Moving things from the application specific DatabaseWindow to generic LMainWindow (Leon framework)

To achieve flexibility the getDatabase call on the context which was application specific to
has been replaced with a type based object registry.

pglab/plugin_support/IPluginContentWidgetContext.h

@@ -2,7 +2,9 @@
 #define IPLUGINCONTENTWIDGETCONTEXT_H
 
 #include <QString>
+#include <map>
 #include <memory>
+#include <typeindex>
 #include "plugin_support/ModuleActionParameters.h"
 
 class OpenDatabase;
@@ -13,6 +15,9 @@ class PluginContentWidget;
  *
  * It provides interface for operating on the context without needing to many details.
  * Actual default implementation is in PluginContentWidgetContextBase.
+ *
+ * objectRegistry implementation is from Igor Tandetnik answer to the following question
+ * https://stackoverflow.com/questions/35413745/using-shared-ptr-with-a-generic-registry-or-shared-object-storage-or-not
  */
 class IPluginContentWidgetContext {
 public:
@@ -32,11 +37,6 @@ public:
 	 */
 	virtual void setIcon(PluginContentWidget *content, const QString &iconname) = 0;
 
-	/** Returns an OpenDatabase object the widget can use to access
-	 * the database.
-	 */
-	virtual std::shared_ptr<OpenDatabase> getDatabase() = 0;
-
 	virtual void showStatusMessage(const QString &msg) = 0;
 
 	virtual void moduleAction(
@@ -46,6 +46,45 @@ public:
 			) = 0;
 
 	virtual void addContentWidget(PluginContentWidget *widget) = 0;
+
+	template<typename T, class...Args>
+	bool addObjects(Args&&...args);
+	template<typename T>
+	bool registerObject(std::shared_ptr<T> object);
+	template<typename T>
+	std::shared_ptr<T> getObject() const;
+private:
+	std::map<std::type_index, std::shared_ptr<void> > m_objectRegistry;
+
 };
 
+template<typename T, class...Args>
+bool IPluginContentWidgetContext::addObjects(Args&&...args)
+{
+	std::type_index key(typeid(T));
+	if (!m_objectRegistry.count(key)) {
+		auto p = std::make_shared<T>(std::forward<Args>(args)...);
+		m_objectRegistry[key] = p;
+		return true;
+	}
+	return false;
+}
+
+template<typename T>
+bool IPluginContentWidgetContext::registerObject(std::shared_ptr<T> object)
+{
+	return m_objectRegistry.emplace(std::type_index(typeid(T)), object).second;
+}
+
+template<typename T>
+std::shared_ptr<T> IPluginContentWidgetContext::getObject() const
+{
+	auto it = m_objectRegistry.find(typeid(T));
+	if (it == m_objectRegistry.end()) {
+		return {};
+	}
+	return std::static_pointer_cast<T>(it->second);
+}
+
+
 #endif // IPLUGINCONTENTWIDGETCONTEXT_H