From 58ce77f19aea54d98cb526453af69facf49a50de Mon Sep 17 00:00:00 2001
From: Alessandro Pasotti <elpaso@itopen.it>
Date: Mon, 9 Nov 2020 12:03:03 +0100
Subject: [PATCH] Paletted: fix ordering from proxy model

---
 src/gui/raster/qgspalettedrendererwidget.cpp | 18 +++++++++++++++---
 src/gui/raster/qgspalettedrendererwidget.h   |  4 ++++
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/gui/raster/qgspalettedrendererwidget.cpp b/src/gui/raster/qgspalettedrendererwidget.cpp
index d995f64a864a..112c054f3645 100644
--- a/src/gui/raster/qgspalettedrendererwidget.cpp
+++ b/src/gui/raster/qgspalettedrendererwidget.cpp
@@ -141,7 +141,7 @@ QgsPalettedRendererWidget::~QgsPalettedRendererWidget()
 
 QgsRasterRenderer *QgsPalettedRendererWidget::renderer()
 {
-  QgsPalettedRasterRenderer::ClassData classes = mModel->classData();
+  QgsPalettedRasterRenderer::ClassData classes = mProxyModel->classData();
   int bandNumber = mBandComboBox->currentBand();
 
   QgsPalettedRasterRenderer *r = new QgsPalettedRasterRenderer( mRasterLayer->dataProvider(), bandNumber, classes );
@@ -342,7 +342,7 @@ void QgsPalettedRendererWidget::applyColorRamp()
 
   disconnect( mModel, &QgsPalettedRendererModel::classesChanged, this, &QgsPalettedRendererWidget::widgetChanged );
 
-  QgsPalettedRasterRenderer::ClassData data = mModel->classData();
+  QgsPalettedRasterRenderer::ClassData data = mProxyModel->classData();
   QgsPalettedRasterRenderer::ClassData::iterator cIt = data.begin();
 
   double numberOfEntries = data.count();
@@ -407,7 +407,7 @@ void QgsPalettedRendererWidget::saveColorTable()
     if ( outputFile.open( QFile::WriteOnly | QIODevice::Truncate ) )
     {
       QTextStream outputStream( &outputFile );
-      outputStream << QgsPalettedRasterRenderer::classDataToString( mModel->classData() );
+      outputStream << QgsPalettedRasterRenderer::classDataToString( mProxyModel->classData() );
       outputStream.flush();
       outputFile.close();
 
@@ -876,4 +876,16 @@ void QgsPalettedRendererClassGatherer::run()
   emit collectedClasses();
 }
 
+
+QgsPalettedRasterRenderer::ClassData QgsPalettedRendererProxyModel::classData() const
+{
+  QgsPalettedRasterRenderer::ClassData data;
+  for ( int i = 0; i < rowCount( ); ++i )
+  {
+    data.push_back( qobject_cast<QgsPalettedRendererModel *>( sourceModel() )->classAtIndex( mapToSource( index( i, 0 ) ) ) );
+  }
+  return data;
+}
+
+
 ///@endcond PRIVATE
diff --git a/src/gui/raster/qgspalettedrendererwidget.h b/src/gui/raster/qgspalettedrendererwidget.h
index 04e6b35aafff..4a5ad852fd6a 100644
--- a/src/gui/raster/qgspalettedrendererwidget.h
+++ b/src/gui/raster/qgspalettedrendererwidget.h
@@ -112,6 +112,7 @@ class QgsPalettedRendererModel : public QAbstractItemModel
     void setClassData( const QgsPalettedRasterRenderer::ClassData &data );
 
     QgsPalettedRasterRenderer::ClassData classData() const { return mData; }
+    QgsPalettedRasterRenderer::Class classAtIndex( const QModelIndex &index ) const { return mData.at( index.row() ); }
 
     QModelIndex index( int row, int column, const QModelIndex &parent = QModelIndex() ) const override;
     QModelIndex parent( const QModelIndex &index ) const override;
@@ -156,6 +157,9 @@ class QgsPalettedRendererProxyModel: public QSortFilterProxyModel
     {
     }
 
+    //! Return sorted class data
+    QgsPalettedRasterRenderer::ClassData classData() const;
+
   protected:
 
     bool lessThan( const QModelIndex &left, const QModelIndex &right ) const override