Adding GUI notifications for important events.

server.py

@@ -11,6 +11,7 @@
 from dial_driver import DialSerialDriver
 from server_config import ServerConfig
 from server_dial_handler import ServerDialHandler
+from vu_notifications import show_error_msg, show_info_msg
 
 BASEDIR_NAME = os.path.dirname(__file__)
 BASEDIR_PATH = os.path.abspath(BASEDIR_NAME)
@@ -517,7 +518,11 @@ def __init__(self):
             self.serialPort = DialSerialDriver.find_gauge_hub()
             if self.serialPort is None:
                 logger.error("Could not find VU1 Dials Hub. Please make sure it's plugged in and (if necessary) drivers are installed.")
-                raise Exception("Could not find VU1 Dials Hub. Please make sure it's plugged in and (if necessary) drivers are installed.")
+                show_error_msg("Hub not found", "Could not find VU1 Hub on the USB bus.\r\n"\
+                               "Please make sure it is plugged in and (if necessary) drivers are installed.\r\n"\
+                               "Then restart the VU Server application.\r\nVU server application will close now.")
+                sys.exit(0)
+                # raise Exception("Could not find VU1 Dials Hub. Please make sure it's plugged in and (if necessary) drivers are installed.")
 
         logger.info("VU1 HUB port: {}".format(self.serialPort))
         self.dial_driver = DialSerialDriver(self.serialPort)
@@ -572,13 +577,15 @@ def run_forever(self):
         logger.info(f"VU1 API server is listening on http://localhost:{port}")
         app.listen(port)
 
-        if master_key:
-            logger.info("Master Key is present in config.yaml")
+        if master_key is not None:
+            logger.info("Master Key is present in config.yaml (or using default)")
             logger.info(f"Provide '{master_key}' to your main application.")
             logger.info("to allow it to manage this server and the VU dials.")
         else:
+            show_error_msg(title='Key missing from config', message='Entry "master_key" is missing from the "config.yaml"!')
             logger.error("Master Key is MISSING from config.yaml")
             logger.error("Check your 'config.yaml' or add it manually under 'server' section.")
+            sys.exit(0)
 
         pc = PeriodicCallback(self.dial_handler.periodic_dial_update, dial_update_period)
         pc.start()
@@ -590,6 +597,7 @@ def signal_handler(signal, frame):
     pid_lock('server', False)
     IOLoop.current().add_callback_from_signal(shutdown)
     print('\r\nYou pressed Ctrl+C!')
+    show_info_msg("CTRL+C", "CTRL+C pressed.\r\nVU Server app will exit now.")  # Remove if becomes annoying
     sys.exit(0)
 
 def shutdown():
@@ -619,11 +627,12 @@ def main(cmd_args=None):
     try:
         Dial_API_Service().run_forever()
     except Exception:
-        logger.exception("Dials API service crashed during setup.")
+        logger.exception("VU Dials API service crashed during setup.")
+        show_error_msg("Crashed", "VU Server has crashed unexpectedly!\r\nPlease check log files for more information.")
     os._exit(0)
 
 if __name__ == '__main__':
-    parser = argparse.ArgumentParser(description='Karanovic Research - Dials API service')
+    parser = argparse.ArgumentParser(description='Karanovic Research - VU Dials API service')
     parser.add_argument('-l', '--logging', type=str, default='info', help='Set logging level. Default is `info`')
     args = parser.parse_args()
     main(args)

server_config.py

@@ -3,12 +3,14 @@
 from ruamel.yaml import YAML
 # import yaml
 from dials.base_logger import logger
+from vu_notifications import show_error_msg, show_warning_msg
 import database as db
 
 class ServerConfig:
     config_path = None
     server = None
-    server_default = {'hostname': 'localhost', 'port': 3000, 'master_key': 'cTpAWYuRpA2zx75Yh961Cg' }
+    hardware = None
+    server_default = {'hostname': 'localhost', 'port': 3000, 'communication_timeout': 10, 'master_key': 'cTpAWYuRpA2zx75Yh961Cg' }
     hardware_default = {'port': None }
     dials = {}
     api_keys = {}
@@ -51,6 +53,9 @@ def _save_config(self):
     def _load_config(self):
         if not os.path.exists(self.config_path):
             logger.error(f"Can not load config. Config file '{self.config_path}' does not exist!")
+            show_error_msg("Can not find config.yaml", f"Config file '{self.config_path}' is missing!\r\n"\
+                           "Please fix this issue by creating a default config.yaml file in the VU Server directory.\r\n"\
+                           "Using default values for this session.")
             self._create_default_config()
             return False
 
@@ -59,18 +64,65 @@ def _load_config(self):
             cfg = yaml.load(file)  # pylint: disable=assignment-from-no-return
 
         if cfg is None:
+            show_error_msg("Empty/corrupt config file!", "Config file exists but it is empty or corrupt!\r\n"\
+                           "Using defaul values for this session.")
             self._create_default_config()
             return False
 
+        # Check that config file meets the minimum requirements
+        if not isinstance(cfg, dict) or 'server' not in cfg or 'hardware' not in cfg:
+            show_warning_msg("Missing Key", f"Config file '{self.config_path}' \r\n"\
+                             "Must have valid entries for 'server' and 'hardware' configuration!\r\n"\
+                             "Using defaul values for this session.")
+            cfg = {}
+            cfg['server'] = self.server_default
+            cfg['hardware'] = self.hardware_default
+
+        elif not isinstance(cfg['server'], dict):
+            show_warning_msg("Invalid server config", f"Config file '{self.config_path}' \r\n"\
+                             "Has invalid `server` config entry.\r\n"\
+                             "Using defaul values for this session.")
+            self._force_default_config()
+            return False
+
+        elif not isinstance(cfg['hardware'], dict):
+            show_warning_msg("Invalid server config", f"Config file '{self.config_path}' \r\n"\
+                             "Has invalid `hardware` config entry.\r\n"\
+                             "Using defaul values for this session.")
+            self._force_default_config()
+            return False
+
+        elif ('hostname' not in cfg['server'] or
+             'port' not in cfg['server'] or
+             'communication_timeout' not in cfg['server'] or
+             'master_key' not in cfg['server']):
+            show_warning_msg("Missing Key", f"Config file '{self.config_path}' \r\n"\
+                             "must have `hostname`, `port`, `communication_timeout` and `master_key` entries!\r\n"\
+                             "Using defaul values for this session.")
+            self._force_default_config()
+            return False
+
+        elif 'port' not in cfg['hardware']:
+            show_warning_msg("Missing Key", f"Config file '{self.config_path}' \r\n"\
+                             "must have hardware `port` entry! (it can be left empty)\r\n"\
+                             "Using defaul values for this session.")
+            self._force_default_config()
+            return False
+
         # Load yaml values
         self.server = cfg.get('server', self.server_default)
         self.hardware = cfg.get('hardware', self.hardware_default)
 
         return True
 
+    def _force_default_config(self):
+        self.server = self.server_default
+        self.hardware = self.hardware_default
+
     def _create_default_config(self):
         logger.info("Using default config values")
         self.server = self.server_default
+        self.hardware = self.hardware_default
 
     # Load API keys from config file
     def _load_API_keys(self):

vu_notifications.py

@@ -0,0 +1,24 @@
+# pylint: disable=import-outside-toplevel
+import sys
+
+# TODO: Add support for Linux and Mac OS
+
+if sys.platform.lower() == "win32":
+    import ctypes
+
+    def show_error_msg(title, message):
+        ctypes.windll.user32.MessageBoxW(0, message, f"VU Server - {title}", 16)
+
+    def show_warning_msg(title, message):
+        ctypes.windll.user32.MessageBoxW(0, message, f"VU Server - {title}", 48)
+
+    def show_info_msg(title, message):
+        ctypes.windll.user32.MessageBoxW(0, message, f"VU Server - {title}", 64)
+
+else:
+    def show_error_msg(title, message):
+        pass
+    def show_warning_msg(title, message):
+        pass
+    def show_info_msg(title, message):
+        pass