Files
bambuddy/spoolbuddy/tests/test_display_control.py
maziggy 18238cfeb2 fix(spoolbuddy): apply screen-blank timeout changes live without kiosk restart
Picking a new "Screen Blank Timeout" in SpoolBuddy Settings → Display
  didn't change actual blanking behaviour: whatever value was active when
  the kiosk last booted continued to fire. A user who started with the
  10m preset and switched to 1m or "Off" still saw the screen blank at 10m.

  Cause: blanking is driven by swayidle, started once by spoolbuddy-idle.sh
  at labwc autostart with the timeout passed as a command-line argument.
  The script fetched blank_timeout from the backend exactly once at startup
  and swayidle has no runtime control surface for changing its timeout.
  The daemon's display.set_blank_timeout() updated an in-memory variable
  that was never reached by swayidle, so UI changes were silently discarded
  until the next kiosk restart.

  Fix: extend the wake FIFO protocol with a "reload-timeout N" message.
  The daemon writes it whenever set_blank_timeout() sees a value that
  differs from the current one (the very first call is suppressed because
  the watchdog already fetched the same value at its own startup —
  signalling there would just thrash swayidle on every cold boot). The
  script's FIFO loop is restructured around start_swayidle / stop_swayidle
  helpers and a case statement: wake → wlopm --on + arm a re-blank at the
  current timeout; reload-timeout N → kill running swayidle, set TIMEOUT=N,
  restart swayidle, wlopm --on so the user sees the change took effect
  even if the screen was already blanked. The script de-dupes too — a
  reload-timeout whose N matches the current value is a no-op. Going from
  any positive timeout to 0 ("Off") stops swayidle and doesn't restart
  it; going from 0 to a positive value starts a fresh swayidle. Both work
  without a kiosk restart.

  The script's main loop opens the FIFO read+write (exec 3<>"$WAKE_FIFO")
  so bash read never sees EOF when the daemon momentarily disconnects
  between writes. A cleanup trap on TERM/INT/HUP stops swayidle, removes
  the FIFO, and exits cleanly.
2026-05-05 13:50:08 +02:00

270 lines
9.3 KiB
Python

"""Tests for daemon.display_control — DisplayControl brightness and blanking."""
import os
import time
import pytest
class TestDisplayControlNoBacklight:
"""DisplayControl behavior when no backlight is present."""
def test_no_backlight_detected(self, monkeypatch, tmp_path):
# Point BACKLIGHT_BASE to an empty directory (no backlight entries)
import daemon.display_control as dc_mod
empty_dir = tmp_path / "backlight"
empty_dir.mkdir()
monkeypatch.setattr(dc_mod, "BACKLIGHT_BASE", empty_dir)
dc = dc_mod.DisplayControl()
assert dc.has_backlight is False
def test_no_backlight_dir_missing(self, monkeypatch, tmp_path):
import daemon.display_control as dc_mod
monkeypatch.setattr(dc_mod, "BACKLIGHT_BASE", tmp_path / "nonexistent")
dc = dc_mod.DisplayControl()
assert dc.has_backlight is False
def test_set_brightness_noop_without_backlight(self, monkeypatch, tmp_path):
import daemon.display_control as dc_mod
empty_dir = tmp_path / "backlight"
empty_dir.mkdir()
monkeypatch.setattr(dc_mod, "BACKLIGHT_BASE", empty_dir)
dc = dc_mod.DisplayControl()
# Should not raise
dc.set_brightness(50)
dc.set_brightness(0)
dc.set_brightness(100)
class TestDisplayControlWithBacklight:
"""DisplayControl behavior with a mock sysfs backlight."""
@pytest.fixture
def display(self, monkeypatch, tmp_path):
import daemon.display_control as dc_mod
bl_dir = tmp_path / "backlight" / "rpi_backlight"
bl_dir.mkdir(parents=True)
(bl_dir / "brightness").write_text("200")
(bl_dir / "max_brightness").write_text("255")
monkeypatch.setattr(dc_mod, "BACKLIGHT_BASE", tmp_path / "backlight")
return dc_mod.DisplayControl(), bl_dir
def test_has_backlight_true(self, display):
dc, _ = display
assert dc.has_backlight is True
def test_set_brightness_100(self, display):
dc, bl_dir = display
dc.set_brightness(100)
assert (bl_dir / "brightness").read_text() == "255"
def test_set_brightness_0(self, display):
dc, bl_dir = display
dc.set_brightness(0)
assert (bl_dir / "brightness").read_text() == "0"
def test_set_brightness_50(self, display):
dc, bl_dir = display
dc.set_brightness(50)
value = int((bl_dir / "brightness").read_text())
# 50% of 255 = 127 or 128 depending on rounding
assert value == round(255 * 50 / 100)
def test_set_brightness_clamped_above_100(self, display):
dc, bl_dir = display
dc.set_brightness(200)
assert (bl_dir / "brightness").read_text() == "255"
def test_set_brightness_clamped_below_0(self, display):
dc, bl_dir = display
dc.set_brightness(-50)
assert (bl_dir / "brightness").read_text() == "0"
def test_max_brightness_fallback_on_missing_file(self, monkeypatch, tmp_path):
"""If max_brightness file doesn't exist, defaults to 255."""
import daemon.display_control as dc_mod
bl_dir = tmp_path / "backlight" / "rpi_backlight"
bl_dir.mkdir(parents=True)
(bl_dir / "brightness").write_text("100")
# No max_brightness file
monkeypatch.setattr(dc_mod, "BACKLIGHT_BASE", tmp_path / "backlight")
dc = dc_mod.DisplayControl()
assert dc._max_brightness == 255
class TestDisplayControlBlanking:
"""Blanking logic: timeout, wake, tick."""
@pytest.fixture
def display(self, monkeypatch, tmp_path):
import daemon.display_control as dc_mod
empty_dir = tmp_path / "backlight"
empty_dir.mkdir()
monkeypatch.setattr(dc_mod, "BACKLIGHT_BASE", empty_dir)
return dc_mod.DisplayControl()
def test_blank_timeout_default_disabled(self, display):
assert display._blank_timeout == 0
def test_set_blank_timeout(self, display):
display.set_blank_timeout(30)
assert display._blank_timeout == 30
def test_set_blank_timeout_negative_clamped(self, display):
display.set_blank_timeout(-10)
assert display._blank_timeout == 0
def test_tick_does_not_blank_when_disabled(self, display):
display.set_blank_timeout(0)
display.tick()
assert display._blanked is False
def test_tick_blanks_after_timeout(self, display, monkeypatch):
display.set_blank_timeout(5)
# Simulate idle for 10 seconds by backdating last_activity
display._last_activity = time.monotonic() - 10
display.tick()
assert display._blanked is True
def test_tick_does_not_blank_before_timeout(self, display):
display.set_blank_timeout(60)
display.wake() # Reset activity
display.tick()
assert display._blanked is False
def test_wake_unblanks(self, display):
display.set_blank_timeout(5)
display._last_activity = time.monotonic() - 10
display.tick()
assert display._blanked is True
display.wake()
assert display._blanked is False
def test_tick_unblanks_when_timeout_disabled_while_blanked(self, display):
"""If timeout is disabled while screen is blanked, tick should unblank."""
display.set_blank_timeout(5)
display._last_activity = time.monotonic() - 10
display.tick()
assert display._blanked is True
display.set_blank_timeout(0)
display.tick()
assert display._blanked is False
def test_wake_resets_activity_timer(self, display):
display.set_blank_timeout(5)
old_time = display._last_activity
time.sleep(0.01)
display.wake()
assert display._last_activity > old_time
class TestDisplayControlFifoMessages:
"""The wake FIFO carries two messages: `wake` and `reload-timeout N`.
These tests pin both — they're the only way the daemon can talk to
the idle watchdog (spoolbuddy-idle.sh) running in the Wayland session.
Regression target: a one-shot swayidle started with a stale timeout
value would never pick up UI changes without these signals.
"""
@pytest.fixture
def display_with_fifo(self, monkeypatch, tmp_path):
import daemon.display_control as dc_mod
empty_dir = tmp_path / "backlight"
empty_dir.mkdir()
monkeypatch.setattr(dc_mod, "BACKLIGHT_BASE", empty_dir)
fifo_path = tmp_path / "spoolbuddy-wake"
os.mkfifo(str(fifo_path), 0o622)
monkeypatch.setattr(dc_mod, "WAKE_FIFO", fifo_path)
# Hold a non-blocking reader open so the daemon's writes don't hit ENXIO.
reader_fd = os.open(str(fifo_path), os.O_RDONLY | os.O_NONBLOCK)
try:
yield dc_mod.DisplayControl(), reader_fd
finally:
os.close(reader_fd)
@staticmethod
def _drain(fd: int) -> bytes:
"""Read whatever is queued on the FIFO without blocking."""
try:
return os.read(fd, 4096)
except BlockingIOError:
return b""
def test_wake_writes_wake_line(self, display_with_fifo):
dc, reader_fd = display_with_fifo
dc.wake()
assert self._drain(reader_fd) == b"wake\n"
def test_first_set_blank_timeout_does_not_signal(self, display_with_fifo):
"""The watchdog already fetched this value at its own startup —
signalling here would just thrash swayidle for nothing."""
dc, reader_fd = display_with_fifo
dc.set_blank_timeout(300)
assert self._drain(reader_fd) == b""
assert dc._blank_timeout == 300
def test_subsequent_change_signals_reload(self, display_with_fifo):
dc, reader_fd = display_with_fifo
dc.set_blank_timeout(300) # init — no signal
dc.set_blank_timeout(60)
assert self._drain(reader_fd) == b"reload-timeout 60\n"
def test_same_value_does_not_signal(self, display_with_fifo):
dc, reader_fd = display_with_fifo
dc.set_blank_timeout(300)
dc.set_blank_timeout(300)
assert self._drain(reader_fd) == b""
def test_disable_after_enable_signals_zero(self, display_with_fifo):
"""Going from "blanking on" to "blanking off" must reach the watchdog
so it can stop swayidle — otherwise the screen keeps blanking even
after the user picks 'Off'."""
dc, reader_fd = display_with_fifo
dc.set_blank_timeout(300) # init
dc.set_blank_timeout(0)
assert self._drain(reader_fd) == b"reload-timeout 0\n"
def test_negative_clamped_to_zero_in_signal(self, display_with_fifo):
dc, reader_fd = display_with_fifo
dc.set_blank_timeout(300) # init
dc.set_blank_timeout(-5)
assert self._drain(reader_fd) == b"reload-timeout 0\n"
def test_signal_no_op_when_fifo_missing(self, monkeypatch, tmp_path):
"""No watchdog running = no FIFO. Writes must not raise."""
import daemon.display_control as dc_mod
empty_dir = tmp_path / "backlight"
empty_dir.mkdir()
monkeypatch.setattr(dc_mod, "BACKLIGHT_BASE", empty_dir)
monkeypatch.setattr(dc_mod, "WAKE_FIFO", tmp_path / "no-such-fifo")
dc = dc_mod.DisplayControl()
dc.set_blank_timeout(300)
dc.set_blank_timeout(60) # would signal if FIFO existed
dc.wake()
# No assertion needed — surviving without raising is the contract.