--- a/Applications/Samples/CMakeLists.txt	Tue Oct 16 08:59:23 2018 +0200
+++ b/Applications/Samples/CMakeLists.txt	Tue Oct 16 11:30:00 2018 +0200
@@ -123,12 +123,13 @@
 
 #BuildSingleFileSample(OrthancStoneEmpty EmptyApplication.h 1)
 #BuildSingleFileSample(OrthancStoneTestPattern TestPatternApplication.h 2)
-#BuildSingleFileSample(OrthancStoneSingleFrame SingleFrameApplication.h 3)
+BuildSingleFileSample(OrthancStoneSingleFrame SingleFrameApplication.h 3)
 #BuildSingleFileSample(OrthancStoneSingleVolume SingleVolumeApplication.h 4)
 #BuildSingleFileSample(OrthancStoneBasicPetCtFusion 5)
 #BuildSingleFileSample(OrthancStoneSynchronizedSeries 6)
 #BuildSingleFileSample(OrthancStoneLayoutPetCtFusion 7)
 BuildSingleFileSample(OrthancStoneSimpleViewerSingleFile SimpleViewerApplicationSingleFile.h 8)  # we keep that one just as a sample before we convert another sample to this pattern
+BuildSingleFileSample(OrthancStoneSingleFrameEditor SingleFrameEditorApplication.h 9)
 
 ##### SimpleViewer sample (Qt and WASM only) #######
 

--- a/Applications/Samples/SampleList.h	Tue Oct 16 08:59:23 2018 +0200
+++ b/Applications/Samples/SampleList.h	Tue Oct 16 11:30:00 2018 +0200
@@ -32,6 +32,10 @@
 #include "SimpleViewerApplicationSingleFile.h"
 typedef OrthancStone::Samples::SimpleViewerApplication SampleApplication;
 
+#elif ORTHANC_STONE_SAMPLE == 9
+#include "SingleFrameEditorApplication.h"
+typedef OrthancStone::Samples::SingleFrameEditorApplication SampleApplication;
+
 #else
 #error Please set the ORTHANC_STONE_SAMPLE macro
 #endif

--- a/Applications/Samples/SingleFrameApplication.h	Tue Oct 16 08:59:23 2018 +0200
+++ b/Applications/Samples/SingleFrameApplication.h	Tue Oct 16 11:30:00 2018 +0200
@@ -34,7 +34,7 @@
   {
     class SingleFrameApplication :
       public SampleApplicationBase,
-      private ILayerSource::IObserver
+      public IObserver
     {
     private:
       class Interactor : public IWorldSceneInteractor
@@ -51,6 +51,7 @@
         virtual IWorldSceneMouseTracker* CreateMouseTracker(WorldSceneWidget& widget,
                                                             const ViewportGeometry& view,
                                                             MouseButton button,
+                                                            KeyboardModifiers modifiers,
                                                             double x,
                                                             double y,
                                                             IStatusBar* statusBar)
@@ -148,7 +149,7 @@
           slice_ = index;
           
 #if 1
-          widget_->SetSlice(source_->GetSlice(slice_).GetGeometry());
+          mainWidget_->SetSlice(source_->GetSlice(slice_).GetGeometry());
 #else
           // TEST for scene extents - Rotate the axes
           double a = 15.0 / 180.0 * M_PI;
@@ -169,46 +170,29 @@
       }
         
       
-      virtual void NotifyGeometryReady(const ILayerSource& source)
+      void OnMainWidgetGeometryReady(const ILayerSource::GeometryReadyMessage& message)
       {
         // Once the geometry of the series is downloaded from Orthanc,
-        // display its first slice, and adapt the viewport to fit this
+        // display its middle slice, and adapt the viewport to fit this
         // slice
-        if (source_ == &source)
+        if (source_ == &message.origin_)
         {
           SetSlice(source_->GetSliceCount() / 2);
         }
 
-        widget_->SetDefaultView();
-      }
-      
-      virtual void NotifyGeometryError(const ILayerSource& source)
-      {
+        mainWidget_->SetDefaultView();
       }
       
-      virtual void NotifyContentChange(const ILayerSource& source)
-      {
-      }
+      LayerWidget*                          mainWidget_;   // ownership is transfered to the application context
+      std::unique_ptr<Interactor>           mainWidgetInteractor_;
+      std::unique_ptr<OrthancApiClient>     orthancApiClient_;
 
-      virtual void NotifySliceChange(const ILayerSource& source,
-                                     const Slice& slice)
-      {
-      }
- 
-      virtual void NotifyLayerReady(std::auto_ptr<ILayerRenderer>& layer,
-                                    const ILayerSource& source,
-                                    const CoordinateSystem3D& slice,
-                                    bool isError)
-      {
-      }
+      const OrthancFrameLayerSource*        source_;
+      unsigned int                          slice_;
 
-      LayerWidget*                    widget_;
-      const OrthancFrameLayerSource*  source_;
-      unsigned int                    slice_;
-      
     public:
-      SingleFrameApplication() : 
-        widget_(NULL),
+      SingleFrameApplication(MessageBroker& broker) :
+        IObserver(broker),
         source_(NULL),
         slice_(0)
       {
@@ -229,11 +213,14 @@
         options.add(generic);    
       }
 
-      virtual void Initialize(IStatusBar& statusBar,
+      virtual void Initialize(StoneApplicationContext* context,
+                              IStatusBar& statusBar,
                               const boost::program_options::variables_map& parameters)
       {
         using namespace OrthancStone;
 
+        context_ = context;
+
         statusBar.SetMessage("Use the key \"s\" to reinitialize the layout");
 
         if (parameters.count("instance") != 1)
@@ -245,17 +232,14 @@
         std::string instance = parameters["instance"].as<std::string>();
         int frame = parameters["frame"].as<unsigned int>();
 
-        std::auto_ptr<LayerWidget> widget(new LayerWidget);
+        orthancApiClient_.reset(new OrthancApiClient(IObserver::broker_, context_->GetWebService()));
+        mainWidget_ = new LayerWidget(broker_, "main-widget");
 
-#if 1
-        std::auto_ptr<OrthancFrameLayerSource> layer
-          (new OrthancFrameLayerSource(context_->GetWebService()));
-        //layer->SetImageQuality(SliceImageQuality_Jpeg50);
+        std::auto_ptr<OrthancFrameLayerSource> layer(new OrthancFrameLayerSource(broker_, *orthancApiClient_));
+        source_ = layer.get();
         layer->LoadFrame(instance, frame);
-        //layer->LoadSeries("6f1b492a-e181e200-44e51840-ef8db55e-af529ab6");
-        layer->Register(*this);
-        source_ = layer.get();
-        widget->AddLayer(layer.release());
+        layer->RegisterObserverCallback(new Callable<SingleFrameApplication, ILayerSource::GeometryReadyMessage>(*this, &SingleFrameApplication::OnMainWidgetGeometryReady));
+        mainWidget_->AddLayer(layer.release());
 
         RenderStyle s;
 
@@ -264,53 +248,17 @@
           s.interpolation_ = ImageInterpolation_Bilinear;
         }
 
-        //s.drawGrid_ = true;
-        widget->SetLayerStyle(0, s);
-#else
-        // 0178023P**
-        // Extent of the CT layer: (-35.068 -20.368) => (34.932 49.632)
-        std::auto_ptr<OrthancFrameLayerSource> ct;
-        ct.reset(new OrthancFrameLayerSource(context_->GetWebService()));
-        //ct->LoadInstance("c804a1a2-142545c9-33b32fe2-3df4cec0-a2bea6d6", 0);
-        //ct->LoadInstance("4bd4304f-47478948-71b24af2-51f4f1bc-275b6c1b", 0);  // BAD SLICE
-        //ct->SetImageQuality(SliceImageQuality_Jpeg50);
-        ct->LoadSeries("dd069910-4f090474-7d2bba07-e5c10783-f9e4fb1d");
-
-        ct->Register(*this);
-        widget->AddLayer(ct.release());
-
-        std::auto_ptr<OrthancFrameLayerSource> pet;
-        pet.reset(new OrthancFrameLayerSource(context_->GetWebService()));
-        //pet->LoadInstance("a1c4dc6b-255d27f0-88069875-8daed730-2f5ee5c6", 0);
-        pet->LoadSeries("aabad2e7-80702b5d-e599d26c-4f13398e-38d58a9e");
-        pet->Register(*this);
-        source_ = pet.get();
-        widget->AddLayer(pet.release());
+        mainWidget_->SetLayerStyle(0, s);
+        mainWidget_->SetTransmitMouseOver(true);
 
-        {
-          RenderStyle s;
-          //s.drawGrid_ = true;
-          s.alpha_ = 1;
-          widget->SetLayerStyle(0, s);
-        }
+        mainWidgetInteractor_.reset(new Interactor(*this));
+        mainWidget_->SetInteractor(*mainWidgetInteractor_);
+      }
 
-        {
-          RenderStyle s;
-          //s.drawGrid_ = true;
-          s.SetColor(255, 0, 0);  // Draw missing PET layer in red
-          s.alpha_ = 0.5;
-          s.applyLut_ = true;
-          s.lut_ = Orthanc::EmbeddedResources::COLORMAP_JET;
-          s.interpolation_ = ImageInterpolation_Bilinear;
-          widget->SetLayerStyle(1, s);
-        }
-#endif
+      virtual void Finalize() {}
+      virtual IWidget* GetCentralWidget() {return mainWidget_;}
+    };
 
-        widget_ = widget.get();
-        widget_->SetTransmitMouseOver(true);
-        widget_->SetInteractor(context_->AddInteractor(new Interactor(*this)));
-        context_->SetCentralWidget(widget.release());
-      }
-    };
+
   }
 }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Applications/Samples/SingleFrameEditorApplication.h	Tue Oct 16 11:30:00 2018 +0200
@@ -0,0 +1,241 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2018 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 "SampleApplicationBase.h"
+
+#include "../../Framework/Layers/OrthancFrameLayerSource.h"
+#include "../../Framework/Widgets/LayerWidget.h"
+
+#include <Core/Logging.h>
+
+namespace OrthancStone
+{
+  namespace Samples
+  {
+    class SingleFrameEditorApplication :
+        public SampleApplicationBase,
+        public IObserver
+    {
+      enum Tools
+      {
+        Tools_Crop,
+        Tools_Windowing,
+        Tools_Zoom,
+        Tools_Pan
+      };
+
+      enum Actions
+      {
+        Actions_Invert,
+        Actions_RotateLeft,
+        Actions_RotateRight
+      };
+
+    private:
+      class Interactor : public IWorldSceneInteractor
+      {
+      private:
+        SingleFrameEditorApplication&  application_;
+        
+      public:
+        Interactor(SingleFrameEditorApplication&  application) :
+          application_(application)
+        {
+        }
+        
+        virtual IWorldSceneMouseTracker* CreateMouseTracker(WorldSceneWidget& widget,
+                                                            const ViewportGeometry& view,
+                                                            MouseButton button,
+                                                            KeyboardModifiers modifiers,
+                                                            double x,
+                                                            double y,
+                                                            IStatusBar* statusBar)
+        {
+          switch (application_.currentTool_) {
+          case Tools_Crop:
+          case Tools_Windowing:
+          case Tools_Zoom:
+          case Tools_Pan:
+            // TODO return the right mouse tracker
+            return NULL;
+          }
+
+          return NULL;
+        }
+
+        virtual void MouseOver(CairoContext& context,
+                               WorldSceneWidget& widget,
+                               const ViewportGeometry& view,
+                               double x,
+                               double y,
+                               IStatusBar* statusBar)
+        {
+          if (statusBar != NULL)
+          {
+            Vector p = dynamic_cast<LayerWidget&>(widget).GetSlice().MapSliceToWorldCoordinates(x, y);
+            
+            char buf[64];
+            sprintf(buf, "X = %.02f Y = %.02f Z = %.02f (in cm)",
+                    p[0] / 10.0, p[1] / 10.0, p[2] / 10.0);
+            statusBar->SetMessage(buf);
+          }
+        }
+
+        virtual void MouseWheel(WorldSceneWidget& widget,
+                                MouseWheelDirection direction,
+                                KeyboardModifiers modifiers,
+                                IStatusBar* statusBar)
+        {
+        }
+
+        virtual void KeyPressed(WorldSceneWidget& widget,
+                                char key,
+                                KeyboardModifiers modifiers,
+                                IStatusBar* statusBar)
+        {
+          switch (key)
+          {
+          case 's':
+            widget.SetDefaultView();
+            break;
+          case 'p':
+            application_.currentTool_ = Tools_Pan;
+            break;
+          case 'z':
+            application_.currentTool_ = Tools_Zoom;
+            break;
+          case 'c':
+            application_.currentTool_ = Tools_Crop;
+            break;
+          case 'w':
+            application_.currentTool_ = Tools_Windowing;
+            break;
+          case 'i':
+            application_.Invert();
+            break;
+          case 'r':
+            if (modifiers == KeyboardModifiers_None)
+              application_.Rotate(90);
+            else
+              application_.Rotate(-90);
+            break;
+          case 'e':
+            application_.Export();
+            break;
+          default:
+            break;
+          }
+        }
+      };
+
+      void OnMainWidgetGeometryReady(const ILayerSource::GeometryReadyMessage& message)
+      {
+        mainWidget_->SetDefaultView();
+      }
+      
+      LayerWidget*                          mainWidget_;   // ownership is transfered to the application context
+      std::unique_ptr<Interactor>           mainWidgetInteractor_;
+      std::unique_ptr<OrthancApiClient>     orthancApiClient_;
+      Tools                                 currentTool_;
+
+      const OrthancFrameLayerSource*        source_;
+      unsigned int                          slice_;
+
+    public:
+      SingleFrameEditorApplication(MessageBroker& broker) :
+        IObserver(broker),
+        currentTool_(Tools_Zoom),
+        source_(NULL),
+        slice_(0)
+      {
+      }
+      
+      virtual void DeclareStartupOptions(boost::program_options::options_description& options)
+      {
+        boost::program_options::options_description generic("Sample options");
+        generic.add_options()
+            ("instance", boost::program_options::value<std::string>(),
+             "Orthanc ID of the instance")
+            ("frame", boost::program_options::value<unsigned int>()->default_value(0),
+             "Number of the frame, for multi-frame DICOM instances")
+            ;
+
+        options.add(generic);
+      }
+
+      virtual void Initialize(StoneApplicationContext* context,
+                              IStatusBar& statusBar,
+                              const boost::program_options::variables_map& parameters)
+      {
+        using namespace OrthancStone;
+
+        context_ = context;
+
+        statusBar.SetMessage("Use the key \"s\" to reinitialize the layout, \"p\" to pan, \"z\" to zoom, \"c\" to crop, \"i\" to invert, \"w\" to change windowing, \"r\" to rotate cw,  \"shift+r\" to rotate ccw");
+
+        if (parameters.count("instance") != 1)
+        {
+          LOG(ERROR) << "The instance ID is missing";
+          throw Orthanc::OrthancException(Orthanc::ErrorCode_ParameterOutOfRange);
+        }
+
+        std::string instance = parameters["instance"].as<std::string>();
+        int frame = parameters["frame"].as<unsigned int>();
+
+        orthancApiClient_.reset(new OrthancApiClient(IObserver::broker_, context_->GetWebService()));
+        mainWidget_ = new LayerWidget(broker_, "main-widget");
+
+        std::auto_ptr<OrthancFrameLayerSource> layer(new OrthancFrameLayerSource(broker_, *orthancApiClient_));
+        source_ = layer.get();
+        layer->LoadFrame(instance, frame);
+        layer->RegisterObserverCallback(new Callable<SingleFrameEditorApplication, ILayerSource::GeometryReadyMessage>(*this, &SingleFrameEditorApplication::OnMainWidgetGeometryReady));
+        mainWidget_->AddLayer(layer.release());
+
+        mainWidget_->SetTransmitMouseOver(true);
+
+        mainWidgetInteractor_.reset(new Interactor(*this));
+        mainWidget_->SetInteractor(*mainWidgetInteractor_);
+      }
+
+      virtual void Finalize() {}
+      virtual IWidget* GetCentralWidget() {return mainWidget_;}
+
+      void Invert()
+      {
+        // TODO
+      }
+
+      void Rotate(int degrees)
+      {
+        // TODO
+      }
+
+      void Export()
+      {
+        // TODO: export dicom file to a temporary file
+      }
+    };
+
+
+  }
+}