implemented top level menu

README.md

@@ -0,0 +1 @@
+A menu-driven application launcher for a Raspberry Pi Zero with an Adafruit OLED bonnet.

cinput.py

@@ -0,0 +1,41 @@
+import board
+from digitalio import DigitalInOut, Direction, Pull
+from enum import Enum, auto
+from time import sleep
+
+class Button(Enum):
+    BTN_A = auto()
+    BTN_B = auto()
+    BTN_C = auto()
+    DIR_U = auto()
+    DIR_R = auto()
+    DIR_D = auto()
+    DIR_L = auto()
+
+class ControlInput:
+    _buttons = {
+            Button.BTN_A: DigitalInOut(board.D5),
+            Button.BTN_B: DigitalInOut(board.D6),
+            Button.BTN_C: DigitalInOut(board.D4),
+            Button.DIR_U: DigitalInOut(board.D17),
+            Button.DIR_R: DigitalInOut(board.D23),
+            Button.DIR_L: DigitalInOut(board.D27),
+            Button.DIR_D: DigitalInOut(board.D22),
+            }
+
+    _pressed = set()
+
+    def __init__(self):
+        for button in self._buttons:
+           self._buttons[button].direction = Direction.INPUT
+           self._buttons[button].pull = Pull.UP
+
+    def get_one_shot(self):
+        while True:
+            for button in self._buttons:
+                if not self._buttons[button].value and not button in self._pressed:
+                    self._pressed.add(button)
+                    return button
+                elif self._buttons[button].value:
+                    self._pressed.discard(button)
+

graphics.py

@@ -0,0 +1,24 @@
+from board import SCL, SDA
+from busio import I2C
+from adafruit_ssd1306 import SSD1306_I2C
+
+class Graphics:
+    OLED_WIDTH = 128
+    OLED_HEIGHT = 64
+    OLED_ADDR = 0x3C
+    LINE_HEIGHT = 9
+    MAX_LINES = 7
+
+    def __init__(self):
+        i2c = I2C(SCL, SDA)
+        self._display = SSD1306_I2C(
+                self.OLED_WIDTH, self.OLED_HEIGHT, i2c, addr = self.OLED_ADDR)
+
+    def clear(self):
+        self._display.fill(0)
+
+    def text(self, text, x, y, c):
+        self._display.text(text, x, y, c)
+
+    def show(self):
+        self._display.show()

main.py

@@ -1,4 +1,24 @@
-from menu import Menu
+import os
-from icecream import ic
+from menu import Menu, MenuItem, MenuType
+from cinput import ControlInput
+from graphics import Graphics
 
-ic(Menu)
+menu_config = [
+        MenuItem("Information",
+            MenuType.EXEC_PLUGIN),
+        MenuItem("Apps",
+            MenuType.SUB_MENU),
+        MenuItem("Reboot",
+            MenuType.EXEC_CMD),
+        MenuItem("Shutdown",
+            MenuType.EXEC_CMD)]
+
+cinput = ControlInput()
+graphics = Graphics()
+menu = Menu(menu_config, cinput, graphics)
+try:
+    menu.get_selection()
+except KeyboardInterrupt:
+    graphics.clear()
+    graphics.show()
+    os._exit(0)

menu.py

@@ -1,5 +1,10 @@
+from board import SCL, SDA
+from busio import I2C
+from adafruit_ssd1306 import SSD1306_I2C
 from enum import Enum, auto
 from dataclasses import dataclass
+from cinput import ControlInput, Button
+from graphics import Graphics
 
 class MenuType(Enum):
     SUB_MENU = auto()
@@ -11,12 +16,35 @@ class MenuItem:
     display: str
     menu_type: MenuType
 
-Menu = [
+class Menu:
-        MenuItem("df -h",
+    def __init__(
-            MenuType.EXEC_CMD),
+            self, config: list[MenuItem], cinput: ControlInput, graphics: Graphics):
-        MenuItem("Chess",
+        self._selected_index = 0
-            MenuType.EXEC_PLUGIN),
+        self._menu = config
-        MenuItem("Reboot",
+        self._input = cinput
-            MenuType.EXEC_CMD),
+        self._graphics = graphics
-        MenuItem("Shutdown",
+
-            MenuType.EXEC_CMD)]
+    def _print(self, items: list[MenuItem]):
+        self._graphics.clear()
+        top_index = 0 if self._selected_index < Graphics.MAX_LINES else Graphics.MAX_LINES - self._selected_index + 1
+
+        for idx in range(top_index, top_index + Graphics.MAX_LINES):
+            if idx >= len(items):
+                break
+            marker = "> " if idx == self._selected_index else "  "
+            self._graphics.text(marker + items[idx].display, 0, (idx - top_index) * Graphics.LINE_HEIGHT, 1)
+
+        self._graphics.show()
+
+    def get_selection(self):
+        while True:
+            self._print(self._menu)
+            pressed = self._input.get_one_shot()
+            if pressed == Button.DIR_U:
+                self._selected_index -= 1
+                if self._selected_index < 0:
+                    self._selected_index = len(self._menu) - 1
+            elif pressed == Button.DIR_D:
+                self._selected_index += 1
+                if self._selected_index >= len(self._menu):
+                    self._selected_index = 0