--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancStone/Sources/Viewport/IViewport.h	Tue Jul 07 16:21:02 2020 +0200
@@ -0,0 +1,72 @@
+/**
+ * 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 "../Scene2D/ICompositor.h"
+#include "../Scene2DViewport/ViewportController.h"
+
+namespace OrthancStone
+{
+  /**
+   * Class that combines a Scene2D with a canvas where to draw the
+   * scene. A call to "Refresh()" will update the content of the
+   * canvas. A "IViewport" can possibly be accessed from several
+   * threads depending on the rendering back-end (e.g. in SDL or Qt):
+   * The "ILock" subclass implements the locking mechanism to modify
+   * the content of the scene. 
+   *
+   * NB: The lock must be a "recursive_mutex", as the viewport
+   * controller can lock it a second time (TODO - Why so?).
+   **/  
+  class IViewport : public boost::noncopyable
+  {
+  public:
+    class ILock : public boost::noncopyable
+    {
+    public:
+      virtual ~ILock()
+      {
+      }
+
+      virtual bool HasCompositor() const = 0;
+
+      /**
+      Do not store the result! Only access the compositor interface through
+      the lock.
+      */
+      virtual ICompositor& GetCompositor() = 0;
+
+      /**
+      Do not store the result! Only access the compositor interface through
+      the lock.
+      */
+      virtual ViewportController& GetController() = 0;
+
+      virtual void Invalidate() = 0;
+    };   
+    
+    virtual ~IViewport()
+    {
+    }
+
+    virtual ILock* Lock() = 0;
+  };
+}