From 5e32bd12ff720b995b9b9c2b7f71ee37aba810bd Mon Sep 17 00:00:00 2001
From: Sven Sager <akira@narux.de>
Date: Sun, 19 Jul 2020 18:20:39 +0200
Subject: [PATCH] Add .changed(io, edge) -> bool function to CycleTools.

You can detect changes of IO values between two cycles. The function will
return True or False.
On bit IO objects you can also use parameter edge RISING or FALLING.
---
 revpimodio2/helper.py | 38 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/revpimodio2/helper.py b/revpimodio2/helper.py
index ae04d68..9fa37c6 100644
--- a/revpimodio2/helper.py
+++ b/revpimodio2/helper.py
@@ -7,6 +7,7 @@ from threading import Event, Lock, Thread
 from timeit import default_timer
 
 from revpimodio2 import BOTH, FALLING, RISING
+from revpimodio2.io import IOBase
 
 __author__ = "Sven Sager"
 __copyright__ = "Copyright (C) 2018 Sven Sager"
@@ -86,7 +87,8 @@ class Cycletools:
     """
 
     __slots__ = "__cycle", "__cycletime", "__ucycle", "__dict_ton", \
-                "__dict_tof", "__dict_tp", "_start_timer", "core", "device", \
+                "__dict_tof", "__dict_tp", "__dict_change", \
+                "_start_timer", "core", "device", \
                 "first", "io", "last", "var", \
                 "flag1c", "flag5c", "flag10c", "flag15c", "flag20c", \
                 "flank5c", "flank10c", "flank15c", "flank20c"
@@ -96,6 +98,7 @@ class Cycletools:
         self.__cycle = 0
         self.__cycletime = cycletime
         self.__ucycle = 0
+        self.__dict_change = {}
         self.__dict_ton = {}
         self.__dict_tof = {}
         self.__dict_tp = {}
@@ -183,6 +186,39 @@ class Cycletools:
             self.flag5c = not self.flag5c
             self.__cycle = 0
 
+        # Process changed values
+        for io in self.__dict_change:
+            self.__dict_change[io] = io.get_value()
+
+    def changed(self, io: IOBase, edge=BOTH):
+        """
+        Check change of IO value from last to this cycle.
+
+        It will always be False on the first use of this function with an
+        IO object.
+
+        :param io: IO to check for changes to last cycle
+        :return: True, if IO value changed
+        """
+        if io in self.__dict_change:
+            if edge == BOTH:
+                return self.__dict_change[io] != io.get_value()
+            else:
+                value = io.get_value()
+                return self.__dict_change[io] != value and (
+                    value and edge == RISING or
+                    not value and edge == FALLING
+                )
+        else:
+            if not isinstance(io, IOBase):
+                raise TypeError("parameter 'io' must be an io object")
+            if not (edge == BOTH or type(io.value) == bool):
+                raise ValueError(
+                    "parameter 'edge' can be used with bit io objects only"
+                )
+            self.__dict_change[io] = None
+            return False
+
     def get_tof(self, name: str) -> bool:
         """
         Wert der Ausschaltverzoegerung.