How can I display the image as a thumbnail

Question

I have a QTreeView to display the hard drives and Directories. also I have a QListView to display the images files as the following:

But I want to display the images as thumbnails, like the following:

My code:

mainWidget::mainWidget(QWidget *parent) : QWidget(parent), ui(new Ui::mainWidget){
    ui->setupUi(this);
    dirsModel = new QFileSystemModel;
    filesModel = new QFileSystemModel;
    dirsModel->setRootPath("");
    ui->treeView->setModel(dirsModel);
    ui->listView->setModel(filesModel);
    dirsModel->setFilter(QDir::AllDirs | QDir::NoDotAndDotDot);
    filesModel->setFilter(QDir::Files);
    ui->treeView->hideColumn(1);
    ui->treeView->hideColumn(2);
    ui->treeView->hideColumn(3);
    ui->treeView->header()->hide();
}

void mainWidget::on_treeView_clicked(const QModelIndex &index){
    ui->listView->setRootIndex(filesModel->setRootPath(dirsModel->filePath(index)));
}

Unfortunately, I don't know what is the way of changing the image view from icon to thumbnail.

Answer 1

Depending on what you are after there are better ways to go about it I think, but here is an example based on a project of mine in python:

What you can do is subclass the QFileIconProvider:

ICON_SIZE = QSize(64,64)
accepted_types = (".jpg",".tiff",".png",".exr",".psd")

# this depends on the plugins you have installed,
# PSD and EXR requires external ones).

class IconProvider(QFileIconProvider):

    def __init__(self) -> None:
        super().__init__()

    def icon(self, type: 'QFileIconProvider.IconType'):

        fn = type.filePath()

        if fn.endswith(accepted_types):
            a = QPixmap(ICON_SIZE)
            a.load(fn)
            return QIcon(a)
        else:
            return super().icon(type)

Then on the Model you use:

self.fileSystemModel.setIconProvider(IconProvider)

Example on TreeView: