Option to clear chapter cache when MainActivity is closed (closes #5651)

app/src/main/java/eu/kanade/tachiyomi/ui/main/MainActivity.kt

@@ -34,6 +34,7 @@ import dev.chrisbanes.insetter.applyInsetter
 import eu.kanade.tachiyomi.BuildConfig
 import eu.kanade.tachiyomi.Migrations
 import eu.kanade.tachiyomi.R
+import eu.kanade.tachiyomi.data.cache.ChapterCache
 import eu.kanade.tachiyomi.data.notification.NotificationReceiver
 import eu.kanade.tachiyomi.data.preference.asImmediateFlow
 import eu.kanade.tachiyomi.data.updater.AppUpdateChecker
@@ -72,6 +73,7 @@ import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.merge
 import kotlinx.coroutines.flow.onEach
 import logcat.LogPriority
+import uy.kohesive.injekt.injectLazy
 
 class MainActivity : BaseViewBindingActivity<MainActivityBinding>() {
 
@@ -94,6 +96,8 @@ class MainActivity : BaseViewBindingActivity<MainActivityBinding>() {
      */
     private val backstackLiftState = mutableMapOf<String, Boolean>()
 
+    private val chapterCache: ChapterCache by injectLazy()
+
     // To be checked by splash screen. If true then splash screen will be removed.
     var ready = false
 
@@ -464,7 +468,10 @@ class MainActivity : BaseViewBindingActivity<MainActivityBinding>() {
             // Exit confirmation (resets after 2 seconds)
             lifecycleScope.launchUI { resetExitConfirmation() }
         } else if (backstackSize == 1 || !router.handleBack()) {
-            // Regular back
+            // Regular back (i.e. closing the app)
+            if (preferences.autoClearChapterCache()) {
+                chapterCache.clear()
+            }
             super.onBackPressed()
         }
     }

app/src/main/java/eu/kanade/tachiyomi/ui/setting/SettingsAdvancedController.kt

@@ -132,6 +132,11 @@ class SettingsAdvancedController : SettingsController() {
 
                 onClick { clearChapterCache() }
             }
+            switchPreference {
+                key = Keys.autoClearChapterCache
+                titleRes = R.string.pref_auto_clear_chapter_cache
+                defaultValue = false
+            }
             preference {
                 key = "pref_clear_database"
                 titleRes = R.string.pref_clear_database