Fixed config load cancelling behavior.

src/user_interface.py

@@ -1357,7 +1357,10 @@ class HardwareConfiguration(Frame):
         # open file selection dialogue at current path and save path of selected file
         filename = filedialog.askopenfilename(initialdir=directory, title="Select Config File",
                                               filetypes=(("Config File", "*.ini*"), ("All Files", "*.*")))
-        if os.path.exists(filename):  # does the file exist?
+        if filename == () or filename == '':
+            # this happens when file selection window is closed without selecting a file
+            ui_print("No file selected, could not load config.")
+        elif os.path.exists(filename):  # does the file exist?
             config.CONFIG_FILE = filename  # set global config file to the new file
             config.CONFIG_OBJECT = config.get_config_from_file(filename)  # load from config file to config object
             config.check_config(config.CONFIG_OBJECT)  # check and display warnings if values are out of bounds
@@ -1365,8 +1368,6 @@ class HardwareConfiguration(Frame):
             ui_print("\nReinitializing devices...")
             g.CAGE_DEVICE.reconnect_hardware_async()  # reinitialize devices and program with new values
             self.update_fields()  # update entry fields to show new values
-        elif filename == '':  # this happens when file selection window is closed without selecting a file
-            ui_print("No file selected, could not load config.")
         else:  # file does not exist
             ui_print("Selected file", filename, "does not exist, could not load config.")