use wxWindowIDRef to transparently implement auto-generated ids ref-counting (slightly modified patch 1835458)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@51035 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/windowid.h

@@ -0,0 +1,189 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        wx/windowid.h
+// Purpose:     wxWindowID class - a class for managing window ids
+// Author:      Brian Vanderburg II
+// Created:     2007-09-21
+// RCS-ID:      $Id$
+// Copyright:   (c) 2007 Brian Vanderburg II
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_WINDOWID_H_
+#define _WX_WINDOWID_H_
+
+// NB: do not include defs.h as we are included from it
+
+typedef int wxWindowID;
+
+// ----------------------------------------------------------------------------
+// wxWindowIDRef: reference counted id value
+// ----------------------------------------------------------------------------
+
+// A wxWindowIDRef object wraps an id value and marks it as (un)used as
+// necessary. All ids returned from wxWindow::NewControlId() should be assigned
+// to an instance of this class to ensure that the id is marked as being in
+// use.
+//
+// This class is always defined but it is trivial if wxUSE_AUTOID_MANAGEMENT is
+// off.
+class WXDLLIMPEXP_CORE wxWindowIDRef
+{
+public:
+    // default ctor
+    wxWindowIDRef()
+    {
+        m_id = wxID_NONE;
+    }
+
+    // ctor taking id values
+    wxWindowIDRef(int id)
+    {
+        Init(id);
+    }
+
+    wxWindowIDRef(long id)
+    {
+        Init(id);
+    }
+
+    wxWindowIDRef(const wxWindowIDRef& id)
+    {
+        Init(id.m_id);
+    }
+
+    // dtor
+    ~wxWindowIDRef()
+    {
+        Assign(wxID_NONE);
+    }
+
+    // assignment
+    wxWindowIDRef& operator=(int id)
+    {
+        Assign(id);
+        return *this;
+    }
+
+    wxWindowIDRef& operator=(long id)
+    {
+        Assign(id);
+        return *this;
+    }
+
+    wxWindowIDRef& operator=(const wxWindowIDRef& id)
+    {
+        Assign(id.m_id);
+        return *this;
+    }
+
+    // access to the stored id value
+    wxWindowID GetValue() const
+    {
+        return m_id;
+    }
+
+    operator wxWindowID() const
+    {
+        return m_id;
+    }
+
+private:
+#if wxUSE_AUTOID_MANAGEMENT
+    // common part of all ctors: call Assign() for our new id
+    void Init(wxWindowID id)
+    {
+        // m_id must be initialized before calling Assign()
+        m_id = wxID_NONE;
+        Assign(id);
+    }
+
+    // increase reference count of id, decrease the one of m_id
+    void Assign(wxWindowID id);
+#else // !wxUSE_AUTOID_MANAGEMENT
+    // trivial stubs for the functions above
+    void Init(wxWindowID id)
+    {
+        m_id = id;
+    }
+
+    void Assign(wxWindowID id)
+    {
+        m_id = id;
+    }
+#endif // wxUSE_AUTOID_MANAGEMENT/!wxUSE_AUTOID_MANAGEMENT
+
+
+    wxWindowID m_id;
+};
+
+// comparison operators
+inline bool operator==(const wxWindowIDRef& lhs, const wxWindowIDRef& rhs)
+{
+    return lhs.GetValue() == rhs.GetValue();
+}
+
+inline bool operator==(const wxWindowIDRef& lhs, int rhs)
+{
+    return lhs.GetValue() == rhs;
+}
+
+inline bool operator==(const wxWindowIDRef& lhs, long rhs)
+{
+    return lhs.GetValue() == rhs;
+}
+
+inline bool operator==(int lhs, const wxWindowIDRef& rhs)
+{
+    return rhs == lhs;
+}
+
+inline bool operator==(long lhs, const wxWindowIDRef& rhs)
+{
+    return rhs == lhs;
+}
+
+inline bool operator!=(const wxWindowIDRef& lhs, const wxWindowIDRef& rhs)
+{
+    return !(lhs == rhs);
+}
+
+inline bool operator!=(const wxWindowIDRef& lhs, int rhs)
+{
+    return !(lhs == rhs);
+}
+
+inline bool operator!=(const wxWindowIDRef& lhs, long rhs)
+{
+    return !(lhs == rhs);
+}
+
+inline bool operator!=(int lhs, const wxWindowIDRef& rhs)
+{
+    return !(lhs == rhs);
+}
+
+inline bool operator!=(long lhs, const wxWindowIDRef& rhs)
+{
+    return !(lhs == rhs);
+}
+
+// ----------------------------------------------------------------------------
+// wxIdManager
+// ----------------------------------------------------------------------------
+
+class WXDLLIMPEXP_CORE wxIdManager
+{
+public:
+    // This returns an id value and not an wxWindowIDRef.  The returned value
+    // should be assigned a.s.a.p to a wxWindowIDRef.  The IDs are marked as
+    // reserved so that another call to ReserveId before assigning the id to a
+    // wxWindowIDRef will not use the same ID
+    static wxWindowID ReserveId(int count = 1);
+
+    // This will release an unused reserved ID.  This should only be called
+    // if the ID returned by ReserveId was NOT assigned to a wxWindowIDRef
+    // for some purpose, maybe an early return from a function
+    static void UnreserveId(wxWindowID id, int count = 1);
+};
+
+#endif // _WX_WINDOWID_H_