ui: basic search view

- Added a basic SearchView (+ controller and qt implementation)
- SearchView can set the active element of other views by dispatching a message.
- SearchView adjusts its text when the active element is changed by other views.
- Added wrappers for Button and EditBox that allow the usage of simple callback functions.

src/lib/component/controller/SearchController.h

@@ -0,0 +1,31 @@
+#ifndef SEARCH_CONTROLLER_H
+#define SEARCH_CONTROLLER_H
+
+#include <string>
+
+#include "component/controller/Controller.h"
+#include "utility/messaging/MessageListener.h"
+#include "utility/messaging/type/MessageActivateToken.h"
+
+class GraphAccess;
+class SearchView;
+
+class SearchController
+	: public Controller
+	, public MessageListener<MessageActivateToken>
+{
+public:
+	SearchController(std::shared_ptr<GraphAccess> graphAccess);
+	~SearchController();
+
+	void search(const std::string& s);
+	//void autocomplete(const std::string& s);
+
+private:
+	virtual void handleMessage(MessageActivateToken* message);
+	SearchView* getView();
+
+	std::shared_ptr<GraphAccess> m_graphAccess;
+};
+
+#endif // SEARCH_CONTROLLER_H