[RASTER] Generate band name with GTiff EXTRA_DIM

Band names can also be retrieved from GeoTIFF files.

Author: seignovert

src/providers/gdal/qgsgdalprovider.cpp

@@ -930,7 +930,7 @@ QString QgsGdalProvider::generateBandName( int bandNumber ) const
   if ( !const_cast<QgsGdalProvider *>( this )->initIfNeeded() )
     return QString();
 
-  if ( strcmp( GDALGetDriverShortName( GDALGetDatasetDriver( mGdalDataset ) ), "netCDF" ) == 0 )
+  if ( strcmp( GDALGetDriverShortName( GDALGetDatasetDriver( mGdalDataset ) ), "netCDF" ) == 0 || strcmp( GDALGetDriverShortName( GDALGetDatasetDriver( mGdalDataset ) ), "GTiff" ) == 0 )
   {
     char **GDALmetadata = GDALGetMetadata( mGdalDataset, nullptr );
 
@@ -943,11 +943,11 @@ QString QgsGdalProvider::generateBandName( int bandNumber ) const
             i != metadata.constEnd(); ++i )
       {
         QString val( *i );
-        if ( !val.startsWith( QLatin1String( "NETCDF_DIM_EXTRA" ) ) && !val.contains( QLatin1String( "#units=" ) ) )
+        if ( !val.startsWith( QLatin1String( "NETCDF_DIM_EXTRA" ) ) && !val.startsWith( QLatin1String( "GTIFF_DIM_EXTRA" ) ) && !val.contains( QLatin1String( "#units=" ) ) )
           continue;
         QStringList values = val.split( '=' );
         val = values.at( 1 );
-        if ( values.at( 0 ) == QLatin1String( "NETCDF_DIM_EXTRA" ) )
+        if ( values.at( 0 ) == QLatin1String( "NETCDF_DIM_EXTRA" ) || values.at( 0 ) == QLatin1String( "GTIFF_DIM_EXTRA" ) )
         {
           dimExtraValues = val.replace( '{', QString() ).replace( '}', QString() ).split( ',' );
           //http://qt-project.org/doc/qt-4.8/qregexp.html#capturedTexts
@@ -970,14 +970,14 @@ QString QgsGdalProvider::generateBandName( int bandNumber ) const
                 i != metadata.constEnd(); ++i )
           {
             QString val( *i );
-            if ( !val.startsWith( QLatin1String( "NETCDF_DIM_" ) ) )
+            if ( !val.startsWith( QLatin1String( "NETCDF_DIM_" ) ) && !val.startsWith( QLatin1String( "GTIFF_DIM_" ) ) )
               continue;
             QStringList values = val.split( '=' );
             for ( QStringList::const_iterator j = dimExtraValues.constBegin();
                   j != dimExtraValues.constEnd(); ++j )
             {
               QString dim = ( *j );
-              if ( values.at( 0 ) != "NETCDF_DIM_" + dim )
+              if ( values.at( 0 ) != "NETCDF_DIM_" + dim && values.at( 0 ) != "GTIFF_DIM_" + dim )
                 continue;
               if ( unitsMap.contains( dim ) && !unitsMap[ dim ].isEmpty() && unitsMap[ dim ] != QLatin1String( "none" ) )
                 bandNameValues.append( dim + '=' + values.at( 1 ) + " (" + unitsMap[ dim ] + ')' );

tests/src/providers/testqgsgdalprovider.cpp

@@ -50,6 +50,7 @@ class TestQgsGdalProvider : public QObject
     void invalidNoDataInSourceIgnored();
     void isRepresentableValue();
     void mask();
+    void bandName(); // test band name based on `gtiff` tags (#7317)
 
   private:
     QString mTestDataDir;
@@ -221,5 +222,19 @@ void TestQgsGdalProvider::mask()
   delete provider;
 }
 
+void TestQgsGdalProvider::bandName()
+{
+  QString raster = QStringLiteral( TEST_DATA_DIR ) + "/raster/gtiff_tags.tif";
+  QgsDataProvider *provider = QgsProviderRegistry::instance()->createProvider( QStringLiteral( "gdal" ), raster, QgsDataProvider::ProviderOptions() );
+  QgsRasterDataProvider *rp = dynamic_cast< QgsRasterDataProvider * >( provider );
+  QVERIFY( rp );
+  if ( rp )
+  {
+    qDebug() << "Band Name 1: " << rp->generateBandName( 1 );
+    QCOMPARE( rp->generateBandName( 1 ), QStringLiteral( "Band 1 / wvln=1.234 (um)" ) );
+  }
+  delete provider;
+}
+
 QGSTEST_MAIN( TestQgsGdalProvider )
 #include "testqgsgdalprovider.moc"