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Nook GL4 Plus: make warmth survive B&N's colour temperature service #620

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Merged
hugleo merged 2 commits into from
Sep 5, 2026
Merged

Nook GL4 Plus: make warmth survive B&N's colour temperature service #620

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Nook GL4 Plus: make warmth survive B&N's colour temperature service
backcountrymountains Aug 13, 2026
2cfaffe
Nook GL4 Plus: shorten added comments
backcountrymountains Sep 5, 2026
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30 changes: 29 additions & 1 deletion app/src/main/java/org/koreader/launcher/device/lights/NookGL4plusController.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,8 @@ import org.koreader.launcher.device.LightsInterface
* Sends action_set_color_temperature (0-100 scale); the service rescales to 0-10 for
* the lm3630a_led hardware and calls PowerManager.setFrontlightBrightnessColor() using
* its own DEVICE_POWER privilege.
* The service also re-applies warmth on every SCREEN_ON, forcing it to cold unless its
* CTM mode is manual, so we assert that mode before the first warmth write.
* see https://github.com/koreader/koreader/issues/14574
*/
class NookGL4plusController : LightsInterface {
Expand All @@ -27,9 +29,13 @@ class NookGL4plusController : LightsInterface {
private const val GLOWLIGHT_SERVICE = "com.nook.partner.service.GlowLightService"
private const val ACTION_SET_COLOR_TEMPERATURE = "action_set_color_temperature"
private const val EXTRA_COLOR_TEMPERATURE = "extra_color_temperature"
private const val ACTION_SET_CTM_MODE = "action_set_ctm_mode"
private const val EXTRA_CTM_MODE = "extra_ctm_mode"
private const val CTM_MODE_MANUAL = 0
}

@Volatile private var currentWarmth: Int = MIN
@Volatile private var ctmModeAsserted: Boolean = false

override fun getPlatform(): String = "nook"
override fun hasFallback(): Boolean = false
Expand Down Expand Up @@ -76,11 +82,33 @@ class NookGL4plusController : LightsInterface {
Log.w(TAG, "warmth value out of range: $warmth")
return
}
if (warmth == getWarmth(activity)) return
// Never skip the first write: it seeds the value the service re-applies.
if (ctmModeAsserted && warmth == getWarmth(activity)) return
Log.v(TAG, "Setting warmth to $warmth of $WARMTH_MAX")
assertManualCtmMode(activity)
setWarmthViaService(activity, warmth)
}

/* GlowLightService is an IntentService, so this is handled before the warmth intent
* that follows it. */
private fun assertManualCtmMode(activity: Activity) {
if (ctmModeAsserted) return
try {
val intent = Intent(ACTION_SET_CTM_MODE).apply {
component = ComponentName(GLOWLIGHT_PACKAGE, GLOWLIGHT_SERVICE)
putExtra(EXTRA_CTM_MODE, CTM_MODE_MANUAL)
}
if (activity.startService(intent) != null) {
ctmModeAsserted = true
Log.v(TAG, "CTM mode set to manual")
} else {
Log.w(TAG, "GlowLightService unavailable, cannot set CTM mode")
}
} catch (e: Exception) {
Log.w(TAG, "setting CTM mode failed: $e")
}
}

private fun setWarmthViaService(activity: Activity, warmth: Int): Boolean {
return try {
val intent = Intent(ACTION_SET_COLOR_TEMPERATURE).apply {
Expand Down
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