[TechDraw] Improve visibility of TD preference icons in combo boxes...

...when using dark style sheets.

src/Mod/TechDraw/App/MattingPropEnum.cpp

@@ -0,0 +1,39 @@
+/***************************************************************************
+ *   Copyright (c) 2020 WandererFan <wandererfan@gmail.com>                *
+ *                                                                         *
+ *   This file is part of the FreeCAD CAx development system.              *
+ *                                                                         *
+ *   This library is free software; you can redistribute it and/or         *
+ *   modify it under the terms of the GNU Library General Public           *
+ *   License as published by the Free Software Foundation; either          *
+ *   version 2 of the License, or (at your option) any later version.      *
+ *                                                                         *
+ *   This library  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 this library; see the file COPYING.LIB. If not,    *
+ *   write to the Free Software Foundation, Inc., 59 Temple Place,         *
+ *   Suite 330, Boston, MA  02111-1307, USA                                *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "PreCompiled.h"
+
+#include "MattingPropEnum.h"
+
+
+namespace TechDraw {
+
+const int   MattingPropEnum::MattingCount = 2;
+const char* MattingPropEnum::MattingTypeEnums[]= {
+    QT_TRANSLATE_NOOP("MattingPropEnum", "Circle"),
+    QT_TRANSLATE_NOOP("MattingPropEnum", "Square"),
+    nullptr};
+
+const std::vector<std::string> MattingPropEnum::MattingTypeIcons = { ":icons/circular.svg",
+                                            ":icons/square.svg"};
+
+}