videoplayer image provider

#pragma once

#include <QtQuick>

Q_DECLARE_LOGGING_CATEGORY(videoPlayerImageProviderCategory)

class VideoPlayerImageProvider
        : public QQuickImageProvider
{

    Q_DECLARE_TR_FUNCTIONS(VideoPlayerImageProvider)

public :

    VideoPlayerImageProvider(QQmlEngine * const engine);

    QImage requestImage(const QString & id, QSize * size, const QSize & requestedSize) Q_DECL_OVERRIDE;

private :

    QQmlEngine * const engine;
    QHash< QString, QImage > images;

};

#include "videoplayerimageprovider.hpp"

Q_LOGGING_CATEGORY(videoPlayerImageProviderCategory, "videoPlayerImageProvider")

VideoPlayerImageProvider::VideoPlayerImageProvider(QQmlEngine * const engine)
    : QQuickImageProvider{QQuickImageProvider::Image}
    , engine{engine}
{ ; }

QImage VideoPlayerImageProvider::requestImage(const QString & id, QSize * size, const QSize & requestedSize)
{
    const auto selector = QQmlFileSelector::get(engine)->selector();
    const auto imagePath = selector->select(QStringLiteral(":/images/videoplayer/%1").arg(id));
#if 0
    qDebug().noquote()
            << tr("Selected filepath: %1. Installed file selectors: %2")
               .arg(imagePath, selector->allSelectors().join(QStringLiteral(", ")));
#endif
    QImage & image = images[imagePath];
    if (image.isNull()) {
        QImageReader imageReader{imagePath};
        if (!imageReader.read(&image)) {
            qCCritical(videoPlayerImageProviderCategory).noquote()
                    << tr("Unable to read image from %1: %3 (%2)")
                       .arg(imagePath, imageReader.errorString()).arg(imageReader.error());
        }
    }
    if (size) {
        *size = image.size();
    }
    if (requestedSize.isEmpty() || (image.size() == requestedSize)) { // avoid returning invalid QImage
        return image;
    }
    return image.scaled(requestedSize, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
}