Make Automatic Reader Theme pick background/text color based on dark mode preference (#5505)

* Make Automatic Reader Theme pick background/text color based on theme

* Use extension method

app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderActivity.kt

@@ -854,6 +854,7 @@ class ReaderActivity : BaseRxActivity<ReaderActivityBinding, ReaderPresenter>()
                         when (preferences.readerTheme().get()) {
                             0 -> android.R.color.white
                             2 -> R.color.reader_background_dark
+                            3 -> automaticBackgroundColor()
                             else -> android.R.color.black
                         }
                     )
@@ -902,6 +903,17 @@ class ReaderActivity : BaseRxActivity<ReaderActivityBinding, ReaderPresenter>()
                 .launchIn(lifecycleScope)
         }
 
+        /**
+         * Picks background color for [ReaderActivity] based on light/dark theme preference
+         */
+        private fun automaticBackgroundColor(): Int {
+            return if (baseContext.isNightMode()) {
+                R.color.reader_background_dark
+            } else {
+                android.R.color.white
+            }
+        }
+
         /**
          * Sets the visibility of the bottom page indicator according to [visible].
          */

app/src/main/java/eu/kanade/tachiyomi/ui/reader/viewer/ReaderTransitionView.kt

@@ -11,6 +11,7 @@ import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.data.preference.PreferencesHelper
 import eu.kanade.tachiyomi.databinding.ReaderTransitionViewBinding
 import eu.kanade.tachiyomi.ui.reader.model.ChapterTransition
+import eu.kanade.tachiyomi.util.system.isNightMode
 import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
 
@@ -23,7 +24,6 @@ class ReaderTransitionView @JvmOverloads constructor(context: Context, attrs: At
         binding = ReaderTransitionViewBinding.inflate(LayoutInflater.from(context), this, true)
         layoutParams = LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)
     }
-
     fun bind(transition: ChapterTransition) {
         when (transition) {
             is ChapterTransition.Prev -> bindPrevChapterTransition(transition)
@@ -34,6 +34,7 @@ class ReaderTransitionView @JvmOverloads constructor(context: Context, attrs: At
 
         val color = when (Injekt.get<PreferencesHelper>().readerTheme().get()) {
             0 -> context.getColor(android.R.color.black)
+            3 -> context.getColor(automaticTextColor())
             else -> context.getColor(android.R.color.white)
         }
         listOf(binding.upperText, binding.warningText, binding.lowerText).forEach {
@@ -41,6 +42,17 @@ class ReaderTransitionView @JvmOverloads constructor(context: Context, attrs: At
         }
     }
 
+    /**
+     * Picks text color for [ReaderActivity] based on light/dark theme preference
+     */
+    private fun automaticTextColor(): Int {
+        return if (context.isNightMode()) {
+            android.R.color.white
+        } else {
+            android.R.color.black
+        }
+    }
+
     /**
      * Binds a previous chapter transition on this view and subscribes to the page load status.
      */