"""Core application engine""" import os import time import pkgutil import importlib import bumblebee.error import bumblebee.modules def modules(): """Return a list of available modules""" result = [] path = os.path.dirname(bumblebee.modules.__file__) for mod in [name for _, name, _ in pkgutil.iter_modules([path])]: result.append({ "name": mod }) return result class Module(object): """Module instance base class Objects of this type represent the modules that the user configures. Concrete module implementations (e.g. CPU utilization, disk usage, etc.) derive from this base class. """ def __init__(self, engine, widgets): self.name = self.__module__.split(".")[-1] self._widgets = [] if widgets: self._widgets = widgets if isinstance(widgets, list) else [widgets] def widgets(self): """Return the widgets to draw for this module""" return self._widgets def update(self, widgets): """By default, update() is a NOP""" pass def parameter(self, name, default=None): """Return the config parameter 'name' for this module""" name = "{}.{}".format(self._config_name, name) return self._config.get(name, default) def set_config(self, config, name): """Set the config for this module""" self._config = config self._config_name = name class Engine(object): """Engine for driving the application This class connects input/output, instantiates all required modules and drives the "event loop" """ def __init__(self, config, output=None): self._output = output self._config = config self._running = True self._modules = [] self.load_modules(config.modules()) def load_modules(self, modules): """Load specified modules and return them as list""" for module in modules: self._modules.append(self.load_module(module["module"], module["name"])) return self._modules def load_module(self, module_name, config_name=None): """Load specified module and return it as object""" if config_name == None: config_name = module_name try: module = importlib.import_module("bumblebee.modules.{}".format(module_name)) except ImportError as error: raise bumblebee.error.ModuleLoadError(error) res = getattr(module, "Module")(self) res.set_config(self._config, config_name) return res def running(self): """Check whether the event loop is running""" return self._running def stop(self): """Stop the event loop""" self._running = False def run(self): """Start the event loop""" self._output.start() while self.running(): self._output.begin() for module in self._modules: module.update(module.widgets()) for widget in module.widgets(): widget.set_module(module) self._output.draw(widget=widget, engine=self) self._output.flush() self._output.end() if self.running(): time.sleep(1) self._output.stop() # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4