Port plugin loading away from KPluginLoader

It is deprecated

This also simplifies the code a lot

src/cantor.cpp

@@ -323,9 +323,10 @@ void CantorShell::addWorksheet(const QString& backendName)
     // this routine will find and load our Part.  it finds the Part by
     // name which is a bad idea usually.. but it's alright in this
     // case since our Part is made for this Shell
-    KPluginLoader loader(QLatin1String("kf5/parts/cantorpart"));
-    KPluginFactory* factory = loader.factory();
-    if (factory)
+
+    const auto partResult = KPluginFactory::instantiatePlugin<KParts::ReadWritePart>(KPluginMetaData(QStringLiteral("kf5/parts/cantorpart")), m_tabWidget, {backendName});
+
+    if (partResult)
     {
         Cantor::Backend* backend = nullptr;
         if (!backendName.isEmpty())
@@ -347,49 +348,42 @@ void CantorShell::addWorksheet(const QString& backendName)
         }
 
         // now that the Part is loaded, we cast it to a Part to get our hands on it
-        auto* part = factory->create<KParts::ReadWritePart>(m_tabWidget, QVariantList()<<backendName);
-        if (part)
-        {
-            connect(part, SIGNAL(setCaption(QString,QIcon)), this, SLOT(setTabCaption(QString,QIcon)));
-            connect(part, SIGNAL(worksheetSave(QUrl)), this, SLOT(onWorksheetSave(QUrl)));
-            connect(part, SIGNAL(showHelp(QString)), this, SIGNAL(showHelp(QString)));
-            connect(part, SIGNAL(hierarchyChanged(QStringList, QStringList, QList<int>)), this, SIGNAL(hierarchyChanged(QStringList, QStringList, QList<int>)));
-            connect(part, SIGNAL(hierarhyEntryNameChange(QString, QString, int)), this, SIGNAL(hierarhyEntryNameChange(QString, QString, int)));
-            connect(this, SIGNAL(requestScrollToHierarchyEntry(QString)), part, SIGNAL(requestScrollToHierarchyEntry(QString)));
-            connect(this, SIGNAL(settingsChanges()), part, SIGNAL(settingsChanges()));
-            connect(part, SIGNAL(requestDocumentation(QString)), this, SIGNAL(requestDocumentation(QString)));
-
-            m_parts.append(part);
-            if (backend) {// If backend empty (loading worksheet from file), then we connect to signal and wait
-                m_parts2Backends[part] = backend->id();
-
-                //show the default help string in the help panel
-                emit showHelp(backend->defaultHelp());
-            }
-            else
-            {
-                m_parts2Backends[part] = QString();
-                connect(part, SIGNAL(setBackendName(QString)), this, SLOT(updateBackendForPart(QString)));
-            }
-            int tab = m_tabWidget->addTab(part->widget(), i18n("Session %1", sessionCount++));
-            m_tabWidget->setCurrentIndex(tab);
-            // Setting focus on worksheet view, because Qt clear focus of added widget inside addTab
-            // This fix https://bugs.kde.org/show_bug.cgi?id=395976
-            part->widget()->findChild<QGraphicsView*>()->setFocus();
-
-            // Force run updateCaption for getting proper backend icon
-            QMetaObject::invokeMethod(part, "updateCaption");
-        }
-        else
+        auto part = partResult.plugin;
+
+        connect(part, SIGNAL(setCaption(QString,QIcon)), this, SLOT(setTabCaption(QString,QIcon)));
+        connect(part, SIGNAL(worksheetSave(QUrl)), this, SLOT(onWorksheetSave(QUrl)));
+        connect(part, SIGNAL(showHelp(QString)), this, SIGNAL(showHelp(QString)));
+        connect(part, SIGNAL(hierarchyChanged(QStringList, QStringList, QList<int>)), this, SIGNAL(hierarchyChanged(QStringList, QStringList, QList<int>)));
+        connect(part, SIGNAL(hierarhyEntryNameChange(QString, QString, int)), this, SIGNAL(hierarhyEntryNameChange(QString, QString, int)));
+        connect(this, SIGNAL(requestScrollToHierarchyEntry(QString)), part, SIGNAL(requestScrollToHierarchyEntry(QString)));
+        connect(this, SIGNAL(settingsChanges()), part, SIGNAL(settingsChanges()));
+        connect(part, SIGNAL(requestDocumentation(QString)), this, SIGNAL(requestDocumentation(QString)));
+
+        m_parts.append(part);
+        if (backend) {// If backend empty (loading worksheet from file), then we connect to signal and wait
+            m_parts2Backends[part] = backend->id();
+
+            //show the default help string in the help panel
+            emit showHelp(backend->defaultHelp());
+        } else
         {
-            qDebug()<<"error creating part ";
+            m_parts2Backends[part] = QString();
+            connect(part, SIGNAL(setBackendName(QString)), this, SLOT(updateBackendForPart(QString)));
         }
+        int tab = m_tabWidget->addTab(part->widget(), i18n("Session %1", sessionCount++));
+        m_tabWidget->setCurrentIndex(tab);
+        // Setting focus on worksheet view, because Qt clear focus of added widget inside addTab
+        // This fix https://bugs.kde.org/show_bug.cgi?id=395976
+        part->widget()->findChild<QGraphicsView*>()->setFocus();
+
+        // Force run updateCaption for getting proper backend icon
+        QMetaObject::invokeMethod(part, "updateCaption");
     }
     else
     {
         // if we couldn't find our Part, we exit since the Shell by
         // itself can't do anything useful
-        KMessageBox::error(this, i18n("Failed to find the Cantor Part with error %1", loader.errorString()));
+        KMessageBox::error(this, i18n("Failed to find the Cantor Part with error %1", partResult.errorString));
         qApp->quit();
         // we return here, cause qApp->quit() only means "exit the
         // next time we enter the event loop...

src/cantor_part.cpp

@@ -752,53 +752,36 @@ void CantorPart::loadAssistants()
 {
     qDebug()<<"loading assistants...";
 
-    QStringList assistantDirs;
-    for (const QString& dir : QCoreApplication::libraryPaths())
-        assistantDirs << dir + QDir::separator() + QLatin1String("cantor/assistants");
+    const QVector<KPluginMetaData> plugins = KPluginMetaData::findPlugins(QStringLiteral("cantor/assistants"));
 
-    QPluginLoader loader;
-    for (const QString& dir : assistantDirs) {
+    for (const KPluginMetaData &plugin : plugins) {
 
-        qDebug() << "dir: " << dir;
-        QStringList assistants;
-        QDir assistantDir = QDir(dir);
+        const auto result = KPluginFactory::instantiatePlugin<Cantor::Assistant>(plugin, this);
 
-        assistants = assistantDir.entryList();
-
-        for (const QString& assistant : assistants) {
-            if (assistant == QLatin1String(".") || assistant == QLatin1String(".."))
-                continue;
-
-            loader.setFileName(dir + QDir::separator() + assistant);
-
-            if (!loader.load()){
-                qDebug() << "Error while loading assistant: " << assistant;
-                continue;
-            }
-
-            KPluginFactory* factory = KPluginLoader(loader.fileName()).factory();
-            auto* plugin = factory->create<Cantor::Assistant>(this);
-            auto* backend=worksheet()->session()->backend();
+        if (!result) {
+            qDebug() << "Error while loading assistant plugin: " << result.errorText;
+            continue;
+        }
 
-            KPluginMetaData info(loader);
-            plugin->setPluginInfo(info);
-            plugin->setBackend(backend);
+        Cantor::Assistant *assistant = result.plugin;
+        auto* backend=worksheet()->session()->backend();
+        assistant->setPluginInfo(plugin);
+        assistant->setBackend(backend);
 
-            bool supported=true;
-            for (const QString& req : plugin->requiredExtensions())
-                supported = supported && backend->extensions().contains(req);
+        bool supported=true;
+        for (const QString& req : assistant->requiredExtensions())
+            supported = supported && backend->extensions().contains(req);
 
-            if(supported)
-            {
-                qDebug() << "plugin " << info.name() << " is supported by " << backend->name() << ", requires extensions " << plugin->requiredExtensions();
-                plugin->initActions();
-                connect(plugin, &Cantor::Assistant::requested, this, &CantorPart::runAssistant);
-            }else
-            {
-                qDebug() << "plugin " << info.name() << " is not supported by "<<backend->name();
-                removeChildClient(plugin);
-                plugin->deleteLater();
-            }
+        if(supported)
+        {
+            qDebug() << "plugin " << plugin.name() << " is supported by " << backend->name() << ", requires extensions " << assistant->requiredExtensions();
+            assistant->initActions();
+            connect(assistant, &Cantor::Assistant::requested, this, &CantorPart::runAssistant);
+        }else
+        {
+            qDebug() << "plugin " << plugin.name() << " is not supported by "<<backend->name();
+            removeChildClient(assistant);
+            assistant->deleteLater();
         }
     }
 }

src/lib/backend.cpp

@@ -15,6 +15,7 @@
 #include <QStandardPaths>
 #include <QPluginLoader>
 
+#include <KPluginFactory>
 #include <KPluginMetaData>
 #include <KPluginFactory>
 #include <KLocalizedString>
@@ -105,46 +106,24 @@ QList<Backend*> Backend::availableBackends()
         return backendCache;
     }
 
-    QStringList pluginDirs;
-    for (const QString& dir : QCoreApplication::libraryPaths()){
-        pluginDirs << dir + QDir::separator() + QLatin1String("cantor/backends");
-    }
-
-    QPluginLoader loader;
-    for (const QString &dir : pluginDirs){
-        qDebug() << "dir: " << dir;
-        QStringList plugins;
-        QDir pluginDir = QDir(dir);
-
-        plugins = pluginDir.entryList();
+    const QVector<KPluginMetaData> plugins = KPluginMetaData::findPlugins(QStringLiteral("cantor/backends"));
 
-        for (const QString &plugin : plugins){
-            if (plugin==QLatin1String(".") || plugin==QLatin1String(".."))
-                continue;
+    for (const KPluginMetaData &plugin : plugins) {
 
-            loader.setFileName(dir + QDir::separator() + plugin);
+        const auto result = KPluginFactory::instantiatePlugin<Backend>(plugin, QCoreApplication::instance());
 
-            if (!loader.load()){
-                qDebug() << "Error while loading plugin: " << plugin;
-                continue;
-            }
-
-            KPluginFactory* factory = KPluginLoader(loader.fileName()).factory();
-            Backend* backend = factory->create<Backend>(QCoreApplication::instance());
+        if (!result) {
+            qDebug() << "Error while loading backend: " << result.errorText;
+            continue;
+        }
 
-            if (!backend){
-                qDebug() << "Error using plugin " << loader.fileName();
-                qDebug() << "Error message: " << loader.errorString();
-                continue;
-            }
+        Backend *backend = result.plugin;
 
-            KPluginMetaData info(loader);
-            backend->d->name=info.name();
-            backend->d->comment=info.description();
-            backend->d->icon=info.iconName();
-            backend->d->url=info.website();
-            backendCache<<backend;
-        }
+        backend->d->name = plugin.name();
+        backend->d->comment = plugin.description();
+        backend->d->icon = plugin.iconName();
+        backend->d->url = plugin.website();
+        backendCache << backend;
     }
 
     return backendCache;

src/lib/cantor_macros.h

@@ -7,7 +7,6 @@
 #define _CANTOR_MACROS_H
 
 #include <KPluginFactory>
-#include <KPluginLoader>
 
 /**
   Exports Backend plugin.

src/lib/panelpluginhandler.cpp

@@ -8,6 +8,8 @@ using namespace Cantor;
 
 #include <QDebug>
 #include <QDir>
+
+#include <KPluginFactory>
 #include <KPluginMetaData>
 #include <KPluginFactory>
 
@@ -33,34 +35,22 @@ PanelPluginHandler::~PanelPluginHandler()
 
 void PanelPluginHandler::loadPlugins()
 {
-    QStringList panelDirs;
-    for (const QString& path : QCoreApplication::libraryPaths()) {
-        const QString& dir = path + QDir::separator() + QLatin1String("cantor/panels");
-        qDebug() << "dir: " << dir;
-        QDir panelDir = QDir(dir);
+    const QVector<KPluginMetaData> plugins = KPluginMetaData::findPlugins(QStringLiteral("cantor/panels"));
 
-        QPluginLoader loader;
-        const QStringList& panels = panelDir.entryList();
+    for (const KPluginMetaData &plugin : plugins) {
 
-        for (const QString& panel : panels)
-        {
-            if (panel==QLatin1String(".") || panel==QLatin1String(".."))
-                continue;
+        const auto result = KPluginFactory::instantiatePlugin<PanelPlugin>(plugin, QCoreApplication::instance());
 
-            loader.setFileName(dir + QDir::separator() + panel);
+        if (!result) {
+            qDebug() << "Error while loading panel: " << result.errorText;
+            continue;
+        }
 
-            if (!loader.load()){
-                qDebug() << "Error while loading panel" << panel << ": \"" << loader.errorString() << "\"";
-                continue;
-            }
+        PanelPlugin *panel = result.plugin;
 
-            KPluginFactory* factory = KPluginLoader(loader.fileName()).factory();
-            PanelPlugin* plugin = factory->create<PanelPlugin>(this);
+        panel->setPluginInfo(plugin);
+        d->plugins.append(panel);
 
-            KPluginMetaData info(loader);
-            plugin->setPluginInfo(info);
-            d->plugins.append(plugin);
-        }
     }
 }