LibCore: Move LibGUI/GObject to LibCore/CObject.

LibCore/CObject.h

@@ -0,0 +1,49 @@
+#pragma once
+
+#include <AK/Function.h>
+#include <AK/Vector.h>
+#include <AK/Weakable.h>
+
+class CEvent;
+class CChildEvent;
+class CTimerEvent;
+
+class CObject : public Weakable<CObject> {
+public:
+    CObject(CObject* parent = nullptr);
+    virtual ~CObject();
+
+    virtual const char* class_name() const { return "CObject"; }
+
+    virtual void event(CEvent&);
+
+    Vector<CObject*>& children() { return m_children; }
+
+    CObject* parent() { return m_parent; }
+    const CObject* parent() const { return m_parent; }
+
+    void start_timer(int ms);
+    void stop_timer();
+    bool has_timer() const { return m_timer_id; }
+
+    void add_child(CObject&);
+    void remove_child(CObject&);
+
+    void delete_later();
+
+    void dump_tree(int indent = 0);
+
+    void deferred_invoke(Function<void(CObject&)>);
+
+    virtual bool is_widget() const { return false; }
+    virtual bool is_window() const { return false; }
+
+protected:
+    virtual void timer_event(CTimerEvent&);
+    virtual void child_event(CChildEvent&);
+
+private:
+    CObject* m_parent { nullptr };
+    int m_timer_id { 0 };
+    Vector<CObject*> m_children;
+};