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_ModelBase.cxx

@@ -0,0 +1,149 @@
+// 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_ModelBase.hxx>
+
+#include <TreeModel_ItemBase.hxx>
+
+// =======================================================================
+// function : Constructor
+// purpose :
+// =======================================================================
+TreeModel_ModelBase::TreeModel_ModelBase (QObject* theParent)
+: QAbstractItemModel (theParent), m_pRootItem (0)
+{
+}
+
+// =======================================================================
+// function :  GetItemByIndex
+// purpose :
+// =======================================================================
+TreeModel_ItemBasePtr TreeModel_ModelBase::GetItemByIndex (const QModelIndex& theIndex)
+{
+  TreeModel_ItemBase* anItem = (TreeModel_ItemBase*)theIndex.internalPointer();
+  return TreeModel_ItemBasePtr (anItem);
+}
+
+// =======================================================================
+// function :  reset
+// purpose :
+// =======================================================================
+void TreeModel_ModelBase::Reset()
+{
+  for (int aColId = 0, aNbColumns = columnCount(); aColId < aNbColumns; aColId++)
+    RootItem (aColId)->Reset();
+}
+
+// =======================================================================
+// function :  index
+// purpose :
+// =======================================================================
+QModelIndex TreeModel_ModelBase::index (int theRow, int theColumn, const QModelIndex& theParent) const
+{
+  if (!hasIndex (theRow, theColumn, theParent))
+    return QModelIndex();
+
+  // to create index on the root item
+  if (!theParent.isValid())
+    return createIndex (theRow, theColumn, getIndexValue (RootItem (theColumn)));
+
+  TreeModel_ItemBasePtr aParentItem;
+  if (!theParent.isValid())
+    aParentItem = RootItem (theColumn);
+  else
+    aParentItem = GetItemByIndex (theParent);
+
+  TreeModel_ItemBasePtr aChildItem = aParentItem->Child (theRow, theColumn);
+  return aChildItem ? createIndex (theRow, theColumn, getIndexValue (aChildItem)) : QModelIndex();
+}
+
+// =======================================================================
+// function :  data
+// purpose :
+// =======================================================================
+QVariant TreeModel_ModelBase::data (const QModelIndex& theIndex, int theRole) const
+{
+  if (!theIndex.isValid())
+    return QVariant ("undefined");
+
+  TreeModel_ItemBasePtr anItem = GetItemByIndex (theIndex);
+  return anItem->data (theIndex, theRole);
+}
+
+// =======================================================================
+// function :  parent
+// purpose :
+// =======================================================================
+QModelIndex TreeModel_ModelBase::parent (const QModelIndex& theIndex) const
+{
+  if (!theIndex.isValid())
+    return QModelIndex();
+
+  TreeModel_ItemBasePtr aChildItem = GetItemByIndex (theIndex);
+  TreeModel_ItemBasePtr aParentItem = aChildItem ? aChildItem->Parent() : TreeModel_ItemBasePtr();
+
+  if (!aParentItem)
+    return QModelIndex();
+
+  return createIndex (aParentItem->Row(), aParentItem->Column(), getIndexValue (aParentItem));
+}
+
+// =======================================================================
+// function :  flags
+// purpose :
+// =======================================================================
+Qt::ItemFlags TreeModel_ModelBase::flags (const QModelIndex& theIndex) const
+{
+  if (!theIndex.isValid())
+    return 0;
+  return Qt::ItemIsEnabled | Qt::ItemIsSelectable;
+}
+
+// =======================================================================
+// function :  rowCount
+// purpose :
+// =======================================================================
+int TreeModel_ModelBase::rowCount (const QModelIndex& theParent) const
+{
+  // to create index on the root item
+  if (!theParent.isValid())
+    return 1;
+
+  TreeModel_ItemBasePtr aParentItem;
+  if (!theParent.isValid())
+    aParentItem = RootItem (0);
+  else
+    aParentItem = GetItemByIndex (theParent);
+
+  return aParentItem ? aParentItem->rowCount() : 0;
+}
+
+// =======================================================================
+// function :  emitLayoutChanged
+// purpose :
+// =======================================================================
+void TreeModel_ModelBase::EmitLayoutChanged()
+{
+  emit layoutChanged();
+}
+
+// =======================================================================
+// function :  getIndexValue
+// purpose :
+// =======================================================================
+void* TreeModel_ModelBase::getIndexValue (const TreeModel_ItemBasePtr& theItem)
+{
+  return theItem.data();
+}