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/*
* Copyright 2002 - 2016, The libsigc++ Development Team
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <sigc++/trackable.h>
namespace sigc
{
trackable::trackable() noexcept : callback_list_(nullptr) {}
/* Don't copy the notification list.
The objects watching src don't need to be notified when the new object dies. */
trackable::trackable(const trackable& /*src*/) noexcept : callback_list_(nullptr) {}
// Don't move the notification list.
// The objects watching src don't need to be notified when the new object dies.
// They need to be notified now, because src probably becomes useless.
//
// If trackable's move constructor is modified, check if Glib::Object's
// move constructor should be modified similarly.
trackable::trackable(trackable&& src) noexcept : callback_list_(nullptr)
{
src.notify_callbacks();
}
trackable&
trackable::operator=(const trackable& src)
{
if (this != &src)
notify_callbacks(); // Make sure that we have finished with existing stuff before replacing it.
return *this;
}
trackable&
trackable::operator=(trackable&& src) noexcept
{
if (this != &src)
{
notify_callbacks(); // Make sure that we have finished with existing stuff before replacing it.
src.notify_callbacks(); // src probably becomes useless.
}
return *this;
}
trackable::~trackable()
{
notify_callbacks();
}
void
trackable::add_destroy_notify_callback(notifiable* data, func_destroy_notify func) const
{
callback_list()->add_callback(data, func);
}
void
trackable::remove_destroy_notify_callback(notifiable* data) const
{
callback_list()->remove_callback(data);
}
void
trackable::notify_callbacks()
{
delete callback_list_; // This invokes all of the callbacks.
callback_list_ = nullptr;
}
internal::trackable_callback_list*
trackable::callback_list() const
{
if (!callback_list_)
callback_list_ = new internal::trackable_callback_list;
return callback_list_;
}
namespace internal
{
trackable_callback_list::~trackable_callback_list()
{
clearing_ = true;
for (auto& callback : callbacks_)
{
if (callback.func_)
callback.func_(callback.data_);
}
}
void
trackable_callback_list::add_callback(notifiable* data, func_destroy_notify func)
{
// TODO: Is it okay to silently ignore attempts to add dependencies when the list
// is being cleared?
// I'd consider this a serious application bug, since the app is likely to segfault.
// But then, how should we handle it? Throw an exception? Martin.
if (!clearing_)
callbacks_.emplace_back(trackable_callback(data, func));
}
void
trackable_callback_list::clear()
{
clearing_ = true;
for (auto& callback : callbacks_)
{
if (callback.func_)
callback.func_(callback.data_);
}
callbacks_.clear();
clearing_ = false;
}
void
trackable_callback_list::remove_callback(notifiable* data)
{
for (auto i = callbacks_.begin(); i != callbacks_.end(); ++i)
{
auto& callback = *i;
if (callback.data_ == data && callback.func_ != nullptr)
{
// Don't remove a list element while the list is being cleared.
// It could invalidate the iterator in ~trackable_callback_list() or clear().
// But it may be necessary to invalidate the callback. See bug 589202.
if (clearing_)
callback.func_ = nullptr;
else
callbacks_.erase(i);
return;
}
}
}
} /* namespace internal */
} /* namespace sigc */
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