src/core/renderer/qgscontinuouscolorrenderer.cpp

Go to the documentation of this file.

/***************************************************************************
                         qgscontinuouscolorrenderer.cpp  -  description
                             -------------------
    begin                : Nov 2003
    copyright            : (C) 2003 by Marco Hugentobler
    email                : [email protected]
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#include "qgscontinuouscolorrenderer.h"
#include "qgsmarkercatalogue.h"
#include "qgssymbol.h"
#include "qgssymbologyutils.h"
#include "qgsvectordataprovider.h"
#include "qgsvectorlayer.h"
#include "qgsrendercontext.h"

#include <cfloat>
#include <QDomElement>
#include <QPainter>
#include <QImage>

QgsContinuousColorRenderer::QgsContinuousColorRenderer( QGis::GeometryType type ): mMinimumSymbol( 0 ), mMaximumSymbol( 0 )
{
  mGeometryType = type;
}

QgsContinuousColorRenderer::QgsContinuousColorRenderer( const QgsContinuousColorRenderer& other )
{
  mGeometryType = other.mGeometryType;
  mClassificationField = other.mClassificationField;
  mMinimumSymbol = new QgsSymbol( *other.mMinimumSymbol );
  mMaximumSymbol = new QgsSymbol( *other.mMaximumSymbol );
}

QgsContinuousColorRenderer& QgsContinuousColorRenderer::operator=( const QgsContinuousColorRenderer & other )
{
  if ( this != &other )
  {
    mGeometryType = other.mGeometryType;
    mClassificationField = other.mClassificationField;
    delete mMinimumSymbol;
    delete mMaximumSymbol;
    mMinimumSymbol = new QgsSymbol( *other.mMinimumSymbol );
    mMaximumSymbol = new QgsSymbol( *other.mMaximumSymbol );
  }
  return *this;
}

QgsContinuousColorRenderer::~QgsContinuousColorRenderer()
{
  delete mMinimumSymbol;
  delete mMaximumSymbol;
}

void QgsContinuousColorRenderer::setMinimumSymbol( QgsSymbol* sy )
{
  delete mMinimumSymbol;
  mMinimumSymbol = sy;
}

void QgsContinuousColorRenderer::setMaximumSymbol( QgsSymbol* sy )
{
  delete mMaximumSymbol;
  mMaximumSymbol = sy;
}

void QgsContinuousColorRenderer::renderFeature( QgsRenderContext &renderContext, QgsFeature & f, QImage* img, bool selected, double opacity )
{
  QPainter *p = renderContext.painter();

  if (( mMinimumSymbol && mMaximumSymbol ) )
  {
    //first find out the value for the classification attribute
    const QgsAttributeMap& attrs = f.attributeMap();
    if ( attrs[mClassificationField].isNull() )
    {
      if ( img )
        *img = QImage();
    }
    double fvalue = attrs[mClassificationField].toDouble();

    //double fvalue = vec[mClassificationField].fieldValue().toDouble();
    double minvalue = mMinimumSymbol->lowerValue().toDouble();
    double maxvalue = mMaximumSymbol->lowerValue().toDouble();

    QColor mincolor, maxcolor;

    if ( mGeometryType == QGis::Line || mGeometryType == QGis::Point )
    {
      mincolor = mMinimumSymbol->pen().color();
      maxcolor = mMaximumSymbol->pen().color();
    }
    else                    //if polygon
    {
      p->setPen( mMinimumSymbol->pen() );
      mincolor = mMinimumSymbol->fillColor();
      maxcolor = mMaximumSymbol->fillColor();
    }

    int red, green, blue;

    if (( maxvalue - minvalue ) != 0 )
    {
      red = int ( maxcolor.red() * ( fvalue - minvalue ) / ( maxvalue - minvalue ) + mincolor.red() * ( maxvalue - fvalue ) / ( maxvalue - minvalue ) );
      green = int ( maxcolor.green() * ( fvalue - minvalue ) / ( maxvalue - minvalue ) + mincolor.green() * ( maxvalue - fvalue ) / ( maxvalue - minvalue ) );
      blue =  int ( maxcolor.blue() * ( fvalue - minvalue ) / ( maxvalue - minvalue ) + mincolor.blue() * ( maxvalue - fvalue ) / ( maxvalue - minvalue ) );
    }
    else
    {
      red = int ( mincolor.red() );
      green = int ( mincolor.green() );
      blue = int ( mincolor.blue() );
    }

    if ( mGeometryType == QGis::Point && img )
    {
      // TODO we must get always new marker -> slow, but continuous color for points
      // probably is not used frequently


      // Use color for both pen and brush (user can add another layer with outpine)
      // later add support for both pen and brush to dialog
      QPen pen = mMinimumSymbol->pen();
      pen.setColor( QColor( red, green, blue ) );
      pen.setWidthF( renderContext.scaleFactor() * pen.widthF() );

      QBrush brush = mMinimumSymbol->brush();

      if ( selected )
      {
        pen.setColor( mSelectionColor );
        brush.setColor( mSelectionColor );
      }
      else
      {
        brush.setColor( QColor( red, green, blue ) );
      }
      brush.setStyle( Qt::SolidPattern );

      *img = QgsMarkerCatalogue::instance()->imageMarker( mMinimumSymbol->pointSymbolName(),
             mMinimumSymbol->pointSize() * renderContext.scaleFactor() * renderContext.rasterScaleFactor(),
             pen, brush, opacity );

    }
    else if ( mGeometryType == QGis::Line )
    {
      QPen linePen;
      linePen.setColor( QColor( red, green, blue ) );
      linePen.setWidthF( renderContext.scaleFactor()*mMinimumSymbol->pen().widthF() );
      p->setPen( linePen );
    }
    else //polygon
    {
      p->setBrush( QColor( red, green, blue ) );
      if ( mDrawPolygonOutline )
      {
        QPen pen;
        pen.setColor( QColor( 0, 0, 0 ) );
        pen.setWidthF( renderContext.scaleFactor()*mMinimumSymbol->pen().widthF() );
        p->setPen( pen );
      }
      else
      {
        p->setPen( Qt::NoPen );
      }
    }
    if ( selected )
    {
      //for polygons we don't use selection color for outline
      //otherwise adjacent features appear merged when selected
      if ( mGeometryType != QGis::Polygon )
      {
        QPen pen = mMinimumSymbol->pen();
        pen.setColor( mSelectionColor );
        p->setPen( pen );
      }
      QBrush brush = mMinimumSymbol->brush();
      brush.setColor( mSelectionColor );
      p->setBrush( brush );
    }
  }
}

int QgsContinuousColorRenderer::readXML( const QDomNode& rnode, QgsVectorLayer& vl )
{
  mGeometryType = vl.geometryType();
  QDomNode classnode = rnode.namedItem( "classificationfield" );
  QString classificationField = classnode.toElement().text();

  QgsVectorDataProvider* theProvider = vl.dataProvider();
  if ( !theProvider )
  {
    return 1;
  }
  int classificationId = theProvider->fieldNameIndex( classificationField );
  if ( classificationId == -1 )
  {
    //go on. Because with joins, it might be the joined layer is not loaded yet
  }
  setClassificationField( classificationId );

  //polygon outline
  QDomNode polyoutlinenode = rnode.namedItem( "polygonoutline" );
  QString polyoutline = polyoutlinenode.toElement().text();
  if ( polyoutline == "0" )
  {
    mDrawPolygonOutline = false;
  }
  else if ( polyoutline == "1" )
  {
    mDrawPolygonOutline = true;
  }

  //read the settings for the renderitem of the minimum value
  QDomNode lowernode = rnode.namedItem( "lowestsymbol" );
  QDomNode lsymbolnode = lowernode.namedItem( "symbol" );
  if ( ! lsymbolnode.isNull() )
  {
    QgsSymbol* lsy = new QgsSymbol( mGeometryType );
    lsy->readXML( lsymbolnode, &vl );
    setMinimumSymbol( lsy );
  }
  QDomNode uppernode = rnode.namedItem( "highestsymbol" );
  QDomNode usymbolnode = uppernode.namedItem( "symbol" );
  if ( ! usymbolnode.isNull() )
  {
    QgsSymbol* usy = new QgsSymbol( mGeometryType );
    usy->readXML( usymbolnode, &vl );
    setMaximumSymbol( usy );
  }
  vl.setRenderer( this );
  return 0;
}

QgsAttributeList QgsContinuousColorRenderer::classificationAttributes() const
{
  QgsAttributeList list;
  list.append( mClassificationField );
  return list;
}

QString QgsContinuousColorRenderer::name() const
{
  return "Continuous Color";
}

bool QgsContinuousColorRenderer::writeXML( QDomNode & layer_node, QDomDocument & document, const QgsVectorLayer& vl ) const
{
  const QgsVectorDataProvider* theProvider = vl.dataProvider();
  if ( !theProvider )
  {
    return false;
  }

  QString classificationFieldName;
  QgsFieldMap::const_iterator field_it = theProvider->fields().find( mClassificationField );
  if ( field_it != theProvider->fields().constEnd() )
  {
    classificationFieldName = field_it.value().name();
  }
  bool returnval = true;

  QDomElement continuoussymbol = document.createElement( "continuoussymbol" );
  layer_node.appendChild( continuoussymbol );
  QDomElement classificationfield = document.createElement( "classificationfield" );
  QDomText classificationfieldtxt = document.createTextNode( classificationFieldName );
  classificationfield.appendChild( classificationfieldtxt );
  continuoussymbol.appendChild( classificationfield );

  //polygon outlines
  QDomElement drawPolygonOutlines = document.createElement( "polygonoutline" );
  int drawPolyInt = mDrawPolygonOutline ? 1 : 0;
  QDomText drawPolygonText = document.createTextNode( QString::number( drawPolyInt ) );
  drawPolygonOutlines.appendChild( drawPolygonText );
  continuoussymbol.appendChild( drawPolygonOutlines );

  QDomElement lowestsymbol = document.createElement( "lowestsymbol" );
  continuoussymbol.appendChild( lowestsymbol );
  if ( mMinimumSymbol )
  {
    mMinimumSymbol->writeXML( lowestsymbol, document, &vl );
  }
  QDomElement highestsymbol = document.createElement( "highestsymbol" );
  continuoussymbol.appendChild( highestsymbol );
  if ( mMaximumSymbol )
  {
    mMaximumSymbol->writeXML( highestsymbol, document, &vl );
  }

  return returnval;
}

const QList<QgsSymbol*> QgsContinuousColorRenderer::symbols() const
{
  QList<QgsSymbol*> list;
  list.append( mMinimumSymbol );
  list.append( mMaximumSymbol );
  return list;
}

QgsRenderer* QgsContinuousColorRenderer::clone() const
{
  QgsContinuousColorRenderer* r = new QgsContinuousColorRenderer( *this );
  return r;
}