setValue of ScrollBar Don't work at first time

[sergio87]

Hi!

I open an image in a QLabel as a QPixmap. When I opened the image I resize it. Then I "center" the image respect to a particular pixel. "Center" the image is to set value to the ScrollBar. The code is:

imageLabelCandidate = new QLabel();
imageLabelCandidate->setBackgroundRole(QPalette::Base);
imageLabelCandidate->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored);
imageLabelCandidate->setScaledContents(true);
 
scrollAreaCandidate = new QScrollArea;
scrollAreaCandidate->setBackgroundRole(QPalette::Dark);
scrollAreaCandidate->setWidget(imageLabelCandidate);
 
void MyClass::openImage(string *path){
QString fileName = QString::fromStdString(*path);
	 if (!fileName.isEmpty()) {
		 QImage image(fileName);
		 if (image.isNull()) {
			 cout << "ERROR opening file" << endl;
			 return;
		 }
		 imageLabelCandidate->setPixmap(QPixmap::fromImage(image));
		 imageLabelCandidate->MPixmap(QPixmap::fromImage(image));
		 imageLabelCandidate->adjustSize();
		 scaleCandidateImage(1.3);
		 scrollAreaCandidate->horizontalScrollBar()->setValue(2000);
	 }
 
void MyClass::scaleCandidateImage(double factor)
{
    Q_ASSERT(imageLabelCandidate->pixmap());
    imageLabelCandidate->resize(factor * imageLabelCandidate->pixmap()->size());
}

imageLabelCandidate = new QLabel();
imageLabelCandidate->setBackgroundRole(QPalette::Base);
imageLabelCandidate->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored);
imageLabelCandidate->setScaledContents(true);

scrollAreaCandidate = new QScrollArea;
scrollAreaCandidate->setBackgroundRole(QPalette::Dark);
scrollAreaCandidate->setWidget(imageLabelCandidate);

void MyClass::openImage(string *path){
QString fileName = QString::fromStdString(*path);
	 if (!fileName.isEmpty()) {
		 QImage image(fileName);
		 if (image.isNull()) {
			 cout << "ERROR opening file" << endl;
			 return;
		 }
		 imageLabelCandidate->setPixmap(QPixmap::fromImage(image));
		 imageLabelCandidate->MPixmap(QPixmap::fromImage(image));
		 imageLabelCandidate->adjustSize();
		 scaleCandidateImage(1.3);
		 scrollAreaCandidate->horizontalScrollBar()->setValue(2000);
	 }

void MyClass::scaleCandidateImage(double factor)
{
    Q_ASSERT(imageLabelCandidate->pixmap());
    imageLabelCandidate->resize(factor * imageLabelCandidate->pixmap()->size());
}

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The problem is that the first time I call "openImage" it don't set the value 2000 to the horizontalScrollBar. The following times it works properly.

Where I make the mistake?

Thanks in advance!!!!!