show and hide touch off setting based on processor

pycam/Plugins/GCodeTouchOff.py

@@ -34,6 +34,8 @@ class GCodeTouchOff(pycam.Plugins.PluginBase):
         if self.gui:
             self.box = self.gui.get_object("TouchOffBox")
             self.box.unparent()
+            self.core.get("register_parameter")("toolpath_processor",
+                    "touch_off", self.box)
             self.core.register_ui("gcode_preferences", "Touch Off",
                     self.box, weight=70)
             self._gtk_handlers = []

pycam/Plugins/ToolpathProcessors.py

@@ -206,6 +206,7 @@ class ToolpathProcessorMilling(pycam.Plugins.PluginBase):
                 "naive_tolerance": 0.0,
                 "spindle_enable": True,
                 "spindle_delay": 3,
+                "touch_off": None,
         }
         self.core.get("register_parameter_set")("toolpath_processor",
                 "milling", "Milling", self.get_filters, parameters=parameters,