QML: Add custom image provider to for showing cover art

CMakeLists.txt

@@ -733,6 +733,7 @@ add_library(mixxx-lib STATIC EXCLUDE_FROM_ALL
   src/skin/legacy/legacyskinparser.cpp
   src/skin/legacy/pixmapsource.cpp
   src/skin/legacy/legacyskin.cpp
+  src/skin/qml/asyncimageprovider.cpp
   src/skin/qml/qmlcontrolproxy.cpp
   src/skin/qml/qmlplayermanagerproxy.cpp
   src/skin/qml/qmlplayerproxy.cpp

src/skin/qml/asyncimageprovider.cpp

@@ -0,0 +1,55 @@
+#include "skin/qml/asyncimageprovider.h"
+
+#include "library/coverartcache.h"
+
+namespace mixxx {
+namespace skin {
+namespace qml {
+
+AsyncImageResponse::AsyncImageResponse(const QString& id, const QSize& requestedSize)
+        : m_id(id), m_requestedSize(requestedSize) {
+    setAutoDelete(false);
+}
+
+QQuickTextureFactory* AsyncImageResponse::textureFactory() const {
+    return QQuickTextureFactory::textureFactoryForImage(m_image);
+}
+
+void AsyncImageResponse::run() {
+    if (m_id.startsWith(QStringLiteral("coverart/"))) {
+        QString trackLocation = QString::fromUtf8(QByteArray::fromBase64(
+                m_id.mid(9).toLatin1(), QByteArray::Base64UrlEncoding));
+
+        // TODO: This code does not allow to override embedded cover art with
+        // a custom image, which is possible in Mixxx. We need to access the
+        // actual CoverInfo of the track instead of constructing a default
+        // instance on the fly.
+        CoverInfo coverInfo(CoverInfoRelative(), trackLocation);
+        coverInfo.type = CoverInfoRelative::METADATA;
+        CoverInfo::LoadedImage loadedImage = coverInfo.loadImage();
+        if (loadedImage.result != CoverInfo::LoadedImage::Result::Ok) {
+            coverInfo.type = CoverInfoRelative::FILE;
+            loadedImage = coverInfo.loadImage();
+        }
+        m_image = loadedImage.image;
+    } else {
+        qWarning() << "ImageProvider: Unknown ID " << m_id;
+    }
+
+    if (!m_image.isNull() && m_requestedSize.isValid()) {
+        m_image = m_image.scaled(m_requestedSize);
+    }
+
+    emit finished();
+}
+
+QQuickImageResponse* AsyncImageProvider::requestImageResponse(
+        const QString& id, const QSize& requestedSize) {
+    AsyncImageResponse* response = new AsyncImageResponse(id, requestedSize);
+    pool.start(response);
+    return response;
+}
+
+} // namespace qml
+} // namespace skin
+} // namespace mixxx

src/skin/qml/asyncimageprovider.h

@@ -0,0 +1,36 @@
+#include <QImage>
+#include <QQuickAsyncImageProvider>
+#include <QRunnable>
+#include <QSize>
+#include <QString>
+#include <QThreadPool>
+
+#include "library/coverart.h"
+
+namespace mixxx {
+namespace skin {
+namespace qml {
+
+class AsyncImageResponse : public QQuickImageResponse, public QRunnable {
+  public:
+    AsyncImageResponse(const QString& id, const QSize& requestedSize);
+    QQuickTextureFactory* textureFactory() const override;
+    void run() override;
+
+    QString m_id;
+    QSize m_requestedSize;
+    QImage m_image;
+};
+
+class AsyncImageProvider : public QQuickAsyncImageProvider {
+  public:
+    QQuickImageResponse* requestImageResponse(
+            const QString& id, const QSize& requestedSize) override;
+
+  private:
+    QThreadPool pool;
+};
+
+} // namespace qml
+} // namespace skin
+} // namespace mixxx

src/skin/qml/qmlplayerproxy.cpp

@@ -86,6 +86,7 @@ void QmlPlayerProxy::slotTrackChanged() {
     emit commentChanged();
     emit keyChanged();
     emit colorChanged();
+    emit coverArtUrlChanged();
 }
 
 PROPERTY_IMPL(QString, artist, getArtist, setArtist)
@@ -118,6 +119,19 @@ void QmlPlayerProxy::setColor(const QColor& value) {
     }
 }
 
+QUrl QmlTrackPlayerProxy::getCoverArtUrl() const {
+    const TrackPointer pTrack = m_pCurrentTrack;
+    if (pTrack == nullptr) {
+        return QUrl();
+    }
+
+    const CoverInfo coverInfo = pTrack->getCoverInfoWithLocation();
+    QUrl url("image://mixxx/coverart/");
+    return url.resolved(
+            QString::fromLatin1(coverInfo.trackLocation.toUtf8().toBase64(
+                    QByteArray::Base64UrlEncoding)));
+}
+
 } // namespace qml
 } // namespace skin
 } // namespace mixxx

src/skin/qml/qmlplayerproxy.h

@@ -1,6 +1,7 @@
 #include <QColor>
 #include <QObject>
 #include <QString>
+#include <QUrl>
 
 #include "track/track.h"
 
@@ -27,6 +28,7 @@ class QmlPlayerProxy : public QObject {
     Q_PROPERTY(QString comment READ getComment WRITE setComment NOTIFY commentChanged)
     Q_PROPERTY(QString key READ getKeyText WRITE setKeyText NOTIFY keyChanged)
     Q_PROPERTY(QColor color READ getColor WRITE setColor NOTIFY colorChanged)
+    Q_PROPERTY(QUrl coverArtUrl READ getCoverArtUrl NOTIFY coverArtUrlChanged)
 
   public:
     explicit QmlPlayerProxy(BaseTrackPlayer* pTrackPlayer, QObject* parent);
@@ -45,6 +47,7 @@ class QmlPlayerProxy : public QObject {
     QString getComment() const;
     QString getKeyText() const;
     QColor getColor() const;
+    QUrl getCoverArtUrl() const;
 
   public slots:
     void slotTrackLoaded(TrackPointer pTrack);
@@ -84,6 +87,7 @@ class QmlPlayerProxy : public QObject {
     void commentChanged();
     void keyChanged();
     void colorChanged();
+    void coverArtUrlChanged();
 
   private:
     BaseTrackPlayer* m_pTrackPlayer;

src/skin/qml/qmlskin.cpp

@@ -4,6 +4,7 @@
 #include <QQuickWidget>
 
 #include "coreservices.h"
+#include "skin/qml/asyncimageprovider.h"
 #include "skin/qml/qmlcontrolproxy.h"
 #include "skin/qml/qmlplayermanagerproxy.h"
 #include "skin/qml/qmlplayerproxy.h"
@@ -119,6 +120,7 @@ QWidget* QmlSkin::loadSkin(QWidget* pParent,
     QQuickWidget* pWidget = new QQuickWidget(pParent);
     pWidget->engine()->setBaseUrl(QUrl::fromLocalFile(m_path.absoluteFilePath()));
     pWidget->engine()->addImportPath(m_path.absoluteFilePath());
+    pWidget->engine()->addImageProvider(QStringLiteral("mixxx"), new AsyncImageProvider());
     pWidget->setSource(QUrl::fromLocalFile(m_path.absoluteFilePath() +
             QStringLiteral("/") + kMainQmlFileName));
     pWidget->setResizeMode(QQuickWidget::SizeRootObjectToView);