Issue change tab QTabWidget & QScrollArea Qt - c++

Question

I'm trying to create a QScrollArea in a QTabWidget.
Versions :
Qt 5.15.0
Qt creator 4.12.4
MSVC2019 64 bits
First of all, I've created the QTabWidget :
tabWidget = new QTabWidget(this);
tabWidget->setGeometry(10, 15, 1200, 665);
tabWidget->setStyleSheet("font-size : 15px");
tab1Content = new QWidget(tabWidget); tabWidget->addTab(tab1Content, "tab1");
tab2Content = new QWidget(tabWidget); tabWidget->addTab(tab2Content, "tab2");
tab3Content = new QWidget(tabWidget); tabWidget->addTab(tab3Content, "tab3");
tab4Content = new QWidget(tabWidget); tabWidget->addTab(tab4Content, "tab4");
I can add
tabWidget->setEnable(true);
And for all tabs, 0 <= i < tabWidget.count
tabWidget->setTabEnabled(i, true);
Click to change tab doesn't work : https://i.stack.imgur.com/8r1Jg.png
Strange thing : color looks like enabled but i can only change tabs with ← → and when i lost tabWidget focus by clicking on an other thing outside the tabWidget, i can't regain focus.
So i've created temporary button to change tabs and linked to tabWidget like that :
connect(changeTab, &QPushButton::clicked, [&]() {onChangeTab();});
void MainWindow::onChangeTab() {
tabWidget->setCurrentIndex(tabWidget->currentIndex() >= tabWidget->count() - 1 ? 0 : tabWidget->currentIndex() + 1);
}
It works well.
Thus, I've start to create the QScrollArea :
First, it doesn't work, so I've tried to found sth on internet :
QScrollArea not working as expected with QWidget and QVBoxLayout
My result : https://i.stack.imgur.com/jvVol.png
I cannot click on a single button and i can't scroll...
And if i try to force scroll like this, it doesn't scroll
scrollArea->scroll(0, 50);
Last thing, there isn't infinite loop or dead lock things because all things around this cursed tabWidget and scroll Area work perfectly.
I don't know why these objects "don't answer" if somedoby had this kind of experiment could you help me please ?
Thank you very much in advance.

Answer 1

try this code
#include "widget.h"
#include<QTabWidget>
#include<QLabel>
#include<QVBoxLayout>
#include<QScrollArea>
Widget::Widget(QWidget *parent)
: QWidget(parent)
{
QTabWidget *tabWidget = new QTabWidget(this);
tabWidget->setGeometry(10, 15, 1200, 665);
tabWidget->setStyleSheet("font-size : 15px");
QWidget * tab1Content = new QWidget;
//preparing tab1content ( e.g.)
QVBoxLayout * verticalLayout = new QVBoxLayout;
// adding items to vertical layout
for(int i=0;i<100;i++)
verticalLayout->addWidget(new QLabel(QString::number(i)));
// set this vertical layout inside tab1content
tab1Content->setLayout(verticalLayout);
// create new scroll area ...
QScrollArea * scroll = new QScrollArea;
// ... and add tab1content in scroll area
scroll->setWidget(tab1Content);
// and finally add scroll area inside tabwidget
tabWidget->addTab(scroll,"tab1");
QWidget * tab2Content = new QWidget; tabWidget->addTab(tab2Content, "tab2");
QWidget * tab3Content = new QWidget; tabWidget->addTab(tab3Content, "tab3");
QWidget * tab4Content = new QWidget; tabWidget->addTab(tab4Content, "tab4");
}
Widget::~Widget()
{
}