fix cpt-city svg parsing and display

Author: etiennesky

src/core/symbology-ng/qgssymbollayerv2utils.cpp

@@ -490,10 +490,12 @@ QIcon QgsSymbolLayerV2Utils::colorRampPreviewIcon( QgsVectorColorRampV2* ramp, Q
 QPixmap QgsSymbolLayerV2Utils::colorRampPreviewPixmap( QgsVectorColorRampV2* ramp, QSize size )
 {
   QPixmap pixmap( size );
+  pixmap.fill( Qt::transparent );
+  // pixmap.fill( Qt::white ); // this makes the background white instead of transparent
   QPainter painter;
   painter.begin( &pixmap );
-  painter.setRenderHint( QPainter::Antialiasing );
-  painter.eraseRect( QRect( QPoint( 0, 0 ), size ) );
+  // antialising makes the colors duller, and no point in antialiasing a color ramp
+  // painter.setRenderHint( QPainter::Antialiasing );
   for ( int i = 0; i < size.width(); i++ )
   {
     QPen pen( ramp->color(( double ) i / size.width() ) );

src/core/symbology-ng/qgsvectorcolorrampv2.cpp

@@ -60,8 +60,9 @@ static QColor _interpolate( QColor c1, QColor c2, double value )
   int r = ( int )( c1.red() + value * ( c2.red() - c1.red() ) );
   int g = ( int )( c1.green() + value * ( c2.green() - c1.green() ) );
   int b = ( int )( c1.blue() + value * ( c2.blue() - c1.blue() ) );
+  int a = ( int )( c1.alpha() + value * ( c2.alpha() - c1.alpha() ) );
 
-  return QColor::fromRgb( r, g, b );
+  return QColor::fromRgb( r, g, b, a );
 }
 
 QColor QgsVectorGradientColorRampV2::color( double value ) const
@@ -269,7 +270,7 @@ QMap< QString, QString > QgsCptCityColorRampV2::mCollectionNames;
 QMap< QString, QStringList > QgsCptCityColorRampV2::mCollectionSelections;
 
 QgsCptCityColorRampV2::QgsCptCityColorRampV2( QString schemeName, QString variantName )
-    : mSchemeName( schemeName ), mVariantName( variantName ), mContinuous( false )
+    : mSchemeName( schemeName ), mVariantName( variantName ), mGradientType( Continuous )
 {
   // TODO replace this with hard-coded data in the default case
   loadFile();
@@ -289,7 +290,7 @@ QgsVectorColorRampV2* QgsCptCityColorRampV2::create( const QgsStringMap& props )
 }
 
 
-
+#if 0
 QColor QgsCptCityColorRampV2::color( double value ) const
 {
   if ( mPalette.isEmpty() || value < 0 || value > 1 )
@@ -333,6 +334,45 @@ QColor QgsCptCityColorRampV2::color( double value ) const
     return upper == lower ? c1 : _interpolate( c1, c2, ( value - lower ) / ( upper - lower ) );
   }
 }
+#endif
+
+QColor QgsCptCityColorRampV2::color( double value ) const
+{
+  if ( mPalette.isEmpty() || value < 0 || value > 1 )
+    return QColor( 255, 0, 0 ); // red color as a warning :)
+
+  int numStops = mPalette.count();
+  if ( numStops < 2 )
+    return QColor( 255, 0, 0 ); // red color as a warning :)
+
+  double lower = 0, upper = 0;
+  QColor c1, c2;
+  c1 = mPalette[0].second;
+  for ( int i = 0; i < numStops; i++ )
+  {
+    if ( mPalette[i].first >= value )
+    {
+      if ( mGradientType == Discrete )
+        return c1;
+
+      upper = mPalette[i].first;
+      c2 = mPalette[i].second;
+
+      return upper == lower ? c1 : _interpolate( c1, c2, ( value - lower ) / ( upper - lower ) );
+    }
+
+    lower = mPalette[i].first;
+    c1 = mPalette[i].second;
+  }
+
+  if ( mGradientType == Discrete )
+    return c1;
+
+  upper = 1;
+  c2 = mPalette[ numStops - 1 ].second;
+
+  return upper == lower ? c1 : _interpolate( c1, c2, ( value - lower ) / ( upper - lower ) );
+}
 
 QgsVectorColorRampV2* QgsCptCityColorRampV2::clone() const
 {
@@ -390,23 +430,6 @@ QStringList QgsCptCityColorRampV2::listSchemeNames( QString collectionName )
   return entries;
 }
 
-QList<int> QgsCptCityColorRampV2::listSchemeVariants( QString schemeName )
-{
-  QList<int> variants;
-
-  QString palette( brewerString );
-  QStringList list = palette.split( QChar( '\n' ) );
-  foreach ( QString entry, list )
-  {
-    QStringList items = entry.split( QChar( '-' ) );
-    if ( items.count() != 3 || items[0] != schemeName )
-      continue;
-    variants << items[1].toInt();
-  }
-
-  return variants;
-}
-
 QString QgsCptCityColorRampV2::getBaseDir()
 {
   // currently hard-coded, but could be also in QGis install path and/or configurable
@@ -436,7 +459,6 @@ bool QgsCptCityColorRampV2::loadFile( QString filename )
   // QgsDebugMsg("filename= "+filename);
 
   mPalette.clear();
-  mPaletteStops.clear();
 
   QString mErrorString = QString();
 
@@ -478,40 +500,38 @@ bool QgsCptCityColorRampV2::loadFile( QString filename )
     return false;
   }
 
-  // initialize self
-  mContinuous = true; // we will detect later if there are overlapping stops
-  mPalette.clear();
-  mPaletteStops.clear();
-
   // loop for all stop tags
   QDomElement e = rampsElement.firstChildElement();
-  // int i = 0;
-  QMap< double, QColor > map;
+  QMap< double, QPair<QColor, QColor> > map;
+
+  QColor prevColor;
   while ( !e.isNull() )
   {
-    // QgsDebugMsg("read "+e.tagName());
     if ( e.tagName() == "stop" )
     {
       //todo integrate this into symbollayerutils, keep here for now...
       double offset;
       QString offsetStr = e.attribute( "offset" ); // offset="50.00%" | offset="0.5"
+      QString colorStr = e.attribute( "stop-color", "" ); // stop-color="rgb(222,235,247)"
+      QString opacityStr = e.attribute( "stop-opacity", "1.0" ); // stop-opacity="1.0000"
       if ( offsetStr.endsWith( "%" ) )
         offset = offsetStr.remove( offsetStr.size() - 1, 1 ).toDouble() / 100.0;
       else
         offset = offsetStr.toDouble();
 
-      QString colorStr = e.attribute( "stop-color", "" ); // stop-color="rgb(222,235,247)"
-      QString opacityStr = e.attribute( "stop-opacity", "1.0" ); // stop-opacity="1.0000"
       // QColor color( 255, 0, 0 ); // red color as a warning :)
       QColor color = QgsSymbolLayerV2Utils::parseColor( colorStr );
       if ( color != QColor() )
       {
         int alpha = opacityStr.toDouble() * 255; // test
         color.setAlpha( alpha );
         if ( map.contains( offset ) )
-          mContinuous = false; // assume discrete if at least one stop is repeated
-        map[offset] = color;
+          map[offset].second = color;
+        else
+          map[offset] = qMakePair( color, color );
       }
+      else
+        QgsDebugMsg( QString( "at offset=%1 invalid color" ).arg( offset ) );
     }
     else
     {
@@ -521,18 +541,51 @@ bool QgsCptCityColorRampV2::loadFile( QString filename )
     e = e.nextSiblingElement();
   }
 
-  // if this is a discrete gradient, remove last stop
-  if ( ! mContinuous )
+  // add colors to palette
+  mPalette.clear();
+  QMap<double, QPair<QColor, QColor> >::const_iterator it, prev;
+  // first detect if file is gradient is continuous or dicrete
+  // discrete: stop contains 2 colors and first color is identical to previous second
+  // multi: stop contains 2 colors and no relation with previous stop
+  mGradientType = Continuous;
+  it = prev = map.constBegin();
+  while ( it != map.constEnd() )
   {
-    if ( map.contains( 1 ) )
-      map.remove( 1 );
+    // look for stops that contain multiple values
+    if ( it != map.constBegin() && ( it.value().first != it.value().second ) )
+    {
+      if ( it.value().first == prev.value().second )
+      {
+        mGradientType = Discrete;
+        break;
+      }
+      else
+      {
+        mGradientType = ContinuousMulti;
+        break;
+      }
+    }
+    prev = it;
+    ++it;
   }
-  // add colors to palette
-  QMap<double, QColor>::const_iterator it = map.constBegin();
+
+  it = prev = map.constBegin();
   while ( it != map.constEnd() )
   {
-    mPaletteStops << it.key();
-    mPalette << it.value();
+    if ( mGradientType == Discrete )
+    {
+      mPalette << qMakePair( it.key(), it.value().second );
+    }
+    else
+    {
+      mPalette << qMakePair( it.key(), it.value().first );
+      if (( mGradientType == ContinuousMulti ) &&
+          ( it.key() != 0.0 && it.key() != 1.0 ) )
+      {
+        mPalette << qMakePair( it.key(), it.value().second );
+      }
+    }
+    prev = it;
     ++it;
   }
 
@@ -782,7 +835,3 @@ bool QgsCptCityColorRampV2::loadSchemes( QString rootDir, bool reset )
   return ( ! mCollections.isEmpty() );
 }
 
-void QgsCptCityColorRampV2::loadPalette()
-{
-  // TODO: IMPLEMENT ME
-}

src/core/symbology-ng/qgsvectorcolorrampv2.h

@@ -168,6 +168,16 @@ class CORE_EXPORT QgsCptCityColorRampV2 : public QgsVectorColorRampV2
     QgsCptCityColorRampV2( QString schemeName = DEFAULT_CPTCITY_SCHEMENAME,
                            QString variantName = DEFAULT_CPTCITY_VARIANTNAME );
 
+
+    enum GradientType
+    {
+      Discrete, //discrete stops, e.g. Color Brewer
+      Continuous, //continuous, e.g. QgsVectorColorRampV2
+      ContinuousMulti //continuous with 2 values in intermediate stops
+    };
+    typedef QList< QPair < double, QColor > > GradientList;
+
+
     static QgsVectorColorRampV2* create( const QgsStringMap& properties = QgsStringMap() );
 
     virtual QColor color( double value ) const;
@@ -183,27 +193,24 @@ class CORE_EXPORT QgsCptCityColorRampV2 : public QgsVectorColorRampV2
     QString schemeName() const { return mSchemeName; }
     QString variantName() const { return mVariantName; }
 
-    /* void setSchemeName( QString schemeName ) { mSchemeName = schemeName; loadPalette(); } */
-    /* void setVariantName( QString variantName ) { mVariantName = variantName; loadPalette(); } */
     /* lazy loading - have to call loadPalette() explicitly */
     void setSchemeName( QString schemeName ) { mSchemeName = schemeName; }
     void setVariantName( QString variantName ) { mVariantName = variantName; }
     void setName( QString schemeName, QString variantName = "" )
     { mSchemeName = schemeName; mVariantName = variantName; loadPalette(); }
 
-    void loadPalette();
-    bool isContinuous() const { return mContinuous; }
+    void loadPalette() { loadFile(); }
+    /* bool isContinuous() const { return mContinuous; } */
+    GradientType gradientType() const { return mGradientType; }
 
     QString getFilename() const;
     bool loadFile( QString filename = "" );
 
-    /* static QList<QColor> listSchemeColors(  QString schemeName, int colors ); */
-    static QList<int> listSchemeVariants( QString schemeName );
-
     static QString getBaseDir();
     static void setBaseDir( QString dirName ) { mBaseDir = dirName; }
     static bool loadSchemes( QString rootDir = "", bool reset = false );
-    /** Is the minimal (free to distribute) set of schemes available? Currently returns hasAllSchemes, because we don't have a minimal set yet. */
+    /** Is the minimal (free to distribute) set of schemes available?
+     * Currently returns hasAllSchemes, because we don't have a minimal set yet. */
     static bool hasBasicSchemes();
     /** Is the entire archive available? Currently tests that there is at least one scheme. */
     static bool hasAllSchemes();
@@ -213,27 +220,19 @@ class CORE_EXPORT QgsCptCityColorRampV2 : public QgsVectorColorRampV2
     static QgsCptCityColorRampV2* colorRampFromSVGString( QString svgString );
 
     static const QMap< QString, QStringList > schemeMap() { return mSchemeMap; }
-    /* static const QMap< QString, int > schemeNumColors() { return mSchemeNumColors; } */
     static const QMap< QString, QStringList > schemeVariants() { return mSchemeVariants; }
     static const QMap< QString, QString > collectionNames() { return mCollectionNames; }
     static const QMap< QString, QStringList > collectionSelections() { return mCollectionSelections; }
 
   protected:
 
-    typedef QMap<double, QColor> StopsMap;
-
     QString mSchemeName;
     QString mVariantName;
-    bool mContinuous;
-    QList< QColor > mPalette;
-    QList< double > mPaletteStops;
-    /* QMap< double, QColor > mPalette; */
-
+    GradientType mGradientType;
+    GradientList mPalette;
     static QString mBaseDir;
     static QStringList mCollections;
     static QMap< QString, QStringList > mSchemeMap; //key is collection, value is schemes
-    /* mSchemeNumColors removed, instead read on demand */
-    /* static QMap< QString, int > mSchemeNumColors; //key is scheme, value is # colors (if no variants) */
     static QMap< QString, QStringList > mSchemeVariants; //key is scheme, value is variants
     static QMap< QString, QString > mCollectionNames; //key is name, value is description
     static QMap< QString, QStringList > mCollectionSelections;

src/gui/symbology-ng/qgscptcitycolorrampv2dialog.cpp

@@ -40,7 +40,6 @@ QgsCptCityColorRampV2Dialog::QgsCptCityColorRampV2Dialog( QgsCptCityColorRampV2*
   setupUi( this );
 
   QgsCptCityColorRampV2::loadSchemes( "" );
-  // QgsCptCityColorRampV2::loadSchemes( "cb" );
 
   // show information on how to install cpt-city files if none are found
   if ( ! QgsCptCityColorRampV2::hasAllSchemes() )
@@ -67,6 +66,7 @@ QgsCptCityColorRampV2Dialog::QgsCptCityColorRampV2Dialog( QgsCptCityColorRampV2*
   populateVariants();
   cboVariantName->setCurrentIndex( cboVariantName->findData( ramp->variantName(), Qt::UserRole ) );
   connect( cboVariantName, SIGNAL( currentIndexChanged( int ) ), this, SLOT( setVariantName() ) );
+
   updatePreview();
 }
 
@@ -265,9 +265,12 @@ void QgsCptCityColorRampV2Dialog::on_treeWidget_itemExpanded( QTreeWidgetItem *
       if ( ramp.loadFile() )
       {
         itemDesc = QString::number( ramp.count() ) + " " + tr( "colors" ) + " - ";
-        if ( ramp.isContinuous() )
+        QgsCptCityColorRampV2::GradientType type = ramp.gradientType();
+        if ( type == QgsCptCityColorRampV2::Continuous )
           itemDesc += tr( "continuous" );
-        else
+        else if ( type == QgsCptCityColorRampV2::ContinuousMulti )
+          itemDesc += tr( "continuous (multi)" );
+        else if ( type == QgsCptCityColorRampV2::Discrete )
           itemDesc += tr( "discrete" );
       }
       childItem->setText( 1, "     " + itemDesc );
@@ -295,7 +298,24 @@ void QgsCptCityColorRampV2Dialog::updatePreview()
 {
   QSize size( 300, 40 );
   mRamp->loadFile();
-  lblPreview->setPixmap( QgsSymbolLayerV2Utils::colorRampPreviewPixmap( mRamp, size ) );
+  // TODO draw checker-board/transparent background
+  // for transparent, add  [ pixmap.fill( Qt::transparent ); ] to QgsSymbolLayerV2Utils::colorRampPreviewPixmap
+
+  QPixmap pixmap = QgsSymbolLayerV2Utils::colorRampPreviewPixmap( mRamp, size );
+  lblPreview->setPixmap( pixmap );
+
+  // this is for testing purposes only
+  // you need to install a mirror of cpt-city files in $HOME/.qgis/cpt-city-state with just the .png files
+  QString basefile = QgsApplication::qgisSettingsDirPath() + "/" + "cpt-city-site" + "/" + mRamp->schemeName() +  mRamp->variantName() + ".png";
+  QFileInfo info( basefile );
+  QString pngfile = info.path() + "/tn/" + info.fileName();
+  if ( QFile::exists( pngfile ) )
+  {
+    QPixmap pixmap2( pngfile );
+    lblPreview2->setPixmap( pixmap2.scaled( size ) );
+  }
+  lblPreview2->setText( "" );
+
 }
 
 void QgsCptCityColorRampV2Dialog::setSchemeName()

src/gui/symbology-ng/qgscptcitycolorrampv2dialog.h

@@ -44,7 +44,6 @@ class GUI_EXPORT QgsCptCityColorRampV2Dialog : public QDialog, private Ui::QgsCp
     void updatePreview();
     QTreeWidgetItem* findPath( QString path );
     QTreeWidgetItem * makeCollectionItem( const QString& path );
-    // TODO rename Scheme to something else, maybe data
     void makeSchemeItem( QTreeWidgetItem *item, const QString& path, const QString& schemeName );
 
     QgsCptCityColorRampV2* mRamp;