Gui: add SoToggleSwitch class

update

src/Gui/CMakeLists.txt

@@ -1079,6 +1079,7 @@ SET(Inventor_CPP_SRCS
     Inventor/SoFCBoundingBox.cpp
     Inventor/SoMouseWheelEvent.cpp
     Inventor/SoFCTransform.cpp
+    Inventor/SoToggleSwitch.cpp
     Inventor/Draggers/SoTransformDragger.cpp
     Inventor/Draggers/SoLinearDragger.cpp
     Inventor/Draggers/SoPlanarDragger.cpp
@@ -1115,6 +1116,7 @@ SET(Inventor_SRCS
     Inventor/SoFCBoundingBox.h
     Inventor/SoMouseWheelEvent.h
     Inventor/SoFCTransform.h
+    Inventor/SoToggleSwitch.h
     Inventor/Draggers/SoTransformDragger.h
     Inventor/Draggers/SoLinearDragger.h
     Inventor/Draggers/SoPlanarDragger.h

src/Gui/Inventor/SoToggleSwitch.cpp

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/****************************************************************************
+ *                                                                          *
+ *   Copyright (c) 2025 Sayantan Deb <sayantandebin[at]gmail.com>           *
+ *                                                                          *
+ *   This file is part of FreeCAD.                                          *
+ *                                                                          *
+ *   FreeCAD is free software: you can redistribute it and/or modify it     *
+ *   under the terms of the GNU Lesser General Public License as            *
+ *   published by the Free Software Foundation, either version 2.1 of the   *
+ *   License, or (at your option) any later version.                        *
+ *                                                                          *
+ *   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       *
+ *   Lesser General Public License for more details.                        *
+ *                                                                          *
+ *   You should have received a copy of the GNU Lesser General Public       *
+ *   License along with FreeCAD. If not, see                                *
+ *   <https://www.gnu.org/licenses/>.                                       *
+ *                                                                          *
+ ***************************************************************************/
+
+#include "SoToggleSwitch.h"
+
+SO_NODE_SOURCE(SoToggleSwitch)
+
+void SoToggleSwitch::initClass()
+{
+    SO_NODE_INIT_CLASS(SoToggleSwitch, SoSwitch, "Switch");
+}
+
+SoToggleSwitch::SoToggleSwitch()
+{
+    SO_NODE_CONSTRUCTOR(SoToggleSwitch);
+    SO_NODE_ADD_FIELD(on, (1));
+
+    whichChild = SO_SWITCH_ALL;
+}
+
+void SoToggleSwitch::toggle()
+{
+    on = !on.getValue();
+}
+
+void SoToggleSwitch::notify(SoNotList* notList)
+{
+    assert(notList);
+    if (notList->getLastField() == &on) {
+        whichChild = on.getValue()? SO_SWITCH_ALL : SO_SWITCH_NONE;
+    }
+
+    inherited::notify(notList);
+}

src/Gui/Inventor/SoToggleSwitch.h

@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/****************************************************************************
+ *                                                                          *
+ *   Copyright (c) 2025 Sayantan Deb <sayantandebin[at]gmail.com>           *
+ *                                                                          *
+ *   This file is part of FreeCAD.                                          *
+ *                                                                          *
+ *   FreeCAD is free software: you can redistribute it and/or modify it     *
+ *   under the terms of the GNU Lesser General Public License as            *
+ *   published by the Free Software Foundation, either version 2.1 of the   *
+ *   License, or (at your option) any later version.                        *
+ *                                                                          *
+ *   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       *
+ *   Lesser General Public License for more details.                        *
+ *                                                                          *
+ *   You should have received a copy of the GNU Lesser General Public       *
+ *   License along with FreeCAD. If not, see                                *
+ *   <https://www.gnu.org/licenses/>.                                       *
+ *                                                                          *
+ ***************************************************************************/
+
+#ifndef SO_TOGGLE_SWITCH
+#define SO_TOGGLE_SWITCH
+
+#include <Inventor/fields/SoSFBool.h>
+#include <Inventor/nodes/SoSwitch.h>
+
+
+/**
+ * A switch that can be used to show or hide all child nodes
+ */
+class SoToggleSwitch: public SoSwitch
+{
+    SO_NODE_HEADER(SoToggleSwitch);
+
+public:
+    static void initClass();
+    SoToggleSwitch();
+
+    // the switch is on be default
+    SoSFBool on;
+    // toggles the switch state
+    void toggle();
+
+protected:
+    ~SoToggleSwitch() override = default;
+
+    void notify(SoNotList* notList) override;
+
+private:
+    using inherited = SoSwitch;
+};
+
+#endif /* SO_TOGGLE_SWITCH */

src/Gui/Utilities.h

@@ -446,9 +446,16 @@ private:
 #define FC_SET_SWITCH(__name__, __state__) \
 do { \
     SoSwitch* sw = SO_GET_ANY_PART(this, __name__, SoSwitch); \
+    assert(sw); \
     sw->whichChild = __state__; \
 } while (0)
 
+#define FC_SET_TOGGLE_SWITCH(__name__, __state__) \
+do { \
+    SoToggleSwitch* sw = SO_GET_ANY_PART(this, __name__, SoToggleSwitch); \
+    assert(sw); \
+    sw->on = __state__; \
+} while (0)
 
 struct RotationComponents {
     float angle;