Fewer bugs, more code, shape done

[hackapet/Adafruit_Blinka_Displayio.git] / displayio / __init__.py

diff --git a/displayio/__init__.py b/displayio/__init__.py
index a908e1aa50bb54441ba43de0c821834af08d3d12..fad912245754a95d6d600a209f7882725a650986 100644 (file)
--- a/displayio/__init__.py
+++ b/displayio/__init__.py
@@ -16,7 +16,7 @@ displayio for Blinka
 * Author(s): Melissa LeBlanc-Williams
 
 """
-
+import threading
 from typing import Union
 from ._fourwire import FourWire
 from ._i2cdisplay import I2CDisplay
@@ -30,19 +30,68 @@ from ._ondiskbitmap import OnDiskBitmap
 from ._palette import Palette
 from ._shape import Shape
 from ._tilegrid import TileGrid
-from ._display import displays
 from ._displaybus import _DisplayBus
+from ._constants import CIRCUITPY_DISPLAY_LIMIT
 
 __version__ = "0.0.0+auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_Blinka_displayio.git"
 
 
+displays = []
+display_buses = []
+
+
+def _background():
+    """Main thread function to loop through all displays and update them"""
+    while True:
+        for display in displays:
+            display.background()
+
+
 def release_displays() -> None:
     """Releases any actively used displays so their busses and pins can be used again.
 
     Use this once in your code.py if you initialize a display. Place it right before the
     initialization so the display is active as long as possible.
     """
-    for _disp in displays:
-        _disp._release()  # pylint: disable=protected-access
+    for display in displays:
+        display.release()
     displays.clear()
+
+    for display_bus in display_buses:
+        display_bus.deinit()
+    display_buses.clear()
+
+
+def allocate_display(new_display: Union[Display, EPaperDisplay]) -> None:
+    """Add a display to the displays pool and return the new display"""
+    if len(displays) >= CIRCUITPY_DISPLAY_LIMIT:
+        raise RuntimeError("Too many displays")
+    displays.append(new_display)
+
+
+def allocate_display_bus(new_display_bus: _DisplayBus) -> None:
+    """Add a display bus to the display_buses pool and return the new display bus"""
+    if len(display_buses) >= CIRCUITPY_DISPLAY_LIMIT:
+        raise RuntimeError(
+            "Too many display busses; forgot displayio.release_displays() ?"
+        )
+    display_buses.append(new_display_bus)
+
+
+background_thread = threading.Thread(target=_background, daemon=True)
+
+
+# Start the background thread
+def _start_background():
+    if not background_thread.is_alive():
+        background_thread.start()
+
+
+def _stop_background():
+    if background_thread.is_alive():
+        # Stop the thread
+        background_thread.join()
+
+
+_start_background()