Fix #459 - properly support remote SPI with pigpio

Sorry! Dave's messing around with the pin implementations again.
Hopefully the last time. The pin_factory is now really a factory object
which can be asked to produce individual pins or pin-based interfaces
like SPI (which can be supported properly via pigpio).

tests/test_mock_pin.py

@@ -11,25 +11,24 @@ from threading import Event
 
 import pytest
 
-from gpiozero.pins.mock import MockPin, MockPWMPin
+from gpiozero.pins.mock import MockPWMPin, MockPin
 from gpiozero import *
 
 
 def teardown_function(function):
-    MockPin.clear_pins()
+    Device._pin_factory.reset()
+
 
 # Some rough tests to make sure our MockPin is up to snuff. This is just
 # enough to get reasonable coverage but it's by no means comprehensive...
 
 def test_mock_pin_init():
-    with pytest.raises(TypeError):
-        MockPin()
     with pytest.raises(ValueError):
-        MockPin(60)
-    assert MockPin(2).number == 2
+        Device._pin_factory.pin(60)
+    assert Device._pin_factory.pin(2).number == 2
 
 def test_mock_pin_defaults():
-    pin = MockPin(2)
+    pin = Device._pin_factory.pin(2)
     assert pin.bounce == None
     assert pin.edges == 'both'
     assert pin.frequency == None
@@ -39,30 +38,23 @@ def test_mock_pin_defaults():
     assert pin.when_changed == None
 
 def test_mock_pin_open_close():
-    pin = MockPin(2)
+    pin = Device._pin_factory.pin(2)
     pin.close()
 
 def test_mock_pin_init_twice_same_pin():
-    pin1 = MockPin(2)
-    pin2 = MockPin(pin1.number)
+    pin1 = Device._pin_factory.pin(2)
+    pin2 = Device._pin_factory.pin(pin1.number)
     assert pin1 is pin2
 
 def test_mock_pin_init_twice_different_pin():
-    pin1 = MockPin(2)
-    pin2 = MockPin(pin1.number+1)
+    pin1 = Device._pin_factory.pin(2)
+    pin2 = Device._pin_factory.pin(pin1.number+1)
     assert pin1 != pin2
     assert pin1.number == 2
     assert pin2.number == pin1.number+1
 
-def test_mock_pwm_pin_init():
-    with pytest.raises(TypeError):
-        MockPWMPin()
-    with pytest.raises(ValueError):
-        MockPWMPin(60)
-    assert MockPWMPin(2).number == 2
-
 def test_mock_pwm_pin_defaults():
-    pin = MockPWMPin(2)
+    pin = Device._pin_factory.pin(2, pin_class=MockPWMPin)
     assert pin.bounce == None
     assert pin.edges == 'both'
     assert pin.frequency == None
@@ -72,38 +64,38 @@ def test_mock_pwm_pin_defaults():
     assert pin.when_changed == None
 
 def test_mock_pwm_pin_open_close():
-    pin = MockPWMPin(2)
+    pin = Device._pin_factory.pin(2, pin_class=MockPWMPin)
     pin.close()
 
 def test_mock_pwm_pin_init_twice_same_pin():
-    pin1 = MockPWMPin(2)
-    pin2 = MockPWMPin(pin1.number)
+    pin1 = Device._pin_factory.pin(2, pin_class=MockPWMPin)
+    pin2 = Device._pin_factory.pin(pin1.number, pin_class=MockPWMPin)
     assert pin1 is pin2
 
 def test_mock_pwm_pin_init_twice_different_pin():
-    pin1 = MockPWMPin(2)
-    pin2 = MockPWMPin(pin1.number+1)
+    pin1 = Device._pin_factory.pin(2, pin_class=MockPWMPin)
+    pin2 = Device._pin_factory.pin(pin1.number + 1, pin_class=MockPWMPin)
     assert pin1 != pin2
     assert pin1.number == 2
     assert pin2.number == pin1.number+1
 
 def test_mock_pin_init_twice_different_modes():
-    pin1 = MockPin(2)
-    pin2 = MockPWMPin(pin1.number+1)
+    pin1 = Device._pin_factory.pin(2, pin_class=MockPin)
+    pin2 = Device._pin_factory.pin(pin1.number + 1, pin_class=MockPWMPin)
     assert pin1 != pin2
     with pytest.raises(ValueError):
-        pin3 = MockPWMPin(pin1.number)
+        Device._pin_factory.pin(pin1.number, pin_class=MockPWMPin)
     with pytest.raises(ValueError):
-        pin4 = MockPin(pin2.number)
+        Device._pin_factory.pin(pin2.number, pin_class=MockPin)
 
 def test_mock_pin_frequency_unsupported():
-    pin = MockPin(2)
+    pin = Device._pin_factory.pin(2)
     pin.frequency = None
     with pytest.raises(PinPWMUnsupported):
         pin.frequency = 100
 
 def test_mock_pin_frequency_supported():
-    pin = MockPWMPin(2)
+    pin = Device._pin_factory.pin(2, pin_class=MockPWMPin)
     pin.function = 'output'
     assert pin.frequency is None
     pin.frequency = 100
@@ -112,7 +104,7 @@ def test_mock_pin_frequency_supported():
     assert not pin.state
 
 def test_mock_pin_pull():
-    pin = MockPin(2)
+    pin = Device._pin_factory.pin(2)
     pin.function = 'input'
     assert pin.pull == 'floating'
     pin.pull = 'up'
@@ -121,7 +113,7 @@ def test_mock_pin_pull():
     assert not pin.state
 
 def test_mock_pin_state():
-    pin = MockPin(2)
+    pin = Device._pin_factory.pin(2)
     with pytest.raises(PinSetInput):
         pin.state = 1
     pin.function = 'output'
@@ -134,7 +126,7 @@ def test_mock_pin_state():
     assert pin.state == 1
 
 def test_mock_pwm_pin_state():
-    pin = MockPWMPin(2)
+    pin = Device._pin_factory.pin(2, pin_class=MockPWMPin)
     with pytest.raises(PinSetInput):
         pin.state = 1
     pin.function = 'output'
@@ -147,7 +139,7 @@ def test_mock_pwm_pin_state():
     assert pin.state == 0.5
 
 def test_mock_pin_edges():
-    pin = MockPin(2)
+    pin = Device._pin_factory.pin(2)
     assert pin.when_changed is None
     fired = Event()
     pin.function = 'input'