- retain search query when navigating *away* from SettingsSearchController

- keep `searchItem` in `expandActionView` state until user goes back (fixes the empty view in `SettingsSearchSearchController` issue)

app/src/main/java/eu/kanade/tachiyomi/data/preference/PreferencesHelper.kt

@@ -2,6 +2,7 @@ package eu.kanade.tachiyomi.data.preference
 
 import android.content.Context
 import android.os.Environment
+import androidx.core.content.edit
 import androidx.core.net.toUri
 import androidx.preference.PreferenceManager
 import com.tfcporciuncula.flow.FlowSharedPreferences
@@ -249,4 +250,8 @@ class PreferencesHelper(val context: Context) {
     fun trustedSignatures() = flowPrefs.getStringSet("trusted_signatures", emptySet())
 
     fun enableDoh() = prefs.getBoolean(Keys.enableDoh, false)
+
+    fun lastSearchQuerySearchSettings() = prefs.getString("last_search_query", "")
+    
+    fun lastSearchQuerySearchSettings(query: String) = prefs.edit { putString("last_search_query", query) }
 }

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

@@ -2,6 +2,7 @@ package eu.kanade.tachiyomi.ui.setting
 
 import android.view.Menu
 import android.view.MenuInflater
+import android.view.MenuItem
 import androidx.appcompat.widget.SearchView
 import androidx.preference.PreferenceScreen
 import eu.kanade.tachiyomi.R
@@ -13,11 +14,6 @@ import eu.kanade.tachiyomi.util.preference.onClick
 import eu.kanade.tachiyomi.util.preference.preference
 import eu.kanade.tachiyomi.util.preference.titleRes
 import eu.kanade.tachiyomi.util.system.getResourceColor
-import kotlinx.coroutines.flow.filterIsInstance
-import kotlinx.coroutines.flow.launchIn
-import kotlinx.coroutines.flow.onEach
-import reactivecircus.flowbinding.appcompat.QueryTextEvent
-import reactivecircus.flowbinding.appcompat.queryTextEvents
 
 class SettingsMainController : SettingsController() {
 
@@ -104,14 +100,16 @@ class SettingsMainController : SettingsController() {
         // Change hint to show global search.
         searchView.queryHint = applicationContext?.getString(R.string.action_search_settings)
 
-        // Create query listener which opens the global search view.
-        searchView.queryTextEvents()
-            .filterIsInstance<QueryTextEvent.QueryChanged>()
-            .onEach {
-                router.pushController(
-                    SettingsSearchController().withFadeTransaction()
-                )
+        searchItem.setOnActionExpandListener(object : MenuItem.OnActionExpandListener {
+            override fun onMenuItemActionExpand(item: MenuItem?): Boolean {
+                preferences.lastSearchQuerySearchSettings("") // reset saved search query
+                router.pushController(SettingsSearchController().withFadeTransaction())
+                return true
             }
-            .launchIn(scope)
+
+            override fun onMenuItemActionCollapse(item: MenuItem?): Boolean {
+                return true
+            }
+        })
     }
 }

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

@@ -27,6 +27,7 @@ class SettingsSearchController :
      * Adapter containing search results grouped by lang.
      */
     protected var adapter: SettingsSearchAdapter? = null
+    lateinit var searchView: SearchView
 
     init {
         setHasOptionsMenu(true)
@@ -69,7 +70,7 @@ class SettingsSearchController :
 
         // Initialize search menu
         val searchItem = menu.findItem(R.id.action_search)
-        val searchView = searchItem.actionView as SearchView
+        searchView = searchItem.actionView as SearchView
         searchView.maxWidth = Int.MAX_VALUE
 
         // Change hint to show "search settings."
@@ -80,22 +81,17 @@ class SettingsSearchController :
 
         searchItem.setOnActionExpandListener(object : MenuItem.OnActionExpandListener {
             override fun onMenuItemActionExpand(item: MenuItem?): Boolean {
-                searchView.onActionViewExpanded() // Required to show the query in the view
-                setItems(getResultSet())
                 return true
             }
 
             override fun onMenuItemActionCollapse(item: MenuItem?): Boolean {
-                searchView.onActionViewCollapsed() // Required to show the query in the view
                 router.popCurrentController()
-                return true
+                return false
             }
         })
 
         searchView.setOnQueryTextListener(object : SearchView.OnQueryTextListener {
             override fun onQueryTextSubmit(query: String?): Boolean {
-                searchItem.collapseActionView()
-                setTitle(query) // Update toolbar title
                 setItems(getResultSet(query))
                 return false
             }
@@ -105,6 +101,8 @@ class SettingsSearchController :
                 return false
             }
         })
+
+        searchView.setQuery(presenter.preferences.lastSearchQuerySearchSettings(), true)
     }
 
     override fun onViewCreated(view: View) {
@@ -161,6 +159,10 @@ class SettingsSearchController :
      * Opens a catalogue with the given search.
      */
     override fun onTitleClick(ctrl: SettingsController) {
+        searchView.query.let {
+            presenter.preferences.lastSearchQuerySearchSettings(it.toString())
+        }
+
         router.pushController(ctrl.withFadeTransaction())
     }
 }