/**
 * 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/>.
 **/


#include "PanSceneTracker.h"
#include "../Scene2DViewport/ViewportController.h"

namespace OrthancStone
{
  PanSceneTracker::PanSceneTracker(boost::weak_ptr<ViewportController> controllerW,
                                   const PointerEvent& event)
    : OneGesturePointerTracker(controllerW)
    , originalSceneToCanvas_(GetController()->GetSceneToCanvasTransform())
    , originalCanvasToScene_(GetController()->GetCanvasToSceneTransform())
  {
    pivot_ = event.GetMainPosition().Apply(originalCanvasToScene_);
  }


  void PanSceneTracker::PointerMove(const PointerEvent& event)
  {
    ScenePoint2D p = event.GetMainPosition().Apply(originalCanvasToScene_);

      // The controller is a weak pointer. It could be deleted when the
      // tracker is still alive (for instance, because of a lost WebGL
      // context)
      if(GetController().get() != NULL)
      {
      GetController()->SetSceneToCanvasTransform(
        AffineTransform2D::Combine(
          originalSceneToCanvas_,
          AffineTransform2D::CreateOffset(p.GetX() - pivot_.GetX(),
                                          p.GetY() - pivot_.GetY())));
      }
  }

  void PanSceneTracker::Cancel()
  {
      if(GetController().get() != NULL)
      {
        GetController()->SetSceneToCanvasTransform(originalSceneToCanvas_);
      }
  }

}