[FEATURE] save and restore color ramp used for singleband pseudocolor rendering

Author: alexbruy

src/core/raster/qgscolorrampshader.cpp

@@ -35,6 +35,7 @@ QgsColorRampShader::QgsColorRampShader( double theMinimumValue, double theMaximu
     , mLUTFactor( 1.0 )
     , mLUTInitialized( false )
     , mClip( false )
+    , mColorRampName( "" )
 {
   QgsDebugMsgLevel( "called.", 4 );
 }
@@ -82,6 +83,12 @@ void QgsColorRampShader::setColorRampType( const QString& theType )
   }
 }
 
+void QgsColorRampShader::setColorRampName( const QString& theName )
+{
+  mColorRampName = theName;
+}
+
+
 bool QgsColorRampShader::shade( double theValue, int* theReturnRedValue, int* theReturnGreenValue, int* theReturnBlueValue, int *theReturnAlphaValue )
 {
   if ( mColorRampItemList.isEmpty() )

src/core/raster/qgscolorrampshader.h

@@ -75,6 +75,9 @@ class CORE_EXPORT QgsColorRampShader : public QgsRasterShaderFunction
     //! \brief Get the color ramp type as a string
     QString colorRampTypeAsQString();
 
+    //! \brief Get the original color ramp name
+    QString colorRampName() const {return mColorRampName;}
+
     //! \brief Set custom colormap
     void setColorRampItemList( const QList<QgsColorRampShader::ColorRampItem>& theList ); //TODO: sort on set
 
@@ -84,6 +87,9 @@ class CORE_EXPORT QgsColorRampShader : public QgsRasterShaderFunction
     //! \brief Set the color ramp type
     void setColorRampType( const QString& theType );
 
+    //! \brief Set the source color ramp name
+    void setColorRampName( const QString& theName );
+
     //! \brief Generates and new RGB value based on one input value
     bool shade( double, int*, int*, int*, int* ) override;
 
@@ -121,6 +127,9 @@ class CORE_EXPORT QgsColorRampShader : public QgsRasterShaderFunction
     double mLUTFactor;
     bool mLUTInitialized;
 
+    /** Colorramp name*/
+    QString mColorRampName;
+
     //! Do not render values out of range
     bool mClip;
 };

src/core/raster/qgsrastershader.cpp

@@ -143,7 +143,8 @@ void QgsRasterShader::writeXml( QDomDocument& doc, QDomElement& parent ) const
   if ( colorRampShader )
   {
     QDomElement colorRampShaderElem = doc.createElement( QStringLiteral( "colorrampshader" ) );
-    colorRampShaderElem.setAttribute( QStringLiteral( "colorRampType" ), colorRampShader->colorRampTypeAsQString() );
+    colorRampShaderElem.setAttribute( "colorRampName", colorRampShader->colorRampName() );
+    colorRampShaderElem.setAttribute( "colorRampType", colorRampShader->colorRampTypeAsQString() );
     colorRampShaderElem.setAttribute( QStringLiteral( "clip" ), colorRampShader->clip() );
     //items
     QList<QgsColorRampShader::ColorRampItem> itemList = colorRampShader->colorRampItemList();
@@ -169,6 +170,7 @@ void QgsRasterShader::readXml( const QDomElement& elem )
   if ( !colorRampShaderElem.isNull() )
   {
     QgsColorRampShader* colorRampShader = new QgsColorRampShader();
+    colorRampShader->setColorRampName( colorRampShaderElem.attribute( "colorRampName", "" ) );
     colorRampShader->setColorRampType( colorRampShaderElem.attribute( QStringLiteral( "colorRampType" ), QStringLiteral( "INTERPOLATED" ) ) );
     colorRampShader->setClip( colorRampShaderElem.attribute( QStringLiteral( "clip" ), QStringLiteral( "0" ) ) == QLatin1String( "1" ) );
 

src/core/raster/qgssinglebandpseudocolorrenderer.cpp

@@ -63,6 +63,7 @@ QgsSingleBandPseudoColorRenderer* QgsSingleBandPseudoColorRenderer::clone() cons
     {
       QgsColorRampShader * colorRampShader = new QgsColorRampShader( mShader->minimumValue(), mShader->maximumValue() );
 
+      colorRampShader->setColorRampName( origColorRampShader->colorRampName() );
       colorRampShader->setColorRampType( origColorRampShader->colorRampType() );
       colorRampShader->setClip( origColorRampShader->clip() );
       colorRampShader->setColorRampItemList( origColorRampShader->colorRampItemList() );

src/gui/raster/qgssinglebandpseudocolorrendererwidget.cpp

@@ -152,6 +152,7 @@ QgsRasterRenderer* QgsSingleBandPseudoColorRendererWidget::renderer()
 
   QgsColorRampShader::ColorRamp_TYPE interpolation = static_cast< QgsColorRampShader::ColorRamp_TYPE >( mColorInterpolationComboBox->currentData().toInt() );
   colorRampShader->setColorRampType( interpolation );
+  colorRampShader->setColorRampName( mColorRampComboBox->currentText() );
   rasterShader->setRasterShaderFunction( colorRampShader );
 
   int bandNumber = mBandComboBox->currentData().toInt();
@@ -792,6 +793,14 @@ void QgsSingleBandPseudoColorRendererWidget::setFromRenderer( const QgsRasterRen
       const QgsColorRampShader* colorRampShader = dynamic_cast<const QgsColorRampShader*>( rasterShader->rasterShaderFunction() );
       if ( colorRampShader )
       {
+        int idx = mColorRampComboBox->findText( colorRampShader->colorRampName() );
+        if ( idx == -1 )
+        {
+          QSettings settings;
+          QString defaultPalette = settings.value( "/Raster/defaultPalette", "Spectral" ).toString();
+          idx = mColorRampComboBox->findText( defaultPalette );
+        }
+        mColorRampComboBox->setCurrentIndex( idx );
         mColorInterpolationComboBox->setCurrentIndex( mColorInterpolationComboBox->findData( colorRampShader->colorRampType() ) );
 
         const QList<QgsColorRampShader::ColorRampItem> colorRampItemList = colorRampShader->colorRampItemList();