qgsrasterrenderer: Introduce refresh

This is similar to what is achieved in
`QgsRasterLayer::refreshRenderer()` to refresh the renderer according
to an extent. Contrary to the first one, this method does not perform
any GUI update or emit any signal.

It is not used at the moment. This will replace the logic to refresh a
renderer in the following commits.

python/PyQt6/core/auto_generated/raster/qgsmultibandcolorrenderer.sip.in

@@ -129,6 +129,7 @@ Ownership of the enhancement is transferred.
     virtual void toSld( QDomDocument &doc, QDomElement &element, const QVariantMap &props = QVariantMap() ) const;
 
 
+
   private:
     QgsMultiBandColorRenderer( const QgsMultiBandColorRenderer & );
     const QgsMultiBandColorRenderer &operator=( const QgsMultiBandColorRenderer & );

python/PyQt6/core/auto_generated/raster/qgsrasterrenderer.sip.in

@@ -222,6 +222,7 @@ should be canceled.
 %End
 
 
+
   protected:
 
     void _writeXml( QDomDocument &doc, QDomElement &rasterRendererElem ) const;

python/PyQt6/core/auto_generated/raster/qgssinglebandgrayrenderer.sip.in

@@ -107,6 +107,7 @@ Ownership of ``settings`` is transferred.
 .. versionadded:: 3.18
 %End
 
+
   private:
     QgsSingleBandGrayRenderer( const QgsSingleBandGrayRenderer & );
     const QgsSingleBandGrayRenderer &operator=( const QgsSingleBandGrayRenderer & );

python/PyQt6/core/auto_generated/raster/qgssinglebandpseudocolorrenderer.sip.in

@@ -120,6 +120,7 @@ Sets the band used by the renderer.
     void setClassificationMin( double min );
     void setClassificationMax( double max );
 
+
   private:
     QgsSingleBandPseudoColorRenderer( const QgsSingleBandPseudoColorRenderer & );
     const QgsSingleBandPseudoColorRenderer &operator=( const QgsSingleBandPseudoColorRenderer & );

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

@@ -129,6 +129,7 @@ Ownership of the enhancement is transferred.
     virtual void toSld( QDomDocument &doc, QDomElement &element, const QVariantMap &props = QVariantMap() ) const;
 
 
+
   private:
     QgsMultiBandColorRenderer( const QgsMultiBandColorRenderer & );
     const QgsMultiBandColorRenderer &operator=( const QgsMultiBandColorRenderer & );

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

@@ -222,6 +222,7 @@ should be canceled.
 %End
 
 
+
   protected:
 
     void _writeXml( QDomDocument &doc, QDomElement &rasterRendererElem ) const;

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

@@ -107,6 +107,7 @@ Ownership of ``settings`` is transferred.
 .. versionadded:: 3.18
 %End
 
+
   private:
     QgsSingleBandGrayRenderer( const QgsSingleBandGrayRenderer & );
     const QgsSingleBandGrayRenderer &operator=( const QgsSingleBandGrayRenderer & );

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

@@ -120,6 +120,7 @@ Sets the band used by the renderer.
     void setClassificationMin( double min );
     void setClassificationMax( double max );
 
+
   private:
     QgsSingleBandPseudoColorRenderer( const QgsSingleBandPseudoColorRenderer & );
     const QgsSingleBandPseudoColorRenderer &operator=( const QgsSingleBandPseudoColorRenderer & );

src/core/raster/qgsmultibandcolorrenderer.cpp

@@ -589,3 +589,43 @@ void QgsMultiBandColorRenderer::toSld( QDomDocument &doc, QDomElement &element,
     }
   }
 }
+
+bool QgsMultiBandColorRenderer::refresh( const QgsRectangle &extent, const QList<double> &min, const QList<double> &max, bool forceRefresh )
+{
+  if ( !needsRefresh( extent ) && !forceRefresh )
+  {
+    return false;
+  }
+
+  bool refreshed = false;
+  if ( min.size() >= 3 && max.size() >= 3 )
+  {
+    mLastRectangleUsedByRefreshContrastEnhancementIfNeeded = extent;
+
+    if ( mRedContrastEnhancement && mRedContrastEnhancement->contrastEnhancementAlgorithm() != QgsContrastEnhancement::NoEnhancement &&
+         !std::isnan( min[0] ) && !std::isnan( max[0] ) )
+    {
+      mRedContrastEnhancement->setMinimumValue( min[0] );
+      mRedContrastEnhancement->setMaximumValue( max[0] );
+      refreshed = true;
+    }
+
+    if ( mGreenContrastEnhancement && mGreenContrastEnhancement->contrastEnhancementAlgorithm() != QgsContrastEnhancement::NoEnhancement &&
+         !std::isnan( min[1] ) && !std::isnan( max[1] ) )
+    {
+      mGreenContrastEnhancement->setMinimumValue( min[1] );
+      mGreenContrastEnhancement->setMaximumValue( max[1] );
+      refreshed = true;
+    }
+
+    if ( mBlueContrastEnhancement && mBlueContrastEnhancement->contrastEnhancementAlgorithm() != QgsContrastEnhancement::NoEnhancement &&
+         !std::isnan( min[2] ) && !std::isnan( max[2] ) )
+    {
+      mBlueContrastEnhancement->setMinimumValue( min[2] );
+      mBlueContrastEnhancement->setMaximumValue( max[2] );
+      refreshed = true;
+    }
+  }
+
+  return refreshed;
+}

src/core/raster/qgsmultibandcolorrenderer.h

@@ -123,6 +123,22 @@ class CORE_EXPORT QgsMultiBandColorRenderer: public QgsRasterRenderer
 
     void toSld( QDomDocument &doc, QDomElement &element, const QVariantMap &props = QVariantMap() ) const override;
 
+    /**
+     * \brief Refreshes the renderer according to the \a min and \a max values associated with the \a extent.
+     * \a min and \a max size need to be at least 3.
+     * If \a min or \a max size is greater than 3, the last values are ignored.
+     * The first value is associated with the red contrast.
+     * The second value is associated with the green contrast.
+     * The third value is associated with the blue contrast.
+     * NaN values are ignored.
+     * If \a forceRefresh is TRUE, this will force the refresh even if needsRefresh() returns FALSE.
+     * \returns TRUE if the renderer has been refreshed
+     * \note not available in Python bindings
+     *
+     * \since QGIS 3.42
+     */
+    bool refresh( const QgsRectangle &extent, const QList<double> &min, const QList<double> &max, bool forceRefresh = false ) override SIP_SKIP;
+
   private:
 #ifdef SIP_RUN
     QgsMultiBandColorRenderer( const QgsMultiBandColorRenderer & );

src/core/raster/qgsrasterrenderer.cpp

@@ -256,3 +256,14 @@ bool QgsRasterRenderer::needsRefresh( const QgsRectangle &extent ) const
 
   return false;
 }
+
+bool QgsRasterRenderer::refresh( const QgsRectangle &extent, const QList<double> &, const QList<double> &, bool forceRefresh )
+{
+  if ( !needsRefresh( extent ) && !forceRefresh )
+  {
+    return false;
+  }
+
+  mLastRectangleUsedByRefreshContrastEnhancementIfNeeded = extent;
+  return true;
+}

src/core/raster/qgsrasterrenderer.h

@@ -231,6 +231,16 @@ class CORE_EXPORT QgsRasterRenderer : public QgsRasterInterface
      */
     bool needsRefresh( const QgsRectangle &extent ) const SIP_SKIP;
 
+    /**
+     * \brief Refreshes the renderer according to the \a min and \a max values associated with the \a extent.
+     * If \a forceRefresh is TRUE, this will force the refresh even if needsRefresh() returns FALSE.
+     * \returns TRUE if the renderer has been refreshed
+     * \note not available in Python bindings
+     *
+     * \since QGIS 3.42
+     */
+    virtual bool refresh( const QgsRectangle &extent, const QList<double> &min, const QList<double> &max, bool forceRefresh = false ) SIP_SKIP;
+
   protected:
 
     //! Write upper class info into rasterrenderer element (called by writeXml method of subclasses)
@@ -262,6 +272,7 @@ class CORE_EXPORT QgsRasterRenderer : public QgsRasterInterface
      */
     QRgb renderColorForNodataPixel() const;
 
+    //! To save computations and possible infinite cycle of notifications
     QgsRectangle mLastRectangleUsedByRefreshContrastEnhancementIfNeeded;
 
   private:

src/core/raster/qgssinglebandgrayrenderer.cpp

@@ -458,3 +458,23 @@ void QgsSingleBandGrayRenderer::setLegendSettings( QgsColorRampLegendNodeSetting
     return;
   mLegendSettings.reset( settings );
 }
+
+bool QgsSingleBandGrayRenderer::refresh( const QgsRectangle &extent, const QList<double> &min, const QList<double> &max, bool forceRefresh )
+{
+  if ( !needsRefresh( extent ) && !forceRefresh )
+  {
+    return false;
+  }
+
+  bool refreshed = false;
+  if ( mContrastEnhancement && mContrastEnhancement->contrastEnhancementAlgorithm() != QgsContrastEnhancement::NoEnhancement &&
+       min.size() >= 1 && max.size() >= 1 )
+  {
+    mLastRectangleUsedByRefreshContrastEnhancementIfNeeded = extent;
+    mContrastEnhancement->setMinimumValue( min[0] );
+    mContrastEnhancement->setMaximumValue( max[0] );
+    refreshed = true;
+  }
+
+  return refreshed;
+}

src/core/raster/qgssinglebandgrayrenderer.h

@@ -102,6 +102,17 @@ class CORE_EXPORT QgsSingleBandGrayRenderer: public QgsRasterRenderer
      */
     void setLegendSettings( QgsColorRampLegendNodeSettings *settings SIP_TRANSFER );
 
+    /**
+     * \brief Refreshes the renderer according to the \a min and \a max values associated with the \a extent.
+     * If \a min or \a max size is greater than 1, the last values are ignored.
+     * If \a forceRefresh is TRUE, this will force the refresh even if needsRefresh() returns FALSE.
+     * \returns TRUE if the renderer has been refreshed
+     * \note not available in Python bindings
+     *
+     * \since QGIS 3.42
+     */
+    bool refresh( const QgsRectangle &extent, const QList<double> &min, const QList<double> &max, bool forceRefresh = false ) override SIP_SKIP;
+
   private:
 #ifdef SIP_RUN
     QgsSingleBandGrayRenderer( const QgsSingleBandGrayRenderer & );

src/core/raster/qgssinglebandpseudocolorrenderer.cpp

@@ -493,3 +493,42 @@ bool QgsSingleBandPseudoColorRenderer::canCreateRasterAttributeTable() const
   return true;
 }
 
+bool QgsSingleBandPseudoColorRenderer::refresh( const QgsRectangle &extent, const QList<double> &min, const QList<double> &max, bool force )
+{
+  if ( !needsRefresh( extent ) && !force )
+  {
+    return false;
+  }
+
+  bool refreshed = false;
+  if ( min.size() >= 1 && max.size() >= 1 )
+  {
+    mLastRectangleUsedByRefreshContrastEnhancementIfNeeded = extent;
+
+    // Do not overwrite min/max with NaN if they were already set,
+    // for example when the style was already loaded from a raster attribute table
+    // in that case we need to respect the style from the attribute table and do
+    // not perform any reclassification.
+    bool refreshed = false;
+
+    if ( !std::isnan( min[0] ) )
+    {
+      setClassificationMin( min[0] );
+      refreshed = true;
+    }
+
+    if ( !std::isnan( max[0] ) )
+    {
+      setClassificationMax( max[0] );
+      refreshed = true;
+    }
+
+    QgsColorRampShader *rampShader = dynamic_cast<QgsColorRampShader *>( mShader->rasterShaderFunction() );
+    if ( rampShader && refreshed )
+    {
+      rampShader->classifyColorRamp( mBand, extent, input() );
+    }
+  }
+
+  return refreshed;
+}

src/core/raster/qgssinglebandpseudocolorrenderer.h

@@ -107,6 +107,18 @@ class CORE_EXPORT QgsSingleBandPseudoColorRenderer: public QgsRasterRenderer
     void setClassificationMin( double min );
     void setClassificationMax( double max );
 
+    /**
+     * \brief Refreshes the renderer according to the \a min and \a max values associated with the \a extent.
+     * If \a min or \a max size is greater than 1, the last values are ignored.
+     * NaN values are ignored.
+     * If \a forceRefresh is TRUE, this will force the refresh even if needsRefresh() returns FALSE.
+     * \returns TRUE if the renderer has been refreshed
+     * \note not available in Python bindings
+     *
+     * \since QGIS 3.42
+     */
+    bool refresh( const QgsRectangle &extent, const QList<double> &min, const QList<double> &max, bool forceRefresh = false ) override SIP_SKIP;
+
   private:
 #ifdef SIP_RUN
     QgsSingleBandPseudoColorRenderer( const QgsSingleBandPseudoColorRenderer & );