- reverted changes in Tools regarding the toggle effect - now they work as expected and added protection against AttributeError that can happen when switching from another tab.

flatcamTools/ToolNonCopperClear.py

@@ -262,6 +262,17 @@ class NonCopperClear(FlatCAMTool, Gerber):
     def run(self, toggle=True):
         self.app.report_usage("ToolNonCopperClear()")
 
+        if toggle:
+            # if the splitter is hidden, display it, else hide it but only if the current widget is the same
+            if self.app.ui.splitter.sizes()[0] == 0:
+                self.app.ui.splitter.setSizes([1, 1])
+            else:
+                try:
+                    if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
+                        self.app.ui.splitter.setSizes([0, 1])
+                except AttributeError:
+                    pass
+
         FlatCAMTool.run(self)
         self.set_tool_ui()