[Draft] Dimension style object

still have to split viewprovider from object.
[Draft] Dimension Style code cleanup

thx @vocx-fc for reviewing
further cleanup


[Draft] Dimension Style improvements

Added a property to the dimension object to link the dimension style.
Improved the update of dimensions when style changes. This can be done in 2 different ways: by setting AutoUpdate property to True or by activating Update function from the viewprovider context menu.

src/Mod/Draft/draftobjects/style_dimension.py

@@ -0,0 +1,54 @@
+# ***************************************************************************
+# *   (c) 2020 Carlo Pavan                                                  *
+# *                                                                         *
+# *   This file is part of the FreeCAD CAx development system.              *
+# *                                                                         *
+# *   This program is free software; you can redistribute it and/or modify  *
+# *   it under the terms of the GNU Lesser General Public License (LGPL)    *
+# *   as published by the Free Software Foundation; either version 2 of     *
+# *   the License, or (at your option) any later version.                   *
+# *   for detail see the LICENCE text file.                                 *
+# *                                                                         *
+# *   FreeCAD is distributed in the hope that it will be useful,            *
+# *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+# *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+# *   GNU Library General Public License for more details.                  *
+# *                                                                         *
+# *   You should have received a copy of the GNU Library General Public     *
+# *   License along with FreeCAD; if not, write to the Free Software        *
+# *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  *
+# *   USA                                                                   *
+# *                                                                         *
+# ***************************************************************************
+
+"""This module provides the object code for Draft DimensionStyle.
+"""
+## @package style_dimension
+# \ingroup DRAFT
+# \brief This module provides the object code for Draft DimensionStyle.
+
+import FreeCAD as App
+import Draft
+from Draft import _DraftObject
+from PySide.QtCore import QT_TRANSLATE_NOOP
+
+if App.GuiUp:
+    import FreeCADGui as Gui
+    from draftviewproviders.view_style_dimension import ViewProviderDraftDimensionStyle
+
+def make_dimension_style(existing_dimension = None):
+    """
+    Make dimension style
+    """
+    if not App.ActiveDocument:
+        App.Console.PrintError("No active document. Aborting\n")
+        return
+    obj = App.ActiveDocument.addObject("App::FeaturePython","DimensionStyle")
+    DimensionStyle(obj)
+    if App.GuiUp:
+        ViewProviderDraftDimensionStyle(obj.ViewObject, existing_dimension)
+    return obj
+
+class DimensionStyle(_DraftObject):
+    def __init__(self, obj):
+        _DraftObject.__init__(self, obj, "DimensionStyle")