType type ) override;
     ProviderCapabilities providerCapabilities() const override;
+    QList< QgsMapLayerType > supportedLayerTypes() const override;
 };
 
 ///@endcond

src/core/providers/ept/qgseptprovider.cpp

@@ -202,6 +202,11 @@ QgsProviderMetadata::ProviderCapabilities QgsEptProviderMetadata::providerCapabi
   return FileBasedUris;
 }
 
+QList<QgsMapLayerType> QgsEptProviderMetadata::supportedLayerTypes() const
+{
+  return { QgsMapLayerType::PointCloudLayer };
+}
+
 QString QgsEptProviderMetadata::encodeUri( const QVariantMap &parts ) const
 {
   const QString path = parts.value( QStringLiteral( "path" ) ).toString();

src/core/providers/ept/qgseptprovider.h

@@ -74,6 +74,7 @@ class QgsEptProviderMetadata : public QgsProviderMetadata
     QVariantMap decodeUri( const QString &uri ) const override;
     QString filters( FilterType type ) override;
     ProviderCapabilities providerCapabilities() const override;
+    QList< QgsMapLayerType > supportedLayerTypes() const override;
 };
 
 ///@endcond

src/core/providers/gdal/qgsgdalprovider.cpp

@@ -3962,6 +3962,11 @@ QStringList QgsGdalProviderMetadata::sidecarFilesForUri( const QString &uri ) co
   return res;
 }
 
+QList<QgsMapLayerType> QgsGdalProviderMetadata::supportedLayerTypes() const
+{
+  return { QgsMapLayerType::RasterLayer };
+}
+
 QgsGdalProviderMetadata::QgsGdalProviderMetadata():
   QgsProviderMetadata( PROVIDER_KEY, PROVIDER_DESCRIPTION )
 {

src/core/providers/gdal/qgsgdalprovider.h

@@ -392,6 +392,7 @@ class QgsGdalProviderMetadata final: public QgsProviderMetadata
     ProviderCapabilities providerCapabilities() const override;
     QList< QgsProviderSublayerDetails > querySublayers( const QString &uri, Qgis::SublayerQueryFlags flags = Qgis::SublayerQueryFlags(), QgsFeedback *feedback = nullptr ) const override;
     QStringList sidecarFilesForUri( const QString &uri ) const override;
+    QList< QgsMapLayerType > supportedLayerTypes() const override;
 };
 
 ///@endcond

src/core/providers/memory/qgsmemoryprovider.cpp

@@ -243,13 +243,6 @@ QString QgsMemoryProvider::providerDescription()
   return TEXT_PROVIDER_DESCRIPTION;
 }
 
-QgsMemoryProvider *QgsMemoryProvider::createProvider( const QString &uri,
-    const ProviderOptions &options,
-    QgsDataProvider::ReadFlags flags )
-{
-  return new QgsMemoryProvider( uri, options, flags );
-}
-
 QgsAbstractFeatureSource *QgsMemoryProvider::featureSource() const
 {
   return new QgsMemoryFeatureSource( this );
@@ -814,4 +807,20 @@ QString QgsMemoryProvider::description() const
   return TEXT_PROVIDER_DESCRIPTION;
 }
 
+
+QgsMemoryProviderMetadata::QgsMemoryProviderMetadata()
+  : QgsProviderMetadata( QgsMemoryProvider::providerKey(), QgsMemoryProvider::providerDescription() )
+{
+}
+
+QgsDataProvider *QgsMemoryProviderMetadata::createProvider( const QString &uri, const QgsDataProvider::ProviderOptions &options, QgsDataProvider::ReadFlags flags )
+{
+  return new QgsMemoryProvider( uri, options, flags );
+}
+
+QList<QgsMapLayerType> QgsMemoryProviderMetadata::supportedLayerTypes() const
+{
+  return { QgsMapLayerType::VectorLayer };
+}
+
 ///@endcond

src/core/providers/memory/qgsmemoryprovider.h

@@ -18,6 +18,7 @@
 #include "qgsvectordataprovider.h"
 #include "qgscoordinatereferencesystem.h"
 #include "qgsfields.h"
+#include "qgsprovidermetadata.h"
 
 ///@cond PRIVATE
 typedef QMap<QgsFeatureId, QgsFeature> QgsFeatureMap;
@@ -41,13 +42,6 @@ class QgsMemoryProvider final: public QgsVectorDataProvider
     //! Returns the memory provider description
     static QString providerDescription();
 
-    /**
-     * Creates a new memory provider, with provider properties embedded within the given \a uri and \a options
-     * argument.
-     */
-    static QgsMemoryProvider *createProvider( const QString &uri, const QgsVectorDataProvider::ProviderOptions &coordinateTransformContext,
-        QgsDataProvider::ReadFlags flags = QgsDataProvider::ReadFlags() );
-
     /* Implementation of functions from QgsVectorDataProvider */
 
     QgsAbstractFeatureSource *featureSource() const override;
@@ -104,4 +98,13 @@ class QgsMemoryProvider final: public QgsVectorDataProvider
     friend class QgsMemoryFeatureSource;
 };
 
+
+class QgsMemoryProviderMetadata final: public QgsProviderMetadata
+{
+  public:
+    QgsMemoryProviderMetadata();
+    QgsDataProvider *createProvider( const QString &uri, const QgsDataProvider::ProviderOptions &options, QgsDataProvider::ReadFlags flags = QgsDataProvider::ReadFlags() ) override;
+    QList< QgsMapLayerType > supportedLayerTypes() const override;
+};
+
 ///@endcond

src/core/providers/meshmemory/qgsmeshmemorydataprovider.cpp

@@ -71,13 +71,6 @@ QString QgsMeshMemoryDataProvider::providerDescription()
   return TEXT_PROVIDER_DESCRIPTION;
 }
 
-QgsMeshMemoryDataProvider *QgsMeshMemoryDataProvider::createProvider( const QString &uri,
-    const ProviderOptions &options,
-    QgsDataProvider::ReadFlags flags )
-{
-  return new QgsMeshMemoryDataProvider( uri, options, flags );
-}
-
 bool QgsMeshMemoryDataProvider::splitMeshSections( const QString &uri )
 {
 #if QT_VERSION < QT_VERSION_CHECK(5, 15, 0)
@@ -658,5 +651,20 @@ QgsRectangle QgsMeshMemoryDataProvider::calculateExtent() const
 }
 
 
+QgsMeshMemoryProviderMetadata::QgsMeshMemoryProviderMetadata()
+  : QgsProviderMetadata( QgsMeshMemoryDataProvider::providerKey(), QgsMeshMemoryDataProvider::providerDescription() )
+{
+
+}
+
+QgsDataProvider *QgsMeshMemoryProviderMetadata::createProvider( const QString &uri, const QgsDataProvider::ProviderOptions &options, QgsDataProvider::ReadFlags flags )
+{
+  return new QgsMeshMemoryDataProvider( uri, options, flags );
+}
+
+QList<QgsMapLayerType> QgsMeshMemoryProviderMetadata::supportedLayerTypes() const
+{
+  return { QgsMapLayerType::MeshLayer };
+}
 
 ///@endcond

src/core/providers/meshmemory/qgsmeshmemorydataprovider.h

@@ -161,10 +161,6 @@ class CORE_EXPORT QgsMeshMemoryDataProvider final: public QgsMeshDataProvider
     static QString providerKey();
     //! Returns the memory provider description
     static QString providerDescription();
-    //! Provider factory
-    static QgsMeshMemoryDataProvider *createProvider( const QString &uri,
-        const QgsDataProvider::ProviderOptions &providerOptions,
-        QgsDataProvider::ReadFlags flags = QgsDataProvider::ReadFlags() );
 
   private:
     QgsRectangle calculateExtent( ) const;
@@ -191,6 +187,14 @@ class CORE_EXPORT QgsMeshMemoryDataProvider final: public QgsMeshDataProvider
     QStringList mExtraDatasetUris;
 };
 
+class QgsMeshMemoryProviderMetadata final: public QgsProviderMetadata
+{
+  public:
+    QgsMeshMemoryProviderMetadata();
+    QgsDataProvider *createProvider( const QString &uri, const QgsDataProvider::ProviderOptions &options, QgsDataProvider::ReadFlags flags = QgsDataProvider::ReadFlags() ) override;
+    QList< QgsMapLayerType > supportedLayerTypes() const override;
+};
+
 ///@endcond
 
 #endif // QGSMESHMEMORYDATAPROVIDER_H

src/core/providers/ogr/qgsogrprovidermetadata.cpp

@@ -1505,6 +1505,11 @@ QStringList QgsOgrProviderMetadata::sidecarFilesForUri( const QString &uri ) con
   return res;
 }
 
+QList<QgsMapLayerType> QgsOgrProviderMetadata::supportedLayerTypes() const
+{
+  return { QgsMapLayerType::VectorLayer };
+}
+
 QMap<QString, QgsAbstractProviderConnection *> QgsOgrProviderMetadata::connections( bool cached )
 {
   return connectionsProtected<QgsGeoPackageProviderConnection, QgsOgrDbConnection>( cached );

src/core/providers/ogr/qgsogrprovidermetadata.h

@@ -44,6 +44,7 @@ class QgsOgrProviderMetadata final: public QgsProviderMetadata
     bool uriIsBlocklisted( const QString &uri ) const override;
     QList< QgsProviderSublayerDetails > querySublayers( const QString &uri, Qgis::SublayerQueryFlags flags = Qgis::SublayerQueryFlags(), QgsFeedback *feedback = nullptr ) const override;
     QStringList sidecarFilesForUri( const QString &uri ) const override;
+    QList< QgsMapLayerType > supportedLayerTypes() const override;
     Qgis::VectorExportResult createEmptyLayer(
       const QString &uri,
       const QgsFields &fields,

src/core/providers/qgsprovidermetadata.cpp

@@ -62,6 +62,11 @@ QgsProviderMetadata::ProviderCapabilities QgsProviderMetadata::providerCapabilit
   return QgsProviderMetadata::ProviderCapabilities();
 }
 
+QList<QgsMapLayerType> QgsProviderMetadata::supportedLayerTypes() const
+{
+  return {};
+}
+
 QString QgsProviderMetadata::library() const
 {
   return mLibrary;

src/core/providers/qgsprovidermetadata.h

@@ -258,6 +258,51 @@ class CORE_EXPORT QgsProviderMetadata : public QObject
      */
     virtual QgsProviderMetadata::ProviderCapabilities providerCapabilities() const;
 
+    /**
+     * Returns a list of the map layer types supported by the provider.
+     *
+     * \since QGIS 3.26
+     */
+#ifndef SIP_RUN
+    virtual QList< QgsMapLayerType > supportedLayerTypes() const;
+#else
+    SIP_PYOBJECT supportedLayerTypes() const SIP_TYPEHINT( List[QgsMapLayerType] );
+    % MethodCode
+    // adapted from the qpymultimedia_qlist.sip file from the PyQt6 sources
+
+    const QList< QgsMapLayerType > cppRes = sipCpp->supportedLayerTypes();
+
+    PyObject *l = PyList_New( cppRes.size() );
+
+    if ( !l )
+      sipIsErr = 1;
+    else
+    {
+      for ( int i = 0; i < cppRes.size(); ++i )
+      {
+        PyObject *eobj = sipConvertFromEnum( static_cast<int>( cppRes.at( i ) ),
+                                             sipType_QgsMapLayerType );
+
+        if ( !eobj )
+        {
+          sipIsErr = 1;
+        }
+
+        PyList_SetItem( l, i, eobj );
+      }
+
+      if ( !sipIsErr )
+      {
+        sipRes = l;
+      }
+      else
+      {
+        Py_DECREF( l );
+      }
+    }
+    % End
+#endif
+
     /**
      * This returns the library file name
      *

src/core/providers/qgsproviderregistry.cpp

@@ -171,16 +171,14 @@ class PdalUnusableUriHandlerInterface : public QgsProviderRegistry::UnusableUriH
 void QgsProviderRegistry::init()
 {
   // add static providers
-  Q_NOWARN_DEPRECATED_PUSH
   {
     const QgsScopedRuntimeProfile profile( QObject::tr( "Create memory layer provider" ) );
-    mProviders[ QgsMemoryProvider::providerKey() ] = new QgsProviderMetadata( QgsMemoryProvider::providerKey(), QgsMemoryProvider::providerDescription(), &QgsMemoryProvider::createProvider );
+    mProviders[ QgsMemoryProvider::providerKey() ] = new QgsMemoryProviderMetadata();
   }
   {
     const QgsScopedRuntimeProfile profile( QObject::tr( "Create mesh memory layer provider" ) );
-    mProviders[ QgsMeshMemoryDataProvider::providerKey() ] = new QgsProviderMetadata( QgsMeshMemoryDataProvider::providerKey(), QgsMeshMemoryDataProvider::providerDescription(), &QgsMeshMemoryDataProvider::createProvider );
+    mProviders[ QgsMeshMemoryDataProvider::providerKey() ] = new QgsMeshMemoryProviderMetadata();
   }
-  Q_NOWARN_DEPRECATED_POP
   {
     const QgsScopedRuntimeProfile profile( QObject::tr( "Create GDAL provider" ) );
     mProviders[ QgsGdalProvider::providerKey() ] = new QgsGdalProviderMetadata();
@@ -877,6 +875,17 @@ QgsProviderMetadata *QgsProviderRegistry::providerMetadata( const QString &provi
   return findMetadata_( mProviders, providerKey );
 }
 
+QSet<QString> QgsProviderRegistry::providersForLayerType( QgsMapLayerType type ) const
+{
+  QSet<QString> lst;
+  for ( Providers::const_iterator it = mProviders.begin(); it != mProviders.end(); ++it )
+  {
+    if ( it->second->supportedLayerTypes().contains( type ) )
+      lst.insert( it->first );
+  }
+  return lst;
+}
+
 QList<QgsProviderRegistry::ProviderCandidateDetails> QgsProviderRegistry::preferredProvidersForUri( const QString &uri ) const
 {
   QList< QgsProviderRegistry::ProviderCandidateDetails > res;

src/core/providers/qgsproviderregistry.h

@@ -338,6 +338,14 @@ class CORE_EXPORT QgsProviderRegistry
     //! Returns metadata of the provider or NULLPTR if not found
     QgsProviderMetadata *providerMetadata( const QString &providerKey ) const;
 
+    /**
+     * Returns a list of the provider keys for available providers which handle the specified
+     * layer \a type.
+     *
+     * \since QGIS 3.26
+     */
+    QSet< QString > providersForLayerType( QgsMapLayerType type ) const;
+
     /**
      * \ingroup core
      *