[FEATURE] Implement raster pseudocolor updated extent auto classifica…

…tion

src/core/raster/qgsrasterlayer.cpp

@@ -1057,8 +1057,30 @@ void QgsRasterLayer::refreshRendererIfNeeded( QgsRasterRenderer* rasterRenderer,
                    SAMPLE_SIZE, min, max );
     sbpcr->setClassificationMin( min );
     sbpcr->setClassificationMax( max );
+
+    if ( sbpcr->shader() )
+    {
+      QgsColorRampShader* colorRampShader = dynamic_cast<QgsColorRampShader*>( sbpcr->shader()->rasterShaderFunction() );
+      if ( colorRampShader )
+      {
+        colorRampShader->classifyColorRamp( sbpcr->band(), theExtent, rasterRenderer->input() );
+      }
+    }
+
+    QgsSingleBandPseudoColorRenderer* r = dynamic_cast<QgsSingleBandPseudoColorRenderer*>( renderer() );
     dynamic_cast<QgsSingleBandPseudoColorRenderer*>( renderer() )->setClassificationMin( min );
     dynamic_cast<QgsSingleBandPseudoColorRenderer*>( renderer() )->setClassificationMax( max );
+
+    if ( r->shader() )
+    {
+      QgsColorRampShader* colorRampShader = dynamic_cast<QgsColorRampShader*>( r->shader()->rasterShaderFunction() );
+      if ( colorRampShader )
+      {
+        colorRampShader->classifyColorRamp( sbpcr->band(), theExtent, rasterRenderer->input() );
+      }
+    }
+
+    emit repaintRequested();
     emit styleChanged();
     emit rendererChanged();
     return;

src/gui/raster/qgssinglebandpseudocolorrendererwidget.cpp

@@ -86,11 +86,8 @@ QgsSingleBandPseudoColorRendererWidget::QgsSingleBandPseudoColorRendererWidget(
   mMinMaxContainerWidget->setLayout( layout );
   layout->addWidget( mMinMaxWidget );
 
-  connect( mMinMaxWidget, &QgsRasterMinMaxWidget::widgetChanged,
-           this, &QgsSingleBandPseudoColorRendererWidget::widgetChanged );
-
-  connect( mMinMaxWidget, &QgsRasterMinMaxWidget::load,
-           this, &QgsSingleBandPseudoColorRendererWidget::loadMinMax );
+  connect( mMinMaxWidget, &QgsRasterMinMaxWidget::widgetChanged, this, &QgsSingleBandPseudoColorRendererWidget::widgetChanged );
+  connect( mMinMaxWidget, &QgsRasterMinMaxWidget::load, this, &QgsSingleBandPseudoColorRendererWidget::loadMinMax );
 
   //fill available bands into combo box
   int nBands = provider->bandCount();
@@ -775,6 +772,7 @@ void QgsSingleBandPseudoColorRendererWidget::loadMinMax( int theBandNo, double t
     mMaxLineEdit->setText( QString::number( theMax ) );
   }
   mDisableMinMaxWidgetRefresh = false;
+  classify();
 }
 
 void QgsSingleBandPseudoColorRendererWidget::setLineEditValue( QLineEdit * theLineEdit, double theValue )