wallpapers/potd: Use singleton to share data between QML files

After dataengine is gone, a singleton is required to share data.

CCBUG: 422934

wallpapers/potd/plugins/potdplugin.cpp

@@ -8,10 +8,23 @@
 #include "potdprovidermodel.h"
 #include <QQmlContext>
 
+Q_GLOBAL_STATIC(PotdProviderModel, potdProviderModelSelf)
+
+PotdProviderModel *self(QQmlEngine *engine, QJSEngine *scriptEngine)
+{
+    Q_UNUSED(engine)
+    Q_UNUSED(scriptEngine)
+
+    QQmlEngine::setObjectOwnership(potdProviderModelSelf, QQmlEngine::CppOwnership);
+
+    return potdProviderModelSelf;
+}
+
 void PotdPlugin::registerTypes(const char *uri)
 {
     Q_ASSERT(uri == QByteArrayLiteral("org.kde.plasma.wallpapers.potd"));
 
     qmlRegisterType<PotdProviderModel>(uri, 1, 0, "PotdProviderModel");
+    qmlRegisterSingletonType<PotdProviderModel>(uri, 1, 0, "PotdProviderModelInstance", self);
     qmlRegisterUncreatableType<PotdProviderModel>(uri, 1, 0, "Global", QStringLiteral("Error: only enums"));
 }

wallpapers/potd/plugins/potdprovidermodel.cpp

@@ -92,26 +92,9 @@ void PotdProviderModel::loadPluginMetaData()
     endResetModel();
 }
 
-KPluginMetaData PotdProviderModel::metadata(int index) const
+int PotdProviderModel::currentIndex() const
 {
-    if (index >= static_cast<int>(m_providers.size()) || index < 0) {
-        return m_providers.at(0);
-    }
-
-    return m_providers.at(index);
-}
-
-int PotdProviderModel::indexOfProvider(const QString &identifier) const
-{
-    const auto it = std::find_if(m_providers.cbegin(), m_providers.cend(), [&identifier](const KPluginMetaData &metadata) {
-        return metadata.value(QStringLiteral("X-KDE-PlasmaPoTDProvider-Identifier")) == identifier;
-    });
-
-    if (it == m_providers.cend()) {
-        return -1;
-    }
-
-    return std::distance(m_providers.cbegin(), it);
+    return m_currentIndex;
 }
 
 bool PotdProviderModel::running() const
@@ -158,7 +141,15 @@ void PotdProviderModel::setIdentifier(const QString &identifier)
     }
 
     m_identifier = identifier;
-    m_currentIndex = indexOfProvider(identifier);
+
+    const auto it = std::find_if(m_providers.cbegin(), m_providers.cend(), [&identifier](const KPluginMetaData &metadata) {
+        return metadata.value(QStringLiteral("X-KDE-PlasmaPoTDProvider-Identifier")) == identifier;
+    });
+    if (it == m_providers.cend()) {
+        m_currentIndex = -1;
+    } else {
+        m_currentIndex = std::distance(m_providers.cbegin(), it);
+    }
 
     // Avoid flickering
     if (const QString path = CachedProvider::identifierToPath(m_identifier); QFile::exists(path)) {
@@ -169,6 +160,7 @@ void PotdProviderModel::setIdentifier(const QString &identifier)
     updateSource();
 
     Q_EMIT identifierChanged();
+    Q_EMIT currentIndexChanged();
 }
 
 QVariantList PotdProviderModel::arguments() const
@@ -404,7 +396,8 @@ bool PotdProviderModel::updateSource(bool refresh)
         return false;
     }
 
-    const auto pluginResult = KPluginFactory::instantiatePlugin<PotdProvider>(metadata(m_currentIndex), this, m_args);
+    const KPluginMetaData &metadata = m_providers.at(m_currentIndex);
+    const auto pluginResult = KPluginFactory::instantiatePlugin<PotdProvider>(metadata, this, m_args);
 
     if (pluginResult) {
         connect(pluginResult.plugin, &PotdProvider::finished, this, &PotdProviderModel::slotFinished);

wallpapers/potd/plugins/potdprovidermodel.h

@@ -32,6 +32,8 @@ class PotdProviderModel : public QAbstractListModel
     Q_PROPERTY(QString identifier READ identifier WRITE setIdentifier NOTIFY identifierChanged)
     Q_PROPERTY(QVariantList arguments READ arguments WRITE setArguments NOTIFY argumentsChanged)
 
+    Q_PROPERTY(int currentIndex READ currentIndex NOTIFY currentIndexChanged)
+
     /**
      * Read-only properties that expose data from the provider.
      */
@@ -88,8 +90,7 @@ public:
     QHash<int, QByteArray> roleNames() const override;
 
     void loadPluginMetaData();
-    KPluginMetaData metadata(int index) const;
-    Q_INVOKABLE int indexOfProvider(const QString &identifier) const;
+    int currentIndex() const;
 
     bool running() const;
     void setRunning(bool flag);
@@ -115,6 +116,7 @@ public:
     Q_INVOKABLE void saveImage();
 
 Q_SIGNALS:
+    void currentIndexChanged();
     void runningChanged();
     void identifierChanged();
     void argumentsChanged();