avoid widget showing up twice

QT5 shows a widget twice when you set a parent at initialization
and reset the parent later. This is exactly what happens when a
widget is initialized and passed to AddWidget in the gosty app.
The solution is to initialize them without a parent and let
the AddWidget function taking care of it.

examples/code_fragments/ui/widget_example.py

@@ -26,7 +26,7 @@ from board import Board
 panels=gui.GostyApp.Instance().perspective.panels
 
 #Create Widget
-tetris=Board(panels.qobject)
+tetris=Board()
 
 #Wrap widget to Qt Widget
 wid=gui.Widget(tetris)

modules/gui/src/gosty_app.cc

@@ -122,17 +122,8 @@ ost::img::gui::DataViewer* GostyApp::CreateDataViewer(const ost::img::ImageHandl
   }
   else
   {
-    viewer=new ost::img::gui::DataViewer(main_,d,name);
-    QMdiSubWindow* mdi=new QMdiSubWindow(this->GetPerspective()->GetMainArea());
-    mdi->setWindowTitle(name);
-    mdi->setWidget(viewer);
-    mdi->setFocusProxy(viewer);
-    viewer->setAttribute(Qt::WA_DeleteOnClose);
-    mdi->setAttribute(Qt::WA_DeleteOnClose);
-    viewer->setParent(mdi);
-    this->GetPerspective()->GetMainArea()->addSubWindow(mdi);
-    mdi->showMaximized();
-    connect(viewer,SIGNAL(released()),mdi,SLOT(close()));
+    viewer=new ost::img::gui::DataViewer(NULL,d,name);
+    this->GetPerspective()->GetMainArea()->AddWidget(name, viewer);
   }
 
   return viewer;