qt: introduce `MLItemId` serialization

modules/gui/qt/medialibrary/medialib.cpp

@@ -107,6 +107,10 @@ static void convertQVariantListToPlaylistMedias(vlc_medialibrary_t* ml, QVariant
     }
 }
 
+MLItemId MediaLib::deserializeMlItemIdFromString(const QString& serialized_id) {
+    return MLItemId::fromString(serialized_id);
+}
+
 void MediaLib::addToPlaylist(const QString& mrl, const QStringList &options)
 {
     QVector<vlc::playlist::Media> medias;

modules/gui/qt/medialibrary/medialib.hpp

@@ -46,6 +46,8 @@ public:
     MediaLib(qt_intf_t* _intf, vlc::playlist::PlaylistController* playlistController, QObject* _parent = nullptr );
     ~MediaLib();
 
+    Q_INVOKABLE static MLItemId deserializeMlItemIdFromString(const QString& serialized_id);
+
     Q_INVOKABLE void addToPlaylist(const MLItemId &itemId, const QStringList &options = {});
     Q_INVOKABLE void addToPlaylist(const QString& mrl, const QStringList &options = {});
     Q_INVOKABLE void addToPlaylist(const QUrl& mrl, const QStringList &options = {});

modules/gui/qt/medialibrary/mlqmltypes.hpp

@@ -23,12 +23,23 @@
 # include "config.h"
 #endif
 
+#include <QHash>
 #include <QObject>
 #include <vlc_common.h>
 #include <vlc_media_library.h>
 
 static constexpr int64_t INVALID_MLITEMID_ID = 0;
 
+static const QHash<QStringView, vlc_ml_parent_type> ml_parent_map = {
+    { QStringLiteral("VLC_ML_PARENT_ALBUM"), VLC_ML_PARENT_ALBUM },
+    { QStringLiteral("VLC_ML_PARENT_ARTIST"), VLC_ML_PARENT_ARTIST },
+    { QStringLiteral("VLC_ML_PARENT_SHOW"), VLC_ML_PARENT_SHOW },
+    { QStringLiteral("VLC_ML_PARENT_GENRE"), VLC_ML_PARENT_GENRE },
+    { QStringLiteral("VLC_ML_PARENT_GROUP"), VLC_ML_PARENT_GROUP },
+    { QStringLiteral("VLC_ML_PARENT_FOLDER"), VLC_ML_PARENT_FOLDER },
+    { QStringLiteral("VLC_ML_PARENT_PLAYLIST"), VLC_ML_PARENT_PLAYLIST }
+};
+
 class MLItemId
 {
     Q_GADGET
@@ -71,6 +82,22 @@ public:
         }
 #undef ML_PARENT_TYPE_CASE
     }
+
+    Q_INVOKABLE static inline MLItemId fromString(const QStringView& serialized_id) {
+        const QList<QStringView> parts = serialized_id.split('-'); // Type, ID
+        if (parts.length() != 2) {
+            return {-1, VLC_ML_PARENT_UNKNOWN};
+        }
+
+        const QStringView type = parts[0].trimmed();
+        bool conversionSuccessful = false;
+        std::int64_t item_id = parts[1].trimmed().toLongLong(&conversionSuccessful);
+        if (!conversionSuccessful) {
+            return {-1, VLC_ML_PARENT_UNKNOWN};
+        }
+
+        return { item_id, ml_parent_map.value(type, VLC_ML_PARENT_UNKNOWN) };
+    }
 };