Bitmap Label does not update using displayio

[EAGrahamJr]

The following code (supplied by todbot on Discord and modified) shows that the bitmap_label does not update (or very slowly/sporadically) while the "regular" version flies.

import time, board,  displayio, i2cdisplaybus, terminalio
import adafruit_displayio_ssd1306

# Select one to run
# from adafruit_display_text import bitmap_label as label
from adafruit_display_text import label as label

displayio.release_displays()
dw,dh = 128, 32

i2c = board.I2C()
display_bus = i2cdisplaybus.I2CDisplayBus(i2c, device_address=0x3C)
display = adafruit_displayio_ssd1306.SSD1306(display_bus, width=dw, height=dh)
display.wake()

maingroup = displayio.Group()
display.root_group = maingroup
text1 = label.Label(terminalio.FONT, text="helloworld...", x=0, y=4)
text2 = label.Label(terminalio.FONT, text="@edgjr       ", x=0, y=19)

for t in (text1, text2):
    maingroup.append(t)

while True:
    try:
        text2.text = "%.1f" % time.monotonic()
        time.sleep(0.1)
    except KeyboardInterrupt:
        break

display.sleep()

Tested on Raspberry Pi Zero W, bookworm 32-bit

requirements.txt

The expectation is that the behavior should be similar. I do not know if this behavior is present on other displays like this since this is the only one I have at the moment 😃

[EAGrahamJr]

NOTE This is not reproducible using "plain ol'" CP -- I put the same SSD1306 display on an RP2040 via the STEMMA port with the following packages:

Found device at /media/edgjr/CIRCUITPY, running CircuitPython 9.1.0.
adafruit_displayio_ssd1306==2.0.2
adafruit_framebuf==1.6.5
adafruit_ticks==1.0.13
adafruit_bus_device==5.2.9
adafruit_bitmap_font==2.1.2
adafruit_display_text==3.1.2

This suggests to me that the issue lies in the Blinka implementation of the bitmap_label.