--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancStone/Sources/Scene2D/MagnifyingGlassTracker.cpp	Mon Oct 31 22:19:57 2022 +0100
@@ -0,0 +1,94 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2022 Osimis S.A., Belgium
+ * Copyright (C) 2021-2022 Sebastien Jodogne, ICTEAM UCLouvain, Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program. If not, see
+ * <http://www.gnu.org/licenses/>.
+ **/
+
+
+#include "MagnifyingGlassTracker.h"
+
+#include "../Scene2DViewport/ViewportController.h"
+#include "../Viewport/ViewportLocker.h"
+
+namespace OrthancStone
+{
+  void MagnifyingGlassTracker::Update(ViewportLocker& locker,
+                                      const PointerEvent& event)
+  {
+    ScenePoint2D p = event.GetMainPosition().Apply(originalCanvasToScene_);
+
+    locker.GetController().SetSceneToCanvasTransform(
+      AffineTransform2D::Combine(
+        originalSceneToCanvas_,
+        AffineTransform2D::CreateOffset(p.GetX(), p.GetY()),
+        AffineTransform2D::CreateScaling(5, 5),
+        AffineTransform2D::CreateOffset(-pivot_.GetX(), -pivot_.GetY())));
+
+    locker.Invalidate();
+  }
+    
+
+  MagnifyingGlassTracker::MagnifyingGlassTracker(boost::weak_ptr<IViewport> viewport,
+                                                 const PointerEvent& event) :
+    viewport_(viewport)
+  {
+    ViewportLocker locker(viewport_);
+    
+    if (locker.IsValid())
+    {
+      originalSceneToCanvas_ = locker.GetController().GetSceneToCanvasTransform();
+      originalCanvasToScene_ = locker.GetController().GetCanvasToSceneTransform();
+      pivot_ = event.GetMainPosition().Apply(locker.GetController().GetCanvasToSceneTransform());
+
+      Update(locker, event);
+    }
+  }
+      
+
+  void MagnifyingGlassTracker::PointerUp(const PointerEvent& event,
+                                         const Scene2D& scene)
+  {
+    Cancel(scene);
+    OneGesturePointerTracker::PointerUp(event, scene);
+  }
+
+  
+  void MagnifyingGlassTracker::PointerMove(const PointerEvent& event,
+                                           const Scene2D& scene)
+  {
+    ViewportLocker locker(viewport_);
+    
+    if (locker.IsValid())
+    {
+      Update(locker, event);
+    }
+  }
+    
+
+  void MagnifyingGlassTracker::Cancel(const Scene2D& scene)
+  {
+    ViewportLocker locker(viewport_);
+    
+    if (locker.IsValid())
+    {
+      locker.GetController().SetSceneToCanvasTransform(originalSceneToCanvas_);
+      locker.Invalidate();
+    }
+  }
+}