gui: add support for loading plugins from a users home folder

Allows for plugins to be loaded from ~/dronecan_gui_tool/plugin builds

Author: joshanne

dronecan_gui_tool/main.py

@@ -83,6 +83,7 @@ def parse_load_modules(argv):
 #
 # Importing other stuff once the logging has been configured
 #
+from pathlib import Path
 from serial import SerialException
 
 import dronecan
@@ -113,6 +114,14 @@ def parse_load_modules(argv):
 from .panels import PANELS
 from .panels import import_panel
 
+# Add the User ~/dronecan_gui_tool/plugins folder to the import path,
+# allowing for custom plugin modules to be loaded from there.
+plugins_dir = Path.home() / "dronecan_gui_tool" / "plugins"
+if plugins_dir.exists():
+    str_plugin_dir = str(plugins_dir)
+    if str_plugin_dir not in sys.path:
+        sys.path.insert(0, str_plugin_dir)
+
 EXT_PLUGINS = []
 modules = args.load_module[0] if args.load_module else []
 if len(modules) > 0: