refs #442 Add CPluginManager class

src/blackcore/plugin_manager.cpp

@@ -0,0 +1,131 @@
+/* Copyright (C) 2013
+ * swift Project Community / Contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
+ * including this file, may be copied, modified, propagated, or distributed except according to the terms
+ * contained in the LICENSE file.
+ */
+
+#include "plugin_manager.h"
+#include "blackmisc/logmessage.h"
+#include "blackmisc/loghandler.h"
+#include <QCoreApplication>
+#include <QDir>
+#include <QDirIterator>
+#include <QLibrary>
+
+using namespace BlackMisc;
+
+namespace BlackCore {
+
+    BlackMisc::CSequence<QJsonObject> CPluginManager::plugins(const QString &iid) const
+    {
+        return m_metadatas.values(iid);
+    }
+
+    QObject *CPluginManager::getPluginById(const QString &identifier)
+    {
+        if (m_instances.contains(identifier))
+        {
+            return m_instances.value(identifier);
+        }
+
+        if (!m_paths.contains(identifier))
+        {
+            CLogMessage(this).warning("Plugin with id %1 does not exist") << identifier;
+            return nullptr;
+        }
+
+        QString path = m_paths.value(identifier);
+        QPluginLoader loader(path);
+        QObject *instance = loader.instance();
+        if (instance)
+        {
+            m_instances.insert(identifier, instance);
+            return instance;
+        }
+        else
+        {
+            CLogMessage(this).error(loader.errorString());
+            return nullptr;
+        }
+    }
+
+    CPluginManager *CPluginManager::getInstance()
+    {
+        static CPluginManager *instance = nullptr;
+        if (!instance)
+        {
+            instance = new CPluginManager();
+        }
+        return instance;
+    }
+
+    CPluginManager::CPluginManager(QObject *parent) : QObject(parent)
+    {
+        collectPlugins();
+
+        connect(qApp, &QCoreApplication::aboutToQuit, this, &CPluginManager::deleteLater);
+    }
+
+    void CPluginManager::collectPlugins()
+    {
+        QDir pluginDir(qApp->applicationDirPath().append("/plugins"));
+        if (!pluginDir.exists())
+        {
+            CLogMessage(this).warning("No plugins directory: %1") << pluginDir.path();
+            return;
+        }
+
+        QDirIterator it(pluginDir, QDirIterator::Subdirectories);
+        while (it.hasNext())
+        {
+            if (!QLibrary::isLibrary(it.next()))
+            {
+                continue;
+            }
+
+            CLogMessage(this).debug() << "Loading plugin: " << it.filePath();
+            QPluginLoader loader(it.filePath());
+            QJsonObject json = loader.metaData();
+            QString identifier = pluginIdentifier(json);
+            if (identifier.isEmpty())
+            {
+                CLogMessage(this).warning("Plugin %1 invalid, not loading it") << it.filePath();
+                continue;
+            }
+
+            m_paths.insert(identifier, it.filePath());
+            m_metadatas.insert(json["IID"].toString(), json);
+        }
+    }
+
+    QString CPluginManager::pluginIdentifier(const QJsonObject &metadata)
+    {
+        if (!metadata.contains("IID") || !metadata["IID"].isString())
+        {
+            return QString();
+        }
+
+        if (!metadata["MetaData"].isObject())
+        {
+            return QString();
+        }
+
+        QJsonObject data = metadata["MetaData"].toObject();
+        if (!data.contains("identifier"))
+        {
+            return QString();
+        }
+
+        QJsonValue identifier = data["identifier"];
+        if (!identifier.isString())
+        {
+            return QString();
+        }
+
+        return identifier.toString();
+    }
+
+} // namespace