qtvcp -pstat: add ability to import the default handler class for subclassing

subclassing the handler file makes customizations much easier/safer

Author: c-morley

lib/python/qtvcp/qt_pstat.py

@@ -419,3 +419,14 @@ def find_vismach_files(self):
                     tmp.append(file)
 
         return tmp
+
+    # tempararily adds the screen directory to path
+    # so the handler can be imported to be used for subclassing
+    def importDefaultHandler(self, module=None):
+        import importlib
+        sys.path.insert(0, self.SCREENDIR)
+        if module is None:
+            module = "{}.{}_handler".format(self.BASEPATH,self.BASEPATH)
+        mod = importlib.import_module(module, self.SCREENDIR)
+        sys.path.remove(self.SCREENDIR)
+        return mod.HandlerClass