--- a/Samples/WebAssembly/BasicMPR.cpp	Wed May 29 15:45:15 2019 +0200
+++ b/Samples/WebAssembly/BasicMPR.cpp	Wed May 29 16:48:56 2019 +0200
@@ -20,273 +20,21 @@
 
 
 
+#include "dev.h"
+
 #include <emscripten.h>
-#include <emscripten/fetch.h>
-#include <emscripten/html5.h>
 
 #include "../../Framework/Loaders/OrthancSeriesVolumeProgressiveLoader.h"
-#include "../../Framework/OpenGL/WebAssemblyOpenGLContext.h"
 #include "../../Framework/Oracle/SleepOracleCommand.h"
 #include "../../Framework/Oracle/WebAssemblyOracle.h"
 #include "../../Framework/Scene2D/GrayscaleStyleConfigurator.h"
-#include "../../Framework/Scene2D/OpenGLCompositor.h"
-#include "../../Framework/Scene2D/PanSceneTracker.h"
-#include "../../Framework/Scene2D/RotateSceneTracker.h"
-#include "../../Framework/Scene2D/ZoomSceneTracker.h"
-#include "../../Framework/Scene2DViewport/IFlexiblePointerTracker.h"
-#include "../../Framework/Scene2DViewport/ViewportController.h"
 #include "../../Framework/StoneInitialization.h"
 #include "../../Framework/Volumes/VolumeSceneLayerSource.h"
 
-#include <Core/OrthancException.h>
-#include <Core/Toolbox.h>
-
-
-static const unsigned int FONT_SIZE = 32;
-
 
 namespace OrthancStone
 {
-  class WebAssemblyViewport : public boost::noncopyable
-  {
-  private:
-    // the construction order is important because compositor_
-    // will hold a reference to the scene that belong to the 
-    // controller_ object
-    OpenGL::WebAssemblyOpenGLContext       context_;
-    boost::shared_ptr<ViewportController>  controller_;
-    OpenGLCompositor                       compositor_;
-
-    void SetupEvents(const std::string& canvas);
-
-  public:
-    WebAssemblyViewport(MessageBroker& broker,
-                        const std::string& canvas) :
-      context_(canvas),
-      controller_(new ViewportController(broker)),
-      compositor_(context_, *controller_->GetScene())
-    {
-      compositor_.SetFont(0, Orthanc::EmbeddedResources::UBUNTU_FONT, 
-                          FONT_SIZE, Orthanc::Encoding_Latin1);
-      SetupEvents(canvas);
-    }
-
-    Scene2D& GetScene()
-    {
-      return *controller_->GetScene();
-    }
-
-    const boost::shared_ptr<ViewportController>& GetController()
-    {
-      return controller_;
-    }
-
-    void UpdateSize()
-    {
-      context_.UpdateSize();
-      compositor_.UpdateSize();
-      Refresh();
-    }
-
-    void Refresh()
-    {
-      compositor_.Refresh();
-    }
-
-    void FitContent()
-    {
-      GetScene().FitContent(context_.GetCanvasWidth(), context_.GetCanvasHeight());
-    }
-
-    const std::string& GetCanvasIdentifier() const
-    {
-      return context_.GetCanvasIdentifier();
-    }
-
-    ScenePoint2D GetPixelCenterCoordinates(int x, int y) const
-    {
-      return compositor_.GetPixelCenterCoordinates(x, y);
-    }
-
-    unsigned int GetCanvasWidth() const
-    {
-      return context_.GetCanvasWidth();
-    }
-
-    unsigned int GetCanvasHeight() const
-    {
-      return context_.GetCanvasHeight();
-    }
-  };
-
-  class ActiveTracker : public boost::noncopyable
-  {
-  private:
-    boost::shared_ptr<IFlexiblePointerTracker> tracker_;
-    std::string                             canvasIdentifier_;
-    bool                                    insideCanvas_;
-    
-  public:
-    ActiveTracker(const boost::shared_ptr<IFlexiblePointerTracker>& tracker,
-                  const WebAssemblyViewport& viewport) :
-      tracker_(tracker),
-      canvasIdentifier_(viewport.GetCanvasIdentifier()),
-      insideCanvas_(true)
-    {
-      if (tracker_.get() == NULL)
-      {
-        throw Orthanc::OrthancException(Orthanc::ErrorCode_NullPointer);
-      }
-    }
-
-    bool IsAlive() const
-    {
-      return tracker_->IsAlive();
-    }
-
-    void PointerMove(const PointerEvent& event)
-    {
-      tracker_->PointerMove(event);
-    }
-
-    void PointerUp(const PointerEvent& event)
-    {
-      tracker_->PointerUp(event);
-    }
-  };
-}
-
-static OrthancStone::PointerEvent* ConvertMouseEvent(
-  const EmscriptenMouseEvent&        source,
-  OrthancStone::WebAssemblyViewport& viewport)
-{
-  std::auto_ptr<OrthancStone::PointerEvent> target(
-    new OrthancStone::PointerEvent);
-
-  target->AddPosition(viewport.GetPixelCenterCoordinates(
-    source.targetX, source.targetY));
-  target->SetAltModifier(source.altKey);
-  target->SetControlModifier(source.ctrlKey);
-  target->SetShiftModifier(source.shiftKey);
-
-  return target.release();
-}
-
-std::auto_ptr<OrthancStone::ActiveTracker> tracker_;
-
-EM_BOOL OnMouseEvent(int eventType, 
-                     const EmscriptenMouseEvent *mouseEvent, 
-                     void *userData)
-{
-  if (mouseEvent != NULL &&
-      userData != NULL)
-  {
-    OrthancStone::WebAssemblyViewport& viewport = 
-      *reinterpret_cast<OrthancStone::WebAssemblyViewport*>(userData);
-
-    switch (eventType)
-    {
-      case EMSCRIPTEN_EVENT_CLICK:
-      {
-        static unsigned int count = 0;
-        char buf[64];
-        sprintf(buf, "click %d", count++);
-
-        std::auto_ptr<OrthancStone::TextSceneLayer> layer(new OrthancStone::TextSceneLayer);
-        layer->SetText(buf);
-        viewport.GetScene().SetLayer(100, layer.release());
-        viewport.Refresh();
-        break;
-      }
-
-      case EMSCRIPTEN_EVENT_MOUSEDOWN:
-      {
-        boost::shared_ptr<OrthancStone::IFlexiblePointerTracker> t;
-
-        {
-          std::auto_ptr<OrthancStone::PointerEvent> event(
-            ConvertMouseEvent(*mouseEvent, viewport));
-
-          switch (mouseEvent->button)
-          {
-            case 0:  // Left button
-              emscripten_console_log("Creating RotateSceneTracker");
-              t.reset(new OrthancStone::RotateSceneTracker(
-                viewport.GetController(), *event));
-              break;
-
-            case 1:  // Middle button
-              emscripten_console_log("Creating PanSceneTracker");
-              LOG(INFO) << "Creating PanSceneTracker" ;
-              t.reset(new OrthancStone::PanSceneTracker(
-                viewport.GetController(), *event));
-              break;
-
-            case 2:  // Right button
-              emscripten_console_log("Creating ZoomSceneTracker");
-              t.reset(new OrthancStone::ZoomSceneTracker(
-                viewport.GetController(), *event, viewport.GetCanvasWidth()));
-              break;
-
-            default:
-              break;
-          }
-        }
-
-        if (t.get() != NULL)
-        {
-          tracker_.reset(
-            new OrthancStone::ActiveTracker(t, viewport));
-          viewport.Refresh();
-        }
-
-        break;
-      }
-
-      case EMSCRIPTEN_EVENT_MOUSEMOVE:
-        if (tracker_.get() != NULL)
-        {
-          std::auto_ptr<OrthancStone::PointerEvent> event(
-            ConvertMouseEvent(*mouseEvent, viewport));
-          tracker_->PointerMove(*event);
-          viewport.Refresh();
-        }
-        break;
-
-      case EMSCRIPTEN_EVENT_MOUSEUP:
-        if (tracker_.get() != NULL)
-        {
-          std::auto_ptr<OrthancStone::PointerEvent> event(
-            ConvertMouseEvent(*mouseEvent, viewport));
-          tracker_->PointerUp(*event);
-          viewport.Refresh();
-          if (!tracker_->IsAlive())
-            tracker_.reset();
-        }
-        break;
-
-      default:
-        break;
-    }
-  }
-
-  return true;
-}
-
-
-void OrthancStone::WebAssemblyViewport::SetupEvents(const std::string& canvas)
-{
-  emscripten_set_mousedown_callback(canvas.c_str(), this, false, OnMouseEvent);
-  emscripten_set_mousemove_callback(canvas.c_str(), this, false, OnMouseEvent);
-  emscripten_set_mouseup_callback(canvas.c_str(), this, false, OnMouseEvent);
-}
-
-
-
-
-namespace OrthancStone
-{
-  class VolumeSlicerViewport : public IObserver
+  class VolumeSlicerWidget : public IObserver
   {
   private:
     OrthancStone::WebAssemblyViewport      viewport_;
@@ -317,7 +65,7 @@
     }
     
   public:
-    VolumeSlicerViewport(MessageBroker& broker,
+    VolumeSlicerWidget(MessageBroker& broker,
                          const std::string& canvas,
                          VolumeProjection projection) :
       IObserver(broker),
@@ -344,8 +92,8 @@
       }
       
       loader.RegisterObserverCallback(
-        new Callable<VolumeSlicerViewport, DicomVolumeImage::GeometryReadyMessage>
-        (*this, &VolumeSlicerViewport::Handle));
+        new Callable<VolumeSlicerWidget, DicomVolumeImage::GeometryReadyMessage>
+        (*this, &VolumeSlicerWidget::Handle));
 
       source_.reset(new VolumeSceneLayerSource(viewport_.GetScene(), layerDepth, slicer));
 
@@ -365,6 +113,11 @@
       }
     }
 
+    size_t GetSlicesCount() const
+    {
+      return planes_.size();
+    }
+
     void Scroll(int delta)
     {
       if (!planes_.empty())
@@ -402,9 +155,9 @@
 
 boost::shared_ptr<OrthancStone::OrthancSeriesVolumeProgressiveLoader>  loader_;
 
-std::auto_ptr<OrthancStone::VolumeSlicerViewport>  viewport1_;
-std::auto_ptr<OrthancStone::VolumeSlicerViewport>  viewport2_;
-std::auto_ptr<OrthancStone::VolumeSlicerViewport>  viewport3_;
+std::auto_ptr<OrthancStone::VolumeSlicerWidget>  widget1_;
+std::auto_ptr<OrthancStone::VolumeSlicerWidget>  widget2_;
+std::auto_ptr<OrthancStone::VolumeSlicerWidget>  widget3_;
 
 OrthancStone::MessageBroker  broker_;
 OrthancStone::WebAssemblyOracle  oracle_(broker_);
@@ -414,19 +167,19 @@
 {
   try
   {
-    if (viewport1_.get() != NULL)
+    if (widget1_.get() != NULL)
     {
-      viewport1_->UpdateSize();
+      widget1_->UpdateSize();
     }
   
-    if (viewport2_.get() != NULL)
+    if (widget2_.get() != NULL)
     {
-      viewport2_->UpdateSize();
+      widget2_->UpdateSize();
     }
   
-    if (viewport3_.get() != NULL)
+    if (widget3_.get() != NULL)
     {
-      viewport3_->UpdateSize();
+      widget3_->UpdateSize();
     }
   }
   catch (Orthanc::OrthancException& e)
@@ -444,19 +197,19 @@
 {
   try
   {
-    if (viewport1_.get() != NULL)
+    if (widget1_.get() != NULL)
     {
-      viewport1_->Refresh();
+      widget1_->Refresh();
     }
   
-    if (viewport2_.get() != NULL)
+    if (widget2_.get() != NULL)
     {
-      viewport2_->Refresh();
+      widget2_->Refresh();
     }
   
-    if (viewport3_.get() != NULL)
+    if (widget3_.get() != NULL)
     {
-      viewport3_->Refresh();
+      widget3_->Refresh();
     }
 
     return true;
@@ -492,12 +245,15 @@
         delta = 1;
       }
 
+      OrthancStone::VolumeSlicerWidget& widget =
+        *reinterpret_cast<OrthancStone::VolumeSlicerWidget*>(userData);
+      
       if (ctrlDown_)
       {
-        delta *= 10;
+        delta *= static_cast<int>(widget.GetSlicesCount() / 10);
       }
-           
-      reinterpret_cast<OrthancStone::VolumeSlicerViewport*>(userData)->Scroll(delta);
+
+      widget.Scroll(delta);
     }
   }
   catch (Orthanc::OrthancException& e)
@@ -509,15 +265,24 @@
 }
 
 
-EM_BOOL OnKey(int eventType,
-              const EmscriptenKeyboardEvent *keyEvent,
-              void *userData)
+EM_BOOL OnKeyDown(int eventType,
+                  const EmscriptenKeyboardEvent *keyEvent,
+                  void *userData)
 {
   ctrlDown_ = keyEvent->ctrlKey;
   return false;
 }
 
 
+EM_BOOL OnKeyUp(int eventType,
+                const EmscriptenKeyboardEvent *keyEvent,
+                void *userData)
+{
+  ctrlDown_ = false;
+  return false;
+}
+
+
 
 
 namespace OrthancStone
@@ -574,26 +339,26 @@
     {
       loader_.reset(new OrthancStone::OrthancSeriesVolumeProgressiveLoader(ct_, oracle_, oracle_));
     
-      viewport1_.reset(new OrthancStone::VolumeSlicerViewport(broker_, "mycanvas1", OrthancStone::VolumeProjection_Axial));
-      viewport1_->SetSlicer(0, loader_, *loader_, new OrthancStone::GrayscaleStyleConfigurator);
-      viewport1_->UpdateSize();
+      widget1_.reset(new OrthancStone::VolumeSlicerWidget(broker_, "mycanvas1", OrthancStone::VolumeProjection_Axial));
+      widget1_->SetSlicer(0, loader_, *loader_, new OrthancStone::GrayscaleStyleConfigurator);
+      widget1_->UpdateSize();
 
-      viewport2_.reset(new OrthancStone::VolumeSlicerViewport(broker_, "mycanvas2", OrthancStone::VolumeProjection_Coronal));
-      viewport2_->SetSlicer(0, loader_, *loader_, new OrthancStone::GrayscaleStyleConfigurator);
-      viewport2_->UpdateSize();
+      widget2_.reset(new OrthancStone::VolumeSlicerWidget(broker_, "mycanvas2", OrthancStone::VolumeProjection_Coronal));
+      widget2_->SetSlicer(0, loader_, *loader_, new OrthancStone::GrayscaleStyleConfigurator);
+      widget2_->UpdateSize();
 
-      viewport3_.reset(new OrthancStone::VolumeSlicerViewport(broker_, "mycanvas3", OrthancStone::VolumeProjection_Sagittal));
-      viewport3_->SetSlicer(0, loader_, *loader_, new OrthancStone::GrayscaleStyleConfigurator);
-      viewport3_->UpdateSize();
+      widget3_.reset(new OrthancStone::VolumeSlicerWidget(broker_, "mycanvas3", OrthancStone::VolumeProjection_Sagittal));
+      widget3_->SetSlicer(0, loader_, *loader_, new OrthancStone::GrayscaleStyleConfigurator);
+      widget3_->UpdateSize();
 
       emscripten_set_resize_callback("#window", NULL, false, OnWindowResize);
 
-      emscripten_set_wheel_callback("mycanvas1", viewport1_.get(), false, OnMouseWheel);
-      emscripten_set_wheel_callback("mycanvas2", viewport2_.get(), false, OnMouseWheel);
-      emscripten_set_wheel_callback("mycanvas3", viewport3_.get(), false, OnMouseWheel);
+      emscripten_set_wheel_callback("mycanvas1", widget1_.get(), false, OnMouseWheel);
+      emscripten_set_wheel_callback("mycanvas2", widget2_.get(), false, OnMouseWheel);
+      emscripten_set_wheel_callback("mycanvas3", widget3_.get(), false, OnMouseWheel);
 
-      emscripten_set_keydown_callback("#window", NULL, false, OnKey);
-      emscripten_set_keyup_callback("#window", NULL, false, OnKey);
+      emscripten_set_keydown_callback("#window", NULL, false, OnKeyDown);
+      emscripten_set_keyup_callback("#window", NULL, false, OnKeyUp);
     
       emscripten_request_animation_frame_loop(OnAnimationFrame, NULL);
 

--- a/Samples/WebAssembly/BasicScene.cpp	Wed May 29 15:45:15 2019 +0200
+++ b/Samples/WebAssembly/BasicScene.cpp	Wed May 29 16:48:56 2019 +0200
@@ -19,38 +19,21 @@
  **/
 
 
+#include "dev.h"
 
 #include <emscripten.h>
 #include <emscripten/html5.h>
 
 // From Stone
-#include "../../Applications/Sdl/SdlOpenGLWindow.h"
-#include "../../Framework/Scene2D/CairoCompositor.h"
 #include "../../Framework/Scene2D/ColorTextureSceneLayer.h"
-#include "../../Framework/Scene2D/OpenGLCompositor.h"
-#include "../../Framework/Scene2D/PanSceneTracker.h"
-#include "../../Framework/Scene2D/RotateSceneTracker.h"
-#include "../../Framework/Scene2D/Scene2D.h"
-#include "../../Framework/Scene2D/ZoomSceneTracker.h"
-#include "../../Framework/Scene2DViewport/ViewportController.h"
 #include "../../Framework/StoneInitialization.h"
-#include "../../Framework/OpenGL/WebAssemblyOpenGLContext.h"
 
 // From Orthanc framework
 #include <Core/Images/Image.h>
 #include <Core/Logging.h>
 #include <Core/OrthancException.h>
 
-#include <boost/make_shared.hpp>
-
-#include <stdio.h>
-
-static const unsigned int FONT_SIZE = 32;
-
-using boost::shared_ptr;
-using boost::make_shared;
-
-void PrepareScene(OrthancStone::Scene2DPtr scene)
+void PrepareScene(OrthancStone::Scene2D& scene)
 {
   using namespace OrthancStone;
 
@@ -77,13 +60,13 @@
     p[4] = 0;
     p[5] = 0;
 
-    scene->SetLayer(12, new ColorTextureSceneLayer(i));
+    scene.SetLayer(12, new ColorTextureSceneLayer(i));
 
     std::auto_ptr<ColorTextureSceneLayer> l(new ColorTextureSceneLayer(i));
     l->SetOrigin(-3, 2);
     l->SetPixelSpacing(1.5, 1);
     l->SetAngle(20.0 / 180.0 * M_PI);
-    scene->SetLayer(14, l.release());
+    scene.SetLayer(14, l.release());
   }
 
   // Texture of 1x1 size
@@ -99,7 +82,7 @@
     std::auto_ptr<ColorTextureSceneLayer> l(new ColorTextureSceneLayer(i));
     l->SetOrigin(-2, 1);
     l->SetAngle(20.0 / 180.0 * M_PI);
-    scene->SetLayer(13, l.release());
+    scene.SetLayer(13, l.release());
   }
 
   // Some lines
@@ -130,7 +113,7 @@
     chain.push_back(ScenePoint2D(4, 2));
     layer->AddChain(chain, false, 0, 0, 255);
 
-    scene->SetLayer(50, layer.release());
+    scene.SetLayer(50, layer.release());
   }
 
   // Some text
@@ -138,243 +121,10 @@
   {
     std::auto_ptr<TextSceneLayer> layer(new TextSceneLayer);
     layer->SetText("Hello");
-    scene->SetLayer(100, layer.release());
+    scene.SetLayer(100, layer.release());
   }
 }
 
-namespace OrthancStone
-{
-  class WebAssemblyViewport : public boost::noncopyable
-  {
-  private:
-    // the construction order is important because compositor_
-    // will hold a reference to the scene that belong to the 
-    // controller_ object
-    OpenGL::WebAssemblyOpenGLContext  context_;
-    ViewportControllerPtr             controller_;
-    OpenGLCompositor                  compositor_;
-
-    void SetupEvents(const std::string& canvas);
-
-  public:
-    WebAssemblyViewport(MessageBroker& broker, const std::string& canvas) :
-      context_(canvas),
-      controller_(make_shared<ViewportController>(broker)),
-      compositor_(context_, *controller_->GetScene())
-    {
-      compositor_.SetFont(0, Orthanc::EmbeddedResources::UBUNTU_FONT, 
-                          FONT_SIZE, Orthanc::Encoding_Latin1);
-      SetupEvents(canvas);
-    }
-
-    Scene2DPtr GetScene()
-    {
-      return controller_->GetScene();
-    }
-
-    ViewportControllerPtr GetController()
-    {
-      return controller_;
-    }
-
-    void UpdateSize()
-    {
-      context_.UpdateSize();
-      compositor_.UpdateSize();
-      Refresh();
-    }
-
-    void Refresh()
-    {
-      compositor_.Refresh();
-    }
-
-    const std::string& GetCanvasIdentifier() const
-    {
-      return context_.GetCanvasIdentifier();
-    }
-
-    ScenePoint2D GetPixelCenterCoordinates(int x, int y) const
-    {
-      return compositor_.GetPixelCenterCoordinates(x, y);
-    }
-
-    unsigned int GetCanvasWidth() const
-    {
-      return context_.GetCanvasWidth();
-    }
-
-    unsigned int GetCanvasHeight() const
-    {
-      return context_.GetCanvasHeight();
-    }
-  };
-
-  class ActiveTracker : public boost::noncopyable
-  {
-  private:
-    OrthancStone::FlexiblePointerTrackerPtr tracker_;
-    std::string                             canvasIdentifier_;
-    bool                                    insideCanvas_;
-    
-  public:
-    ActiveTracker(FlexiblePointerTrackerPtr tracker,
-                  const WebAssemblyViewport& viewport) :
-      tracker_(tracker),
-      canvasIdentifier_(viewport.GetCanvasIdentifier()),
-      insideCanvas_(true)
-    {
-      if (tracker_.get() == NULL)
-      {
-        throw Orthanc::OrthancException(Orthanc::ErrorCode_NullPointer);
-      }
-    }
-
-    bool IsAlive() const
-    {
-      return tracker_->IsAlive();
-    }
-
-    void PointerMove(const PointerEvent& event)
-    {
-      tracker_->PointerMove(event);
-    }
-
-    void PointerUp(const PointerEvent& event)
-    {
-      tracker_->PointerUp(event);
-    }
-  };
-}
-
-static OrthancStone::PointerEvent* ConvertMouseEvent(
-  const EmscriptenMouseEvent&        source,
-  OrthancStone::WebAssemblyViewport& viewport)
-{
-  std::auto_ptr<OrthancStone::PointerEvent> target(
-    new OrthancStone::PointerEvent);
-
-  target->AddPosition(viewport.GetPixelCenterCoordinates(
-    source.targetX, source.targetY));
-  target->SetAltModifier(source.altKey);
-  target->SetControlModifier(source.ctrlKey);
-  target->SetShiftModifier(source.shiftKey);
-
-  return target.release();
-}
-
-std::auto_ptr<OrthancStone::ActiveTracker> tracker_;
-
-EM_BOOL OnMouseEvent(int eventType, 
-                     const EmscriptenMouseEvent *mouseEvent, 
-                     void *userData)
-{
-  if (mouseEvent != NULL &&
-      userData != NULL)
-  {
-    OrthancStone::WebAssemblyViewport& viewport = 
-      *reinterpret_cast<OrthancStone::WebAssemblyViewport*>(userData);
-
-    switch (eventType)
-    {
-      case EMSCRIPTEN_EVENT_CLICK:
-      {
-        static unsigned int count = 0;
-        char buf[64];
-        sprintf(buf, "click %d", count++);
-
-        std::auto_ptr<OrthancStone::TextSceneLayer> layer(new OrthancStone::TextSceneLayer);
-        layer->SetText(buf);
-        viewport.GetScene()->SetLayer(100, layer.release());
-        viewport.Refresh();
-        break;
-      }
-
-      case EMSCRIPTEN_EVENT_MOUSEDOWN:
-      {
-        OrthancStone::FlexiblePointerTrackerPtr t;
-
-        {
-          std::auto_ptr<OrthancStone::PointerEvent> event(
-            ConvertMouseEvent(*mouseEvent, viewport));
-
-          switch (mouseEvent->button)
-          {
-            case 0:  // Left button
-              emscripten_console_log("Creating RotateSceneTracker");
-              t.reset(new OrthancStone::RotateSceneTracker(
-                viewport.GetController(), *event));
-              break;
-
-            case 1:  // Middle button
-              emscripten_console_log("Creating PanSceneTracker");
-              LOG(INFO) << "Creating PanSceneTracker" ;
-              t.reset(new OrthancStone::PanSceneTracker(
-                viewport.GetController(), *event));
-              break;
-
-            case 2:  // Right button
-              emscripten_console_log("Creating ZoomSceneTracker");
-              t.reset(new OrthancStone::ZoomSceneTracker(
-                viewport.GetController(), *event, viewport.GetCanvasWidth()));
-              break;
-
-            default:
-              break;
-          }
-        }
-
-        if (t.get() != NULL)
-        {
-          tracker_.reset(
-            new OrthancStone::ActiveTracker(t, viewport));
-          viewport.Refresh();
-        }
-
-        break;
-      }
-
-      case EMSCRIPTEN_EVENT_MOUSEMOVE:
-        if (tracker_.get() != NULL)
-        {
-          std::auto_ptr<OrthancStone::PointerEvent> event(
-            ConvertMouseEvent(*mouseEvent, viewport));
-          tracker_->PointerMove(*event);
-          viewport.Refresh();
-        }
-        break;
-
-      case EMSCRIPTEN_EVENT_MOUSEUP:
-        if (tracker_.get() != NULL)
-        {
-          std::auto_ptr<OrthancStone::PointerEvent> event(
-            ConvertMouseEvent(*mouseEvent, viewport));
-          tracker_->PointerUp(*event);
-          viewport.Refresh();
-          if (!tracker_->IsAlive())
-            tracker_.reset();
-        }
-        break;
-
-      default:
-        break;
-    }
-  }
-
-  return true;
-}
-
-
-void OrthancStone::WebAssemblyViewport::SetupEvents(const std::string& canvas)
-{
-#if 0
-  emscripten_set_click_callback(canvas.c_str(), this, false, OnMouseEvent);
-#else
-  emscripten_set_mousedown_callback(canvas.c_str(), this, false, OnMouseEvent);
-  emscripten_set_mousemove_callback(canvas.c_str(), this, false, OnMouseEvent);
-  emscripten_set_mouseup_callback(canvas.c_str(), this, false, OnMouseEvent);
-#endif
-}
 
 std::auto_ptr<OrthancStone::WebAssemblyViewport>  viewport1_;
 std::auto_ptr<OrthancStone::WebAssemblyViewport>  viewport2_;

--- a/Samples/WebAssembly/CMakeLists.txt	Wed May 29 15:45:15 2019 +0200
+++ b/Samples/WebAssembly/CMakeLists.txt	Wed May 29 16:48:56 2019 +0200
@@ -70,7 +70,7 @@
   )
 
 
-if (OFF)
+if (ON)
   add_executable(BasicScene
     BasicScene.cpp
     )

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Samples/WebAssembly/ConfigurationLocalSJO.json	Wed May 29 16:48:56 2019 +0200
@@ -0,0 +1,20 @@
+{
+  "Plugins": [
+    "/home/jodogne/Subversion/orthanc-webviewer/r/libOrthancWebViewer.so",
+    "/home/jodogne/Subversion/orthanc/r/libServeFolders.so"
+  ],
+  "StorageDirectory" : "/tmp/orthanc-db",
+  "IndexDirectory" : "/tmp/orthanc-db",
+  "RemoteAccessAllowed" : true,
+  "AuthenticationEnabled" : false,
+  "ServeFolders" : {
+    "AllowCache" : false,
+    "GenerateETag" : true,
+    "Folders" : {
+      "/stone" : "/tmp/stone"
+    }
+  },
+  "WebViewer" : {
+    "CachePath" : "/tmp/orthanc-db/WebViewerCache"
+  }
+}

--- a/Samples/WebAssembly/NOTES.txt	Wed May 29 15:45:15 2019 +0200
+++ b/Samples/WebAssembly/NOTES.txt	Wed May 29 16:48:56 2019 +0200
@@ -1,9 +1,19 @@
+Docker
+------
+
 $ source ~/Downloads/emsdk/emsdk_env.sh
 $ cmake -G Ninja -DCMAKE_TOOLCHAIN_FILE=${EMSCRIPTEN}/cmake/Modules/Platform/Emscripten.cmake -DCMAKE_BUILD_TYPE=Release -DALLOW_DOWNLOADS=ON .. -DCMAKE_INSTALL_PREFIX=/tmp/stone
 $ ninja install
-$ docker run -p 4242:4242 -p 8042:8042 --rm -v /tmp/stone:/root/stone:ro -v /tmp/stone-db/:/var/lib/orthanc/db/ jodogne/orthanc-plugins:1.5.6 /root/stone/Configuration.json --verbose
+$ docker run -p 4242:4242 -p 8042:8042 --rm -v /tmp/stone:/root/stone:ro -v /tmp/stone-db/:/var/lib/orthanc/db/ jodogne/orthanc-plugins:latest /root/stone/Configuration.json --verbose
+
+WARNING: This won't work using "orthanc-plugins:1.5.6", as support for
+PAM is mandatatory in "/instances/.../image-uint16".
 
-notes BGO :
+
+
+notes BGO
+---------
+
 source ~/apps/emsdk/emsdk_env.sh
 cd /mnt/c/osi/dev/orthanc-stone/Samples/WebAssembly
 mkdir build
@@ -12,3 +22,18 @@
 ninja install
 
 docker run -p 4242:4242 -p 8042:8042 --rm -v "C:/osi/dev/orthanc-stone/Samples/WebAssembly/installDir:/root/stone:ro" jodogne/orthanc-plugins:1.5.6 /root/stone/Configuration.json --verbose
+
+
+
+
+Local SJO
+---------
+
+$ source ~/Downloads/emsdk/emsdk_env.sh
+$ cmake -G Ninja -DCMAKE_TOOLCHAIN_FILE=${EMSCRIPTEN}/cmake/Modules/Platform/Emscripten.cmake -DCMAKE_BUILD_TYPE=Release -DALLOW_DOWNLOADS=ON .. -DCMAKE_INSTALL_PREFIX=/tmp/stone
+$ ninja install
+
+$ make -C ~/Subversion/orthanc/r -j4
+$ make -C ~/Subversion/orthanc-webviewer/r -j4
+$ ~/Subversion/orthanc/r/Orthanc ../ConfigurationLocalSJO.json
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Samples/WebAssembly/dev.h	Wed May 29 16:48:56 2019 +0200
@@ -0,0 +1,271 @@
+/**
+ * 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/>.
+ **/
+
+
+#pragma once
+
+#include "../../Framework/OpenGL/WebAssemblyOpenGLContext.h"
+#include "../../Framework/Scene2D/OpenGLCompositor.h"
+#include "../../Framework/Scene2D/PanSceneTracker.h"
+#include "../../Framework/Scene2D/RotateSceneTracker.h"
+#include "../../Framework/Scene2D/ZoomSceneTracker.h"
+#include "../../Framework/Scene2DViewport/ViewportController.h"
+
+#include <Core/OrthancException.h>
+
+#include <emscripten/html5.h>
+
+static const unsigned int FONT_SIZE = 32;
+
+namespace OrthancStone
+{
+  class WebAssemblyViewport : public boost::noncopyable
+  {
+  private:
+    // the construction order is important because compositor_
+    // will hold a reference to the scene that belong to the 
+    // controller_ object
+    OpenGL::WebAssemblyOpenGLContext       context_;
+    boost::shared_ptr<ViewportController>  controller_;
+    OpenGLCompositor                       compositor_;
+
+    void SetupEvents(const std::string& canvas);
+
+  public:
+    WebAssemblyViewport(MessageBroker& broker,
+                        const std::string& canvas) :
+      context_(canvas),
+      controller_(new ViewportController(broker)),
+      compositor_(context_, *controller_->GetScene())
+    {
+      compositor_.SetFont(0, Orthanc::EmbeddedResources::UBUNTU_FONT, 
+                          FONT_SIZE, Orthanc::Encoding_Latin1);
+      SetupEvents(canvas);
+    }
+
+    Scene2D& GetScene()
+    {
+      return *controller_->GetScene();
+    }
+
+    const boost::shared_ptr<ViewportController>& GetController()
+    {
+      return controller_;
+    }
+
+    void UpdateSize()
+    {
+      context_.UpdateSize();
+      compositor_.UpdateSize();
+      Refresh();
+    }
+
+    void Refresh()
+    {
+      compositor_.Refresh();
+    }
+
+    void FitContent()
+    {
+      GetScene().FitContent(context_.GetCanvasWidth(), context_.GetCanvasHeight());
+    }
+
+    const std::string& GetCanvasIdentifier() const
+    {
+      return context_.GetCanvasIdentifier();
+    }
+
+    ScenePoint2D GetPixelCenterCoordinates(int x, int y) const
+    {
+      return compositor_.GetPixelCenterCoordinates(x, y);
+    }
+
+    unsigned int GetCanvasWidth() const
+    {
+      return context_.GetCanvasWidth();
+    }
+
+    unsigned int GetCanvasHeight() const
+    {
+      return context_.GetCanvasHeight();
+    }
+  };
+
+  class ActiveTracker : public boost::noncopyable
+  {
+  private:
+    boost::shared_ptr<IFlexiblePointerTracker> tracker_;
+    std::string                             canvasIdentifier_;
+    bool                                    insideCanvas_;
+    
+  public:
+    ActiveTracker(const boost::shared_ptr<IFlexiblePointerTracker>& tracker,
+                  const WebAssemblyViewport& viewport) :
+      tracker_(tracker),
+      canvasIdentifier_(viewport.GetCanvasIdentifier()),
+      insideCanvas_(true)
+    {
+      if (tracker_.get() == NULL)
+      {
+        throw Orthanc::OrthancException(Orthanc::ErrorCode_NullPointer);
+      }
+    }
+
+    bool IsAlive() const
+    {
+      return tracker_->IsAlive();
+    }
+
+    void PointerMove(const PointerEvent& event)
+    {
+      tracker_->PointerMove(event);
+    }
+
+    void PointerUp(const PointerEvent& event)
+    {
+      tracker_->PointerUp(event);
+    }
+  };
+}
+
+static OrthancStone::PointerEvent* ConvertMouseEvent(
+  const EmscriptenMouseEvent&        source,
+  OrthancStone::WebAssemblyViewport& viewport)
+{
+  std::auto_ptr<OrthancStone::PointerEvent> target(
+    new OrthancStone::PointerEvent);
+
+  target->AddPosition(viewport.GetPixelCenterCoordinates(
+    source.targetX, source.targetY));
+  target->SetAltModifier(source.altKey);
+  target->SetControlModifier(source.ctrlKey);
+  target->SetShiftModifier(source.shiftKey);
+
+  return target.release();
+}
+
+std::auto_ptr<OrthancStone::ActiveTracker> tracker_;
+
+EM_BOOL OnMouseEvent(int eventType, 
+                     const EmscriptenMouseEvent *mouseEvent, 
+                     void *userData)
+{
+  if (mouseEvent != NULL &&
+      userData != NULL)
+  {
+    OrthancStone::WebAssemblyViewport& viewport = 
+      *reinterpret_cast<OrthancStone::WebAssemblyViewport*>(userData);
+
+    switch (eventType)
+    {
+      case EMSCRIPTEN_EVENT_CLICK:
+      {
+        static unsigned int count = 0;
+        char buf[64];
+        sprintf(buf, "click %d", count++);
+
+        std::auto_ptr<OrthancStone::TextSceneLayer> layer(new OrthancStone::TextSceneLayer);
+        layer->SetText(buf);
+        viewport.GetScene().SetLayer(100, layer.release());
+        viewport.Refresh();
+        break;
+      }
+
+      case EMSCRIPTEN_EVENT_MOUSEDOWN:
+      {
+        boost::shared_ptr<OrthancStone::IFlexiblePointerTracker> t;
+
+        {
+          std::auto_ptr<OrthancStone::PointerEvent> event(
+            ConvertMouseEvent(*mouseEvent, viewport));
+
+          switch (mouseEvent->button)
+          {
+            case 0:  // Left button
+              emscripten_console_log("Creating RotateSceneTracker");
+              t.reset(new OrthancStone::RotateSceneTracker(
+                viewport.GetController(), *event));
+              break;
+
+            case 1:  // Middle button
+              emscripten_console_log("Creating PanSceneTracker");
+              LOG(INFO) << "Creating PanSceneTracker" ;
+              t.reset(new OrthancStone::PanSceneTracker(
+                viewport.GetController(), *event));
+              break;
+
+            case 2:  // Right button
+              emscripten_console_log("Creating ZoomSceneTracker");
+              t.reset(new OrthancStone::ZoomSceneTracker(
+                viewport.GetController(), *event, viewport.GetCanvasWidth()));
+              break;
+
+            default:
+              break;
+          }
+        }
+
+        if (t.get() != NULL)
+        {
+          tracker_.reset(
+            new OrthancStone::ActiveTracker(t, viewport));
+          viewport.Refresh();
+        }
+
+        break;
+      }
+
+      case EMSCRIPTEN_EVENT_MOUSEMOVE:
+        if (tracker_.get() != NULL)
+        {
+          std::auto_ptr<OrthancStone::PointerEvent> event(
+            ConvertMouseEvent(*mouseEvent, viewport));
+          tracker_->PointerMove(*event);
+          viewport.Refresh();
+        }
+        break;
+
+      case EMSCRIPTEN_EVENT_MOUSEUP:
+        if (tracker_.get() != NULL)
+        {
+          std::auto_ptr<OrthancStone::PointerEvent> event(
+            ConvertMouseEvent(*mouseEvent, viewport));
+          tracker_->PointerUp(*event);
+          viewport.Refresh();
+          if (!tracker_->IsAlive())
+            tracker_.reset();
+        }
+        break;
+
+      default:
+        break;
+    }
+  }
+
+  return true;
+}
+
+
+void OrthancStone::WebAssemblyViewport::SetupEvents(const std::string& canvas)
+{
+  emscripten_set_mousedown_callback(canvas.c_str(), this, false, OnMouseEvent);
+  emscripten_set_mousemove_callback(canvas.c_str(), this, false, OnMouseEvent);
+  emscripten_set_mouseup_callback(canvas.c_str(), this, false, OnMouseEvent);
+}