bumblebee-status/bumblebee/engine.py
Tobi-wan Kenobi f645203579 [core] Widget creation/update overhaul
Until now, widgets were re-created during each iteration. For multiple,
reasons, using static widget objects is much easier, so instead of
creating new widgets continuously, modules now create the widgets during
instantiation and get the list of widgets passed as parameter whenever
an update occurs. During the update, they can still manipulate the
widget list by removing and adding elements as needed.

Advantages:
* Less memory fragmentation (fewer (de)allocations)
* Easier event management (widgets now have static IDs)
* Easier module code (widget contents can simply be the result of a
  callback)

see #23
2016-12-08 08:44:54 +01:00

71 lines
2.1 KiB
Python

"""Core application engine"""
import time
import importlib
import bumblebee.error
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._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
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._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"]))
return self._modules
def load_module(self, module_name):
"""Load specified module and return it as object"""
try:
module = importlib.import_module("bumblebee.modules.{}".format(module_name))
except ImportError as error:
raise bumblebee.error.ModuleLoadError(error)
return getattr(module, "Module")(self)
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():
for module in self._modules:
module.update(module.widgets())
self._output.draw(widgets=module.widgets(), engine=self)
self._output.flush()
if self.running():
time.sleep(1)
self._output.stop()
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