How to add scroll bar action

[Kinesis]

I want to add scroll bar that can be scrolled down and up until the top or bottom of my list widget . I already add the scroll bar but not the action.How can I add action of my scroll bar.I would appreciate any answers.
Here is my code: mainwindow.cpp

    ui->listWidget_2->setFlow(QListView::LeftToRight);
    ui->listWidget_2->setMinimumSize(1000,740);
    ui->listWidget_2->setGridSize(QSize(1200, 410));
    ui->listWidget_2->setResizeMode(QListView::Adjust);
    ui->listWidget_2->setViewMode(QListView::ListMode);
    ui->listWidget_2->setWrapping(true);
    
    
    
    
    
    ui->listWidget_image->setFlow(QListView::LeftToRight);
    // ui->listWidget_image->setMinimumSize(1000,340);
    ui->listWidget_image->setGridSize(QSize(380, 360));
    ui->listWidget_image->setResizeMode(QListView::Adjust);
    ui->listWidget_image->setViewMode(QListView::ListMode);
    //ui->listWidget_image->setViewMode(QListWidget::IconMode);
    //ui->listWidget_image->setIconSize(QSize(400,360));
    // ui->listWidget_image->setResizeMode(QListWidget::Adjust);
    ui->listWidget_image->setWrapping(true);
    
    
    
    ui->listWidget_read->setFlow(QListView::LeftToRight);
    //ui->listWidget_read->setMinimumSize(860,380);
    ui->listWidget_read->setGridSize(QSize(380, 360));
    ui->listWidget_read->setResizeMode(QListView::Adjust);
    ui->listWidget_read->setViewMode(QListView::ListMode);
    ui->listWidget_read->setWrapping(true);
    auto    item = new QListWidgetItem("", ui->listWidget_2);
    auto    widget = new QWidget;
    auto    vb = new QVBoxLayout;
    auto    hb = new QHBoxLayout;
    vb->addWidget(ui->pushButton);
    
    
    vb->addWidget(ui->listWidget_image);
    vb->addWidget(ui->listWidget_read);
    hb->addLayout(vb);
    hb->addWidget(ui->verticalScrollBar);
    widget->setLayout(hb);
    widget->setMinimumSize(1200,730);
    ui->listWidget_2->setItemWidget(item,widget);
    
    
    QDir directory = QFileDialog::getExistingDirectory(this, tr("Open Directory"),"/home",
                                                       
                                                       QFileDialog::ShowDirsOnly| QFileDialog::DontResolveSymlinks);
    
    
    
    
    directory.setNameFilters({"*.log", "*.txt" , "*.sh" , "*.yml"});
    
    for(const QFileInfo & finfo: directory.entryInfoList()){
        
        m_textEdit = new QTextEdit;
        m_textEdit -> setReadOnly(true);
        QFile data(finfo.absoluteFilePath()) ;
        data.open(QIODevice::ReadOnly);
        QTextStream stream(&data);
        QString content = stream.readAll();
        data.close();
        
        m_textEdit->setText(content);
        auto    item = new QListWidgetItem("", ui->listWidget_read);
        auto    widget = new QWidget;
        auto    label = new QLabel(finfo.fileName());
        auto    vb = new QVBoxLayout;
        
        vb->addWidget(label);
        vb->addWidget(m_textEdit);
        
        widget->setLayout(vb);
        widget->setMinimumSize(340, 340);
        ui->listWidget_read->setItemWidget(item, widget);
        
        
        
    }
    
    
    
    
    directory.setNameFilters({"*.mp4" , "*.avi" , "*.flv" , "*.mwv"});
    
    for(const QFileInfo & finfo: directory.entryInfoList()){
        QMediaPlayer *mediaPlayer = new QMediaPlayer();
        mediaPlayer->setMedia(QUrl::fromLocalFile(finfo.absoluteFilePath()));
        videoItem = new QGraphicsVideoItem;
        videoItem->setSize(QSize(320,240));
        QGraphicsScene *scene = new QGraphicsScene(this);
        QGraphicsView *graphicsView = new QGraphicsView(scene);
        mediaPlayer->setVideoOutput(videoItem);
        
        QPushButton *m_playButton = new QPushButton();
        m_playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
        
        connect(m_playButton, &QAbstractButton::clicked, [mediaPlayer]() {
            switch (mediaPlayer->state()) {
            case QMediaPlayer::PlayingState:
                mediaPlayer->pause();
                break;
            default:
                mediaPlayer->play();
                break;
            }
        });
        
        
        connect(mediaPlayer, &QMediaPlayer::stateChanged, [m_playButton, this](QMediaPlayer::State state) {
            switch(state) {
            case QMediaPlayer::PlayingState:
                m_playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPause));
                break;
            default:
                m_playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
                break;
            }
        });
        
        
        
        QSlider *m_positionSlider = new QSlider(Qt::Horizontal,this);
        m_positionSlider->setRange(0,mediaPlayer->duration() / 1000);
        
        
        connect(mediaPlayer, &QMediaPlayer::positionChanged ,[m_positionSlider, this](qint64 position){
            
            m_positionSlider->setValue(position);
        });
        
        connect(mediaPlayer, &QMediaPlayer::durationChanged ,[m_positionSlider, this](qint64 duration){
            
            m_positionSlider->setRange(0,duration);
        });
        
        
        connect(m_positionSlider ,&QAbstractSlider::sliderMoved, [mediaPlayer ,this] (int position){
            
            mediaPlayer->setPosition(position);
        });
        
        
        
        
        auto    item = new QListWidgetItem("", ui->listWidget_image);
        auto    widget = new QWidget;
        auto    label = new QLabel(finfo.fileName());
        auto    vb = new QVBoxLayout;
        
        QBoxLayout *controlLayout = new QHBoxLayout;
        controlLayout->setMargin(0);
        controlLayout->addWidget(m_playButton);
        controlLayout->addWidget(m_positionSlider);
        
        vb->addWidget(label);
        vb->addWidget(graphicsView);
        vb->addLayout(controlLayout);
        widget->setLayout(vb);
        widget->setMinimumSize(340, 340);
        ui->listWidget_image->setItemWidget(item,widget);
        player.append(mediaPlayer);
        scene->addItem(videoItem);
        
        
        
    }

[jsulm]

@Kinesis What action do you mean?

[Kinesis]

@jsulm
I just need to scroll down or up to see the items . I can't see all of my items on the display because of the listWidget frame size .That's why I need to scroll down to see other items . I don't know how can I add scrolling action .

[jsulm]

@Kinesis said in How to add scroll bar action:

I don't know how can I add scrolling action

Like shown here: http://doc.qt.io/qt-5/qscrollarea.html

[Kinesis]

@jsulm
So , can I just add my listwidget on scrollarea ??

[jsulm]

@Kinesis Sure, you can. Did you try?

[SGaist]

Hi,

QListWidget already has scrollbars so why do you want to put it in a QScrollArea since it already provides that functionality ?

[Kinesis]

@SGaist
If so , how can I use these functionality?

[Kinesis]

@jsulm
Thanks . I get it now. it's working :)

[SGaist]

The scroll bars appear as soon as the content exceeds the size of the widget itself, unless you force the policy to always on.

[Kinesis]

@SGaist
Ya, I know that the scroll area will appear like u said . But in my case it wont appear . That's why I need to use scrollarea.

[SGaist]

Did you try to determine why they don't appear ?