--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Scene2D/PanSceneTracker.cpp	Fri Apr 26 17:05:14 2019 +0200
@@ -0,0 +1,46 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2019 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/>.
+ **/
+
+
+#include "PanSceneTracker.h"
+
+namespace OrthancStone
+{
+  PanSceneTracker::PanSceneTracker(Scene2D& scene,
+                                   const PointerEvent& event) :
+    scene_(scene),
+    originalSceneToCanvas_(scene_.GetSceneToCanvasTransform()),
+    originalCanvasToScene_(scene_.GetCanvasToSceneTransform())
+  {
+    pivot_ = event.GetMainPosition().Apply(originalCanvasToScene_);
+  }
+
+
+  void PanSceneTracker::Update(const PointerEvent& event)
+  {
+    ScenePoint2D p = event.GetMainPosition().Apply(originalCanvasToScene_);
+      
+    scene_.SetSceneToCanvasTransform(
+      AffineTransform2D::Combine(
+        originalSceneToCanvas_,
+        AffineTransform2D::CreateOffset(p.GetX() - pivot_.GetX(),
+                                        p.GetY() - pivot_.GetY())));
+  }
+}