ClickHouse/base/poco/Foundation/include/Poco/AbstractDelegate.h

100 lines
2.4 KiB
C++

//
// AbstractDelegate.h
//
// Library: Foundation
// Package: Events
// Module: AbstractDelegate
//
// Implementation of the AbstractDelegate template.
//
// Copyright (c) 2006-2011, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_AbstractDelegate_INCLUDED
#define Foundation_AbstractDelegate_INCLUDED
#include "Poco/Foundation.h"
namespace Poco
{
template <class TArgs>
class AbstractDelegate
/// Base class for Delegate and Expire.
{
public:
AbstractDelegate() { }
AbstractDelegate(const AbstractDelegate & /*del*/) { }
virtual ~AbstractDelegate() { }
virtual bool notify(const void * sender, TArgs & arguments) = 0;
/// Invokes the delegate's callback function.
/// Returns true if successful, or false if the delegate
/// has been disabled or has expired.
virtual bool equals(const AbstractDelegate & other) const = 0;
/// Compares the AbstractDelegate with the other one for equality.
virtual AbstractDelegate * clone() const = 0;
/// Returns a deep copy of the AbstractDelegate.
virtual void disable() = 0;
/// Disables the delegate, which is done prior to removal.
virtual const AbstractDelegate * unwrap() const
/// Returns the unwrapped delegate. Must be overridden by decorators
/// like Expire.
{
return this;
}
};
template <>
class AbstractDelegate<void>
/// Base class for Delegate and Expire.
{
public:
AbstractDelegate() { }
AbstractDelegate(const AbstractDelegate &) { }
virtual ~AbstractDelegate() { }
virtual bool notify(const void * sender) = 0;
/// Invokes the delegate's callback function.
/// Returns true if successful, or false if the delegate
/// has been disabled or has expired.
virtual bool equals(const AbstractDelegate & other) const = 0;
/// Compares the AbstractDelegate with the other one for equality.
virtual AbstractDelegate * clone() const = 0;
/// Returns a deep copy of the AbstractDelegate.
virtual void disable() = 0;
/// Disables the delegate, which is done prior to removal.
virtual const AbstractDelegate * unwrap() const
/// Returns the unwrapped delegate. Must be overridden by decorators
/// like Expire.
{
return this;
}
};
} // namespace Poco
#endif // Foundation_AbstractDelegate_INCLUDED