QT Viewer main structure.

CMake: added an entry at main CMake script that makes QTViewer an optional build.
QT Viewer main structure only, libQGLViewer or any 3D functionality can be added to mainWindow as a widget later on.

src/qtviewer/mainwindow.h

@@ -0,0 +1,49 @@
+
+
+#ifndef MAINWINDOW_H
+#define MAINWINDOW_H
+
+#include <qobject.h>
+#include <QMainWindow>
+#include <QString>
+#include <qobject.h>
+#include "../ifcgeom/IfcGeomObjects.h"
+
+class ObjectsView;
+
+class QGLViewer;
+
+QT_BEGIN_NAMESPACE
+class QAction;
+class QGraphicsView;
+class QGraphicsScene;
+class QGraphicsRectItem;
+QT_END_NAMESPACE
+
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    MainWindow();
+
+
+public Q_SLOTS:
+  void draw();
+
+public slots:
+    void openFile(const QString &path = QString());
+    void setRenderer(QAction *action);
+
+private:
+    QAction *m_nativeAction;
+    QAction *m_glAction;
+    QAction *m_imageAction;
+    QAction *m_highQualityAntialiasingAction;
+    QAction *m_backgroundAction;
+    QAction *m_outlineAction;
+
+    QString m_currentPath;
+};
+
+#endif