diff --git a/src/layouts/QskLinearBox.cpp b/src/layouts/QskLinearBox.cpp
index 66470c42..f8c9c785 100644
--- a/src/layouts/QskLinearBox.cpp
+++ b/src/layouts/QskLinearBox.cpp
@@ -290,15 +290,8 @@ bool QskLinearBox::event( QEvent* event )
 
 void QskLinearBox::setDimension( uint dimension )
 {
-    if ( dimension < 1 )
-        dimension = 1;
-
-    auto& engine = m_data->engine;
-
-    if ( dimension != engine.dimension() )
+    if ( m_data->engine.setDimension( dimension ) )
     {
-        engine.setDimension( dimension );
-
         polish();
         resetImplicitSize();
 
@@ -313,12 +306,8 @@ uint QskLinearBox::dimension() const
 
 void QskLinearBox::setOrientation( Qt::Orientation orientation )
 {
-    auto& engine = m_data->engine;
-
-    if ( engine.orientation() != orientation )
+    if ( m_data->engine.setOrientation( orientation ) )
     {
-        engine.setOrientation( orientation );
-
         polish();
         resetImplicitSize();
 
@@ -356,13 +345,8 @@ void QskLinearBox::transpose()
 
 void QskLinearBox::setDefaultAlignment( Qt::Alignment alignment )
 {
-    auto& engine = m_data->engine;
-
-    if ( alignment != engine.defaultAlignment() )
-    {
-        engine.setDefaultAlignment( alignment );
+    if ( m_data->engine.setDefaultAlignment( alignment ) )
         Q_EMIT defaultAlignmentChanged();
-    }
 }
 
 Qt::Alignment QskLinearBox::defaultAlignment() const
@@ -377,15 +361,11 @@ void QskLinearBox::setSpacing( qreal spacing )
         but need to create an API for Qml in QskQml
         using qmlAttachedPropertiesObject then. TODO ...
      */
-    spacing = qMax( spacing, 0.0 );
 
-    auto& engine = m_data->engine;
-
-    if ( spacing != engine.spacing( Qt::Horizontal ) )
+    if ( m_data->engine.setSpacing(
+        spacing, Qt::Horizontal | Qt::Vertical ) )
     {
-        engine.setSpacing( spacing, Qt::Horizontal | Qt::Vertical );
         polish();
-
         Q_EMIT spacingChanged();
     }
 }
diff --git a/src/layouts/QskLinearLayoutEngine.cpp b/src/layouts/QskLinearLayoutEngine.cpp
index 75650f09..438c1c59 100644
--- a/src/layouts/QskLinearLayoutEngine.cpp
+++ b/src/layouts/QskLinearLayoutEngine.cpp
@@ -620,10 +620,13 @@ QskLinearLayoutEngine::~QskLinearLayoutEngine()
 {
 }
 
-void QskLinearLayoutEngine::setOrientation( Qt::Orientation orientation )
+bool QskLinearLayoutEngine::setOrientation( Qt::Orientation orientation )
 {
-    if ( m_data->entryTable.setOrientation( orientation ) )
+    const bool isModified = m_data->entryTable.setOrientation( orientation );
+    if ( isModified )
         invalidate( CellCache | LayoutCache );
+
+    return isModified;
 }
 
 Qt::Orientation QskLinearLayoutEngine::orientation() const
@@ -631,13 +634,18 @@ Qt::Orientation QskLinearLayoutEngine::orientation() const
     return m_data->entryTable.orientation();
 }
 
-void QskLinearLayoutEngine::setDimension( uint dimension )
+bool QskLinearLayoutEngine::setDimension( uint dimension )
 {
     if ( dimension < 1 )
         dimension = 1;
 
-    if ( m_data->entryTable.setDimension( dimension ) )
+    const bool isModified =
+        m_data->entryTable.setDimension( dimension );
+
+    if ( isModified )
         invalidate( CellCache | LayoutCache );
+
+    return isModified;
 }
 
 uint QskLinearLayoutEngine::dimension() const
@@ -660,10 +668,15 @@ int QskLinearLayoutEngine::columnCount() const
     return m_data->entryTable.effectiveCount( Qt::Horizontal );
 }
 
-void QskLinearLayoutEngine::setRetainSizeWhenHiddenAt( int index, bool on )
+bool QskLinearLayoutEngine::setRetainSizeWhenHiddenAt( int index, bool on )
 {
-    if ( m_data->entryTable.setRetainSizeWhenHiddenAt( index, on ) )
+    const bool isModified =
+        m_data->entryTable.setRetainSizeWhenHiddenAt( index, on );
+
+    if ( isModified )
         invalidate( CellCache | LayoutCache );
+
+    return isModified;
 }
 
 bool QskLinearLayoutEngine::retainSizeWhenHiddenAt( int index ) const
@@ -671,10 +684,15 @@ bool QskLinearLayoutEngine::retainSizeWhenHiddenAt( int index ) const
     return m_data->entryTable.retainSizeWhenHiddenAt( index );
 }
 
-void QskLinearLayoutEngine::setStretchFactorAt( int index, int stretchFactor )
+bool QskLinearLayoutEngine::setStretchFactorAt( int index, int stretchFactor )
 {
-    if ( m_data->entryTable.setStretchFactorAt( index, stretchFactor ) )
+    const bool isModified =
+        m_data->entryTable.setStretchFactorAt( index, stretchFactor );
+
+    if ( isModified )
         invalidate( CellCache | LayoutCache );
+
+    return isModified;
 }
 
 int QskLinearLayoutEngine::stretchFactorAt( int index ) const
@@ -682,9 +700,9 @@ int QskLinearLayoutEngine::stretchFactorAt( int index ) const
     return m_data->entryTable.stretchFactorAt( index );
 }
 
-void QskLinearLayoutEngine::setAlignmentAt( int index, Qt::Alignment alignment )
+bool QskLinearLayoutEngine::setAlignmentAt( int index, Qt::Alignment alignment )
 {
-    m_data->entryTable.setAlignmentAt( index, alignment );
+    return m_data->entryTable.setAlignmentAt( index, alignment );
 }
 
 Qt::Alignment QskLinearLayoutEngine::alignmentAt( int index ) const
@@ -692,21 +710,23 @@ Qt::Alignment QskLinearLayoutEngine::alignmentAt( int index ) const
     return m_data->entryTable.alignmentAt( index );
 }
 
-void QskLinearLayoutEngine::setSpacing( qreal spacing, Qt::Orientations orientations )
+bool QskLinearLayoutEngine::setSpacing( qreal spacing, Qt::Orientations orientations )
 {
     if ( spacing < 0.0 )
         spacing = 0.0;
 
-    bool doInvalidate = false;
+    bool isModified = false;
 
     if ( orientations & Qt::Horizontal )
-        doInvalidate |= m_data->colChain.setSpacing( spacing );
+        isModified |= m_data->colChain.setSpacing( spacing );
 
     if ( orientations & Qt::Vertical )
-        doInvalidate |= m_data->rowChain.setSpacing( spacing );
+        isModified |= m_data->rowChain.setSpacing( spacing );
 
-    if ( doInvalidate )
+    if ( isModified )
         invalidate( CellCache | LayoutCache );
+
+    return isModified;
 }
 
 qreal QskLinearLayoutEngine::spacing( Qt::Orientation orientation ) const
@@ -717,10 +737,10 @@ qreal QskLinearLayoutEngine::spacing( Qt::Orientation orientation ) const
         return m_data->rowChain.spacing();
 }
 
-void QskLinearLayoutEngine::setExtraSpacingAt( Qt::Edges edges )
+bool QskLinearLayoutEngine::setExtraSpacingAt( Qt::Edges edges )
 {
     if ( edges == m_data->extraSpacingAt )
-        return;
+        return false;
 
     m_data->extraSpacingAt = edges;
 
@@ -743,6 +763,7 @@ void QskLinearLayoutEngine::setExtraSpacingAt( Qt::Edges edges )
     m_data->rowChain.setExtraSpacingAt( rowEdges );
 
     invalidate( LayoutCache );
+    return true;
 }
 
 Qt::Edges QskLinearLayoutEngine::extraSpacingAt() const
@@ -750,9 +771,9 @@ Qt::Edges QskLinearLayoutEngine::extraSpacingAt() const
     return m_data->extraSpacingAt;
 }
 
-void QskLinearLayoutEngine::setDefaultAlignment( Qt::Alignment alignment )
+bool QskLinearLayoutEngine::setDefaultAlignment( Qt::Alignment alignment )
 {
-    m_data->entryTable.setDefaultAlignment( alignment );
+    return m_data->entryTable.setDefaultAlignment( alignment );
 }
 
 Qt::Alignment QskLinearLayoutEngine::defaultAlignment() const
@@ -935,9 +956,15 @@ qreal QskLinearLayoutEngine::heightForWidth( qreal width ) const
     return sizeHint( Qt::PreferredSize, constraint ).height();
 }
 
-void QskLinearLayoutEngine::setVisualDirection(Qt::LayoutDirection direction)
+bool QskLinearLayoutEngine::setVisualDirection(Qt::LayoutDirection direction)
 {
-    m_data->visualDirection = direction;
+    if ( m_data->visualDirection != direction )
+    {
+        m_data->visualDirection = direction;
+        return true;
+    }
+
+    return false;
 }
 
 Qt::LayoutDirection QskLinearLayoutEngine::visualDirection() const
diff --git a/src/layouts/QskLinearLayoutEngine.h b/src/layouts/QskLinearLayoutEngine.h
index bf4262d3..86154e39 100644
--- a/src/layouts/QskLinearLayoutEngine.h
+++ b/src/layouts/QskLinearLayoutEngine.h
@@ -19,26 +19,30 @@ class QskLinearLayoutEngine
     ~QskLinearLayoutEngine();
 
     Qt::Orientation orientation() const;
-    void setOrientation( Qt::Orientation );
+    bool setOrientation( Qt::Orientation );
 
-    void setDimension( uint dimension );
+    bool setDimension( uint dimension );
     uint dimension() const;
 
-    void setDefaultAlignment( Qt::Alignment );
+    bool setDefaultAlignment( Qt::Alignment );
     Qt::Alignment defaultAlignment() const;
 
-    void setExtraSpacingAt( Qt::Edges );
+    bool setExtraSpacingAt( Qt::Edges );
     Qt::Edges extraSpacingAt() const;
 
+    bool setVisualDirection( Qt::LayoutDirection );
+    Qt::LayoutDirection visualDirection() const;
+
+    bool setSpacing( qreal spacing, Qt::Orientations );
+    qreal spacing( Qt::Orientation ) const;
+
+    qreal defaultSpacing( Qt::Orientation ) const;
+
     int count() const;
 
     int rowCount() const;
     int columnCount() const;
 
-    void setSpacing( qreal spacing, Qt::Orientations );
-    qreal spacing( Qt::Orientation ) const;
-    qreal defaultSpacing( Qt::Orientation ) const;
-
     void insertItem( QQuickItem*, int index );
     void addItem( QQuickItem* );
 
@@ -50,13 +54,13 @@ class QskLinearLayoutEngine
     QQuickItem* itemAt( int index ) const;
     int spacerAt( int index ) const;
 
-    void setRetainSizeWhenHiddenAt( int index, bool on );
+    bool setRetainSizeWhenHiddenAt( int index, bool on );
     bool retainSizeWhenHiddenAt( int index ) const;
 
-    void setAlignmentAt( int index, Qt::Alignment );
+    bool setAlignmentAt( int index, Qt::Alignment );
     Qt::Alignment alignmentAt( int index ) const;
 
-    void setStretchFactorAt( int index, int stretchFactor );
+    bool setStretchFactorAt( int index, int stretchFactor );
     int stretchFactorAt( int index ) const;
 
     void setGeometries( const QRectF& );
@@ -66,9 +70,6 @@ class QskLinearLayoutEngine
 
     QSizeF sizeHint( Qt::SizeHint, const QSizeF& contraint ) const;
 
-    void setVisualDirection( Qt::LayoutDirection );
-    Qt::LayoutDirection visualDirection() const;
-
     enum
     {
         EntryCache  = 1 << 0,