--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancStone/Sources/Messages/IMessage.h	Tue Jul 07 16:21:02 2020 +0200
@@ -0,0 +1,161 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2020 Osimis S.A., Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Affero General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This program 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
+ * Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#pragma once
+
+#include <boost/lexical_cast.hpp>
+#include <boost/noncopyable.hpp>
+
+#include <string.h>
+
+namespace OrthancStone 
+{
+  class MessageIdentifier
+  {
+  private:
+    const char*  file_;
+    int          line_;
+
+    bool IsEqual(const MessageIdentifier& other) const
+    {
+      return (line_ == other.line_ &&
+              strcmp(file_, other.file_) == 0);
+    }
+
+  public:
+    MessageIdentifier(const char* file,
+                      int line) :
+      file_(file),
+      line_(line)
+    {
+    }
+
+    MessageIdentifier() :
+      file_(NULL),
+      line_(0)
+    {
+    }
+
+    std::string AsString() const
+    {
+      return std::string(file_) + ":" + boost::lexical_cast<std::string>(line_);
+    }
+
+    bool operator< (const MessageIdentifier& other) const
+    {
+      if (file_ == NULL)
+      {
+        return false;
+      }
+      else if (line_ != other.line_)
+      {
+        return line_ < other.line_;
+      }
+      else
+      {
+        return strcmp(file_, other.file_) < 0;
+      }
+    }
+
+    bool operator== (const MessageIdentifier& other) const
+    {
+      return IsEqual(other);
+    }
+
+    bool operator!= (const MessageIdentifier& other) const
+    {
+      return !IsEqual(other);
+    }
+  };
+
+    
+  /**
+   * Base messages that are exchanged between IObservable and
+   * IObserver. Messages are distinguished by the "__FILE__" and
+   * "__LINE__" macro, as in "Orthanc::SQLite::StatementId".
+   **/
+  class IMessage : public boost::noncopyable
+  {
+  public:
+    virtual ~IMessage()
+    {
+    }
+
+    virtual const MessageIdentifier& GetIdentifier() const = 0;
+  };
+
+
+  /**
+   * Simple message implementation when no payload is needed but the
+   * origin is required. Sample usage:
+   * typedef OriginMessage<OrthancSlicesLoader> SliceGeometryErrorMessage;
+   **/
+  template <typename TOrigin>
+  class OriginMessage : public IMessage
+  {
+  private:
+    const TOrigin&  origin_;
+
+  public:
+    OriginMessage(const TOrigin& origin) :
+      origin_(origin)
+    {
+    }
+
+    const TOrigin& GetOrigin() const
+    {
+      return origin_;
+    }
+  };
+}
+
+
+#define ORTHANC_STONE_MESSAGE(FILE, LINE)                               \
+  public:                                                               \
+  static const ::OrthancStone::MessageIdentifier& GetStaticIdentifier() \
+  {                                                                     \
+    static const ::OrthancStone::MessageIdentifier id(FILE, LINE);      \
+    return id;                                                          \
+  }                                                                     \
+                                                                        \
+  virtual const ::OrthancStone::MessageIdentifier& GetIdentifier() const \
+  {                                                                     \
+    return GetStaticIdentifier();                                       \
+  }
+
+
+#define ORTHANC_STONE_DEFINE_ORIGIN_MESSAGE(FILE, LINE, NAME, ORIGIN)   \
+  class NAME : public ::OrthancStone::OriginMessage<ORIGIN>             \
+  {                                                                     \
+    ORTHANC_STONE_MESSAGE(FILE, LINE);                                  \
+                                                                        \
+    NAME(const ORIGIN& origin) :                                        \
+      OriginMessage(origin)                                             \
+    {                                                                   \
+    }                                                                   \
+  };
+
+
+#define ORTHANC_STONE_DEFINE_EMPTY_MESSAGE(FILE, LINE, NAME)            \
+  class NAME : public ::OrthancStone::IMessage                          \
+  {                                                                     \
+    ORTHANC_STONE_MESSAGE(FILE, LINE);                                  \
+  };