Fix scene rect centering when expanding (paceholder#120)

Author: paceholder

src/GraphicsView.cpp

@@ -48,6 +48,11 @@ GraphicsView(QWidget *parent)
   setViewportUpdateMode(QGraphicsView::BoundingRectViewportUpdate);
 
   //setViewport(new QGLWidget(QGLFormat(QGL::SampleBuffers)));
+
+  // Sets the scene rect to its maximum possible ranges to avoid autu scene range
+  // re-calculation when expanding the all QGraphicsItems common rect.
+  int maxSize = 32767;
+  setSceneRect(-maxSize, -maxSize, (maxSize * 2), (maxSize * 2));
 }