0027398: Integrate Qt Browser Widget to Open CASCADE Technology

The following implementation has been made:
- CMake procedure is extended to compile Qt tools. This is optional and is handled by USE_QT_TOOLS option(OFF by default)
- It is possible to build Qt tools using Qt5 or Qt4, it is settled with USE_QT4 option.
- Sample of DFBrowser tool is available in samples/tools/TInspectorEXE. It is build with tools, executable is placed in binaries. To start the sample, use dfbrowser.bat command.
- DFBrowser tool may be started from DRAW

tools/DFBrowser/DFBrowser_TreeLevelViewModel.hxx

@@ -0,0 +1,102 @@
+// Created on: 2017-06-16
+// Created by: Natalia ERMOLAEVA
+// Copyright (c) 2017 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 DFBrowser_TreeLevelViewModel_H
+#define DFBrowser_TreeLevelViewModel_H
+
+#include <Standard.hxx>
+#include <Standard_Macro.hxx>
+
+#ifdef _MSC_VER
+#pragma warning(disable : 4127) // conditional expression is constant
+#endif
+#include <QAbstractTableModel>
+#include <QVariant>
+
+class QObject;
+
+//! \class DFBrowser_TreeLevelViewModel
+//! Tree Model of one level of OCAF tree view model. It is initialized by tree view index and
+//! contains children and attributes of this label.
+class DFBrowser_TreeLevelViewModel : public QAbstractTableModel
+{
+public:
+
+  //! Constructor
+  DFBrowser_TreeLevelViewModel (QObject* theParent) : QAbstractTableModel (theParent), myRowCount (0) {}
+
+  //! Destructor
+  virtual ~DFBrowser_TreeLevelViewModel() Standard_OVERRIDE {}
+
+  //! Reset OCAF tree model index
+  void Reset() { myIndex = QModelIndex(); }
+
+  //! Fills OCAF tree model index
+  //! \param theTreeIndex an index
+  Standard_EXPORT void Init (const QModelIndex& theTreeIndex);
+
+  //! Returns true if the index is filled
+  bool IsInitialized() const { return myIndex.isValid(); }
+
+  //! Return OCAF tree view model index on level defined by column of the parameter index
+  //! \param theIndex a tree level view model index
+  //! \return model index
+  Standard_EXPORT QModelIndex GetTreeViewIndex (const QModelIndex& theIndex) const;
+
+  //! Emits the layoutChanged signal from outside of this class
+  void EmitLayoutChanged() { emit layoutChanged(); }
+
+  //! It returns value only for DisplayRole for column = 1
+  //! \param theSection an index of value in the container 
+  //! \param theIndex a model index
+  //! \param theRole a view role
+  //! \return value intepreted depending on the given role
+  Standard_EXPORT virtual QVariant headerData (int theSection, Qt::Orientation theOrientation,
+                                               int theRole = Qt::DisplayRole) const Standard_OVERRIDE;
+
+  //! Creates new model index
+  //! \param theRow the index row position
+  //! \param theColummn the index column position
+  //! \param theParent the parent index
+  //! \return the model index
+  Standard_EXPORT virtual QModelIndex index (int theRow, int theColumn,
+                                             const QModelIndex& theParent = QModelIndex()) const Standard_OVERRIDE;
+
+  //! Returns item information(short) for display role.
+  //! \param theIndex a model index
+  //! \param theRole a view role
+  //! \return value intepreted depending on the given role
+  Standard_EXPORT virtual QVariant data (const QModelIndex& theIndex,
+                                         int theRole = Qt::DisplayRole) const Standard_OVERRIDE;
+
+  //! Returns Enabled and Selectable item for any index
+  //! \param theIndex a model index
+  //! \return flags
+  Standard_EXPORT virtual Qt::ItemFlags flags (const QModelIndex& theIndex) const Standard_OVERRIDE;
+
+  //! Returns number of rows
+  virtual int rowCount (const QModelIndex& theParent = QModelIndex()) const Standard_OVERRIDE
+  { (void)theParent; return myRowCount; }
+
+  //! Returns 2 columns
+  virtual int columnCount (const QModelIndex& theParent = QModelIndex()) const Standard_OVERRIDE
+  { (void)theParent; return 2; }
+
+private:
+
+  QModelIndex myIndex; //!< OCAF tree view model index
+  int myRowCount; //!< number of rows of item of treeview model index
+};
+#endif