ポリゴンのシンボルQgsFillSymbolの設定（構築）はQgsFillSymbolクラスのメソッドcreateSimpleにスタイルを渡して設定する。

内部の色、外周の色を設定する時は
[code]
QgsFillSymbol.createSimple({‘color’: ‘0,0,0,0’,’outline_color’: ‘255,0,0,255’})
[/code]

更に内部のパターンを設定する時は
[code]
QgsFillSymbol.createSimple({‘color’: ‘0,0,0,0’,’outline_color’: ‘255,0,0,255’,’style’ : ‘diagonal_x’})
[/code]

設定のキーはQgsSymbolLayer::createを参考
[code]
QgsSymbolLayer *QgsSimpleFillSymbolLayer::create( const QgsStringMap &props )
{
QColor color = DEFAULT_SIMPLEFILL_COLOR;
Qt::BrushStyle style = DEFAULT_SIMPLEFILL_STYLE;
QColor strokeColor = DEFAULT_SIMPLEFILL_BORDERCOLOR;
Qt::PenStyle strokeStyle = DEFAULT_SIMPLEFILL_BORDERSTYLE;
double strokeWidth = DEFAULT_SIMPLEFILL_BORDERWIDTH;
Qt::PenJoinStyle penJoinStyle = DEFAULT_SIMPLEFILL_JOINSTYLE;
QPointF offset;

if ( props.contains( QStringLiteral( "color" ) ) )
color = QgsSymbolLayerUtils::decodeColor( props[QStringLiteral( "color" )] );
if ( props.contains( QStringLiteral( "style" ) ) )
style = QgsSymbolLayerUtils::decodeBrushStyle( props[QStringLiteral( "style" )] );
if ( props.contains( QStringLiteral( "color_border" ) ) )
{
//pre 2.5 projects used "color_border"
strokeColor = QgsSymbolLayerUtils::decodeColor( props[QStringLiteral( "color_border" )] );
}
else if ( props.contains( QStringLiteral( "outline_color" ) ) )
{
strokeColor = QgsSymbolLayerUtils::decodeColor( props[QStringLiteral( "outline_color" )] );
}
else if ( props.contains( QStringLiteral( "line_color" ) ) )
{
strokeColor = QgsSymbolLayerUtils::decodeColor( props[QStringLiteral( "line_color" )] );
}

if ( props.contains( QStringLiteral( "style_border" ) ) )
{
//pre 2.5 projects used "style_border"
strokeStyle = QgsSymbolLayerUtils::decodePenStyle( props[QStringLiteral( "style_border" )] );
}
else if ( props.contains( QStringLiteral( "outline_style" ) ) )
{
strokeStyle = QgsSymbolLayerUtils::decodePenStyle( props[QStringLiteral( "outline_style" )] );
}
else if ( props.contains( QStringLiteral( "line_style" ) ) )
{
strokeStyle = QgsSymbolLayerUtils::decodePenStyle( props[QStringLiteral( "line_style" )] );
}
if ( props.contains( QStringLiteral( "width_border" ) ) )
{
//pre 2.5 projects used "width_border"
strokeWidth = props[QStringLiteral( "width_border" )].toDouble();
}
else if ( props.contains( QStringLiteral( "outline_width" ) ) )
{
strokeWidth = props[QStringLiteral( "outline_width" )].toDouble();
}
else if ( props.contains( QStringLiteral( "line_width" ) ) )
{
strokeWidth = props[QStringLiteral( "line_width" )].toDouble();
}
if ( props.contains( QStringLiteral( "offset" ) ) )
offset = QgsSymbolLayerUtils::decodePoint( props[QStringLiteral( "offset" )] );
if ( props.contains( QStringLiteral( "joinstyle" ) ) )
penJoinStyle = QgsSymbolLayerUtils::decodePenJoinStyle( props[QStringLiteral( "joinstyle" )] );

QgsSimpleFillSymbolLayer *sl = new QgsSimpleFillSymbolLayer( color, style, strokeColor, strokeStyle, strokeWidth, penJoinStyle );
sl->setOffset( offset );
if ( props.contains( QStringLiteral( "border_width_unit" ) ) )
{
sl->setStrokeWidthUnit( QgsUnitTypes::decodeRenderUnit( props[QStringLiteral( "border_width_unit" )] ) );
}
else if ( props.contains( QStringLiteral( "outline_width_unit" ) ) )
{
sl->setStrokeWidthUnit( QgsUnitTypes::decodeRenderUnit( props[QStringLiteral( "outline_width_unit" )] ) );
}
else if ( props.contains( QStringLiteral( "line_width_unit" ) ) )
{
sl->setStrokeWidthUnit( QgsUnitTypes::decodeRenderUnit( props[QStringLiteral( "line_width_unit" )] ) );
}
if ( props.contains( QStringLiteral( "offset_unit" ) ) )
sl->setOffsetUnit( QgsUnitTypes::decodeRenderUnit( props[QStringLiteral( "offset_unit" )] ) );

if ( props.contains( QStringLiteral( "border_width_map_unit_scale" ) ) )
sl->setStrokeWidthMapUnitScale( QgsSymbolLayerUtils::decodeMapUnitScale( props[QStringLiteral( "border_width_map_unit_scale" )] ) );
if ( props.contains( QStringLiteral( "offset_map_unit_scale" ) ) )
sl->setOffsetMapUnitScale( QgsSymbolLayerUtils::decodeMapUnitScale( props[QStringLiteral( "offset_map_unit_scale" )] ) );

sl->restoreOldDataDefinedProperties( props );

return sl;
}
[/code]

設定値はQgsSymbolLayerUtilsを参照

[code]
Qt::BrushStyle QgsSymbolLayerUtils::decodeBrushStyle( const QString &str )
{
if ( str == QLatin1String( "solid" ) ) return Qt::SolidPattern;
if ( str == QLatin1String( "horizontal" ) ) return Qt::HorPattern;
if ( str == QLatin1String( "vertical" ) ) return Qt::VerPattern;
if ( str == QLatin1String( "cross" ) ) return Qt::CrossPattern;
if ( str == QLatin1String( "b_diagonal" ) ) return Qt::BDiagPattern;
if ( str == QLatin1String( "f_diagonal" ) ) return Qt::FDiagPattern;
if ( str == QLatin1String( "diagonal_x" ) ) return Qt::DiagCrossPattern;
if ( str == QLatin1String( "dense1" ) ) return Qt::Dense1Pattern;
if ( str == QLatin1String( "dense2" ) ) return Qt::Dense2Pattern;
if ( str == QLatin1String( "dense3" ) ) return Qt::Dense3Pattern;
if ( str == QLatin1String( "dense4" ) ) return Qt::Dense4Pattern;
if ( str == QLatin1String( "dense5" ) ) return Qt::Dense5Pattern;
if ( str == QLatin1String( "dense6" ) ) return Qt::Dense6Pattern;
if ( str == QLatin1String( "dense7" ) ) return Qt::Dense7Pattern;
if ( str == QLatin1String( "no" ) ) return Qt::NoBrush;
return Qt::SolidPattern;
}

QString QgsSymbolLayerUtils::encodeSldBrushStyle( Qt::BrushStyle style )
{
switch ( style )
{
case Qt::CrossPattern:
return QStringLiteral( "cross" );
case Qt::DiagCrossPattern:
return QStringLiteral( "x" );

/* The following names are taken from the presentation "GeoServer
* Cartographic Rendering" by Andrea Aime at the FOSS4G 2010.
* (see http://2010.foss4g.org/presentations/3588.pdf)
*/
case Qt::HorPattern:
return QStringLiteral( "horline" );
case Qt::VerPattern:
return QStringLiteral( "line" );
case Qt::BDiagPattern:
return QStringLiteral( "slash" );
case Qt::FDiagPattern:
return QStringLiteral( "backslash" );

/* define the other names following the same pattern used above */
case Qt::Dense1Pattern:
case Qt::Dense2Pattern:
case Qt::Dense3Pattern:
case Qt::Dense4Pattern:
case Qt::Dense5Pattern:
case Qt::Dense6Pattern:
case Qt::Dense7Pattern:
return QStringLiteral( "brush://%1" ).arg( encodeBrushStyle( style ) );

default:
return QString();
}
}

[/code]