[SOLVED] Display big image in QListWidget

Issue

I want to use QListWidget to display big images, e.g. 3508×4961 size in pixels, each list item will display one image. The image is set in a Qlabel and the Qlabel is set into the QListWidgetItem by setItemWidget(). When my program is running, the list item cannot display the entire image because the image is too large. It only displays the upper part of an image. When I scroll down, the list item changes to the next image immediately instead of showing the lower part of the current image gradually. Does anyone know how to show the lower part of each image by scrolling?

Here is my code,

    QImage *image = new QImage("/home/sk/image1.png");
    QLabel *label = new QLabel;
    label->setPixmap(QPixmap(QPixmap::fromImage(*image)));
    QListWidgetItem *ite = new QListWidgetItem;
    auto size = label->sizeHint();
    ite->setSizeHint(label->sizeHint());
    size = ite->sizeHint();
    ui->listWidget->addItem(ite);
    ui->listWidget->setItemWidget(ite, label);

    image = new QImage("/home/sk/image2.png");
    label = new QLabel;
    label->setPixmap(QPixmap(QPixmap::fromImage(*image)));
    ite = new QListWidgetItem;
    ite->setSizeHint(label->sizeHint());
    ui->listWidget->addItem(ite);
    ui->listWidget->setItemWidget(ite, label);

    image = new QImage("/home/sk/image3.png");
    label = new QLabel;
    label->setPixmap(QPixmap(QPixmap::fromImage(*image)));
    ite = new QListWidgetItem;
    ite->setSizeHint(label->sizeHint());
    ui->listWidget->addItem(ite);
    ui->listWidget->setItemWidget(ite, label);

Solution

have you tried changing the scroll mode to ScrollPerPixel

setVerticalScrollMode

and

setHorizontalScrollMode

    ui->listWidget->setVerticalScrollMode(QListWidget::ScrollPerPixel);

and in order to change the scroll step

    ui->listWidget->verticalScrollBar()->setSingleStep(10);
    ui->listWidget->verticalScrollBar()->setPageStep(20);

these values will be used for scrolling

Answered By – arutar

Answer Checked By – Mary Flores (BugsFixing Volunteer)