Fix #115

Adds when_held event hook to Button (via extension of the EventsMixin
class). Also fixes some minor notes and activates codecov coverage
tracking.

.travis.yml

@@ -9,5 +9,11 @@ python:
     - "pypy3"
 install: "pip install -e .[test]"
 script: make test
+before_install:
+    # Coverage 4.0 no longer supports py3.2 and codecov depends on latest coverage
+    - if [[ $TRAVIS_PYTHON_VERSION == '3.2' ]]; then pip install "coverage<4.0dev"; fi
+    - pip install codecov
+after_success:
+    - codecov
 notifications:
     slack: raspberrypifoundation:YoIHtVdg8Hd6gcA09QEmCYXN

docs/api_exc.rst

@@ -43,6 +43,10 @@ Errors
 
 .. autoexception:: BadEventHandler
 
+.. autoexception:: BadQueueLen
+
+.. autoexception:: BadWaitTime
+
 .. autoexception:: CompositeDeviceError
 
 .. autoexception:: CompositeDeviceBadName
@@ -63,10 +67,6 @@ Errors
 
 .. autoexception:: GPIOPinMissing
 
-.. autoexception:: GPIOBadQueueLen
-
-.. autoexception:: GPIOBadSampleWait
-
 .. autoexception:: InputDeviceError
 
 .. autoexception:: OutputDeviceError

docs/api_generic.rst

@@ -37,6 +37,9 @@ There are also several `mixin classes`_:
 * :class:`EventsMixin` which adds activated/deactivated events to devices
   along with the machinery to trigger those events
 
+* :class:`HoldMixin` which derives from :class:`EventsMixin` and adds the
+  held event to devices along with the machinery to repeatedly trigger it
+
 .. _mixin classes: https://en.wikipedia.org/wiki/Mixin
 
 The current class hierarchies are displayed below. For brevity, the mixin
@@ -141,3 +144,6 @@ Mixin Classes
 .. autoclass:: EventsMixin(...)
     :members:
 
+.. autoclass:: HoldMixin(...)
+    :members:
+

docs/api_pins.rst

@@ -72,7 +72,7 @@ to utilize pins that are part of IO extender chips. For example::
 
 .. warning::
 
-    The astute and mischievious reader may note that it is possible to mix pin
+    The astute and mischievous reader may note that it is possible to mix pin
     implementations, e.g. using ``RPiGPIOPin`` for one pin, and ``NativePin``
     for another. This is unsupported, and if it results in your script
     crashing, your components failing, or your Raspberry Pi turning into an

gpiozero/__init__.py

@@ -17,6 +17,8 @@
     GPIOZeroError,
     DeviceClosed,
     BadEventHandler,
+    BadWaitTime,
+    BadQueueLen,
     CompositeDeviceError,
     CompositeDeviceBadName,
     CompositeDeviceBadOrder,
@@ -28,8 +30,6 @@
     GPIODeviceClosed,
     GPIOPinInUse,
     GPIOPinMissing,
-    GPIOBadQueueLen,
-    GPIOBadSampleWait,
     InputDeviceError,
     OutputDeviceError,
     OutputDeviceBadValue,
@@ -61,6 +61,7 @@
     SourceMixin,
     ValuesMixin,
     EventsMixin,
+    HoldMixin,
 )
 from .input_devices import (
     InputDevice,

gpiozero/exc.py

@@ -16,6 +16,12 @@ class DeviceClosed(GPIOZeroError):
 class BadEventHandler(GPIOZeroError, ValueError):
     "Error raised when an event handler with an incompatible prototype is specified"
 
+class BadWaitTime(GPIOZeroError, ValueError):
+    "Error raised when an invalid wait time is specified"
+
+class BadQueueLen(GPIOZeroError, ValueError):
+    "Error raised when non-positive queue length is specified"
+
 class CompositeDeviceError(GPIOZeroError):
     "Base class for errors specific to the CompositeDevice hierarchy"
 
@@ -49,15 +55,6 @@ class GPIOPinInUse(GPIODeviceError):
 class GPIOPinMissing(GPIODeviceError, ValueError):
     "Error raised when a pin number is not specified"
 
-class GPIOBadQueueLen(GPIODeviceError, ValueError):
-    "Error raised when non-positive queue length is specified"
-
-class GPIOBadSampleWait(GPIODeviceError, ValueError):
-    "Error raised when a negative sampling wait period is specified"
-
-class GPIOBadSourceDelay(GPIODeviceError, ValueError):
-    "Error raised when a negative source delay is specified"
-
 class InputDeviceError(GPIODeviceError):
     "Base class for errors specific to the InputDevice hierarchy"
 

gpiozero/input_devices.py

@@ -12,7 +12,7 @@
 
 from .exc import InputDeviceError, DeviceClosed
 from .devices import GPIODevice
-from .mixins import GPIOQueue, EventsMixin
+from .mixins import GPIOQueue, EventsMixin, HoldMixin
 
 
 class InputDevice(GPIODevice):
@@ -222,7 +222,7 @@ def is_active(self):
         return self.value > self.threshold
 
 
-class Button(DigitalInputDevice):
+class Button(HoldMixin, DigitalInputDevice):
     """
     Extends :class:`DigitalInputDevice` and represents a simple push button
     or switch.
@@ -254,11 +254,24 @@ class Button(DigitalInputDevice):
         If ``None`` (the default), no software bounce compensation will be
         performed. Otherwise, this is the length in time (in seconds) that the
         component will ignore changes in state after an initial change.
+
+    :param float hold_time:
+        The length of time (in seconds) to wait after the button is pushed,
+        until executing the :attr:`when_held` handler.
+
+    :param bool hold_repeat:
+        If ``True``, the :attr:`when_held` handler will be repeatedly executed
+        as long as the device remains active, every *hold_time* seconds.
     """
-    def __init__(self, pin=None, pull_up=True, bounce_time=None):
+    def __init__(
+            self, pin=None, pull_up=True, bounce_time=None,
+            hold_time=1, hold_repeat=False):
         super(Button, self).__init__(pin, pull_up, bounce_time)
+        self.hold_time = hold_time
+        self.hold_repeat = hold_repeat
 
 Button.is_pressed = Button.is_active
+Button.pressed_time = Button.active_time
 Button.when_pressed = Button.when_activated
 Button.when_released = Button.when_deactivated
 Button.wait_for_press = Button.wait_for_active