--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Deprecated/Samples/Sdl/TrackerSampleApp.cpp	Wed Apr 29 20:50:53 2020 +0200
@@ -0,0 +1,733 @@
+/**
+ * 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/>.
+ **/
+
+#include "TrackerSampleApp.h"
+
+#include "../../Framework/OpenGL/SdlOpenGLContext.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/UndoStack.h"
+#include "../../Framework/Scene2DViewport/CreateAngleMeasureTracker.h"
+#include "../../Framework/Scene2DViewport/CreateLineMeasureTracker.h"
+#include "../../Framework/StoneInitialization.h"
+
+// From Orthanc framework
+#include <Core/Logging.h>
+#include <Core/OrthancException.h>
+#include <Core/Images/Image.h>
+#include <Core/Images/ImageProcessing.h>
+#include <Core/Images/PngWriter.h>
+
+#include <boost/ref.hpp>
+#include <boost/make_shared.hpp>
+#include <SDL.h>
+
+#include <stdio.h>
+
+namespace OrthancStone
+{
+  const char* MeasureToolToString(size_t i)
+  {
+    static const char* descs[] = {
+      "GuiTool_Rotate",
+      "GuiTool_Pan",
+      "GuiTool_Zoom",
+      "GuiTool_LineMeasure",
+      "GuiTool_CircleMeasure",
+      "GuiTool_AngleMeasure",
+      "GuiTool_EllipseMeasure",
+      "GuiTool_LAST"
+    };
+    if (i >= GuiTool_LAST)
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError, "Wrong tool index");
+    }
+    return descs[i];
+  }
+
+  void TrackerSampleApp::SelectNextTool()
+  {
+    currentTool_ = static_cast<GuiTool>(currentTool_ + 1);
+    if (currentTool_ == GuiTool_LAST)
+      currentTool_ = static_cast<GuiTool>(0);;
+    printf("Current tool is now: %s\n", MeasureToolToString(currentTool_));
+  }
+
+  void TrackerSampleApp::DisplayInfoText()
+  {
+    // do not try to use stuff too early!
+    std::stringstream msg;
+	
+	for (std::map<std::string, std::string>::const_iterator kv = infoTextMap_.begin();
+		kv != infoTextMap_.end(); ++kv)
+    {
+      msg << kv->first << " : " << kv->second << std::endl;
+    }
+	std::string msgS = msg.str();
+
+    TextSceneLayer* layerP = NULL;
+    if (controller_->GetScene().HasLayer(FIXED_INFOTEXT_LAYER_ZINDEX))
+    {
+      TextSceneLayer& layer = dynamic_cast<TextSceneLayer&>(
+        controller_->GetScene().GetLayer(FIXED_INFOTEXT_LAYER_ZINDEX));
+      layerP = &layer;
+    }
+    else
+    {
+      std::unique_ptr<TextSceneLayer> layer(new TextSceneLayer);
+      layerP = layer.get();
+      layer->SetColor(0, 255, 0);
+      layer->SetFontIndex(1);
+      layer->SetBorder(20);
+      layer->SetAnchor(BitmapAnchor_TopLeft);
+      //layer->SetPosition(0,0);
+      controller_->GetScene().SetLayer(FIXED_INFOTEXT_LAYER_ZINDEX, layer.release());
+    }
+    // position the fixed info text in the upper right corner
+    layerP->SetText(msgS.c_str());
+    double cX = GetCompositor().GetCanvasWidth() * (-0.5);
+    double cY = GetCompositor().GetCanvasHeight() * (-0.5);
+    controller_->GetScene().GetCanvasToSceneTransform().Apply(cX,cY);
+    layerP->SetPosition(cX, cY);
+  }
+
+  void TrackerSampleApp::DisplayFloatingCtrlInfoText(const PointerEvent& e)
+  {
+    ScenePoint2D p = e.GetMainPosition().Apply(controller_->GetScene().GetCanvasToSceneTransform());
+
+    char buf[128];
+    sprintf(buf, "S:(%0.02f,%0.02f) C:(%0.02f,%0.02f)", 
+      p.GetX(), p.GetY(), 
+      e.GetMainPosition().GetX(), e.GetMainPosition().GetY());
+
+    if (controller_->GetScene().HasLayer(FLOATING_INFOTEXT_LAYER_ZINDEX))
+    {
+      TextSceneLayer& layer =
+        dynamic_cast<TextSceneLayer&>(controller_->GetScene().GetLayer(FLOATING_INFOTEXT_LAYER_ZINDEX));
+      layer.SetText(buf);
+      layer.SetPosition(p.GetX(), p.GetY());
+    }
+    else
+    {
+      std::unique_ptr<TextSceneLayer> layer(new TextSceneLayer);
+      layer->SetColor(0, 255, 0);
+      layer->SetText(buf);
+      layer->SetBorder(20);
+      layer->SetAnchor(BitmapAnchor_BottomCenter);
+      layer->SetPosition(p.GetX(), p.GetY());
+      controller_->GetScene().SetLayer(FLOATING_INFOTEXT_LAYER_ZINDEX, layer.release());
+    }
+  }
+
+  void TrackerSampleApp::HideInfoText()
+  {
+    controller_->GetScene().DeleteLayer(FLOATING_INFOTEXT_LAYER_ZINDEX);
+  }
+
+  ScenePoint2D TrackerSampleApp::GetRandomPointInScene() const
+  {
+    unsigned int w = GetCompositor().GetCanvasWidth();
+    LOG(TRACE) << "GetCompositor().GetCanvasWidth() = " << 
+      GetCompositor().GetCanvasWidth();
+    unsigned int h = GetCompositor().GetCanvasHeight();
+    LOG(TRACE) << "GetCompositor().GetCanvasHeight() = " << 
+      GetCompositor().GetCanvasHeight();
+
+    if ((w >= RAND_MAX) || (h >= RAND_MAX))
+      LOG(WARNING) << "Canvas is too big : tools will not be randomly placed";
+
+    int x = rand() % w;
+    int y = rand() % h;
+    LOG(TRACE) << "random x = " << x << "random y = " << y;
+
+    ScenePoint2D p = controller_->GetViewport().GetPixelCenterCoordinates(x, y);
+    LOG(TRACE) << "--> p.GetX() = " << p.GetX() << " p.GetY() = " << p.GetY();
+
+    ScenePoint2D r = p.Apply(controller_->GetScene().GetCanvasToSceneTransform());
+    LOG(TRACE) << "--> r.GetX() = " << r.GetX() << " r.GetY() = " << r.GetY();
+    return r;
+  }
+
+  void TrackerSampleApp::CreateRandomMeasureTool()
+  {
+    static bool srandCalled = false;
+    if (!srandCalled)
+    {
+      srand(42);
+      srandCalled = true;
+    }
+
+    int i = rand() % 2;
+    LOG(TRACE) << "random i = " << i;
+    switch (i)
+    {
+    case 0:
+      // line measure
+      {
+        boost::shared_ptr<CreateLineMeasureCommand> cmd = 
+          boost::make_shared<CreateLineMeasureCommand>(
+		  boost::ref(IObserver::GetBroker()),
+            controller_,
+            GetRandomPointInScene());
+        cmd->SetEnd(GetRandomPointInScene());
+        controller_->PushCommand(cmd);
+      }
+      break;
+    case 1:
+      // angle measure
+      {
+      boost::shared_ptr<CreateAngleMeasureCommand> cmd =
+        boost::make_shared<CreateAngleMeasureCommand>(
+          boost::ref(IObserver::GetBroker()),
+          controller_,
+          GetRandomPointInScene());
+        cmd->SetCenter(GetRandomPointInScene());
+        cmd->SetSide2End(GetRandomPointInScene());
+        controller_->PushCommand(cmd);
+      }
+      break;
+    }
+  }
+
+  void TrackerSampleApp::HandleApplicationEvent(
+    const SDL_Event & event)
+  {
+    DisplayInfoText();
+
+    if (event.type == SDL_MOUSEMOTION)
+    {
+      int scancodeCount = 0;
+      const uint8_t* keyboardState = SDL_GetKeyboardState(&scancodeCount);
+
+      if (activeTracker_.get() == NULL &&
+        SDL_SCANCODE_LALT < scancodeCount &&
+        keyboardState[SDL_SCANCODE_LALT])
+      {
+        // The "left-ctrl" key is down, while no tracker is present
+        // Let's display the info text
+        PointerEvent e;
+        e.AddPosition(controller_->GetViewport().GetPixelCenterCoordinates(
+          event.button.x, event.button.y));
+
+        DisplayFloatingCtrlInfoText(e);
+      }
+      else if (activeTracker_.get() != NULL)
+      {
+        HideInfoText();
+        //LOG(TRACE) << "(event.type == SDL_MOUSEMOTION)";
+        if (activeTracker_.get() != NULL)
+        {
+          //LOG(TRACE) << "(activeTracker_.get() != NULL)";
+          PointerEvent e;
+          e.AddPosition(controller_->GetViewport().GetPixelCenterCoordinates(
+            event.button.x, event.button.y));
+          
+          //LOG(TRACE) << "event.button.x = " << event.button.x << "     " <<
+          //  "event.button.y = " << event.button.y;
+          LOG(TRACE) << "activeTracker_->PointerMove(e); " <<
+            e.GetMainPosition().GetX() << " " << e.GetMainPosition().GetY();
+          
+          activeTracker_->PointerMove(e);
+          if (!activeTracker_->IsAlive())
+            activeTracker_.reset();
+        }
+      }
+      else
+      {
+        HideInfoText();
+
+        PointerEvent e;
+        e.AddPosition(controller_->GetViewport().GetPixelCenterCoordinates(event.button.x, event.button.y));
+
+        ScenePoint2D scenePos = e.GetMainPosition().Apply(
+          controller_->GetScene().GetCanvasToSceneTransform());
+        //auto measureTools = GetController()->HitTestMeasureTools(scenePos);
+        //LOG(TRACE) << "# of hit tests: " << measureTools.size();
+        
+        // this returns the collection of measuring tools where hit test is true
+        std::vector<boost::shared_ptr<MeasureTool> > measureTools = controller_->HitTestMeasureTools(scenePos);
+
+        // let's refresh the measuring tools highlighted state
+        // first let's tag them as "unhighlighted"
+        controller_->ResetMeasuringToolsHighlight();
+
+        // then immediately take the first one and ask it to highlight the 
+        // measuring tool UI part that is hot
+        if (measureTools.size() > 0)
+        {
+          measureTools[0]->Highlight(scenePos);
+        }
+      }
+    }
+    else if (event.type == SDL_MOUSEBUTTONUP)
+    {
+      if (activeTracker_)
+      {
+        PointerEvent e;
+        e.AddPosition(controller_->GetViewport().GetPixelCenterCoordinates(event.button.x, event.button.y));
+        activeTracker_->PointerUp(e);
+        if (!activeTracker_->IsAlive())
+          activeTracker_.reset();
+      }
+    }
+    else if (event.type == SDL_MOUSEBUTTONDOWN)
+    {
+      PointerEvent e;
+      e.AddPosition(controller_->GetViewport().GetPixelCenterCoordinates(
+        event.button.x, event.button.y));
+      if (activeTracker_)
+      {
+        activeTracker_->PointerDown(e);
+        if (!activeTracker_->IsAlive())
+          activeTracker_.reset();
+      }
+      else
+      {
+        // we ATTEMPT to create a tracker if need be
+        activeTracker_ = CreateSuitableTracker(event, e);
+      }
+    }
+    else if (event.type == SDL_KEYDOWN &&
+      event.key.repeat == 0 /* Ignore key bounce */)
+    {
+      switch (event.key.keysym.sym)
+      {
+      case SDLK_ESCAPE:
+        if (activeTracker_)
+        {
+          activeTracker_->Cancel();
+          if (!activeTracker_->IsAlive())
+            activeTracker_.reset();
+        }
+        break;
+
+      case SDLK_t:
+        if (!activeTracker_)
+          SelectNextTool();
+        else
+        {
+          LOG(WARNING) << "You cannot change the active tool when an interaction"
+            " is taking place";
+        }
+        break;
+
+      case SDLK_m:
+        CreateRandomMeasureTool();
+        break;
+      case SDLK_s:
+        controller_->FitContent(GetCompositor().GetCanvasWidth(),
+          GetCompositor().GetCanvasHeight());
+        break;
+
+      case SDLK_z:
+        LOG(TRACE) << "SDLK_z has been pressed. event.key.keysym.mod == " << event.key.keysym.mod;
+        if (event.key.keysym.mod & KMOD_CTRL)
+        {
+          if (controller_->CanUndo())
+          {
+            LOG(TRACE) << "Undoing...";
+            controller_->Undo();
+          }
+          else
+          {
+            LOG(WARNING) << "Nothing to undo!!!";
+          }
+        }
+        break;
+
+      case SDLK_y:
+        LOG(TRACE) << "SDLK_y has been pressed. event.key.keysym.mod == " << event.key.keysym.mod;
+        if (event.key.keysym.mod & KMOD_CTRL)
+        {
+          if (controller_->CanRedo())
+          {
+            LOG(TRACE) << "Redoing...";
+            controller_->Redo();
+          }
+          else
+          {
+            LOG(WARNING) << "Nothing to redo!!!";
+          }
+        }
+        break;
+
+      case SDLK_c:
+        TakeScreenshot(
+          "screenshot.png",
+          GetCompositor().GetCanvasWidth(),
+          GetCompositor().GetCanvasHeight());
+        break;
+
+      default:
+        break;
+      }
+    }
+  }
+
+
+  void TrackerSampleApp::OnSceneTransformChanged(
+    const ViewportController::SceneTransformChanged& message)
+  {
+    DisplayInfoText();
+  }
+
+  boost::shared_ptr<IFlexiblePointerTracker> TrackerSampleApp::CreateSuitableTracker(
+    const SDL_Event & event,
+    const PointerEvent & e)
+  {
+    using namespace Orthanc;
+
+    switch (event.button.button)
+    {
+    case SDL_BUTTON_MIDDLE:
+      return boost::shared_ptr<IFlexiblePointerTracker>(new PanSceneTracker
+        (controller_, e));
+
+    case SDL_BUTTON_RIGHT:
+      return boost::shared_ptr<IFlexiblePointerTracker>(new ZoomSceneTracker
+        (controller_, e, GetCompositor().GetCanvasHeight()));
+
+    case SDL_BUTTON_LEFT:
+    {
+      //LOG(TRACE) << "CreateSuitableTracker: case SDL_BUTTON_LEFT:";
+      // TODO: we need to iterate on the set of measuring tool and perform
+      // a hit test to check if a tracker needs to be created for edition.
+      // Otherwise, depending upon the active tool, we might want to create
+      // a "measuring tool creation" tracker
+
+      // TODO: if there are conflicts, we should prefer a tracker that 
+      // pertains to the type of measuring tool currently selected (TBD?)
+      boost::shared_ptr<IFlexiblePointerTracker> hitTestTracker = TrackerHitTest(e);
+
+      if (hitTestTracker != NULL)
+      {
+        //LOG(TRACE) << "hitTestTracker != NULL";
+        return hitTestTracker;
+      }
+      else
+      {
+        switch (currentTool_)
+        {
+        case GuiTool_Rotate:
+          //LOG(TRACE) << "Creating RotateSceneTracker";
+          return boost::shared_ptr<IFlexiblePointerTracker>(new RotateSceneTracker(
+            controller_, e));
+        case GuiTool_Pan:
+          return boost::shared_ptr<IFlexiblePointerTracker>(new PanSceneTracker(
+            controller_, e));
+        case GuiTool_Zoom:
+          return boost::shared_ptr<IFlexiblePointerTracker>(new ZoomSceneTracker(
+            controller_, e, GetCompositor().GetCanvasHeight()));
+        //case GuiTool_AngleMeasure:
+        //  return new AngleMeasureTracker(GetScene(), e);
+        //case GuiTool_CircleMeasure:
+        //  return new CircleMeasureTracker(GetScene(), e);
+        //case GuiTool_EllipseMeasure:
+        //  return new EllipseMeasureTracker(GetScene(), e);
+        case GuiTool_LineMeasure:
+          return boost::shared_ptr<IFlexiblePointerTracker>(new CreateLineMeasureTracker(
+            IObserver::GetBroker(), controller_, e));
+        case GuiTool_AngleMeasure:
+          return boost::shared_ptr<IFlexiblePointerTracker>(new CreateAngleMeasureTracker(
+            IObserver::GetBroker(), controller_, e));
+        case GuiTool_CircleMeasure:
+          LOG(ERROR) << "Not implemented yet!";
+          return boost::shared_ptr<IFlexiblePointerTracker>();
+        case GuiTool_EllipseMeasure:
+          LOG(ERROR) << "Not implemented yet!";
+          return boost::shared_ptr<IFlexiblePointerTracker>();
+        default:
+          throw OrthancException(ErrorCode_InternalError, "Wrong tool!");
+        }
+      }
+    }
+    default:
+      return boost::shared_ptr<IFlexiblePointerTracker>();
+    }
+  }
+
+
+  TrackerSampleApp::TrackerSampleApp(MessageBroker& broker) : IObserver(broker)
+    , currentTool_(GuiTool_Rotate)
+    , undoStack_(new UndoStack)
+    , viewport_("Hello", 1024, 1024, false) // False means we do NOT let Windows treat this as a legacy application that needs to be scaled
+  {
+    controller_ = boost::shared_ptr<ViewportController>(
+      new ViewportController(undoStack_, broker, viewport_));
+
+    controller_->RegisterObserverCallback(
+      new Callable<TrackerSampleApp, ViewportController::SceneTransformChanged>
+      (*this, &TrackerSampleApp::OnSceneTransformChanged));
+
+    TEXTURE_2x2_1_ZINDEX = 1;
+    TEXTURE_1x1_ZINDEX = 2;
+    TEXTURE_2x2_2_ZINDEX = 3;
+    LINESET_1_ZINDEX = 4;
+    LINESET_2_ZINDEX = 5;
+    FLOATING_INFOTEXT_LAYER_ZINDEX = 6;
+    FIXED_INFOTEXT_LAYER_ZINDEX = 7;
+  }
+
+  void TrackerSampleApp::PrepareScene()
+  {
+    // Texture of 2x2 size
+    {
+      Orthanc::Image i(Orthanc::PixelFormat_RGB24, 2, 2, false);
+
+      uint8_t* p = reinterpret_cast<uint8_t*>(i.GetRow(0));
+      p[0] = 255;
+      p[1] = 0;
+      p[2] = 0;
+
+      p[3] = 0;
+      p[4] = 255;
+      p[5] = 0;
+
+      p = reinterpret_cast<uint8_t*>(i.GetRow(1));
+      p[0] = 0;
+      p[1] = 0;
+      p[2] = 255;
+
+      p[3] = 255;
+      p[4] = 0;
+      p[5] = 0;
+
+      controller_->GetScene().SetLayer(TEXTURE_2x2_1_ZINDEX, new ColorTextureSceneLayer(i));
+
+      std::unique_ptr<ColorTextureSceneLayer> l(new ColorTextureSceneLayer(i));
+      l->SetOrigin(-3, 2);
+      l->SetPixelSpacing(1.5, 1);
+      l->SetAngle(20.0 / 180.0 * M_PI);
+      controller_->GetScene().SetLayer(TEXTURE_2x2_2_ZINDEX, l.release());
+    }
+
+    // Texture of 1x1 size
+    {
+      Orthanc::Image i(Orthanc::PixelFormat_RGB24, 1, 1, false);
+
+      uint8_t* p = reinterpret_cast<uint8_t*>(i.GetRow(0));
+      p[0] = 255;
+      p[1] = 0;
+      p[2] = 0;
+
+      std::unique_ptr<ColorTextureSceneLayer> l(new ColorTextureSceneLayer(i));
+      l->SetOrigin(-2, 1);
+      l->SetAngle(20.0 / 180.0 * M_PI);
+      controller_->GetScene().SetLayer(TEXTURE_1x1_ZINDEX, l.release());
+    }
+
+    // Some lines
+    {
+      std::unique_ptr<PolylineSceneLayer> layer(new PolylineSceneLayer);
+
+      layer->SetThickness(1);
+
+      PolylineSceneLayer::Chain chain;
+      chain.push_back(ScenePoint2D(0 - 0.5, 0 - 0.5));
+      chain.push_back(ScenePoint2D(0 - 0.5, 2 - 0.5));
+      chain.push_back(ScenePoint2D(2 - 0.5, 2 - 0.5));
+      chain.push_back(ScenePoint2D(2 - 0.5, 0 - 0.5));
+      layer->AddChain(chain, true, 255, 0, 0);
+
+      chain.clear();
+      chain.push_back(ScenePoint2D(-5, -5));
+      chain.push_back(ScenePoint2D(5, -5));
+      chain.push_back(ScenePoint2D(5, 5));
+      chain.push_back(ScenePoint2D(-5, 5));
+      layer->AddChain(chain, true, 0, 255, 0);
+
+      double dy = 1.01;
+      chain.clear();
+      chain.push_back(ScenePoint2D(-4, -4));
+      chain.push_back(ScenePoint2D(4, -4 + dy));
+      chain.push_back(ScenePoint2D(-4, -4 + 2.0 * dy));
+      chain.push_back(ScenePoint2D(4, 2));
+      layer->AddChain(chain, false, 0, 0, 255);
+
+      controller_->GetScene().SetLayer(LINESET_1_ZINDEX, layer.release());
+    }
+
+    // Some text
+    {
+      std::unique_ptr<TextSceneLayer> layer(new TextSceneLayer);
+      layer->SetText("Hello");
+      controller_->GetScene().SetLayer(LINESET_2_ZINDEX, layer.release());
+    }
+  }
+
+
+  void TrackerSampleApp::DisableTracker()
+  {
+    if (activeTracker_)
+    {
+      activeTracker_->Cancel();
+      activeTracker_.reset();
+    }
+  }
+
+  void TrackerSampleApp::TakeScreenshot(const std::string& target,
+    unsigned int canvasWidth,
+    unsigned int canvasHeight)
+  {
+    CairoCompositor compositor(controller_->GetScene(), canvasWidth, canvasHeight);
+    compositor.SetFont(0, Orthanc::EmbeddedResources::UBUNTU_FONT, FONT_SIZE_0, Orthanc::Encoding_Latin1);
+    compositor.Refresh();
+
+    Orthanc::ImageAccessor canvas;
+    compositor.GetCanvas().GetReadOnlyAccessor(canvas);
+
+    Orthanc::Image png(Orthanc::PixelFormat_RGB24, canvas.GetWidth(), canvas.GetHeight(), false);
+    Orthanc::ImageProcessing::Convert(png, canvas);
+
+    Orthanc::PngWriter writer;
+    writer.WriteToFile(target, png);
+  }
+
+
+  boost::shared_ptr<IFlexiblePointerTracker> TrackerSampleApp::TrackerHitTest(const PointerEvent & e)
+  {
+    // std::vector<boost::shared_ptr<MeasureTool>> measureTools_;
+    ScenePoint2D scenePos = e.GetMainPosition().Apply(
+      controller_->GetScene().GetCanvasToSceneTransform());
+
+    std::vector<boost::shared_ptr<MeasureTool> > measureTools = controller_->HitTestMeasureTools(scenePos);
+
+    if (measureTools.size() > 0)
+    {
+      return measureTools[0]->CreateEditionTracker(e);
+    }
+    return boost::shared_ptr<IFlexiblePointerTracker>();
+  }
+
+  static void GLAPIENTRY
+    OpenGLMessageCallback(GLenum source,
+      GLenum type,
+      GLuint id,
+      GLenum severity,
+      GLsizei length,
+      const GLchar* message,
+      const void* userParam)
+  {
+    if (severity != GL_DEBUG_SEVERITY_NOTIFICATION)
+    {
+      fprintf(stderr, "GL CALLBACK: %s type = 0x%x, severity = 0x%x, message = %s\n",
+        (type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : ""),
+        type, severity, message);
+    }
+  }
+
+  static bool g_stopApplication = false;
+  
+  ICompositor& TrackerSampleApp::GetCompositor()
+  {
+    using namespace Orthanc;
+    try
+    {
+      SdlViewport& viewport = dynamic_cast<SdlViewport&>(viewport_);
+      return viewport.GetCompositor();
+    }
+    catch (std::bad_cast e)
+    {
+      throw OrthancException(ErrorCode_InternalError, "Wrong viewport type!");
+     }
+  }
+
+  const ICompositor& TrackerSampleApp::GetCompositor() const
+  {
+    using namespace Orthanc;
+    try
+    {
+      SdlViewport& viewport = const_cast<SdlViewport&>(dynamic_cast<const SdlViewport&>(viewport_));
+      return viewport.GetCompositor();
+    }
+    catch (std::bad_cast e)
+    {
+      throw OrthancException(ErrorCode_InternalError, "Wrong viewport type!");
+    }
+  }
+
+
+  void TrackerSampleApp::Run()
+  {
+    controller_->FitContent(viewport_.GetCanvasWidth(), viewport_.GetCanvasHeight());
+
+    glEnable(GL_DEBUG_OUTPUT);
+    glDebugMessageCallback(OpenGLMessageCallback, 0);
+
+    GetCompositor().SetFont(0, Orthanc::EmbeddedResources::UBUNTU_FONT,
+      FONT_SIZE_0, Orthanc::Encoding_Latin1);
+    GetCompositor().SetFont(1, Orthanc::EmbeddedResources::UBUNTU_FONT,
+      FONT_SIZE_1, Orthanc::Encoding_Latin1);
+
+    while (!g_stopApplication)
+    {
+      GetCompositor().Refresh();
+
+      SDL_Event event;
+      while (!g_stopApplication && SDL_PollEvent(&event))
+      {
+        if (event.type == SDL_QUIT)
+        {
+          g_stopApplication = true;
+          break;
+        }
+        else if (event.type == SDL_WINDOWEVENT &&
+          event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)
+        {
+          DisableTracker(); // was: tracker.reset(NULL);
+        }
+        else if (event.type == SDL_KEYDOWN &&
+          event.key.repeat == 0 /* Ignore key bounce */)
+        {
+          switch (event.key.keysym.sym)
+          {
+          case SDLK_f:
+            viewport_.GetWindow().ToggleMaximize();
+            break;
+
+          case SDLK_q:
+            g_stopApplication = true;
+            break;
+          default:
+            break;
+          }
+        }
+        HandleApplicationEvent(event);
+      }
+      SDL_Delay(1);
+    }
+  }
+
+  void TrackerSampleApp::SetInfoDisplayMessage(
+    std::string key, std::string value)
+  {
+    if (value == "")
+      infoTextMap_.erase(key);
+    else
+      infoTextMap_[key] = value;
+    DisplayInfoText();
+  }
+
+}