color filter: Add option to substitute alpha value

Resolves #253

skins/material3/QskMaterial3Skin.cpp

@@ -670,6 +670,7 @@ void Editor::setupPushButton()
 
     setColor( Q::Text, m_pal.onPrimary );
     setColor( Q::Text | Q::Disabled, m_pal.onSurface38 );
+    setGraphicRole( Q::Graphic | Q::Disabled, QskMaterial3Skin::GraphicRoleOnSurface38 );
 
     setTextOptions( Q::Text, Qt::ElideMiddle, QskTextOptions::NoWrap );
 
@@ -1337,34 +1338,42 @@ void QskMaterial3Skin::setupFonts()
 void QskMaterial3Skin::setupGraphicFilters( const QskMaterial3Theme& palette )
 {
     QskColorFilter onPrimaryFilter;
+    onPrimaryFilter.setSubstituteAlphaValue( true );
     onPrimaryFilter.addColorSubstitution( Qt::white, palette.onPrimary );
     setGraphicFilter( GraphicRoleOnPrimary, onPrimaryFilter );
 
     QskColorFilter onSecondaryContainerFilter;
+    onSecondaryContainerFilter.setSubstituteAlphaValue( true );
     onSecondaryContainerFilter.addColorSubstitution( Qt::white, palette.onSecondaryContainer );
     setGraphicFilter( GraphicRoleOnSecondaryContainer, onSecondaryContainerFilter );
 
     QskColorFilter onErrorFilter;
+    onErrorFilter.setSubstituteAlphaValue( true );
     onErrorFilter.addColorSubstitution( Qt::white, palette.onError );
     setGraphicFilter( GraphicRoleOnError, onErrorFilter );
 
     QskColorFilter onSurfaceFilter;
+    onSurfaceFilter.setSubstituteAlphaValue( true );
     onSurfaceFilter.addColorSubstitution( Qt::white, palette.onSurface );
     setGraphicFilter( GraphicRoleOnSurface, onSurfaceFilter );
 
     QskColorFilter onSurfaceFilter38;
+    onSurfaceFilter38.setSubstituteAlphaValue( true );
     onSurfaceFilter38.addColorSubstitution( Qt::white, palette.onSurface38 );
     setGraphicFilter( GraphicRoleOnSurface38, onSurfaceFilter38 );
 
     QskColorFilter onSurfaceVariantFilter;
+    onSurfaceVariantFilter.setSubstituteAlphaValue( true );
     onSurfaceVariantFilter.addColorSubstitution( Qt::white, palette.onSurfaceVariant );
     setGraphicFilter( GraphicRoleOnSurfaceVariant, onSurfaceVariantFilter );
 
     QskColorFilter primaryFilter;
+    primaryFilter.setSubstituteAlphaValue( true );
     primaryFilter.addColorSubstitution( Qt::white, palette.primary );
     setGraphicFilter( GraphicRolePrimary, primaryFilter );
 
     QskColorFilter surfaceFilter;
+    surfaceFilter.setSubstituteAlphaValue( true );
     surfaceFilter.addColorSubstitution( Qt::white, palette.surface );
     setGraphicFilter( GraphicRoleSurface, surfaceFilter );
 }

src/graphic/QskColorFilter.cpp

@@ -11,19 +11,21 @@
 #include <qvariant.h>
 
 static inline QRgb qskSubstitutedRgb(
-    const QVector< QPair< QRgb, QRgb > >& substitions, QRgb rgba )
+    const QVector< QPair< QRgb, QRgb > >& substitions, QRgb rgba, bool substituteAlpha )
 {
     // usually we have 2-3 substitutions, so we can simply iterate
     // and don't need to introduce some sort of sorting or search index
 
-    const QRgb rgb = rgba | QskRgb::AlphaMask;
+    const QRgb rgb = substituteAlpha ? rgba : ( rgba | QskRgb::AlphaMask );
 
     for ( const auto& s : substitions )
     {
         if ( rgb == s.first )
         {
-            return ( s.second & QskRgb::ColorMask ) |
+            const auto ret = substituteAlpha ? s.second
-                ( rgba & QskRgb::AlphaMask );
+                                             : ( s.second & QskRgb::ColorMask )
+                                               | ( rgba & QskRgb::AlphaMask );
+            return ret;
         }
     }
 
@@ -31,13 +33,13 @@ static inline QRgb qskSubstitutedRgb(
 }
 
 static inline QColor qskSubstitutedColor(
-    const QVector< QPair< QRgb, QRgb > >& substitions, const QColor& color )
+    const QVector< QPair< QRgb, QRgb > >& substitions, const QColor& color, bool substituteAlpha )
 {
-    return QColor::fromRgba( qskSubstitutedRgb( substitions, color.rgba() ) );
+    return QColor::fromRgba( qskSubstitutedRgb( substitions, color.rgba(), substituteAlpha ) );
 }
 
 static inline QBrush qskSubstitutedBrush(
-    const QVector< QPair< QRgb, QRgb > >& substitions, const QBrush& brush )
+    const QVector< QPair< QRgb, QRgb > >& substitions, const QBrush& brush, bool substituteAlpha )
 {
     QBrush newBrush;
 
@@ -48,7 +50,7 @@ static inline QBrush qskSubstitutedBrush(
         auto stops = gradient->stops();
         for ( auto& stop : stops )
         {
-            const QColor c = qskSubstitutedColor( substitions, stop.second );
+            const QColor c = qskSubstitutedColor( substitions, stop.second, substituteAlpha );
             if ( c != stop.second )
             {
                 stop.second = c;
@@ -66,7 +68,7 @@ static inline QBrush qskSubstitutedBrush(
     }
     else
     {
-        const QColor c = qskSubstitutedColor( substitions, brush.color() );
+        const QColor c = qskSubstitutedColor( substitions, brush.color(), substituteAlpha );
         if ( c != brush.color() )
         {
             newBrush = brush;
@@ -166,7 +168,7 @@ QPen QskColorFilter::substituted( const QPen& pen ) const
     if ( m_substitutions.isEmpty() || pen.style() == Qt::NoPen )
         return pen;
 
-    const auto newBrush = qskSubstitutedBrush( m_substitutions, pen.brush() );
+    const auto newBrush = qskSubstitutedBrush( m_substitutions, pen.brush(), m_substituteAlphaValue );
     if ( newBrush.style() == Qt::NoBrush )
         return pen;
 
@@ -180,18 +182,28 @@ QBrush QskColorFilter::substituted( const QBrush& brush ) const
     if ( m_substitutions.isEmpty() || brush.style() == Qt::NoBrush )
         return brush;
 
-    const auto newBrush = qskSubstitutedBrush( m_substitutions, brush );
+    const auto newBrush = qskSubstitutedBrush( m_substitutions, brush, m_substituteAlphaValue );
     return ( newBrush.style() != Qt::NoBrush ) ? newBrush : brush;
 }
 
 QColor QskColorFilter::substituted( const QColor& color ) const
 {
-    return qskSubstitutedColor( m_substitutions, color );
+    return qskSubstitutedColor( m_substitutions, color, m_substituteAlphaValue );
 }
 
 QRgb QskColorFilter::substituted( const QRgb& rgb ) const
 {
-    return qskSubstitutedRgb( m_substitutions, rgb );
+    return qskSubstitutedRgb( m_substitutions, rgb, m_substituteAlphaValue );
+}
+
+bool QskColorFilter::substituteAlphaValue() const noexcept
+{
+    return m_substituteAlphaValue;
+}
+
+void QskColorFilter::setSubstituteAlphaValue( bool on )
+{
+    m_substituteAlphaValue = on;
 }
 
 QskColorFilter QskColorFilter::interpolated(

src/graphic/QskColorFilter.h

@@ -37,6 +37,9 @@ class QSK_EXPORT QskColorFilter
 
     bool isIdentity() const noexcept;
 
+    bool substituteAlphaValue() const noexcept;
+    void setSubstituteAlphaValue( bool );
+
     bool operator==( const QskColorFilter& other ) const noexcept;
     bool operator!=( const QskColorFilter& other ) const noexcept;
 
@@ -51,6 +54,7 @@ class QSK_EXPORT QskColorFilter
 
   private:
     QVector< QPair< QRgb, QRgb > > m_substitutions;
+    bool m_substituteAlphaValue = false;
 };
 
 inline bool QskColorFilter::isIdentity() const noexcept