gui: Add support for loading external installed modules

dronecan_gui_tool/main.py

@@ -15,6 +15,12 @@
 
 assert sys.version[0] == '3'
 
+def parse_load_modules(argv):
+    modules = [m.strip() for m in argv.split(",") if m.strip()]
+    if not modules:
+        return None
+    return modules
+
 from argparse import ArgumentParser
 parser = ArgumentParser(description='DroneCAN GUI tool')
 
@@ -30,6 +36,8 @@
 parser.add_argument("--target-system", help="set the targetted system", type=int, default=0)
 parser.add_argument("--source-system", help="set the source system", type=int, default=250)
 
+parser.add_argument("--load-module", type=parse_load_modules, nargs=1,  help="Comma-separated list of modules to load (e.g. mod1,mod2).") # exactly one argument required if flag is present
+
 args = parser.parse_args()
 
 #
@@ -75,6 +83,7 @@
 #
 # Importing other stuff once the logging has been configured
 #
+from pathlib import Path
 from serial import SerialException
 
 import dronecan
@@ -103,7 +112,26 @@
 from .widgets.can_adapter_control_panel import spawn_window as spawn_can_adapter_control_panel
 
 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:
+    for module in modules:
+        try:
+            panel = import_panel(module)
+            EXT_PLUGINS.append(panel)
+        except Exception as ex:
+            print(f"Unable to load {module}: {ex}")
+    print(f"Loaded {len(EXT_PLUGINS)} plugin modules!")
 
 NODE_NAME = 'org.dronecan.gui_tool'
 
@@ -212,6 +240,39 @@ def __init__(self, node, iface_name, iface_kwargs):
             action.triggered.connect(lambda state, panel=panel: panel.safe_spawn(self, self._node))
             panels_menu.addAction(action)
 
+        #
+        # External Modules menu
+        #
+        def get_or_create_submenu(parent_menu, menu_name):
+            """
+            Find a submenu with menu_name under parent_menu, or create it if not found.
+            """
+            for action in parent_menu.actions():
+                submenu = action.menu()
+                if submenu and submenu.title() == menu_name:
+                    return submenu
+            # Not found, create new submenu
+            return parent_menu.addMenu(menu_name)
+
+        if len(EXT_PLUGINS) > 0:
+            extern_modules_menu = self.menuBar().addMenu('P&lugins')
+            for idx, panel in enumerate(EXT_PLUGINS):
+                menu_path = getattr(panel, "menu_path", "")
+                path_parts = [p for p in menu_path.split("/") if p]
+
+                current_menu = extern_modules_menu
+                for part in path_parts:
+                    current_menu = get_or_create_submenu(current_menu, part)
+
+                action = QAction(panel.name, self)
+                icon = panel.get_icon()
+                if icon:
+                    action.setIcon(icon)
+                if idx < 9:
+                    action.setShortcut(QKeySequence(f'Ctrl+Shift+[,{(idx + 1)}'))
+                action.triggered.connect(lambda state, panel=panel: panel.safe_spawn(self, self._node))
+                current_menu.addAction(action)
+
         #
         # Help menu
         #

dronecan_gui_tool/panels/__init__.py

@@ -18,6 +18,8 @@
 from . import hobbywing_esc
 from . import rc_panel
 
+import importlib.util
+
 class PanelDescriptor:
     def __init__(self, module):
         self.name = module.PANEL_NAME
@@ -36,6 +38,23 @@ def safe_spawn(self, parent, node):
         except Exception as ex:
             show_error('Panel error', 'Could not spawn panel', ex)
 
+def import_panel(name):
+    """Given a package name like 'foo.bar.quux', imports the package
+    and returns the desired module."""
+    spec = importlib.util.find_spec(name)
+    mod = None
+    if spec is None:
+        raise Exception(f"Module '{name}' not found!")
+    else:
+        mod = importlib.import_module(name)
+        print(f"Successfully imported {name} from {mod.__file__}")
+    return PluginPanelDescriptor(mod)
+
+class PluginPanelDescriptor(PanelDescriptor):
+    def __init__(self, module):
+        super().__init__(module)
+
+        self.menu_path = getattr(module, "MENU_PATH", "")
 
 PANELS = [
     PanelDescriptor(esc_panel),