fixed PropertyCollectionWidget changing visibility of property widgets from...

fixed PropertyCollectionWidget changing visibility of property widgets from non-Qt thread (now using Qt signals).

application/gui/properties/propertycollectionwidget.cpp

@@ -71,6 +71,7 @@ namespace campvis {
         _layout->setSpacing(8);
         _layout->setMargin(0);
         setLayout(_layout);
+        connect(this, SIGNAL(s_widgetVisibilityChanged(QWidget*, bool)), this, SLOT(onWidgetVisibilityChanged(QWidget*, bool)));
     }
 
     void PropertyCollectionWidget::clearWidgetMap() {
@@ -87,7 +88,11 @@ namespace campvis {
         // const_cast does not harm anything.
         std::map<AbstractProperty*, QWidget*>::iterator item = _widgetMap.find(const_cast<AbstractProperty*>(prop));
         if (item != _widgetMap.end())
-            item->second->setVisible(item->first->isVisible());
+            emit s_widgetVisibilityChanged(item->second, item->first->isVisible());
+    }
+
+    void PropertyCollectionWidget::onWidgetVisibilityChanged(QWidget* widget, bool visibility) {
+        widget->setVisible(visibility);
     }
 
 }
\ No newline at end of file

application/gui/properties/propertycollectionwidget.h

@@ -67,6 +67,15 @@ namespace campvis {
          * \param prop  Property that emitted the signal
          */
         void onPropertyVisibilityChanged(const AbstractProperty* prop);
+        
+    protected slots:
+        /**
+         * Gets called when the property has changed, so that widget can update its state.
+         */
+        virtual void onWidgetVisibilityChanged(QWidget* widget, bool visibility);
+
+    signals:
+        void s_widgetVisibilityChanged(QWidget* widget, bool visibility);
 
     private:
         /**