From 7fb1131c2eda5f2330f4e44d9984802f855e9381 Mon Sep 17 00:00:00 2001
From: frank <mailbox@shampoo.ooo>
Date: Fri, 13 Jan 2023 20:27:32 -0500
Subject: [PATCH] save previously detected pin state for buttons to avoid
 multiple fires

---
 electric_sieve/ElectricSieve.py | 35 ++++++++++++++++++++++++---------
 1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/electric_sieve/ElectricSieve.py b/electric_sieve/ElectricSieve.py
index a65b04d..c351dde 100644
--- a/electric_sieve/ElectricSieve.py
+++ b/electric_sieve/ElectricSieve.py
@@ -60,6 +60,12 @@ class ElectricSieve(Game):
                 "int": ["gradient", "height", "x-step"],
                 "float": ["altitude-ratio", "spacing-factor", "velocity-ratio", "fade-speed"]
             }})
+ 
+        # Member dict for tracking pin state changes. Start at 1 because high means unpressed.
+        self.pin_states = {
+            self.PIN_BUTTON_LEFT: 1,
+            self.PIN_BUTTON_RIGHT: 1
+        }
 
         # Rotate the display if requested on the command line or in the configuration
         if self.check_command_line("-rotate"):
@@ -117,18 +123,29 @@ class ElectricSieve(Game):
 
     def gpio_input(self, pin):
         """
-        Translate GPIO input into PGFW commands, so Raspberry Pi wired controllers be used for input. The pin will be checked for a low 
-        signal, meaning the pin has been connected to ground, which is translated to a button press. If the low signal is not detected, it
-        is translated to a button release. Usually called as a callback by `GPIO.add_event_detect` but can be called directly.
+        Translate GPIO input into PGFW commands, so Raspberry Pi wired controllers be used for input. 
+
+        Compare the pin state to what is stored in memory. Only fire an event if there has been a change in state. A change
+        from high to low triggers a press event. A change from low to high triggers a press cancel event.
 
         @param pin   Raspberry Pi pin number as read by the RPi.GPIO library
         """
-        cancel = not (GPIO.input(pin) == GPIO.LOW)
-        if pin == ElectricSieve.PIN_BUTTON_LEFT:
-            self.input.post_command("left", cancel=cancel)
-        elif pin == ElectricSieve.PIN_BUTTON_RIGHT:
-            self.input.post_command("right", cancel=cancel)
-        self.input.post_any_command(id=pin, cancel=cancel)
+        if "--debug" in sys.argv:
+            pin_name = "left" if pin == ElectricSieve.PIN_BUTTON_LEFT else "right"
+            left_pin_state = GPIO.input(ElectricSieve.PIN_BUTTON_LEFT)
+            right_pin_state = GPIO.input(ElectricSieve.PIN_BUTTON_RIGHT)
+            print(f"Received {pin} ({pin_name}) input. Left state is {left_pin_state}. Right state is {right_pin_state}")
+
+        # If the saved state of the pin is the same, there hasn't been a real button press or release, so don't continue
+        if self.pin_states[pin] != GPIO.input(pin):
+            self.pin_states[pin] = GPIO.input(pin)
+            # A high signal means the button is released, and a low signal means it is pressed
+            cancel = not (GPIO.input(pin) == GPIO.LOW)
+            if pin == ElectricSieve.PIN_BUTTON_LEFT:
+                self.input.post_command("left", cancel=cancel)
+            elif pin == ElectricSieve.PIN_BUTTON_RIGHT:
+                self.input.post_command("right", cancel=cancel)
+            self.input.post_any_command(id=pin, cancel=cancel)
 
     def orient(self, geometry):
         """