gui: Add support for loading external installed modules

[joshanne]

I've been using a modified version of this for some time now.

It borrows from the idea that a user could extend the interface to provide their own functionality.

The most basic of plugin modules looks like so:

import dronecan
from PyQt6.QtWidgets import QVBoxLayout, QWidget, QLabel, QDialog, QPlainTextEdit
from PyQt6.QtCore import Qt
from logging import getLogger

__all__ = 'PANEL_NAME', 'spawn', 'get_icon'

PANEL_NAME = 'Custom Panel'

logger = getLogger(__name__)

_singleton = None

class CustomPanel(QDialog):
    def __init__(self, parent, node):
        super(CustomPanel, self).__init__(parent)
        self.setWindowTitle('My Custom Panel')
        self.setAttribute(Qt.WA_DeleteOnClose)

        self._node = node

        layout = QVBoxLayout(self)
        layout.addWidget(QLabel('This is a label!', self))
        self.setLayout(layout)

    def closeEvent(self, event):
        global _singleton
        _singleton = None
        super(CustomPanel, self).closeEvent(event)

def spawn(parent, node):
    global _singleton
    if _singleton is None:
        _singleton = CustomPanel(parent, node)

    _singleton.show()
    _singleton.raise_()
    _singleton.activateWindow()

    return _singleton

def get_icon():
    return None

These modules can then be distributed as wheels and loaded by the user when required.

[Copilot]

Pull request overview

This PR adds a simple plugin mechanism that allows the GUI tool to load externally installed panel modules (e.g., distributed as wheels) and surface them in the UI as additional menu entries.

Changes:

• Adds dynamic import support for panel modules via a new import_panel() helper and PluginPanelDescriptor.
• Introduces a --load-module CLI flag to load one or more plugin modules at startup and register them into a new “Plugins” menu.
• Adds support for optional hierarchical plugin menu placement via a MENU_PATH attribute.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
dronecan_gui_tool/panels/init.py	Adds plugin import helper and a descriptor subclass to wrap external panel modules.
dronecan_gui_tool/main.py	Adds CLI parsing, sys.path plugin directory injection, plugin loading, and a Plugins menu builder.

Suppressed comments (2)

dronecan_gui_tool/panels/init.py:45

• import_panel() raises a generic Exception and prints to stdout. Using ModuleNotFoundError/ImportError keeps error handling idiomatic, and avoiding print prevents noisy output (the app already has logging configured).

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

dronecan_gui_tool/main.py:273

• The shortcut string for plugin panels is malformed ("Ctrl+Shift+[,{n}") and likely won’t register as intended. The built-in Panels menu uses the standard Ctrl+Shift+ format.

                if idx < 9:
                    action.setShortcut(QKeySequence(f'Ctrl+Shift+[,{(idx + 1)}'))
                action.triggered.connect(lambda state, panel=panel: panel.safe_spawn(self, self._node))

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[joshanne]

Copilot found some legitimate issues.
They have been resolved.