Gui enhancements

python/core/auto_generated/raster/qgsrasterlayer.sip.in

@@ -261,7 +261,7 @@ Returns the (possibly NULL) raster attribute table for the given band ``bandNumb
 .. versionadded:: 3.30
 %End
 
-    int attributeTableCount( );
+    int attributeTableCount( ) const;
 %Docstring
 Returns the number of attribute tables for the raster by counting the number of bands that have an associated attribute table.
 

python/gui/auto_generated/raster/qgsrasterattributetablewidget.sip.in

@@ -46,6 +46,33 @@ Sets the raster layer and an optional band number.
     bool isDirty( ) const;
 %Docstring
 Returns ``True`` if the associated raster attribute table is dirty
+%End
+
+    void setMessageBar( QgsMessageBar *bar );
+%Docstring
+Sets the message ``bar`` associated with the widget. This allows the widget to push feedback messages
+to the appropriate message bar.
+
+.. seealso:: :py:func:`messageBar`
+%End
+
+  signals:
+
+    void rendererChanged( );
+%Docstring
+This signal is emitted after a successful classify operation which changed the raster renderer.
+%End
+
+  public slots:
+
+    void saveChanges();
+%Docstring
+Save the changes in the raster attribute table.
+%End
+
+    bool setEditable( bool editable );
+%Docstring
+Set the editable state, it may trigger save changes if the attribute table has unsave changes.
 %End
 
 };

src/app/qgisapp.cpp

@@ -4380,6 +4380,12 @@ void QgisApp::setupConnections()
 
   connect( QgsProject::instance(), &QgsProject::transactionGroupsChanged, this, &QgisApp::onTransactionGroupsChanged );
 
+  // Handle dirty raster attribute tables
+  connect( QgsProject::instance(), qOverload<const QList< QgsMapLayer * > & >( &QgsProject::layersWillBeRemoved ), this, [ = ]( const QList< QgsMapLayer * > &layers )
+  {
+    checkUnsavedRasterAttributeTableEdits( layers, false );
+  } );
+
   // connect preview modes actions
   connect( mActionPreviewModeOff, &QAction::triggered, this, &QgisApp::disablePreviewMode );
   connect( mActionPreviewModeMono, &QAction::triggered, this, &QgisApp::activateMonoPreview );
@@ -5600,7 +5606,7 @@ void QgisApp::fileExit()
   }
 
   QgsCanvasRefreshBlocker refreshBlocker;
-  if ( checkUnsavedLayerEdits() && checkMemoryLayers() && saveDirty() && checkExitBlockers() )
+  if ( checkUnsavedLayerEdits() && checkMemoryLayers() && saveDirty() && checkExitBlockers() && checkUnsavedRasterAttributeTableEdits() )
   {
     closeProject();
     userProfileManager()->setDefaultFromActive();
@@ -5638,7 +5644,7 @@ bool QgisApp::fileNew( bool promptToSaveFlag, bool forceBlank )
 
   if ( promptToSaveFlag )
   {
-    if ( !checkUnsavedLayerEdits() || !checkMemoryLayers() || !saveDirty() )
+    if ( !checkUnsavedLayerEdits() || !checkMemoryLayers() || !saveDirty() || !checkUnsavedRasterAttributeTableEdits() )
     {
       return false; //cancel pressed
     }
@@ -5710,7 +5716,7 @@ bool QgisApp::fileNewFromTemplate( const QString &fileName )
   if ( checkTasksDependOnProject() )
     return false;
 
-  if ( !checkUnsavedLayerEdits() || !checkMemoryLayers() || !saveDirty() )
+  if ( !checkUnsavedLayerEdits() || !checkMemoryLayers() || !saveDirty() || !checkUnsavedRasterAttributeTableEdits() )
   {
     return false; //cancel pressed
   }
@@ -6206,7 +6212,7 @@ void QgisApp::fileOpen()
     return;
 
   // possibly save any pending work before opening a new project
-  if ( checkUnsavedLayerEdits() && checkMemoryLayers() && saveDirty() )
+  if ( checkUnsavedLayerEdits() && checkMemoryLayers() && saveDirty() && checkUnsavedRasterAttributeTableEdits() )
   {
     // Retrieve last used project dir from persistent settings
     QgsSettings settings;
@@ -6262,7 +6268,7 @@ void QgisApp::fileRevert()
                               QMessageBox::Yes | QMessageBox::No, QMessageBox::No ) == QMessageBox::No )
     return;
 
-  if ( !checkUnsavedLayerEdits() || !checkMemoryLayers() )
+  if ( !checkUnsavedLayerEdits() || !checkMemoryLayers() || ! checkUnsavedRasterAttributeTableEdits() )
     return;
 
   // re-open the current project
@@ -6760,7 +6766,7 @@ void QgisApp::openProject( QAction *action )
   if ( checkTasksDependOnProject() )
     return;
 
-  if ( checkUnsavedLayerEdits() && checkMemoryLayers() && saveDirty() )
+  if ( checkUnsavedLayerEdits() && checkMemoryLayers() && saveDirty() && checkUnsavedRasterAttributeTableEdits() )
     addProject( project );
 }
 
@@ -6805,7 +6811,7 @@ void QgisApp::openProject( const QString &fileName )
     return;
 
   // possibly save any pending work before opening a different project
-  if ( checkUnsavedLayerEdits() && checkMemoryLayers() && saveDirty() )
+  if ( checkUnsavedLayerEdits() && checkMemoryLayers() && saveDirty() && checkUnsavedRasterAttributeTableEdits() )
   {
     // error handling and reporting is in addProject() function
     addProject( fileName );
@@ -12027,6 +12033,30 @@ void QgisApp::openRasterAttributeTable()
   }
 }
 
+void QgisApp::loadRasterAttributeTableFromFile( )
+{
+  if ( !mLayerTreeView )
+    return;
+
+  //find current Layer
+  QgsMapLayer *currentLayer = mLayerTreeView->currentLayer();
+  if ( !currentLayer )
+    return;
+
+  QgsRasterLayer *layer = qobject_cast<QgsRasterLayer *>( currentLayer );
+
+  int bandNumber { 0 };
+
+  if ( layer )
+  {
+    QgsCreateRasterAttributeTableDialog dlg { layer };
+    if ( dlg.exec() == QDialog::Accepted )
+    {
+      // TODO!
+    }
+  }
+}
+
 void QgisApp::createRasterAttributeTable()
 {
   if ( !mLayerTreeView )
@@ -12053,7 +12083,7 @@ void QgisApp::createRasterAttributeTable()
       if ( ! rat )
       {
         visibleMessageBar()->pushMessage( tr( "Error Creating Raster Attribute Table" ),
-                                          tr( "The Raster Attribute Table could not be created." ),
+                                          tr( "The raster attribute table could not be created." ),
                                           Qgis::MessageLevel::Critical );
         return;
       }
@@ -13381,6 +13411,94 @@ bool QgisApp::checkUnsavedLayerEdits()
   return true;
 }
 
+bool QgisApp::checkUnsavedRasterAttributeTableEdits( const QList<QgsMapLayer *> &mapLayers, bool allowCancel )
+{
+  bool retVal { true };
+
+  QVector<QgsRasterLayer *> rasterLayers;
+
+  if ( ! mapLayers.isEmpty() )
+  {
+    for ( QgsMapLayer *mapLayer : std::as_const( mapLayers ) )
+    {
+      if ( QgsRasterLayer *rasterLayer = qobject_cast< QgsRasterLayer *>( mapLayer ) )
+      {
+        rasterLayers.push_back( rasterLayer );
+      }
+    }
+  }
+  else
+  {
+    rasterLayers = QgsProject::instance()->layers<QgsRasterLayer *>();
+  }
+
+  for ( QgsRasterLayer *rasterLayer : std::as_const( rasterLayers ) )
+  {
+    QStringList dirtyBands;
+    QList<QgsRasterAttributeTable *> dirtyRats;
+
+    for ( int bandNo = 1; bandNo < rasterLayer->bandCount(); ++bandNo )
+    {
+      if ( QgsRasterAttributeTable *rat = rasterLayer->attributeTable( bandNo ); rat && rat->isDirty() )
+      {
+        dirtyBands.push_back( QString::number( bandNo ) );
+        dirtyRats.push_back( rat );
+      }
+    }
+    if ( ! dirtyBands.isEmpty( ) )
+    {
+      QMessageBox::StandardButtons buttons = QMessageBox::Save | QMessageBox::Discard;
+      if ( allowCancel )
+      {
+        buttons |= QMessageBox::Cancel;
+      }
+
+      switch ( QMessageBox::question( nullptr,
+                                      tr( "Save Raster Attribute Table" ),
+                                      tr( "Do you want to save the changes to the attribute tables (bands: %1) associated with layer '%2'?" ).arg( dirtyBands.join( QStringLiteral( ", " ) ), rasterLayer->name() ),
+                                      buttons ) )
+      {
+
+        case QMessageBox::Save:
+        {
+          for ( QgsRasterAttributeTable *rat : std::as_const( dirtyRats ) )
+          {
+            QString errorMessage;
+            if ( rat->filePath().isEmpty( ) )
+            {
+              if ( ! rasterLayer->dataProvider()->writeNativeAttributeTable( &errorMessage ) )
+              {
+                visibleMessageBar()->pushMessage( tr( "Error Saving Raster Attribute Table" ),
+                                                  tr( "An error occourred while saving raster attribute table for layer '%1': %2" ).arg( rasterLayer->name(), errorMessage ),
+                                                  Qgis::MessageLevel::Critical );
+                retVal = false;
+              }
+            }
+            else
+            {
+              if ( ! rat->writeToFile( rat->filePath(), &errorMessage ) )
+              {
+                visibleMessageBar()->pushMessage( tr( "Error Saving Raster Attribute Table" ),
+                                                  tr( "An error occourred while saving raster attribute table for layer '%1' to VAT.DBF file '%2': %3" ).arg( rasterLayer->name(), rat->filePath(), errorMessage ),
+                                                  Qgis::MessageLevel::Critical );
+                retVal = false;
+              }
+            }
+          }
+          break;
+        }
+        case QMessageBox::Cancel:
+          retVal = false;
+          break;
+        case QMessageBox::Discard:
+        default:
+          break;
+      }
+    }
+  }
+  return retVal;
+}
+
 bool QgisApp::checkMemoryLayers()
 {
   if ( !QgsSettings().value( QStringLiteral( "askToSaveMemoryLayers" ), true, QgsSettings::App ).toBool() )
@@ -16175,6 +16293,8 @@ void QgisApp::showLayerProperties( QgsMapLayer *mapLayer, const QString &page )
       {
         rasterLayerPropertiesDialog->deleteLater();
       } );
+
+
       break;
     }
 

src/app/qgisapp.h

@@ -1106,7 +1106,7 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
     void legendLayerStretchUsingCurrentExtent();
 
     /**
-     * Open the RasterAttributeTable for the raster layer.
+     * Open the Raster Attribute Table for the raster layer.
      * Only works on raster layers.
      *
      * \since QGIS 3.30
@@ -1114,7 +1114,7 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
     void openRasterAttributeTable();
 
     /**
-     * Creates a new RasterAttributeTable from the raster layer renderer if the
+     * Creates a new Raster Attribute Table from the raster layer renderer if the
      * renderer supports it.
      *
      * Only works on raster layers.
@@ -1123,6 +1123,15 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
      */
     void createRasterAttributeTable();
 
+    /**
+     * Loads a Raster Attribute Table from a VAT.DBF file.
+     *
+     * Only works on raster layers.
+     *
+     * \since QGIS 3.30
+     */
+    void loadRasterAttributeTableFromFile();
+
     //! Watch for QFileOpenEvent.
     bool event( QEvent *event ) override;
 
@@ -1339,6 +1348,19 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
      */
     bool checkUnsavedLayerEdits();
 
+    /**
+     * Checks for unsaved changes in raster attribute tables and prompts the user to save
+     * or discard these changes for each raster attribute table.
+     *
+     * Returns TRUE if there are no unsaved raster attribute table remaining, or the user
+     * opted to discard them all. Returns FALSE if the user opted to cancel
+     * on any raster attribute table.
+     *
+     * \param mapLayers optional list of layers to check, if empty all project raster layers will be checked.
+     * \param allowCancel optional flag (default TRUE) that switches on the "Cancel" button.
+     */
+    bool checkUnsavedRasterAttributeTableEdits( const QList<QgsMapLayer *> &mapLayers = QList<QgsMapLayer *>(), bool allowCancel = true );
+
     /**
      * Checks whether memory layers (with features) exist in the project, and if so
      * shows a warning to users that their contents will be lost on

src/app/qgsapplayertreeviewmenuprovider.cpp

@@ -229,8 +229,10 @@ QMenu *QgsAppLayerTreeViewMenuProvider::createContextMenu()
         }
         else if ( rlayer->canCreateRasterAttributeTable() )
         {
-          menu->addAction( QgsApplication::getThemeIcon( QStringLiteral( "/mActionAddTable.svg" ) ), tr( "Create Raster Attribute Table" ), QgisApp::instance(), &QgisApp::createRasterAttributeTable );
+          menu->addAction( QgsApplication::getThemeIcon( QStringLiteral( "/mActionCreateTable.svg" ) ), tr( "Create Raster Attribute Table" ), QgisApp::instance(), &QgisApp::createRasterAttributeTable );
         }
+
+        menu->addAction( QgsApplication::getThemeIcon( QStringLiteral( "/mActionAddTable.svg" ) ), tr( "Load Raster Attribute Table from VAT.DBF" ), QgisApp::instance(), &QgisApp::loadRasterAttributeTableFromFile );
       }
 
       // No raster support in createSqlVectorLayer (yet)

src/core/providers/gdal/qgsgdalprovider.cpp

@@ -3212,25 +3212,10 @@ bool QgsGdalProvider::writeNativeAttributeTable( QString *errorMessage ) //#spel
     }
 
     // Needs to be in write mode for HFA and perhaps other formats!
-    if ( GDALGetAccess( mGdalDataset ) == GA_ReadOnly )
+    if ( ! isEditable() )
     {
       QgsDebugMsg( QStringLiteral( "re-opening the dataset in read/write mode" ) );
-      GDALClose( mGdalDataset );
+      setEditable( true );
-
-      mGdalBaseDataset = gdalOpen( dataSourceUri( true ), GDAL_OF_UPDATE );
-
-      // if the dataset couldn't be opened in read / write mode, tell the user
-      if ( !mGdalBaseDataset )
-      {
-        mGdalBaseDataset = gdalOpen( dataSourceUri( true ), GDAL_OF_READONLY );
-        //Since we are not a virtual warped dataset, mGdalDataSet and mGdalBaseDataset are supposed to be the same
-        mGdalDataset = mGdalBaseDataset;
-        if ( errorMessage )
-        {
-          *errorMessage = tr( "GDAL Error reopening dataset in write mode, raster attribute table could not be saved." );
-        }
-        return false;
-      }
       wasReopenedReadWrite = true;
     }
 
@@ -3327,17 +3312,7 @@ bool QgsGdalProvider::writeNativeAttributeTable( QString *errorMessage ) //#spel
   if ( wasReopenedReadWrite )
   {
     QgsDebugMsg( QStringLiteral( "re-opening the dataset in read-only mode" ) );
-    GDALClose( mGdalDataset );
+    setEditable( false );
-
-    mGdalBaseDataset = gdalOpen( dataSourceUri( true ), GDAL_OF_READONLY );
-
-    // if the dataset couldn't be opened in read / write mode, tell the user
-    if ( !mGdalBaseDataset )
-    {
-      mGdalBaseDataset = gdalOpen( dataSourceUri( true ), GDAL_OF_UPDATE );
-      //Since we are not a virtual warped dataset, mGdalDataSet and mGdalBaseDataset are supposed to be the same
-      mGdalDataset = mGdalBaseDataset;
-    }
   }
 
   return success;

src/core/raster/qgsrasterattributetable.cpp

@@ -479,6 +479,7 @@ bool QgsRasterAttributeTable::removeRow( int position, QString *errorMessage )
     return false;
   }
   mData.removeAt( position );
+  setDirty( true );
   return true;
 }
 
@@ -723,8 +724,12 @@ bool QgsRasterAttributeTable::setValue( const int row, const int column, const Q
   }
 
   const QVariant oldVal = mData[ row ][ column ];
-  mData[ row ][ column ] = newVal;
+
-  setDirty( newVal != oldVal );
+  if ( newVal != oldVal )
+  {
+    mData[ row ][ column ] = newVal;
+    setDirty( true );
+  }
 
   return true;
 }
@@ -1508,7 +1513,7 @@ QgsRasterRenderer *QgsRasterAttributeTable::createRenderer( QgsRasterDataProvide
     pseudoColorRenderer->setClassificationMin( minValue() );
     pseudoColorRenderer->setClassificationMax( maxValue() );
     // Use discrete for single colors, interpolated for ramps
-    pseudoColorRenderer->createShader( ramp, hasColor() ? QgsColorRampShader::Type::Discrete : QgsColorRampShader::Type::Interpolated, QgsColorRampShader::ClassificationMode::Continuous, ramp->stops().count() + 2, true );
+    pseudoColorRenderer->createShader( ramp, hasRamp() ? QgsColorRampShader::Type::Interpolated : QgsColorRampShader::Type::Discrete, QgsColorRampShader::ClassificationMode::Continuous, ramp->stops().count() + 2, true );
     pseudoColorRenderer->shader()->setMaximumValue( maxValue() );
     pseudoColorRenderer->shader()->setMinimumValue( minValue() );
     // Set labels
@@ -1516,10 +1521,30 @@ QgsRasterRenderer *QgsRasterAttributeTable::createRenderer( QgsRasterDataProvide
     {
       shaderFunction->setMinimumValue( minValue() );
       shaderFunction->setMaximumValue( maxValue() );
-      const QList<QgsColorRampShader::ColorRampItem> itemList { shaderFunction->colorRampItemList() };
+      const bool labelsAreUsable { ramp->count() > 2 && labels.count() == ramp->count() - 1 };
-      const bool labelsAreUsable { labels.count() == itemList.count() };
+
-      if ( ! itemList.isEmpty() )
+      if ( labelsAreUsable )
       {
+        QList<QgsColorRampShader::ColorRampItem> deduplicatedDitemList;
+        const double range { maxValue() - minValue() };
+        int stopIdx { 0 };
+        for ( const QString &label : std::as_const( labels ) )
+        {
+          if ( stopIdx >= ramp->count() - 2 )
+          {
+            break;
+          }
+          double value { minValue() + ramp->stops().at( stopIdx ).offset * range };
+          QgsColorRampShader::ColorRampItem item { value, ramp->stops().at( stopIdx ).color, label };
+          deduplicatedDitemList.push_back( item );
+          stopIdx++;
+        }
+
+        QgsColorRampShader::ColorRampItem item { maxValue(), ramp->color2(), labels.last() };
+        deduplicatedDitemList.push_back( item );
+
+
+#if 0
         QList<QgsColorRampShader::ColorRampItem> deduplicatedDitemList;
         // Deduplicate entries, this is necessary when the ramp for athematic
         // ramp rasters creates a stop for each class limit (min and max) which
@@ -1548,6 +1573,8 @@ QgsRasterRenderer *QgsRasterAttributeTable::createRenderer( QgsRasterDataProvide
             deduplicatedDitemList.push_back( item );
           }
         }
+#endif
+
         shaderFunction->setColorRampItemList( deduplicatedDitemList );
       }
     }

src/core/raster/qgsrasterlayer.cpp

@@ -257,7 +257,7 @@ QgsRasterAttributeTable *QgsRasterLayer::attributeTable( int bandNoInt ) const
   return mDataProvider->attributeTable( bandNoInt );
 }
 
-int QgsRasterLayer::attributeTableCount()
+int QgsRasterLayer::attributeTableCount() const
 {
   if ( !mDataProvider )
     return 0;

src/core/raster/qgsrasterlayer.h

@@ -326,7 +326,7 @@ class CORE_EXPORT QgsRasterLayer : public QgsMapLayer, public QgsAbstractProfile
      * Returns the number of attribute tables for the raster by counting the number of bands that have an associated attribute table.
      * \since QGIS 3.30
      */
-    int attributeTableCount( );
+    int attributeTableCount( ) const;
 
     /**
      * Returns TRUE if the raster renderer is suitable for creation of a raster attribute table. The supported renderers are QgsPalettedRasterRenderer and QgsSingleBandPseudoColorRenderer.

src/gui/raster/qgsrasterattributetabledialog.cpp

@@ -16,11 +16,9 @@
 #include "qgsrasterattributetabledialog.h"
 #include "qgsrasterlayer.h"
 
-#include <QMessageBox>
 
 QgsRasterAttributeTableDialog::QgsRasterAttributeTableDialog( QgsRasterLayer *rasterLayer, int bandNumber, QWidget *parent )
   : QDialog( parent )
-  , mRasterLayer( rasterLayer )
 {
   Q_ASSERT( rasterLayer );
   setupUi( this );
@@ -28,40 +26,15 @@ QgsRasterAttributeTableDialog::QgsRasterAttributeTableDialog( QgsRasterLayer *ra
   setWindowTitle( tr( "Raster Attribute Table for %1" ).arg( rasterLayer->name() ) );
 
   connect( mButtonBox, &QDialogButtonBox::rejected, this, &QgsRasterAttributeTableDialog::reject );
+  connect( rasterLayer, &QgsRasterLayer::dataSourceChanged, this, &QgsRasterAttributeTableDialog::reject );
+  connect( rasterLayer, &QgsRasterLayer::willBeDeleted, this, &QgsRasterAttributeTableDialog::reject );
 
 }
 
 void QgsRasterAttributeTableDialog::reject()
 {
-  QList<int> dirtyBands;
+  if ( mRatWidget->setEditable( false ) )
-  for ( int bandNo = 1;  bandNo <= mRasterLayer->bandCount(); ++bandNo )
   {
-    if ( QgsRasterAttributeTable *rat = mRasterLayer->attributeTable( bandNo ) )
+    QDialog::reject();
-    {
-      if ( rat->isDirty() )
-      {
-        dirtyBands.push_back( bandNo );
-      }
-    }
   }
-
-  if ( ! dirtyBands.isEmpty() )
-  {
-    QString bandsStr;
-    for ( int i = 0; i < dirtyBands.size(); i++ )
-    {
-      bandsStr.append( QString::number( dirtyBands[i] ) );
-      if ( i < dirtyBands.size() - 1 )
-        bandsStr.append( QStringLiteral( ", " ) );
-    }
-
-    QString msg { dirtyBands.count( ) > 1 ? tr( "Attribute table bands (%1) contain unsaved changes, close without saving?" ).arg( bandsStr ) : tr( "Attribute table band %1 contains unsaved changes, close without saving?" ).arg( bandsStr ) };
-
-    if ( QMessageBox::question( nullptr, tr( "Save Attribute Table" ), msg ) != QMessageBox::Yes )
-    {
-      return;
-    }
-  }
-
-  QDialog::reject();
 }

src/gui/raster/qgsrasterattributetabledialog.h

@@ -26,13 +26,13 @@ class QgsRasterLayer;
 
 /**
  * \ingroup gui
- * \brief The QgsRasterAttributeTableDialog class embeds an attribute table widget
+ * \brief The QgsRasterAttributeTableDialog class embeds an attribute table widget.
- * and contains logic to handle confirmation when closing with unsaved changes.
  * \since QGIS 3.30
  */
 class GUI_EXPORT QgsRasterAttributeTableDialog: public QDialog, private Ui::QRasterAttributeTableDialogBase
 {
     Q_OBJECT
+
   public:
 
     QgsRasterAttributeTableDialog( QgsRasterLayer *rasterLayer, int bandNumber = 0, QWidget *parent SIP_TRANSFERTHIS = nullptr );
@@ -42,9 +42,6 @@ class GUI_EXPORT QgsRasterAttributeTableDialog: public QDialog, private Ui::QRas
 
     void reject() override;
 
-  private:
-
-    QgsRasterLayer *mRasterLayer = nullptr;
 };
 
 #endif // QGSRASTERATTRIBUTETABLEDIALOG_H

src/gui/raster/qgsrasterattributetablewidget.cpp

@@ -90,14 +90,14 @@ void QgsRasterAttributeTableWidget::setRasterLayer( QgsRasterLayer *rasterLayer,
 
 bool QgsRasterAttributeTableWidget::isDirty() const
 {
-  return mAttributeTable && mAttributeTable->isDirty();
+  return mAttributeTableBuffer && mAttributeTableBuffer->isDirty();
 }
 
 void QgsRasterAttributeTableWidget::init( int bandNumber )
 {
 
   disconnect( mRasterBandsComboBox, qOverload<int>( &QComboBox::currentIndexChanged ), this, &QgsRasterAttributeTableWidget::bandChanged );
-  mAttributeTable = nullptr;
+  mAttributeTableBuffer = nullptr;
   mCurrentBand = 0;
   mRasterBandsComboBox->clear();
 
@@ -120,22 +120,22 @@ void QgsRasterAttributeTableWidget::init( int bandNumber )
       if ( availableRats.contains( bandNumber ) )
       {
         mCurrentBand = bandNumber;
-        mAttributeTable = mRasterLayer->attributeTable( mCurrentBand );
-        mRasterBandsComboBox->setCurrentIndex( availableRats.indexOf( mCurrentBand ) );
       }
       else if ( ! availableRats.isEmpty() )
       {
         mCurrentBand = availableRats.first();
-        mAttributeTable = mRasterLayer->attributeTable( mCurrentBand );
-        mRasterBandsComboBox->setCurrentIndex( availableRats.indexOf( mCurrentBand ) );
       }
+
+      mAttributeTableBuffer = std::make_unique<QgsRasterAttributeTable>( *mRasterLayer->attributeTable( mCurrentBand ) );
+      mRasterBandsComboBox->setCurrentIndex( availableRats.indexOf( mCurrentBand ) );
     }
   }
 
-  if ( mAttributeTable )
+  if ( mAttributeTableBuffer )
   {
-    mModel.reset( new QgsRasterAttributeTableModel( mAttributeTable ) );
+    mModel.reset( new QgsRasterAttributeTableModel( mAttributeTableBuffer.get() ) );
     mModel->setEditable( mEditable );
+
     connect( mModel.get(), &QgsRasterAttributeTableModel::dataChanged, this, [ = ]( const QModelIndex &, const QModelIndex &, const QVector<int> & )
     {
       updateButtons();
@@ -166,14 +166,15 @@ void QgsRasterAttributeTableWidget::init( int bandNumber )
 
 void QgsRasterAttributeTableWidget::updateButtons()
 {
-  const bool enableEditingButtons { static_cast<bool>( mAttributeTable ) &&mEditable &&mRATView->selectionModel()->currentIndex().isValid() };
+  const bool enableEditingButtons( static_cast<bool>( mAttributeTableBuffer ) && mEditable && mRATView->selectionModel()->currentIndex().isValid() );
+  mActionToggleEditing->setChecked( mEditable );
   mActionAddColumn->setEnabled( mEditable );
   mActionRemoveColumn->setEnabled( enableEditingButtons );
   mActionAddRow->setEnabled( enableEditingButtons );
   mActionRemoveRow->setEnabled( enableEditingButtons );
-  mActionSaveChanges->setEnabled( mAttributeTable && mAttributeTable->isDirty() );
+  mActionSaveChanges->setEnabled( mAttributeTableBuffer && mAttributeTableBuffer->isDirty() );
-  mClassifyButton->setEnabled( mAttributeTable && mRasterLayer );
+  mClassifyButton->setEnabled( mAttributeTableBuffer && mRasterLayer );
-  mClassifyComboBox->setEnabled( mAttributeTable && mRasterLayer );
+  mClassifyComboBox->setEnabled( mAttributeTableBuffer && mRasterLayer );
 }
 
 void QgsRasterAttributeTableWidget::setMessageBar( QgsMessageBar *bar )
@@ -181,83 +182,109 @@ void QgsRasterAttributeTableWidget::setMessageBar( QgsMessageBar *bar )
   mMessageBar = bar;
 }
 
-void QgsRasterAttributeTableWidget::setEditable( bool editable )
+bool QgsRasterAttributeTableWidget::setEditable( bool editable )
 {
-  bool isDirty { false };
+  const bool isDirty { mAttributeTableBuffer &&mAttributeTableBuffer->isDirty() &&mCurrentBand > 0 && mRasterLayer->attributeTable( mCurrentBand ) };
-
+  bool retVal { true };
-  for ( int bandNo = 1; bandNo <= mRasterLayer->bandCount(); ++bandNo )
+  // Switch to read-only
+  if ( ! editable && isDirty )
   {
-    if ( mRasterLayer->dataProvider()->attributeTable( bandNo ) && mRasterLayer->dataProvider()->attributeTable( bandNo )->isDirty() )
+    const QMessageBox::StandardButtons buttons { QMessageBox::Button::Cancel | QMessageBox::Button::Yes |  QMessageBox::Button::No };
+    switch ( QMessageBox::question( nullptr, tr( "Save Attribute Table" ), tr( "Attribute table contains unsaved changes, do you want to save the changes?" ), buttons ) )
     {
-      isDirty = true;
+      case QMessageBox::Button::Cancel:
-      break;
+      {
+        retVal = false;
+        break;
+      }
+      case QMessageBox::Button::Yes:
+      {
+        saveChanges();
+        retVal = true;
+        break;
+      }
+      case QMessageBox::Button::No:
+      default:
+      {
+        // Reset to its original state
+        mAttributeTableBuffer = std::make_unique<QgsRasterAttributeTable>( *mRasterLayer->attributeTable( mCurrentBand ) );
+        init( mCurrentBand );
+        retVal = true;
+        break;
+      }
     }
   }
-  if ( isDirty && QMessageBox::question( nullptr, tr( "Save Attribute Table" ), tr( "Attribute table contains unsaved changes, do you want to save the changes?" ) ) == QMessageBox::Yes )
+
+  if ( retVal )
   {
-    saveChanges();
+    mEditable = editable;
+    mModel->setEditable( editable );
   }
 
-  mEditable = editable;
-  mModel->setEditable( editable );
   updateButtons();
+
+  return retVal;
 }
 
 void QgsRasterAttributeTableWidget::saveChanges()
 {
-  if ( mRasterLayer )
+  if ( mRasterLayer && mAttributeTableBuffer && mAttributeTableBuffer->isDirty() && mCurrentBand > 0 )
   {
-    for ( int bandNo = 1; bandNo <= mRasterLayer->bandCount(); ++bandNo )
+    QgsRasterAttributeTable *attributeTable { mRasterLayer->dataProvider()->attributeTable( mCurrentBand ) };
+    if ( ! attributeTable )
     {
-      QgsRasterAttributeTable *attributeTable { mRasterLayer->dataProvider()->attributeTable( bandNo ) };
+      QgsDebugMsg( QStringLiteral( "Error saving RAT: RAT for band %1 is unexpectedly gone!" ).arg( mCurrentBand ) );
-      if ( attributeTable && attributeTable->isDirty() )
+    }
+    else
+    {
+      *attributeTable = *mAttributeTableBuffer;
+      QString errorMessage;
+      QString newPath { attributeTable->filePath() };
+      const bool nativeRatSupported = mRasterLayer->dataProvider()->providerCapabilities().testFlag( QgsRasterDataProvider::ProviderCapability::NativeRasterAttributeTable );
+      bool saveToNative { false };
+
+      if ( newPath.isEmpty() && ! nativeRatSupported )
       {
-        QString errorMessage;
+        newPath = QFileDialog::getOpenFileName( nullptr, tr( "Save Raster Attribute Table (band %1) To File" ).arg( mCurrentBand ), QFile::exists( mRasterLayer->dataProvider()->dataSourceUri( ) ) ? mRasterLayer->dataProvider()->dataSourceUri( ) + ".vat.dbf" : QString(), QStringLiteral( "VAT DBF Files (*.vat.dbf)" ) );
-        QString newPath { attributeTable->filePath() };
+        if ( newPath.isEmpty() )
-        const bool nativeRatSupported = mRasterLayer->dataProvider()->providerCapabilities().testFlag( QgsRasterDataProvider::ProviderCapability::NativeRasterAttributeTable );
-        bool saveToNative { false };
-
-        if ( newPath.isEmpty() && ! nativeRatSupported )
-        {
-          newPath = QFileDialog::getOpenFileName( nullptr, tr( "Save Raster Attribute Table (band %1) To File" ).arg( bandNo ), QFile::exists( mRasterLayer->dataProvider()->dataSourceUri( ) ) ? mRasterLayer->dataProvider()->dataSourceUri( ) + ".vat.dbf" : QString(), QStringLiteral( "VAT DBF Files (*.vat.dbf)" ) );
-          if ( newPath.isEmpty() )
-          {
-            // Aborted by user
-            return;
-          }
-        }
-        else if ( newPath.isEmpty() )
-        {
-          saveToNative = true;
-        }
-
-        bool writeSuccess { false };
-
-        // Save to file
-        if ( ! saveToNative && ! newPath.isEmpty() )
-        {
-          writeSuccess = attributeTable->writeToFile( attributeTable->filePath(), &errorMessage );
-        }
-        else if ( saveToNative )
-        {
-          writeSuccess = mRasterLayer->dataProvider()->writeNativeAttributeTable( &errorMessage );
-        }
-
-        if ( writeSuccess )
-        {
-          notify( tr( "Attribute Table Write Success" ), tr( "The raster attibute table has been successfully saved." ), Qgis::MessageLevel::Success );
-        }
-        else
-        {
-          notify( tr( "Attribute Table Write Error" ), errorMessage, Qgis::MessageLevel::Critical );
-        }
-
-        // Save to native saves RATs for all bands, no need to loop further.
-        if ( saveToNative )
         {
+          // Aborted by user
           return;
         }
       }
+      else if ( newPath.isEmpty() )
+      {
+        saveToNative = true;
+      }
+
+      bool writeSuccess { false };
+
+      // Save to file
+      if ( ! saveToNative && ! newPath.isEmpty() )
+      {
+        writeSuccess = attributeTable->writeToFile( attributeTable->filePath(), &errorMessage );
+      }
+      else if ( saveToNative )
+      {
+        writeSuccess = mRasterLayer->dataProvider()->writeNativeAttributeTable( &errorMessage );
+      }
+
+      if ( writeSuccess )
+      {
+        mAttributeTableBuffer->setDirty( false );
+        notify( tr( "Attribute Table Write Success" ), tr( "The raster attibute table has been successfully saved." ), Qgis::MessageLevel::Success );
+      }
+      else
+      {
+        notify( tr( "Attribute Table Write Error" ), errorMessage, Qgis::MessageLevel::Critical );
+      }
+
+      // Save to native saves RATs for all bands, no need to loop further.
+      if ( saveToNative )
+      {
+        return;
+      }
+
     }
   }
 
@@ -267,7 +294,7 @@ void QgsRasterAttributeTableWidget::saveChanges()
 void QgsRasterAttributeTableWidget::classify()
 {
 
-  if ( ! mAttributeTable )
+  if ( ! mAttributeTableBuffer )
   {
     notify( tr( "Classification Error" ), tr( "The raster attribute table is not set." ), Qgis::MessageLevel::Critical );
     return;
@@ -279,13 +306,22 @@ void QgsRasterAttributeTableWidget::classify()
     return;
   }
 
-  if ( QMessageBox::question( nullptr, tr( "Apply Style From Attribute Table" ), tr( "The existing style for the raster will be replaced by a new style from the attribute table and any unsaved changes to the current style will be lost, do you want to proceed?" ) ) == QMessageBox::Yes )
+  QString confirmMessage;
+  QString errorMessage;
+
+  if ( ! mAttributeTableBuffer->isValid( &errorMessage ) )
+  {
+    confirmMessage = tr( "The attribute table does not seem to be valid and it may produce an unusable symbology, validation errors:<br>%1<br>" ).arg( errorMessage );
+  }
+
+  if ( QMessageBox::question( nullptr, tr( "Apply Style From Attribute Table" ), confirmMessage.append( tr( "The existing symbology for the raster will be replaced by a new symbology from the attribute table and any unsaved changes to the current symbology will be lost, do you want to proceed?" ) ) ) == QMessageBox::Yes )
   {
 
-    if ( QgsRasterRenderer *renderer = mAttributeTable->createRenderer( mRasterLayer->dataProvider(), mCurrentBand, mClassifyComboBox->currentData().toInt() ) )
+    if ( QgsRasterRenderer *renderer = mAttributeTableBuffer->createRenderer( mRasterLayer->dataProvider(), mCurrentBand, mClassifyComboBox->currentData().toInt() ) )
     {
       mRasterLayer->setRenderer( renderer );
       mRasterLayer->triggerRepaint( );
+      emit rendererChanged();
     }
     else
     {
@@ -296,9 +332,9 @@ void QgsRasterAttributeTableWidget::classify()
 
 void QgsRasterAttributeTableWidget::addColumn()
 {
-  if ( mAttributeTable )
+  if ( mAttributeTableBuffer )
   {
-    QgsRasterAttributeTableAddColumnDialog dlg { mAttributeTable };
+    QgsRasterAttributeTableAddColumnDialog dlg { mAttributeTableBuffer.get() };
     if ( dlg.exec() == QDialog::Accepted )
     {
       QString errorMessage;
@@ -330,7 +366,7 @@ void QgsRasterAttributeTableWidget::addColumn()
 void QgsRasterAttributeTableWidget::removeColumn()
 {
   const QModelIndex currentIndex { mProxyModel->mapToSource( mRATView->selectionModel()->currentIndex() ) };
-  if ( mAttributeTable && currentIndex.isValid() && currentIndex.column() < mAttributeTable->fields().count() )
+  if ( mAttributeTableBuffer && currentIndex.isValid() && currentIndex.column() < mAttributeTableBuffer->fields().count() )
   {
     if ( QMessageBox::question( nullptr, tr( "Remove Column" ), tr( "Do you want to remove the selected column? This action cannot be undone." ) ) == QMessageBox::Yes )
     {
@@ -345,7 +381,7 @@ void QgsRasterAttributeTableWidget::removeColumn()
 
 void QgsRasterAttributeTableWidget::addRow()
 {
-  if ( mAttributeTable )
+  if ( mAttributeTableBuffer )
   {
     // Default to append
     int position { mModel->rowCount( QModelIndex() ) };
@@ -372,7 +408,7 @@ void QgsRasterAttributeTableWidget::addRow()
 
     QVariantList rowData;
 
-    QList<QgsRasterAttributeTable::Field> fields { mAttributeTable->fields() };
+    QList<QgsRasterAttributeTable::Field> fields { mAttributeTableBuffer->fields() };
     for ( const QgsRasterAttributeTable::Field &field : std::as_const( fields ) )
     {
       rowData.push_back( QVariant( field.type ) );
@@ -393,7 +429,7 @@ void QgsRasterAttributeTableWidget::addRow()
 
 void QgsRasterAttributeTableWidget::removeRow()
 {
-  if ( mAttributeTable && mRATView->selectionModel()->currentIndex().isValid() )
+  if ( mAttributeTableBuffer && mRATView->selectionModel()->currentIndex().isValid() )
   {
     if ( QMessageBox::question( nullptr, tr( "Remove Row" ), tr( "Do you want to remove the selected row? This action cannot be undone." ) ) == QMessageBox::Yes )
     {
@@ -409,8 +445,13 @@ void QgsRasterAttributeTableWidget::removeRow()
 void QgsRasterAttributeTableWidget::bandChanged( const int index )
 {
   const QVariant itemData = mRasterBandsComboBox->itemData( index );
+
   if ( itemData.isValid() )
   {
+    if ( mEditable )
+    {
+      setEditable( false );
+    }
     init( itemData.toInt( ) );
   }
 }
@@ -449,9 +490,9 @@ void QgsRasterAttributeTableWidget::notify( const QString &title, const QString
 void QgsRasterAttributeTableWidget::setDelegates()
 {
   mClassifyComboBox->clear();
-  if ( mAttributeTable )
+  if ( mAttributeTableBuffer )
   {
-    const QList<QgsRasterAttributeTable::Field> tableFields { mAttributeTable->fields() };
+    const QList<QgsRasterAttributeTable::Field> tableFields { mAttributeTableBuffer->fields() };
     int fieldIdx { 0 };
     const QHash<Qgis::RasterAttributeTableFieldUsage, QgsRasterAttributeTable::UsageInformation> usageInfo { QgsRasterAttributeTable::usageInformation() };
     for ( const QgsRasterAttributeTable::Field &f : std::as_const( tableFields ) )
@@ -465,26 +506,26 @@ void QgsRasterAttributeTableWidget::setDelegates()
       fieldIdx++;
     }
 
-    if ( mAttributeTable->hasColor() )
+    if ( mAttributeTableBuffer->hasColor() )
     {
-      if ( mAttributeTable->usages().contains( Qgis::RasterAttributeTableFieldUsage::Alpha ) )
+      if ( mAttributeTableBuffer->usages().contains( Qgis::RasterAttributeTableFieldUsage::Alpha ) )
       {
-        mRATView->setItemDelegateForColumn( mAttributeTable->fields().count( ), new ColorAlphaDelegate( mRATView ) );
+        mRATView->setItemDelegateForColumn( mAttributeTableBuffer->fields().count( ), new ColorAlphaDelegate( mRATView ) );
       }
       else
       {
-        mRATView->setItemDelegateForColumn( mAttributeTable->fields().count( ), new ColorDelegate( mRATView ) );
+        mRATView->setItemDelegateForColumn( mAttributeTableBuffer->fields().count( ), new ColorDelegate( mRATView ) );
       }
     }
-    else if ( mAttributeTable->hasRamp() )
+    else if ( mAttributeTableBuffer->hasRamp() )
     {
-      if ( mAttributeTable->usages().contains( Qgis::RasterAttributeTableFieldUsage::AlphaMin ) )
+      if ( mAttributeTableBuffer->usages().contains( Qgis::RasterAttributeTableFieldUsage::AlphaMin ) )
       {
-        mRATView->setItemDelegateForColumn( mAttributeTable->fields().count( ), new ColorRampAlphaDelegate( mRATView ) );
+        mRATView->setItemDelegateForColumn( mAttributeTableBuffer->fields().count( ), new ColorRampAlphaDelegate( mRATView ) );
       }
       else
       {
-        mRATView->setItemDelegateForColumn( mAttributeTable->fields().count( ), new ColorRampDelegate( mRATView ) );
+        mRATView->setItemDelegateForColumn( mAttributeTableBuffer->fields().count( ), new ColorRampDelegate( mRATView ) );
       }
     }
   }

src/gui/raster/qgsrasterattributetablewidget.h

@@ -122,10 +122,48 @@ class GUI_EXPORT QgsRasterAttributeTableWidget : public QWidget, private Ui::Qgs
      */
     bool isDirty( ) const;
 
+    /**
+     * Sets the message \a bar associated with the widget. This allows the widget to push feedback messages
+     * to the appropriate message bar.
+     * \see messageBar()
+     */
+    void setMessageBar( QgsMessageBar *bar );
+
+  signals:
+
+    /**
+     * This signal is emitted after a successful classify operation which changed the raster renderer.
+     */
+    void rendererChanged( );
+
+  public slots:
+
+    /**
+     * Save the changes in the raster attribute table.
+     */
+    void saveChanges();
+
+    /**
+     * Set the editable state, it may trigger save changes if the attribute table has unsave changes.
+     */
+    bool setEditable( bool editable );
+
+  private slots:
+
+
+    void classify();
+    void addColumn();
+    void removeColumn();
+    void addRow();
+    void removeRow();
+    void bandChanged( const int index );
+    void notify( const QString &title, const QString &message, Qgis::MessageLevel level = Qgis::MessageLevel::Info );
+    void setDelegates( );
+
   private:
 
     QgsRasterLayer *mRasterLayer = nullptr;
-    QgsRasterAttributeTable *mAttributeTable = nullptr;
+    std::unique_ptr<QgsRasterAttributeTable> mAttributeTableBuffer;
     // Default to invalid (bands are 1-indexed)
     int mCurrentBand = 0;
     bool mEditable = false;
@@ -144,28 +182,6 @@ class GUI_EXPORT QgsRasterAttributeTableWidget : public QWidget, private Ui::Qgs
 
     void init( int bandNumber = 0 );
     void updateButtons();
-
-    /**
-     * Sets the message \a bar associated with the widget. This allows the widget to push feedback messages
-     * to the appropriate message bar.
-     * \see messageBar()
-     */
-    void setMessageBar( QgsMessageBar *bar );
-
-
-  private slots:
-
-    void setEditable( bool editable );
-    void saveChanges();
-    void classify();
-    void addColumn();
-    void removeColumn();
-    void addRow();
-    void removeRow();
-    void bandChanged( const int index );
-    void notify( const QString &title, const QString &message, Qgis::MessageLevel level = Qgis::MessageLevel::Info );
-    void setDelegates( );
-
 };
 
 #endif // QGSRASTERATTRIBUTETABLEWIDGET_H

src/gui/raster/qgsrasterlayerproperties.cpp

@@ -68,6 +68,7 @@
 #include "qgsdoublevalidator.h"
 #include "qgsmaplayerconfigwidgetfactory.h"
 #include "qgsprojectutils.h"
+#include "qgsrasterattributetablewidget.h"
 
 #include "qgsrasterlayertemporalpropertieswidget.h"
 #include "qgsprojecttimesettings.h"
@@ -234,6 +235,21 @@ QgsRasterLayerProperties::QgsRasterLayerProperties( QgsMapLayer *lyr, QgsMapCanv
     return;
   }
 
+  // Setup raster attribute table
+  if ( mRasterLayer->attributeTableCount() > 0 )
+  {
+    mRasterAttributeTableWidget = new QgsRasterAttributeTableWidget( this, mRasterLayer );
+    mOptsPage_RasterAttributeTable->layout()->addWidget( mRasterAttributeTableWidget );
+    // When the renderer changes we need to sync the style options page
+    connect( mRasterAttributeTableWidget, &QgsRasterAttributeTableWidget::rendererChanged, this, &QgsRasterLayerProperties::syncToLayer );
+    mNoRasterAttributeTableWidget->hide();
+  }
+  else
+  {
+    mNoRasterAttributeTableWidget->show();
+  }
+
+
   mBackupCrs = mRasterLayer->crs();
 
   // Handles window modality raising canvas

src/gui/raster/qgsrasterlayerproperties.h

@@ -46,6 +46,7 @@ class QgsMapLayerConfigWidgetFactory;
 class QgsMapLayerConfigWidget;
 class QgsPropertyOverrideButton;
 class QgsRasterTransparencyWidget;
+class QgsRasterAttributeTableWidget;
 
 
 /**
@@ -296,5 +297,7 @@ class GUI_EXPORT QgsRasterLayerProperties : public QgsOptionsDialogBase, private
     friend class QgsAppScreenShots;
 
     QgsCoordinateReferenceSystem mBackupCrs;
+
+    QgsRasterAttributeTableWidget *mRasterAttributeTableWidget = nullptr;
 };
 #endif

src/ui/qgsrasterlayerpropertiesbase.ui

@@ -93,7 +93,7 @@
           <bool>true</bool>
          </property>
          <property name="currentRow">
-          <number>0</number>
+          <number>-1</number>
          </property>
          <item>
           <property name="text">
@@ -203,6 +203,18 @@
             <normaloff>:/images/themes/default/legend.svg</normaloff>:/images/themes/default/legend.svg</iconset>
           </property>
          </item>
+         <item>
+          <property name="text">
+           <string>Attribute Tables</string>
+          </property>
+          <property name="toolTip">
+           <string>Manage Raster Attribute Tables</string>
+          </property>
+          <property name="icon">
+           <iconset resource="../../images/images.qrc">
+            <normaloff>:/images/themes/default/propertyicons/attributes.svg</normaloff>:/images/themes/default/propertyicons/attributes.svg</iconset>
+          </property>
+         </item>
          <item>
           <property name="text">
            <string>QGIS Server</string>
@@ -254,7 +266,7 @@
           </sizepolicy>
          </property>
          <property name="currentIndex">
-          <number>0</number>
+          <number>10</number>
          </property>
          <widget class="QWidget" name="mOptsPage_Information">
           <layout class="QVBoxLayout" name="verticalLayout_20">
@@ -299,8 +311,8 @@
                <rect>
                 <x>0</x>
                 <y>0</y>
-                <width>253</width>
+                <width>648</width>
-                <height>392</height>
+                <height>690</height>
                </rect>
               </property>
               <layout class="QVBoxLayout" name="verticalLayout_7">
@@ -1438,6 +1450,55 @@ p, li { white-space: pre-wrap; }
            </item>
           </layout>
          </widget>
+         <widget class="QWidget" name="mOptsPage_RasterAttributeTable">
+          <layout class="QVBoxLayout" name="verticalLayout_rat">
+           <property name="leftMargin">
+            <number>0</number>
+           </property>
+           <property name="topMargin">
+            <number>0</number>
+           </property>
+           <property name="rightMargin">
+            <number>0</number>
+           </property>
+           <property name="bottomMargin">
+            <number>0</number>
+           </property>
+           <item>
+            <widget class="QWidget" name="mNoRasterAttributeTableWidget" native="true">
+             <layout class="QVBoxLayout" name="verticalLayout_5">
+              <item>
+               <widget class="QLabel" name="mRasterAttributeTableLabel">
+                <property name="text">
+                 <string>There are no raster attribute tables associated with this data source. 
+
+If the current symbology can be converted to an attribute table you can create a new attribute table using the context menu available in the layer tree.
+
+From the layer tree context menu it you can also import an existing raster attribute table from a VAT.DBF file and associate it with a raster band.</string>
+                </property>
+                <property name="wordWrap">
+                 <bool>true</bool>
+                </property>
+               </widget>
+              </item>
+              <item>
+               <spacer name="verticalSpacer_2">
+                <property name="orientation">
+                 <enum>Qt::Vertical</enum>
+                </property>
+                <property name="sizeHint" stdset="0">
+                 <size>
+                  <width>20</width>
+                  <height>40</height>
+                 </size>
+                </property>
+               </spacer>
+              </item>
+             </layout>
+            </widget>
+           </item>
+          </layout>
+         </widget>
          <widget class="QWidget" name="mOptsPage_Server">
           <layout class="QVBoxLayout" name="verticalLayout_8">
            <property name="leftMargin">
@@ -1466,7 +1527,7 @@ p, li { white-space: pre-wrap; }
                 <x>0</x>
                 <y>0</y>
                 <width>263</width>
-                <height>566</height>
+                <height>600</height>
                </rect>
               </property>
               <layout class="QGridLayout" name="gridLayout_12">
@@ -1994,6 +2055,8 @@ p, li { white-space: pre-wrap; }
  </tabstops>
  <resources>
   <include location="../../images/images.qrc"/>
+  <include location="../../images/images.qrc"/>
+  <include location="../../images/images.qrc"/>
  </resources>
  <connections>
   <connection>

src/ui/raster/qgscreaterasterattributetabledialogbase.ui

@@ -17,7 +17,7 @@
    <item>
     <widget class="QLabel" name="mCreateInfoLabel">
      <property name="text">
-      <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Create a new Raster Attribute Table (RAT) from the current symbology.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+      <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Create a new Raster Attribute Table from the current symbology.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
      </property>
      <property name="wordWrap">
       <bool>true</bool>

src/ui/raster/qgsrasterattributetableaddcolumndialogbase.ui

@@ -111,6 +111,9 @@
         <property name="text">
          <string>After</string>
         </property>
+        <property name="checked">
+         <bool>true</bool>
+        </property>
        </widget>
       </item>
       <item row="3" column="0">
@@ -119,7 +122,7 @@
          <string>Before</string>
         </property>
         <property name="checked">
-         <bool>true</bool>
+         <bool>false</bool>
         </property>
        </widget>
       </item>