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/TreeModel/TreeModel_ItemBase.cxx

@@ -0,0 +1,93 @@
+// 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. 
+
+#include <TreeModel_ItemBase.hxx>
+
+#include <TreeModel_ItemRole.hxx>
+
+#include <QStringList>
+
+// =======================================================================
+// function : Constructor
+// purpose :
+// =======================================================================
+TreeModel_ItemBase::TreeModel_ItemBase (TreeModel_ItemBasePtr theParent, const int theRow, const int theColumn)
+ : m_bInitialized (false)
+{
+  m_pParent = theParent;
+  m_iRow = theRow;
+  m_iColumn = theColumn;
+}
+
+// =======================================================================
+// function :  reset
+// purpose :
+// =======================================================================
+void TreeModel_ItemBase::Reset()
+{
+  for (PositionToItemHash::const_iterator aChildrenIt = m_ChildItems.begin(); aChildrenIt != m_ChildItems.end(); aChildrenIt++)
+  {
+    TreeModel_ItemBasePtr anItem = aChildrenIt.value();
+    if (anItem)
+      anItem->Reset();
+  }
+  m_bInitialized = false;
+  mycachedValues.clear();
+
+}
+
+// =======================================================================
+// function :  child
+// purpose :
+// =======================================================================
+TreeModel_ItemBasePtr TreeModel_ItemBase::Child (int theRow, int theColumn, const bool isToCreate)
+{
+  QPair<int, int> aPos = qMakePair (theRow, theColumn);
+
+  if (m_ChildItems.contains (aPos))
+    return m_ChildItems[aPos];
+
+  TreeModel_ItemBasePtr anItem;
+  if (isToCreate) {
+    anItem = createChild (theRow, theColumn);
+    if (anItem)
+      m_ChildItems[aPos] = anItem;
+  }
+  return anItem;
+}
+
+// =======================================================================
+// function :  currentItem
+// purpose :
+// =======================================================================
+const TreeModel_ItemBasePtr TreeModel_ItemBase::currentItem()
+{
+  return TreeModel_ItemBasePtr (this);
+}
+
+// =======================================================================
+// function :  cachedValue
+// purpose :
+// =======================================================================
+QVariant TreeModel_ItemBase::cachedValue (const int theItemRole) const
+{
+  if (mycachedValues.contains (theItemRole))
+    return mycachedValues[theItemRole];
+
+  const_cast<TreeModel_ItemBase*>(this)->mycachedValues.insert (theItemRole,
+    theItemRole == TreeModel_ItemRole_RowCountRole ? QVariant (initRowCount()) : initValue (theItemRole));
+
+  return mycachedValues.contains (theItemRole) ? mycachedValues[theItemRole] : QVariant();
+}