Identify

qgis · Nov 8, 2022 · be9b864 · be9b864
1 parent 5a88611
commit be9b864
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Showing 6 changed files with 95 additions and 8 deletions.
diff --git a/python/core/auto_generated/raster/qgsrasterattributetable.sip.in b/python/core/auto_generated/raster/qgsrasterattributetable.sip.in
@@ -286,9 +286,14 @@ Sets the ``value`` for ``row`` and ``column``.
 :return: ``True`` on success.
 %End
 
-    QVariant value( const int row, const int column );
+    QVariant value( const int row, const int column ) const;
 %Docstring
 Returns the ``value`` for ``row`` and ``column``.
+%End
+
+    QVariantList row( const double matchValue ) const;
+%Docstring
+Returns a row of data for the given ``matchValue`` or and empty row if there is not match.
 %End
 
     static Qgis::RasterAttributeTableFieldUsage guessFieldUsage( const QString &name, const QVariant::Type type );

diff --git a/src/core/raster/qgsrasterattributetable.cpp b/src/core/raster/qgsrasterattributetable.cpp
@@ -640,7 +640,7 @@ bool QgsRasterAttributeTable::setValue( const int row, const int column, const Q
   return true;
 }
 
-QVariant QgsRasterAttributeTable::value( const int row, const int column )
+QVariant QgsRasterAttributeTable::value( const int row, const int column ) const
 {
   if ( row < 0 || row >= mData.count( ) || column < 0 || column >=  mData[ row ].count( ) )
   {
@@ -649,6 +649,46 @@ QVariant QgsRasterAttributeTable::value( const int row, const int column )
   return mData[ row ][ column ];
 }
 
+QVariantList QgsRasterAttributeTable::row( const double matchValue ) const
+{
+  if ( ! isValid() )
+  {
+    return QVariantList();
+  }
+
+  const QList<Qgis::RasterAttributeTableFieldUsage> fieldUsages { usages() };
+
+  if ( fieldUsages.contains( Qgis::RasterAttributeTableFieldUsage::MinMax ) )
+  {
+    const int colIdx { fieldUsages.indexOf( Qgis::RasterAttributeTableFieldUsage::MinMax ) };
+    for ( int rowIdx = 0; rowIdx < mData.count(); ++rowIdx )
+    {
+      bool ok;
+      if ( matchValue == value( rowIdx, colIdx ).toDouble( &ok ) && ok )
+      {
+        return mData.at( rowIdx );
+      }
+    }
+  }
+  else
+  {
+    const int minColIdx { fieldUsages.indexOf( Qgis::RasterAttributeTableFieldUsage::Min ) };
+    const int maxColIdx { fieldUsages.indexOf( Qgis::RasterAttributeTableFieldUsage::Max ) };
+    for ( int rowIdx = 0; rowIdx < mData.count(); ++rowIdx )
+    {
+      bool ok;
+      if ( matchValue >= value( rowIdx, minColIdx ).toDouble( &ok ) && ok )
+      {
+        if ( matchValue < value( rowIdx, maxColIdx ).toDouble( &ok ) && ok )
+        {
+          return mData.at( rowIdx );
+        }
+      }
+    }
+  }
+  return QVariantList();
+}
+
 Qgis::RasterAttributeTableFieldUsage QgsRasterAttributeTable::guessFieldUsage( const QString &name, const QVariant::Type type )
 {
   static const QStringList minValueNames { {

diff --git a/src/core/raster/qgsrasterattributetable.h b/src/core/raster/qgsrasterattributetable.h
@@ -275,7 +275,12 @@ class CORE_EXPORT QgsRasterAttributeTable
     /**
      * Returns the \a value for \a row and \a column.
      */
-    QVariant value( const int row, const int column );
+    QVariant value( const int row, const int column ) const;
+
+    /**
+     * Returns a row of data for the given \a matchValue or and empty row if there is not match.
+     */
+    QVariantList row( const double matchValue ) const;
 
     /**
      * Try to determine the field usage from its \a name and \a type.

diff --git a/src/core/raster/qgsrasterdataprovider.cpp b/src/core/raster/qgsrasterdataprovider.cpp
@@ -315,19 +315,18 @@ QgsRasterIdentifyResult QgsRasterDataProvider::identify( const QgsPointXY &point
   const double yMin = yMax - yres;
   const QgsRectangle pixelExtent( xMin, yMin, xMax, yMax );
 
-  for ( int i = 1; i <= bandCount(); i++ )
+  for ( int bandNumber = 1; bandNumber <= bandCount(); bandNumber++ )
   {
-    std::unique_ptr< QgsRasterBlock > bandBlock( block( i, pixelExtent, 1, 1 ) );
+    std::unique_ptr< QgsRasterBlock > bandBlock( block( bandNumber, pixelExtent, 1, 1 ) );
 
     if ( bandBlock )
     {
       const double value = bandBlock->value( 0 );
-
-      results.insert( i, value );
+      results.insert( bandNumber, value );
     }
     else
     {
-      results.insert( i, QVariant() );
+      results.insert( bandNumber, QVariant() );
     }
   }
   return QgsRasterIdentifyResult( QgsRaster::IdentifyFormatValue, results );

diff --git a/src/gui/qgsmaptoolidentify.cpp b/src/gui/qgsmaptoolidentify.cpp
@@ -1079,6 +1079,39 @@ bool QgsMapToolIdentify::identifyRasterLayer( QList<IdentifyResult> *results, Qg
             valueString = QgsRasterBlock::printValue( value.toDouble() );
           }
         }
+        if ( const QgsRasterAttributeTable *rat = layer->attributeTable( it.key() ) )
+        {
+          bool ok;
+          const double doubleValue { it.value().toDouble( &ok ) };
+          if ( ok )
+          {
+            const QVariantList row = rat->row( doubleValue );
+            if ( ! row.isEmpty() )
+            {
+              for ( int colIdx = 0; colIdx < std::min( rat->fields().count( ), row.count() ); ++colIdx )
+              {
+                const QgsRasterAttributeTable::Field ratField { rat->fields().at( colIdx ) };
+                QString ratValue;
+                switch ( ratField.type )
+                {
+                  case QVariant::Type::Char:
+                  case QVariant::Type::Int:
+                  case QVariant::Type::UInt:
+                  case QVariant::Type::LongLong:
+                  case QVariant::Type::ULongLong:
+                    ratValue = QLocale().toString( row.at( colIdx ).toLongLong() );
+                    break;
+                  case QVariant::Type::Double:
+                    ratValue = QLocale().toString( row.at( colIdx ).toDouble( ) );
+                    break;
+                  default:
+                    ratValue = row.at( colIdx ).toString();
+                }
+                derivedAttributes.insert( ratField.name, ratValue );
+              }
+            }
+          }
+        }
         attributes.insert( dprovider->generateBandName( it.key() ), valueString );
       }
       QString label = layer->name();

diff --git a/tests/src/python/test_qgsrasterattributetable.py b/tests/src/python/test_qgsrasterattributetable.py
@@ -515,6 +515,11 @@ def testClassification(self):
         classes = rat.minMaxClasses(4)
         self.assertEqual(len(classes), 0)
 
+        # Test row function
+        self.assertEqual(rat.row(0), [0, 'zero', 'zero', 'even', 0, 0, 0])
+        self.assertEqual(rat.row(2.0), [2, 'two', 'not0', 'even', 2, 2, 2])
+        self.assertEqual(rat.row(100.0), [])
+
     def testPalettedRenderer(self):
 
         # Create RAT for 16 bit raster