From 4a7de80164ce6ec60dde5ba99d6ac84aa147d8d4 Mon Sep 17 00:00:00 2001
From: William Brawner <me@wbrawner.com>
Date: Mon, 21 Dec 2020 19:42:02 -0700
Subject: [PATCH] Improve handling of background dark mode changes

The wallpaper doesn't currently update if the dark mode setting changes while the device is asleep. I'm hoping this workaround solves that problem but we'll see.
---
 .../wbrawner/flatscapes/DesertLandscapeService.kt    | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/app/src/main/java/com/wbrawner/flatscapes/DesertLandscapeService.kt b/app/src/main/java/com/wbrawner/flatscapes/DesertLandscapeService.kt
index 8d47711..987804d 100644
--- a/app/src/main/java/com/wbrawner/flatscapes/DesertLandscapeService.kt
+++ b/app/src/main/java/com/wbrawner/flatscapes/DesertLandscapeService.kt
@@ -6,7 +6,6 @@ import android.graphics.Canvas
 import android.graphics.Rect
 import android.graphics.drawable.Drawable
 import android.service.wallpaper.WallpaperService
-import android.util.Log
 import android.util.TypedValue
 import android.view.SurfaceHolder
 import androidx.core.content.ContextCompat
@@ -20,6 +19,8 @@ class DesertLandscapeService : WallpaperService() {
     inner class Engine : WallpaperService.Engine() {
         private val random = Random(24849010328)
         private val stars = mutableListOf<Drawable>()
+        private var lastKnownUiModeConfig: Int? = null
+        private var holder: SurfaceHolder? = null
 
         override fun onCreate(surfaceHolder: SurfaceHolder?) {
             super.onCreate(surfaceHolder)
@@ -34,6 +35,8 @@ class DesertLandscapeService : WallpaperService() {
 
         override fun onSurfaceRedrawNeeded(holder: SurfaceHolder?) {
             super.onSurfaceRedrawNeeded(holder)
+            this.holder = holder
+            lastKnownUiModeConfig = applicationContext?.resources?.configuration?.uiMode?.and(Configuration.UI_MODE_NIGHT_MASK)
             holder?.draw { canvas ->
                 val canvasRect = Rect(0, 0, canvas.width, canvas.height)
                 ContextCompat.getDrawable(applicationContext, R.drawable.wallpaper_sky)
@@ -58,6 +61,13 @@ class DesertLandscapeService : WallpaperService() {
             }
         }
 
+        override fun onVisibilityChanged(visible: Boolean) {
+            super.onVisibilityChanged(visible)
+            if (applicationContext?.resources?.configuration?.uiMode?.and(Configuration.UI_MODE_NIGHT_MASK) != lastKnownUiModeConfig) {
+                onSurfaceRedrawNeeded(this.holder)
+            }
+        }
+
         private fun drawStars(canvas: Canvas) {
             canvas.save()
             var totalY = 0f