helper-observer.cpp

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// SPDX-License-Identifier: GPL-2.0-or-later
 * Authors: see git history
 *
 * Copyright (C) 2018 Authors
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */
 
#include "helper-observer.h"
 
#include "object/sp-object.h"
 
namespace Inkscape {
namespace XML {
 
// Very simple observer that just emits a signal if anything happens to a node
SignalObserver::SignalObserver()
    : _oldsel(nullptr)
{}
 
SignalObserver::~SignalObserver()
{
    set(nullptr); // if _oldsel!=nullptr, remove observer and decrease refcount
}
 
// Add this observer to the SPObject and remove it from any previous object
void SignalObserver::set(SPObject* o)
{
  // XML Tree being used directly in this function in the following code
  //   while it shouldn't be
  // Pointer to object is stored, so refcounting should be increased/decreased
    if(_oldsel) {
        if (_oldsel->getRepr()) {
            _oldsel->getRepr()->removeObserver(*this);
        }
        sp_object_unref(_oldsel);
        _oldsel = nullptr;
    }
    if(o) {
        if (o->getRepr()) {
            o->getRepr()->addObserver(*this);
            sp_object_ref(o);
            _oldsel = o;
        }
    }
}
 
void SignalObserver::notifyChildAdded(XML::Node&, XML::Node&, XML::Node*)
{ signal_changed()(); }
 
void SignalObserver::notifyChildRemoved(XML::Node&, XML::Node&, XML::Node*)
{ signal_changed()(); }
 
void SignalObserver::notifyChildOrderChanged(XML::Node&, XML::Node&, XML::Node*, XML::Node*)
{ signal_changed()(); }
 
void SignalObserver::notifyContentChanged(XML::Node&, Util::ptr_shared, Util::ptr_shared)
{}
 
void SignalObserver::notifyAttributeChanged(XML::Node&, GQuark, Util::ptr_shared, Util::ptr_shared)
{ signal_changed()(); }
 
void SignalObserver::notifyElementNameChanged(Node&, GQuark, GQuark)
{
    signal_changed()();
}
 
sigc::signal<void ()>& SignalObserver::signal_changed()
{
    return _signal_changed;
}
 
} //namespace XML
} //namespace Inkscape