Feature/keyboard events

arduino/arduino.py

@@ -2,7 +2,7 @@
 from time import sleep_ms, ticks_us
 from random import randrange
 from math import sin, cos, radians, floor, ceil
-from sys import exit
+from .key_handler import KeyHandler
 
 OUTPUT = Pin.OUT
 INPUT = Pin.IN
@@ -110,13 +110,40 @@ def copy_sketch(source_path = '', destination_path = '.', name = None, overwrite
   return create_sketch(sketch_name = name, destination_path = destination_path, overwrite = overwrite, source_path = source_path)
 
 # RUNTIME
+
+# KEY EVENTS IN REPL
+KEY_UP = KeyHandler.UP
+KEY_DOWN = KeyHandler.DOWN
+KEY_LEFT = KeyHandler.LEFT
+KEY_RIGHT = KeyHandler.RIGHT
+KEY_ESC = KeyHandler.ESC
+KEY_ENTER = KeyHandler.ENTER
+KEY_SPACE = KeyHandler.SPACE
+
+_key_handler = KeyHandler()
+def add_key_listener(key, callback, *params):
+  _key_handler.add_key_listener(key, callback, *params)
+
+def remove_key_listener(key = None):
+  if key is None:
+     return _key_handler.remove_all_listeners()
+  return _key_handler.remove_key_listener(key)
+
+def read_keys():
+  _key_handler.read_keys()
+
+
+# RUN LOOP
+
 def start(setup=None, loop=None, cleanup = None, preload = None):
+  remove_key_listener()
   if preload is not None:
     preload()
   if setup is not None:
     setup()
   try:
     while True:
+      read_keys()
       if loop is not None:
         loop()
       if not NON_BLOCKING:

arduino/examples/03_keyboard_REPL.py

@@ -0,0 +1,57 @@
+# Keyboard use in REPL
+# by Ubi de Feo
+#
+# This demo code shows how to implement interactive behaviour in REPL.
+# When running this code in a REPL session, using keys can trigger actions.
+# 
+# Simply add a listener for a key (KEY_UP, KEY_DOWN, ENTER, ESC, etc.) and a callback.
+# Supports variable arguments which must be handled by the callback (see setup())
+
+from arduino import *
+
+item_selected = None
+
+def inventory(open = True):
+  if open:
+    print('- open inventory -')
+    print('(a) Potion - Get more energy')
+    print('(b) Key - Open a door')
+    print('(c) Sword - Defend from enemy')
+  else:
+    print('- closing inventory -')
+
+def select_item(item, description):
+  global item_selected
+  item_selected = item
+  print(f'Item selected: {item}')
+  print(f'Description: {description}')
+
+def use_item():
+  print(f'using {item_selected}')
+
+def player_move(direction):
+  print(f'Player moving {direction}')
+
+def setup():
+  add_key_listener(KEY_ESC, inventory, False)
+  add_key_listener(KEY_ENTER, inventory)
+  add_key_listener(KEY_SPACE, use_item)
+  add_key_listener(KEY_UP, player_move, 'UP')
+  add_key_listener(KEY_DOWN, player_move, 'DOWN')
+  add_key_listener(KEY_LEFT, player_move, 'LEFT')
+  add_key_listener(KEY_RIGHT, player_move, 'RIGHT')
+  add_key_listener('a', select_item, 'potion', 'get more energy')
+  add_key_listener('b', select_item, 'key', 'open a door')
+  add_key_listener('c', select_item, 'sword', 'defend from enemy')
+  print('starting...')
+  print('Arrows: move')
+  print('Enter: open inventory')
+  print('ESC: close inventory')
+  print('a: select potion')
+  print('b: select key')
+  print('c: select sword')
+
+def loop():
+  delay(10)
+
+start(setup, loop)

arduino/key_handler.py

@@ -0,0 +1,77 @@
+import select
+from sys import stdin
+
+class KeyHandler:
+  UP = "arrow_up"
+  DOWN = "arrow_down"
+  LEFT = "arrow_left"
+  RIGHT = "arrow_right"
+  ESC = "esc"
+  ENTER = "enter"
+  SPACE = " "
+  ESCAPE_SEQUENCE_TIMEOUT = 0.01
+  def __init__(self):
+    self._key_events = {}
+
+  def add_key_listener(self, key, callback, *params):
+    key_event = KeyEvent(key, callback, params if params else None)
+    self._key_events[key] = key_event
+
+  def remove_key_listener(self, key):
+    if key in self._key_events:
+      del self._key_events[key]
+      return True
+    return False
+
+  def remove_all_listeners(self):
+    self._key_events.clear()
+    return True
+
+  def _key_is_down(self):
+    if stdin in select.select([stdin], [], [], KeyHandler.ESCAPE_SEQUENCE_TIMEOUT)[0]:
+      ch = stdin.read(1)
+
+      if ch == '\n' or ch == '\r':
+        return self.ENTER
+
+      if ch == '\x1b':
+        # Wait briefly for escape sequence
+        if stdin in select.select([stdin], [], [], KeyHandler.ESCAPE_SEQUENCE_TIMEOUT)[0]:
+          next_ch = stdin.read(1)
+          if next_ch == '[':
+            if stdin in select.select([stdin], [], [], KeyHandler.ESCAPE_SEQUENCE_TIMEOUT)[0]:
+              arrow_ch = stdin.read(1)
+              if arrow_ch == 'A':
+                return self.UP
+              elif arrow_ch == 'B':
+                return self.DOWN
+              elif arrow_ch == 'C':
+                return self.RIGHT
+              elif arrow_ch == 'D':
+                return self.LEFT
+        return self.ESC
+
+      return ch
+
+    return None
+
+  def read_keys(self):
+    while True:
+      detected_key = self._key_is_down()
+      if detected_key is None:
+        break
+      if detected_key in self._key_events:
+        self._key_events[detected_key].trigger()
+
+
+class KeyEvent:
+  def __init__(self, key=None, callback=None, args=None):
+    self.key = key
+    self.callback = callback
+    self.callback_arguments = args
+
+  def trigger(self):
+    if self.callback_arguments is None:
+      self.callback()
+    else:
+      self.callback(*self.callback_arguments)

arduino/test.py

@@ -0,0 +1,22 @@
+# The following functions are used for testing only
+# and provide a faux implementation of the user's functions
+from arduino import *
+
+def preload():
+  print('preload')
+
+def setup():
+  add_key_listener(KEY_UP, print, 'key:', 'up')
+  add_key_listener(KEY_DOWN, print, 'key:', 'down')
+  add_key_listener(KEY_LEFT, print, 'key:', 'left')
+  add_key_listener(KEY_RIGHT, print, 'key:', 'right')
+  print('setup')
+
+def loop():
+  print('loop')
+  delay(100)
+
+def cleanup():
+  print('cleanup')
+
+start(setup, loop, cleanup, preload)