Permit built-in (C implemented) methods and functions to be used as
event callbacks. Given that prototype introspection is not available for
such routines, assume that they take no (mandatory) parameters.
This finishes off implementing values and source for all (current)
classes in gpiozero. I'm afraid things get rather complex in this
commit. For starters, we've now got quite a few "aggregate" classes
which necessarily don't descend from GPIODevice. To implement values and
source on these I could either repeat a helluva lot of code or ... turn
to mixin classes. Yeah, it's multiple inheritance time, baby!
Unfortunately multiple inheritance doesn't work with __slots__ but we
really ought to keep functionality that they provide us (raise
AttributeError when an unknown attribute is set). So I've implemented
this with ... erm ... metaclasses. Sorry!
Makes `value` an alias of `is_active` in the base `GPIODevice`, and
`values` an infinite iterable of this value. Then adds `source` property
to `OutputDevice` allowing simple linkage of devices via iterators.
Add more property aliases and do them properly (no more lambdas and
string lookups) which means we can remove `_alias`. This commit also
defines `__slots__` for all classes which should prevent assignation of
invalid attributes with an AttributeError (more friendly than silently
doing the wrong thing). Finally, it cleans up all the property defs to
use Ben's preferred decorator style.
This PR adds the `active_high` parameter (defaulted to `True`) to the
`OutputDevice` class. This permits flipping the logic of an output
device in a similar manner to `pull_up` on `InputDevice`.
It also adds a `Relay` class derived from `DigitalOutputDevice` which
uses this parameter to flip the logic (as this is typically required
with relays).
Actually, this isn't so much a fix as a re-working of RGBLED. This
renames the `rgb` property to `color` because that's what the property
really represents (combined with `picamera.Color` this lets you do stuff
like `rgb_led.color = Color('red')`), and simplifies the internals of
the class. It also adds the common `close` method and context manager
capabilities.
Finally, it corrects an error I hadn't noticed earlier where
PWMOutputDevice isn't properly cleaning up PWM threads on close.
Make MotionSensor more responsive by effectively removing the averaging
queue. Also add note on how to smooth out "jittery" PIR sensors by
increasing the queue length back up to 5.
