Implement querySublayers for mdal provider

nyalldawson · nyalldawson · commit 04a735798ee3 · 2021-06-23T19:35:11.000+10:00
diff --git a/src/providers/mdal/qgsmdalprovider.cpp b/src/providers/mdal/qgsmdalprovider.cpp
@@ -23,7 +23,9 @@
 #include "qgsapplication.h"
 #include "qgsmdaldataitems.h"
 #include "qgsmeshdataprovidertemporalcapabilities.h"
+#include "qgsprovidersublayerdetails.h"
 
+#include <QFileInfo>
 
 const QString QgsMdalProvider::MDAL_PROVIDER_KEY = QStringLiteral( "mdal" );
 const QString QgsMdalProvider::MDAL_PROVIDER_DESCRIPTION = QStringLiteral( "MDAL provider" );
@@ -998,6 +1000,56 @@ QgsProviderMetadata::ProviderCapabilities QgsMdalProviderMetadata::providerCapab
   return FileBasedUris;
 }
 
+QList<QgsProviderSublayerDetails> QgsMdalProviderMetadata::querySublayers( const QString &uri, Qgis::SublayerQueryFlags, QgsFeedback * ) const
+{
+  if ( uri.isEmpty() )
+    return {};
+
+  // get suffix, removing .gz if present
+  const QFileInfo info( uri );
+  // allow only normal files
+  if ( !info.isFile() )
+    return {};
+
+  const QString suffix = info.suffix().toLower();
+
+  static QStringList sExtensions;
+  static std::once_flag initialized;
+  std::call_once( initialized, [ = ]( )
+  {
+    QStringList meshExtensions;
+    QStringList datasetsExtensions;
+    QgsMdalProvider::fileMeshExtensions( sExtensions, datasetsExtensions );
+    Q_UNUSED( datasetsExtensions )
+  } );
+
+  // Filter files by extension
+  if ( !sExtensions.contains( suffix ) )
+    return {};
+
+  const QStringList meshNames = QString( MDAL_MeshNames( uri.toUtf8() ) ).split( QStringLiteral( ";;" ) );
+
+  QList<QgsProviderSublayerDetails> res;
+  res.reserve( meshNames.size() );
+  int layerIndex = 0;
+  for ( const QString &layerUri : meshNames )
+  {
+    QgsProviderSublayerDetails details;
+    details.setUri( layerUri );
+    details.setProviderKey( QStringLiteral( "mdal" ) );
+    details.setType( QgsMapLayerType::MeshLayer );
+    details.setLayerNumber( layerIndex );
+
+    // strip the driver name and path from the MDAL uri to get the layer name
+    details.setName( layerUri.mid( layerUri.indexOf( uri ) + uri.length() + 2 ) );
+
+    res << details;
+
+    layerIndex++;
+  }
+  return res;
+}
+
 QString QgsMdalProviderMetadata::filters( FilterType type )
 {
   switch ( type )
diff --git a/src/providers/mdal/qgsmdalprovider.h b/src/providers/mdal/qgsmdalprovider.h
@@ -146,6 +146,7 @@ class QgsMdalProviderMetadata: public QgsProviderMetadata
     QVariantMap decodeUri( const QString &uri ) const override;
     QString encodeUri( const QVariantMap &parts ) const override;
     ProviderCapabilities providerCapabilities() const override;
+    QList< QgsProviderSublayerDetails > querySublayers( const QString &uri, Qgis::SublayerQueryFlags flags = Qgis::SublayerQueryFlags(), QgsFeedback *feedback = nullptr ) const override;
 };
 
 #endif //QGSMDALPROVIDER_H
diff --git a/tests/src/core/testqgsmeshlayer.cpp b/tests/src/core/testqgsmeshlayer.cpp
@@ -30,6 +30,8 @@
 #include "qgsmeshlayertemporalproperties.h"
 
 #include "qgsmeshdataprovidertemporalcapabilities.h"
+#include "qgsprovidermetadata.h"
+#include "qgsprovidersublayerdetails.h"
 
 /**
  * \ingroup UnitTests
@@ -92,6 +94,8 @@ class TestQgsMeshLayer : public QObject
     void test_memory_dataset_group_1d();
 
     void test_setDataSource();
+
+    void testMdalProviderQuerySublayers();
 };
 
 QString TestQgsMeshLayer::readFile( const QString &fname ) const
@@ -1582,6 +1586,43 @@ void TestQgsMeshLayer::test_setDataSource()
   QCOMPARE( QgsMeshDatasetValue( 2.0 ), layerWithBadDataSource.datasetValue( QgsMeshDatasetIndex( 4, 0 ), 1 ) );
 }
 
+void TestQgsMeshLayer::testMdalProviderQuerySublayers()
+{
+  // test querying sub layers for a mesh layer
+  QgsProviderMetadata *mdalMetadata = QgsProviderRegistry::instance()->providerMetadata( QStringLiteral( "mdal" ) );
+
+  // invalid uri
+  QList< QgsProviderSublayerDetails >res = mdalMetadata->querySublayers( QString() );
+  QVERIFY( res.empty() );
+
+  // not a mesh
+  res = mdalMetadata->querySublayers( QString( TEST_DATA_DIR ) + "/lines.shp" );
+  QVERIFY( res.empty() );
+
+  // single layer mesh
+  res = mdalMetadata->querySublayers( mDataDir + "/quad_and_triangle.2dm" );
+  QCOMPARE( res.count(), 1 );
+  QCOMPARE( res.at( 0 ).layerNumber(), 0 );
+  QCOMPARE( res.at( 0 ).name(), QString( ) );
+  QCOMPARE( res.at( 0 ).uri(), QStringLiteral( "2DM:\"%1/quad_and_triangle.2dm\"" ).arg( mDataDir ) );
+  QCOMPARE( res.at( 0 ).providerKey(), QStringLiteral( "mdal" ) );
+  QCOMPARE( res.at( 0 ).type(), QgsMapLayerType::MeshLayer );
+
+  // mesh with two layers
+  res = mdalMetadata->querySublayers( mDataDir + "/manzese_1d2d_small_map.nc" );
+  QCOMPARE( res.count(), 2 );
+  QCOMPARE( res.at( 0 ).layerNumber(), 0 );
+  QCOMPARE( res.at( 0 ).name(), QStringLiteral( "mesh1d" ) );
+  QCOMPARE( res.at( 0 ).uri(), QStringLiteral( "Ugrid:\"%1/manzese_1d2d_small_map.nc\":mesh1d" ).arg( mDataDir ) );
+  QCOMPARE( res.at( 0 ).providerKey(), QStringLiteral( "mdal" ) );
+  QCOMPARE( res.at( 0 ).type(), QgsMapLayerType::MeshLayer );
+  QCOMPARE( res.at( 1 ).layerNumber(), 1 );
+  QCOMPARE( res.at( 1 ).name(), QStringLiteral( "mesh2d" ) );
+  QCOMPARE( res.at( 1 ).uri(), QStringLiteral( "Ugrid:\"%1/manzese_1d2d_small_map.nc\":mesh2d" ).arg( mDataDir ) );
+  QCOMPARE( res.at( 1 ).providerKey(), QStringLiteral( "mdal" ) );
+  QCOMPARE( res.at( 1 ).type(), QgsMapLayerType::MeshLayer );
+}
+
 void TestQgsMeshLayer::test_temporal()
 {
   qint64 relativeTime_0 = -1000;
diff --git a/tests/testdata/mesh/manzese_1d2d_small_map.nc b/tests/testdata/mesh/manzese_1d2d_small_map.nc
