wxwidgets/include/wx/tracker.h
Vadim Zeitlin 4f4c5fcfdf Use nullptr instead of NULL in the code and documentation
This is a combination of running clang-tidy with modernize-use-nullptr
check for some ports (GTK, X11, OSX) and manual changes to the ports for
which it couldn't be used easily (MSW, DFB) and also manually updating
the docs.

Also replace NULL with null or nullptr in the comments as this is more
consistent with the use of nullptr in the code and makes it simpler to
grep for the remaining occurrences of NULL itself.

And also use null in the assert messages.

Only a few occurrences of "NULL" are still left in non-C files, mostly
corresponding to unclear comments or string output which it might not be
safe to change.
2022-10-18 01:25:25 +02:00

91 lines
2.5 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: wx/tracker.h
// Purpose: Support class for object lifetime tracking (wxWeakRef<T>)
// Author: Arne Steinarson
// Created: 28 Dec 07
// Copyright: (c) 2007 Arne Steinarson
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_TRACKER_H_
#define _WX_TRACKER_H_
#include "wx/defs.h"
class wxEventConnectionRef;
// This class represents an object tracker and is stored in a linked list
// in the tracked object. It is only used in one of its derived forms.
class WXDLLIMPEXP_BASE wxTrackerNode
{
public:
wxTrackerNode() : m_nxt(nullptr) { }
virtual ~wxTrackerNode() { }
virtual void OnObjectDestroy() = 0;
virtual wxEventConnectionRef *ToEventConnection() { return nullptr; }
private:
wxTrackerNode *m_nxt;
friend class wxTrackable; // For list access
friend class wxEvtHandler; // For list access
};
// Add-on base class for a trackable object.
class WXDLLIMPEXP_BASE wxTrackable
{
public:
void AddNode(wxTrackerNode *prn)
{
prn->m_nxt = m_first;
m_first = prn;
}
void RemoveNode(wxTrackerNode *prn)
{
for ( wxTrackerNode **pprn = &m_first; *pprn; pprn = &(*pprn)->m_nxt )
{
if ( *pprn == prn )
{
*pprn = prn->m_nxt;
return;
}
}
wxFAIL_MSG( "removing invalid tracker node" );
}
wxTrackerNode *GetFirst() const { return m_first; }
protected:
// this class is only supposed to be used as a base class but never be
// created nor destroyed directly so all ctors and dtor are protected
wxTrackable() : m_first(nullptr) { }
// copy ctor and assignment operator intentionally do not copy m_first: the
// objects which track the original trackable shouldn't track the new copy
wxTrackable(const wxTrackable& WXUNUSED(other)) : m_first(nullptr) { }
wxTrackable& operator=(const wxTrackable& WXUNUSED(other)) { return *this; }
// dtor is not virtual: this class is not supposed to be used
// polymorphically and adding a virtual table to it would add unwanted
// overhead
~wxTrackable()
{
// Notify all registered refs
while ( m_first )
{
wxTrackerNode * const first = m_first;
m_first = first->m_nxt;
first->OnObjectDestroy();
}
}
wxTrackerNode *m_first;
};
#endif // _WX_TRACKER_H_