--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancStone/Sources/Scene2DViewport/MeasureTool.h	Tue Jul 07 16:21:02 2020 +0200
@@ -0,0 +1,160 @@
+/**
+ * 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/>.
+ **/
+
+#pragma once
+
+#include "../Messages/ObserverBase.h"
+#include "../Scene2D/PolylineSceneLayer.h"
+#include "../Scene2D/Scene2D.h"
+#include "../Scene2D/ScenePoint2D.h"
+#include "../Scene2D/TextSceneLayer.h"
+#include "../Scene2DViewport/PredeclaredTypes.h"
+#include "../Scene2DViewport/ViewportController.h"
+
+#include <boost/weak_ptr.hpp>
+
+#include <vector>
+#include <cmath>
+
+namespace OrthancStone
+{
+  class IFlexiblePointerTracker;
+  class MeasureToolMemento;
+
+  class MeasureTool : public ObserverBase<MeasureTool>
+  {
+  public:
+    virtual ~MeasureTool()
+    {
+    }
+
+    /**
+    Enabled tools are rendered in the scene.
+    */
+    void Enable();
+
+    /**
+    Disabled tools are not rendered in the scene. This is useful to be able
+    to use them as their own memento in command stacks (when a measure tool
+    creation command has been undone, the measure remains alive in the
+    command object but is disabled so that it can be redone later on easily)
+    */
+    void Disable();
+
+    /**
+    This method is called when the scene transform changes. It allows to 
+    recompute the visual elements whose content depend upon the scene transform
+    */
+    void OnSceneTransformChanged(
+      const ViewportController::SceneTransformChanged& message);
+    
+    /**
+    This function must be implemented by the measuring tool to return whether
+    a given point in scene coords is close to the measuring tool.
+
+    This is used for mouse hover highlighting.
+
+    It is assumed that if the pointer position leads to this function returning
+    true, then a click at that position will return a tracker to edit the 
+    measuring tool
+    */
+    virtual bool HitTest(ScenePoint2D p) = 0;
+
+    /**
+    This method must return a memento the captures the tool state (not including
+    the highlighting state
+    */
+    virtual boost::shared_ptr<MeasureToolMemento> GetMemento() const = 0;
+
+    /**
+    This method must apply the supplied memento (this requires RTTI to check
+    the type)
+    */
+    virtual void SetMemento(boost::shared_ptr<MeasureToolMemento>) = 0;
+
+    /**
+    This must create an edition tracker suitable for the supplied click position,
+    or an empty pointer if no hit test (although this should have been checked
+    first)
+    */
+    virtual boost::shared_ptr<IFlexiblePointerTracker> CreateEditionTracker(const PointerEvent& e) = 0;
+
+    /**
+    Will change the measuring tool to provide visual feedback on the GUI 
+    element that is in the pointer hit zone
+    */
+    virtual void Highlight(ScenePoint2D p) = 0;
+
+    /**
+    This function must reset the visual highlighted hot zone feedback
+    */
+    virtual void ResetHighlightState() = 0;
+
+    /**
+    A description of the measuring tool, useful in debug logs
+    */
+    virtual std::string GetDescription() = 0;
+
+  protected:
+    MeasureTool(boost::shared_ptr<IViewport> viewport);
+
+    void PostConstructor();
+
+    /**
+    The measuring tool may exist in a standalone fashion, without any available
+    scene (because the controller is dead or dying). This call allows to check 
+    before accessing the scene.
+    */
+    bool IsSceneAlive() const;
+    
+    /**
+    This is the meat of the tool: this method must [create (if needed) and]
+    update the layers and their data according to the measure tool kind and
+    current state. This is repeatedly called during user interaction
+    */
+    virtual void RefreshScene() = 0;
+
+    /**
+    enabled_ is not accessible by subclasses because there is a state machine
+    that we do not wanna mess with
+    */
+    bool IsEnabled() const;
+
+    /**
+    Protected to allow sub-classes to use this weak pointer in factory methods
+    (pass them to created objects)
+    */
+    boost::shared_ptr<IViewport> viewport_;
+
+
+  private:
+    bool     enabled_;
+  };
+
+  class MeasureToolMemento
+  {
+    public:
+      virtual ~MeasureToolMemento() {};
+  };
+
+}
+
+ //extern void TrackerSample_SetInfoDisplayMessage(
+ //  std::string key, std::string value);