0030507: Visualization - introduce AIS_ViewController

ViewerTest_EventManager now inherits AIS_ViewController.
Platform-dependent user input handling within ViewerTest has been revised
to process events in common way through AIS_ViewController.
The mouse navigation has been changed, so that left mouse clicked
without modifers now rotates View.
The rubber-band selection can be activated via Alt+LeftMouseButton.
Selection is now done on mouse unclick and keyboard short-cuts take effect on unclick.

Aspect_Window::SetTitle() - added new method configuring Window title.
Introduced new types Aspect_Touch, Aspect_VKey, Aspect_ScrollDelta
for processing window events in platform-independent way.

src/Aspect/Aspect_Touch.hxx

@@ -0,0 +1,49 @@
+// Copyright (c) 2016-2019 OPEN CASCADE SAS
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#ifndef _Aspect_Touch_HeaderFile
+#define _Aspect_Touch_HeaderFile
+
+#include <NCollection_Vec2.hxx>
+#include <Standard_Boolean.hxx>
+#include <Standard_Real.hxx>
+
+//! Structure holding touch position - original and current location.
+class Aspect_Touch
+{
+public:
+
+  NCollection_Vec2<Standard_Real> From;            //!< original touch position
+  NCollection_Vec2<Standard_Real> To;              //!< current  touch position
+  Standard_Boolean                IsPreciseDevice; //!< precise device input (e.g. mouse cursor, NOT emulated from touch screen)
+
+  //! Return values delta.
+  NCollection_Vec2<Standard_Real> Delta() const { return To - From; }
+
+  //! Empty constructor
+  Aspect_Touch()
+  : From (0.0, 0.0), To (0.0, 0.0), IsPreciseDevice (false) {}
+
+  //! Constructor with initialization.
+  Aspect_Touch (const NCollection_Vec2<Standard_Real>& thePnt,
+                Standard_Boolean theIsPreciseDevice)
+  : From (thePnt), To (thePnt), IsPreciseDevice (theIsPreciseDevice) {}
+
+  //! Constructor with initialization.
+  Aspect_Touch (Standard_Real theX, Standard_Real theY,
+                Standard_Boolean theIsPreciseDevice)
+  : From (theX, theY), To (theX, theY), IsPreciseDevice (theIsPreciseDevice) {}
+
+};
+
+#endif // _Aspect_Touch_HeaderFile