--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Framework/Widgets/WidgetBase.cpp	Fri Oct 14 15:34:11 2016 +0200
@@ -0,0 +1,190 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * In addition, as a special exception, the copyright holders of this
+ * program give permission to link the code of its release with the
+ * OpenSSL project's "OpenSSL" library (or with modified versions of it
+ * that use the same license as the "OpenSSL" library), and distribute
+ * the linked executables. You must obey the GNU General Public License
+ * in all respects for all of the code used other than "OpenSSL". If you
+ * modify file(s) with this exception, you may extend this exception to
+ * your version of the file(s), but you are not obligated to do so. If
+ * you do not wish to do so, delete this exception statement from your
+ * version. If you delete this exception statement from all source files
+ * in the program, then also delete it here.
+ * 
+ * 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#include "WidgetBase.h"
+
+#include "../Orthanc/Core/OrthancException.h"
+#include "../Orthanc/Core/Images/ImageProcessing.h"
+#include "../Orthanc/Core/Logging.h"
+
+namespace OrthancStone
+{
+  void WidgetBase::ClearBackgroundOrthanc(Orthanc::ImageAccessor& target) const 
+  {
+    // Clear the background using Orthanc
+
+    if (backgroundCleared_)
+    {
+      Orthanc::ImageProcessing::Set(target, 
+                                    backgroundColor_[0],
+                                    backgroundColor_[1],
+                                    backgroundColor_[2],
+                                    255 /* alpha */);
+    }
+  }
+
+
+  void WidgetBase::ClearBackgroundCairo(CairoContext& context) const
+  {
+    // Clear the background using Cairo
+
+    if (IsBackgroundCleared())
+    {
+      uint8_t red, green, blue;
+      GetBackgroundColor(red, green, blue);
+
+      context.SetSourceColor(red, green, blue);
+      cairo_paint(context.GetObject());
+    }
+  }
+
+
+  void WidgetBase::ClearBackgroundCairo(Orthanc::ImageAccessor& target) const
+  {
+    CairoSurface surface(target);
+    CairoContext context(surface);
+    ClearBackgroundCairo(context);
+  }
+
+
+  void WidgetBase::NotifyChange()
+  {
+    observers_.NotifyChange(this);
+  }
+
+
+  void WidgetBase::UpdateStatusBar(const std::string& message)
+  {
+    if (statusBar_ != NULL)
+    {
+      statusBar_->SetMessage(message);
+    }
+  }
+
+
+  void WidgetBase::WorkerThread(WidgetBase* that)
+  {
+    while (that->started_)
+    {
+      that->UpdateStep();
+    }
+  }
+
+
+  WidgetBase::WidgetBase() :
+    statusBar_(NULL),
+    started_(false),
+    backgroundCleared_(false)
+  {
+    backgroundColor_[0] = 0;
+    backgroundColor_[1] = 0;
+    backgroundColor_[2] = 0;
+  }
+
+
+  void WidgetBase::SetBackgroundColor(uint8_t red,
+                                      uint8_t green,
+                                      uint8_t blue)
+  {
+    backgroundColor_[0] = red;
+    backgroundColor_[1] = green;
+    backgroundColor_[2] = blue;
+  }
+
+  void WidgetBase::GetBackgroundColor(uint8_t& red,
+                                      uint8_t& green,
+                                      uint8_t& blue) const
+  {
+    red = backgroundColor_[0];
+    green = backgroundColor_[1];
+    blue = backgroundColor_[2];
+  }
+
+
+  void WidgetBase::Register(IChangeObserver& observer)
+  {
+    observers_.Register(observer);
+  }
+
+
+  void WidgetBase::Unregister(IChangeObserver& observer)
+  {
+    observers_.Unregister(observer);
+  }
+
+
+  void WidgetBase::Start()
+  {
+    if (started_)
+    {
+      LOG(ERROR) << "Cannot Start() twice";
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+    }
+
+    started_ = true;
+
+    if (HasUpdateThread())
+    {
+      thread_ = boost::thread(WorkerThread, this);
+    }
+  }
+
+
+  void WidgetBase::Stop()
+  {
+    if (!started_)
+    {
+      LOG(ERROR) << "Cannot Stop() if Start() has not been invoked";
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_BadSequenceOfCalls);
+    }
+
+    started_ = false;
+
+    if (HasUpdateThread() &&
+        thread_.joinable())
+    {
+      thread_.join();
+    }
+  }
+
+
+  bool WidgetBase::Render(Orthanc::ImageAccessor& surface)
+  {
+#if 0
+    ClearBackgroundOrthanc(surface);
+#else
+    ClearBackgroundCairo(surface);  // Faster than Orthanc
+#endif
+
+    return true;
+  }
+}