Im tring to update a qml Image URL via signal:

This is working perfectly fine when executed in this method:

Qt Code: 
  1. void Sentinel::startQmlEngine()
  2. {
  3.     QQmlApplicationEngine qmlEngine;
  4.  
  5.     qmlRegisterType<ImageItem>("ImageItem",1,0,"ImageItem");
  6.     qmlEngine.rootContext()->setContextProperty("imageUrlClass", &image);
  7.  
  8.     QQmlComponent component(&qmlEngine, "qrc:/main.qml");
  9.     object = component.create();
  10.     assert(object);
  11.  
  12.     image.setUrl(getPathToImage());
  13. }
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As soon as I outsource setting the URL the signal is not emitted

Qt Code: 
  1. void Sentinel::updateGui()
  2. {
  3.     image.setUrl(getPathToImage());
  4. }
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How can this be?

Here my Qml

Qt Code: 
  1. import QtQuick 2.12
  2. import QtQuick.Window 2.12
  3. import ImageItem 1.0
  4.  
  5.  
  6. Rectangle {
  7.  
  8.     width: 768
  9.     height: 576
  10.  
  11.     Connections {
  12.         target: imageUrlClass
  13.         onUrlChanged: {
  14.             image.update();
  15.             console.log("image UURL-" + imageUrlClass.imageUrl);
  16.         }
  17.     }
  18.  
  19.     Image {
  20.         id: image
  21.         objectName: "image"
  22.         x: 0
  23.         y: 0
  24.         width: 768
  25.         height: 576
  26.         source: imageUrlClass.imageUrl
  27.         opacity: 1
  28.         clip: true
  29.         fillMode: Image.PreserveAspectFit
  30.         cache: false
  31.     }
  32.  
  33. }
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ImageItem class header:

Qt Code: 
  1. #pragma once
  2.  
  3. #include <QQuickPaintedItem>
  4.  
  5. //---------------------------------------------------------------------------
  6.  
  7.  
  8. class ImageItem: public QQuickPaintedItem
  9. {
  10.     Q_OBJECT
  11.     Q_PROPERTY(QVariant imageUrl READ getUrl() WRITE setUrl NOTIFY urlChanged)
  12.  
  13. public:
  14.  
  15.     explicit ImageItem(QQuickItem *parent = nullptr);
  16.  
  17.     virtual void paint(QPainter* painter);
  18.  
  19.     QVariant getUrl() const;
  20.     void setUrl(const QVariant &value);
  21.  
  22. signals:
  23.  
  24.     void urlChanged();
  25.  
  26. private:
  27.     QVariant url;
  28.  
  29. };
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And Cpp:

Qt Code: 
  1. #include "ImageItem.h"
  2.  
  3. //---------------------------------------------------------------------------
  4.  
  5. ImageItem::ImageItem(QQuickItem *parent) :
  6.     QQuickPaintedItem(parent)
  7. {
  8. }
  9.  
  10. QVariant ImageItem::getUrl() const
  11. {
  12.     return url;
  13. }
  14.  
  15. void ImageItem::setUrl(const QVariant &value)
  16. {
  17.     url = value;
  18.     emit urlChanged();
  19. }
  20.  
  21. void ImageItem::paint(QPainter* painter)
  22. {
  23.     paint(painter);
  24. }
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Thanks!