startHintTransitions added to be able to start transitions withot

changing the state

src/controls/QskSkinnable.cpp

@@ -1302,28 +1302,52 @@ void QskSkinnable::setSkinStates( QskAspect::States newStates )
     auto control = owningControl();
 
 #if DEBUG_STATE
-    qDebug() << control->className() << ":"
+    const auto className = control ? control->className() : "QskSkinnable";
+    qDebug() << className << ":"
         << skinStateAsPrintable( m_data->skinState ) << "->"
         << skinStateAsPrintable( newState );
 #endif
 
-    const auto skin = effectiveSkin();
+    if ( control && control->window() )
-
-    if ( skin )
     {
-        const auto mask = skin->hintTable().states() | m_data->hintTable.states();
+        const bool needUpdate = startHintTransitions( m_data->skinStates, newStates );
-
+        if ( needUpdate )
-        if ( ( newStates & mask ) == ( m_data->skinStates & mask ) )
         {
-            // the modified bits are not handled by the skin
+            if ( control->flags() & QQuickItem::ItemHasContents )
+                control->update();
+        }
+    }
 
     m_data->skinStates = newStates;
-            return;
+}
-        }
+
+bool QskSkinnable::startHintTransitions(
+    QskAspect::States oldStates, QskAspect::States newStates )
+{
+    const auto skin = effectiveSkin();
+    auto control = owningControl();
+
+    if ( skin == nullptr || control == nullptr || control->window() == nullptr )
+        return false;
+
+    const auto mask = m_data->hintTable.states() | skin->hintTable().states();
+    if ( ( newStates & mask ) == ( oldStates & mask ) )
+    {
+        /*
+            When there are no aspects for the changed state bits we know
+            that there won't be any animated transitions
+         */
+        return false;
     }
 
-    if ( control->window() && isTransitionAccepted( QskAspect() ) )
+    if ( !isTransitionAccepted( QskAspect() ) )
     {
+        // the control does not like any animated transition at the moment
+        return false;
+    }
+
+    bool started = false; // at least one transition has been started
+
     QskAspect aspect;
     aspect.setPlacement( effectivePlacement() );
     aspect.setSection( section() );
@@ -1376,17 +1400,15 @@ void QskSkinnable::setSkinStates( QskAspect::States newStates )
                     {
                         startHintTransition( aspect, hint,
                             storedHint( a1 ), storedHint( a2 ) );
-                        }
+
+                        started = true;
                     }
                 }
             }
         }
     }
 
-    m_data->skinStates = newStates;
+    return started;
-
-    if ( control->flags() & QQuickItem::ItemHasContents )
-        control->update();
 }
 
 QskSkin* QskSkinnable::effectiveSkin() const

src/controls/QskSkinnable.h

@@ -258,6 +258,7 @@ class QSK_EXPORT QskSkinnable
   private:
     Q_DISABLE_COPY( QskSkinnable )
 
+    bool startHintTransitions( QskAspect::States, QskAspect::States );
     void startHintTransition( QskAspect,
         QskAnimationHint, const QVariant& from, const QVariant& to );