using QString() instead of QString::null

src/controls/QskPushButton.cpp

@@ -171,7 +171,7 @@ void QskPushButton::setGraphic( const QskGraphic& graphic )
 
         if ( !m_data->graphicSource.isEmpty() )
         {
-            m_data->graphicSource = QString::null;
+            m_data->graphicSource = QString();
             m_data->isGraphicSourceDirty = false;
 
             Q_EMIT graphicSourceChanged();

src/controls/QskSetup.cpp

@@ -235,7 +235,7 @@ QskSkin* QskSetup::skin()
 {
     if ( m_data->skin == nullptr )
     {
-        m_data->skin = QskSkinManager::instance()->createSkin( QString::null );
+        m_data->skin = QskSkinManager::instance()->createSkin( QString() );
         Q_ASSERT( m_data->skin );
 
         m_data->skin->setParent( this );

src/controls/QskSimpleListBox.cpp

@@ -56,7 +56,7 @@ QString QskSimpleListBox::entryAt( int row ) const
     if ( row >= 0 && row < m_data->entries.size() )
         return m_data->entries[row];
 
-    return QString::null;
+    return QString();
 }
 
 QVariant QskSimpleListBox::valueAt( int row, int col ) const

src/controls/QskTabBar.cpp

@@ -285,7 +285,7 @@ QString QskTabBar::buttonTextAt( int index ) const
     if ( const QskTabButton* btn = buttonAt( index ) )
         return btn->text();
 
-    return QString::null;
+    return QString();
 }
 
 int QskTabBar::indexOf( QskTabButton* button ) const

src/dialogs/QskInputWindow.cpp

@@ -83,7 +83,7 @@ void QskInputWindow::setInfoText( const QString& text )
 
 QString QskInputWindow::infoText() const
 {
-    return m_subWindow ? m_subWindow->infoText() : QString::null;
+    return m_subWindow ? m_subWindow->infoText() : QString();
 }
 
 void QskInputWindow::setInfoTextOptions( const QskTextOptions& options )

src/nodes/QskRichTextRenderer.cpp

@@ -220,5 +220,5 @@ void QskRichTextRenderer::updateNode( const QString& text,
     }
 
     textItem.updateTextNode( item->window(), node );
-    textItem.setText( QString::null );
+    textItem.setText( QString() );
 }