From 3e52078450a4205fdfaa2d4ba2448bce3d3d19d7 Mon Sep 17 00:00:00 2001
From: Ben Nuttall <ben@bennuttall.com>
Date: Mon, 14 Sep 2015 13:46:08 +0100
Subject: [PATCH] Add wait_for_input and add_callback methods to InputDevice

---
 gpio_components/input_devices.py | 33 +++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/gpio_components/input_devices.py b/gpio_components/input_devices.py
index 125cd9e..3155a4a 100644
--- a/gpio_components/input_devices.py
+++ b/gpio_components/input_devices.py
@@ -6,13 +6,36 @@ GPIO.setwarnings(False)
 
 
 class InputDevice(object):
-    def __init__(self, pin):
-        self.pin = pin
-        GPIO.setup(pin, GPIO.IN, GPIO.PUD_UP)
+    def __init__(self, pin=None):
+        if pin is None:
+            raise InputDeviceError('No GPIO pin number given')
 
-    def is_pressed(self):
-        return GPIO.input(self.pin) == 0
+        self.pin = pin
+        self.pull = GPIO.PUD_UP
+        self.edge = GPIO.FALLING
+        self.active = 0
+        self.inactive = 1
+        GPIO.setup(pin, GPIO.IN, self.pull)
+
+    def is_active(self):
+        return GPIO.input(self.pin) == self.active
+
+    def wait_for_input(self):
+        GPIO.wait_for_edge(self.pin, self.edge)
+
+    def add_callback(self, callback=None, bouncetime=1000):
+        if callback is None:
+            raise InputDeviceError('No callback function given')
+
+        GPIO.add_event_detect(self.pin, self.edge, callback, bouncetime)
+
+    def remove_callback(self):
+        GPIO.remove_event_detect(self.pin)
 
 
 class Button(InputDevice):
     pass
+
+
+class InputDeviceError(Exception):
+    pass