PictureImageProvider.cpp

#include "PictureImageProvider.h"

#include "PictureModel.h"

const QString PICTURE_SIZE_FULL = "full";
const QString PICTURE_SIZE_THUMBNAIL = "thumbnail";
const QSize PictureImageProvider::THUMBNAIL_SIZE = QSize(350, 350);

PictureImageProvider::PictureImageProvider(PictureModel* pictureModel) :
    QQuickImageProvider(QQuickImageProvider::Pixmap),
    mPictureModel(pictureModel),
    mPicturesCache()
{

}

QPixmap PictureImageProvider::requestPixmap(const QString& id, QSize* /*size*/, const QSize& /*requestedSize*/)
{
    QStringList query = id.split('/');
    if (!mPictureModel || query.size() < 2) {
        return QPixmap();
    }

    int rowId = query[0].toInt();
    QString pictureSize = query[1];

    QUrl fileUrl = mPictureModel->data(mPictureModel->index(rowId, 0), PictureModel::Roles::UrlRole).toUrl();
    return *pictureFromCache(fileUrl.toLocalFile(), pictureSize);
}

QPixmap* PictureImageProvider::pictureFromCache(const QString& filepath, const QString& pictureSize)
{
    QString key = QStringList{ pictureSize, filepath }
                    .join("-");

    QPixmap* cachePicture = nullptr;
    if (!mPicturesCache.contains(key)) {
        QPixmap originalPicture(filepath);
        if (pictureSize == PICTURE_SIZE_THUMBNAIL) {
            cachePicture = new QPixmap(originalPicture
                                  .scaled(THUMBNAIL_SIZE,
                                          Qt::KeepAspectRatio,
                                          Qt::SmoothTransformation));
        } else if (pictureSize == PICTURE_SIZE_FULL) {
            cachePicture = new QPixmap(originalPicture);
        }
        mPicturesCache.insert(key, cachePicture);
    } else {
        cachePicture = mPicturesCache[key];
    }

    return cachePicture;
}