ladybird/Libraries/LibCore/CObject.h
Andreas Kling 10c35d345a LibCore: Add comment about child events for partially-constructed children.
Since ChildAdded events originate from the CObject constructor, they are not
fully constructed when their parent learns that they were added.
Added a little comment about this to the child_event() declaration.
2019-07-27 09:31:46 +02:00

113 lines
2.9 KiB
C++

#pragma once
#include <AK/AKString.h>
#include <AK/Function.h>
#include <AK/StdLibExtras.h>
#include <AK/Vector.h>
#include <AK/Weakable.h>
class CEvent;
class CChildEvent;
class CCustomEvent;
class CTimerEvent;
#define C_OBJECT(klass) \
public: \
virtual const char* class_name() const override { return #klass; }
class CObject : public Weakable<CObject> {
// NOTE: No C_OBJECT macro for CObject itself.
public:
virtual ~CObject();
virtual const char* class_name() const = 0;
virtual void event(CEvent&);
const String& name() const { return m_name; }
void set_name(const StringView& name) { m_name = name; }
Vector<CObject*>& children() { return m_children; }
const Vector<CObject*>& children() const { return m_children; }
template<typename Callback>
void for_each_child(Callback callback)
{
for (auto* child : m_children) {
if (callback(*child) == IterationDecision::Break)
return;
}
}
template<typename T, typename Callback>
void for_each_child_of_type(Callback callback);
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&)>);
bool is_widget() const { return m_widget; }
virtual bool is_window() const { return false; }
protected:
CObject(CObject* parent = nullptr, bool is_widget = false);
virtual void timer_event(CTimerEvent&);
virtual void custom_event(CCustomEvent&);
// NOTE: You may get child events for children that are not yet fully constructed!
virtual void child_event(CChildEvent&);
private:
CObject* m_parent { nullptr };
String m_name;
int m_timer_id { 0 };
bool m_widget { false };
Vector<CObject*> m_children;
};
template<typename T>
inline bool is(const CObject&) { return false; }
template<>
inline bool is<CObject>(const CObject&) { return true; }
template<typename T>
inline T& to(CObject& object)
{
ASSERT(is<typename RemoveConst<T>::Type>(object));
return static_cast<T&>(object);
}
template<typename T>
inline const T& to(const CObject& object)
{
ASSERT(is<typename RemoveConst<T>::Type>(object));
return static_cast<const T&>(object);
}
template<typename T, typename Callback>
inline void CObject::for_each_child_of_type(Callback callback)
{
for_each_child([&](auto& child) {
if (is<T>(child))
return callback(to<T>(child));
return IterationDecision::Continue;
});
}
inline const LogStream& operator<<(const LogStream& stream, const CObject& object)
{
return stream << object.class_name() << '{' << &object << '}';
}