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_TreeLevelLineModel.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 <DFBrowser_TreeLevelLineModel.hxx>
+
+#include <DFBrowser_ItemBase.hxx>
+#include <TreeModel_ModelBase.hxx>
+
+#include <QIcon>
+#include <QWidget>
+
+// =======================================================================
+// function : Init
+// purpose :
+// =======================================================================
+void DFBrowser_TreeLevelLineModel::Init (const QModelIndex& theTreeIndex)
+{
+  myTreeIndex = theTreeIndex;
+  myLevelItems.clear();
+
+  if (theTreeIndex.isValid())
+  {
+    myLevelItems.prepend (theTreeIndex);
+    QModelIndex aParent = theTreeIndex.parent();
+    while (aParent.isValid())
+    {
+      myLevelItems.prepend (aParent);
+      aParent = aParent.parent();
+    }
+  }
+  emit layoutChanged();
+}
+
+// =======================================================================
+// function : data
+// purpose :
+// =======================================================================
+QVariant DFBrowser_TreeLevelLineModel::data (const QModelIndex& theIndex, int theRole) const
+{
+  QVariant aValue;
+  int aColumns = theIndex.column();
+  if (aColumns < myLevelItems.size())
+  {
+    QModelIndex aTreeIndex = myLevelItems[aColumns];
+    if (theRole == Qt::DecorationRole) //! do not show icons presented in tree view
+      return aValue;
+    TreeModel_ItemBasePtr anItemBase = TreeModel_ModelBase::GetItemByIndex (aTreeIndex);
+    if (anItemBase)
+    {
+      DFBrowser_ItemBasePtr aDBrowserItem = itemDynamicCast<DFBrowser_ItemBase> (anItemBase);
+      bool aPrevValue = aDBrowserItem->SetUseAdditionalInfo (false);
+      aValue = aDBrowserItem->data (aTreeIndex, theRole);
+      aDBrowserItem->SetUseAdditionalInfo (aPrevValue);
+
+    }
+    if (theRole == Qt::DisplayRole)
+      aValue = aValue.toString() + "  "; //! TEMPORARY to leave place for the action icon
+  }
+  return aValue;
+}
+
+// =======================================================================
+// function : headerData
+// purpose :
+// =======================================================================
+QVariant DFBrowser_TreeLevelLineModel::headerData (int theSection, Qt::Orientation theOrientation, int theRole) const
+{
+  QVariant aValue;
+  if (theOrientation == Qt::Horizontal && theSection < myLevelItems.size())
+  {
+    QModelIndex aTreeIndex = myLevelItems[theSection];
+    if (!aTreeIndex.isValid()) // level change action
+    {
+      if (theRole == Qt::SizeHintRole)
+        aValue = QSize (2, 2);
+      else if (theRole == Qt::DisplayRole)
+        aValue = "";
+    }
+  }
+  return aValue;
+}