0031570: Samples - add Qt samples similar to standard MFC samples

Added Qt sample OCCTOverview providing examples of use of OCCT API with relevant code and demonstration of results in the viewer.

Off-topic: some unused images are removed from dox/introduction/images/

samples/OCCTOverview/code/TOcafFunction_BoxDriver.cxx

@@ -0,0 +1,148 @@
+// Copyright (c) 2020 OPEN CASCADE SAS
+//
+// This file is part of the examples of the Open CASCADE Technology software library.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE
+
+#include "TOcafFunction_BoxDriver.h"
+
+#include <BRepPrimAPI_MakeBox.hxx>
+#include <Standard_GUID.hxx>
+#include <TDataStd_Real.hxx>
+#include <TNaming_Builder.hxx>
+
+//=======================================================================
+//function : GetID
+//purpose  :
+//=======================================================================
+const Standard_GUID& TOcafFunction_BoxDriver::GetID()
+{
+  static const Standard_GUID anID("22D22E51-D69A-11d4-8F1A-0060B0EE18E8");
+  return anID;
+}
+
+//=======================================================================
+//function : Validate
+//purpose  :
+//=======================================================================
+void TOcafFunction_BoxDriver::Validate(Handle(TFunction_Logbook)& log) const
+{
+  // We validate the object label ( Label() ), all the arguments and the results of the object:
+  log->SetValid(Label(), Standard_True);
+}
+
+//=======================================================================
+//function : MustExecute
+//purpose  :
+//=======================================================================
+Standard_Boolean TOcafFunction_BoxDriver::MustExecute(const Handle(TFunction_Logbook)& log) const
+{
+  // If the object's label is modified:
+  if (log->IsModified(Label())) return Standard_True;
+
+  // Cut (in our simple case) has two arguments: The original shape, and the tool shape.
+  // They are on the child labels of the box's label:
+  // So, OriginalNShape  - is attached to the first  child label
+  //     ToolNShape - is attached to the second child label.
+  //
+  // Let's check them:
+  if (log->IsModified(Label().FindChild(1)))
+  {
+    return Standard_True; // width.
+  }
+  if (log->IsModified(Label().FindChild(2)))
+  {
+    return Standard_True; // length,
+  }
+  if (log->IsModified(Label().FindChild(3)))
+  {
+    return Standard_True; // width.
+  }
+  if (log->IsModified(Label().FindChild(4)))
+  {
+    return Standard_True; // length,
+  }
+  if (log->IsModified(Label().FindChild(5)))
+  {
+    return Standard_True; // width.
+  }
+  if (log->IsModified(Label().FindChild(6)))
+  {
+    return Standard_True; // length,
+  }
+  // if there are no any modifications concerned the box,
+  // it's not necessary to recompute (to call the method Execute()):
+  return Standard_False;
+}
+
+//=======================================================================
+//function : Execute
+//purpose  :
+//=======================================================================
+Standard_Integer TOcafFunction_BoxDriver::Execute(Handle(TFunction_Logbook)& /*log*/) const
+{
+  // Get the values of dimension and position attributes
+  Handle(TDataStd_Real) TSR;
+  Standard_Real x, y, z, l, h, w;
+  if (!Label().FindChild(1).FindAttribute(TDataStd_Real::GetID(), TSR))
+  {
+    return 1;
+  }
+  l = TSR->Get();
+
+  if (!Label().FindChild(2).FindAttribute(TDataStd_Real::GetID(), TSR))
+  {
+    return 1;
+  }
+  h = TSR->Get();
+
+  if (!Label().FindChild(3).FindAttribute(TDataStd_Real::GetID(), TSR))
+  {
+    return 1;
+  }
+  w = TSR->Get();
+
+  if (!Label().FindChild(4).FindAttribute(TDataStd_Real::GetID(), TSR))
+  {
+    return 1;
+  }
+  x = TSR->Get();
+
+  if (!Label().FindChild(5).FindAttribute(TDataStd_Real::GetID(), TSR))
+  {
+    return 1;
+  }
+  y = TSR->Get();
+
+  if (!Label().FindChild(6).FindAttribute(TDataStd_Real::GetID(), TSR))
+  {
+    return 1;
+  }
+  z = TSR->Get();
+
+  // Build a box using the dimension and position attributes
+  BRepPrimAPI_MakeBox mkBox(gp_Pnt(x, y, z), l, h, w);
+  TopoDS_Shape ResultShape = mkBox.Shape();
+
+  // Build a TNaming_NamedShape using built box
+  TNaming_Builder B(Label());
+  B.Generated(ResultShape);
+  // That's all:
+  // If there are no any mistakes we return 0:
+  return 0;
+}