android: Add per‑game Custom Settings with explicit overrides

- Save per‑game INIs to config/custom/.ini
  - Always persist explicit choices (even if equal to global); track touched keys
  - JNI overlays per‑game before ApplySettings
  - Show “Use default” per setting; hide when already default
  - Fix presenter to update model on change

src/android/app/src/main/java/org/citra/citra_emu/adapters/GameAdapter.kt

@@ -56,6 +56,8 @@ import org.citra.citra_emu.model.Game
 import org.citra.citra_emu.utils.FileUtil
 import org.citra.citra_emu.utils.GameIconUtils
 import org.citra.citra_emu.viewmodel.GamesViewModel
+import org.citra.citra_emu.features.settings.ui.SettingsActivity
+import org.citra.citra_emu.features.settings.utils.SettingsFile
 
 class GameAdapter(private val activity: AppCompatActivity, private val inflater: LayoutInflater,  private val openImageLauncher: ActivityResultLauncher<String>?) :
     ListAdapter<Game, GameViewHolder>(AsyncDifferConfig.Builder(DiffCallback()).build()),
@@ -441,6 +443,15 @@ class GameAdapter(private val activity: AppCompatActivity, private val inflater:
             bottomSheetDialog.dismiss()
         }
 
+        bottomSheetView.findViewById<MaterialButton>(R.id.application_settings).setOnClickListener {
+            SettingsActivity.launch(
+                context,
+                SettingsFile.FILE_NAME_CONFIG,
+                String.format("%016X", holder.game.titleId)
+            )
+            bottomSheetDialog.dismiss()
+        }
+
         bottomSheetView.findViewById<MaterialButton>(R.id.menu_button_open).setOnClickListener {
             showOpenContextMenu(it, game)
         }

src/android/app/src/main/java/org/citra/citra_emu/features/settings/model/Settings.kt

@@ -15,6 +15,7 @@ class Settings {
     private var gameId: String? = null
 
     var isLoaded = false
+    private val touchedKeys: MutableSet<String> = mutableSetOf()
 
     /**
      * A HashMap<String></String>, SettingSection> that constructs a new SettingSection instead of returning null
@@ -42,6 +43,7 @@ class Settings {
 
     fun loadSettings(view: SettingsActivityView? = null) {
         sections = SettingsSectionMap()
+        touchedKeys.clear()
         loadCitraSettings(view)
         if (!TextUtils.isEmpty(gameId)) {
             loadCustomGameSettings(gameId!!, view)
@@ -86,11 +88,92 @@ class Settings {
                 val iniSections = TreeMap<String, SettingSection?>()
                 for (section in sectionNames) {
                     iniSections[section] = sections[section]
-                }
-                SettingsFile.saveFile(fileName, iniSections, view)
             }
+            SettingsFile.saveFile(fileName, iniSections, view)
+        }
         } else {
-            // TODO: Implement per game settings
+            // Save per-game settings to config/custom/<gameId>.ini.
+            // Compare current (merged) values to global config.ini and include explicit choices.
+            val globalSections = SettingsFile.readFile(SettingsFile.FILE_NAME_CONFIG, view)
+
+            val overrides = TreeMap<String, SettingSection?>()
+            val priorOverrides = SettingsFile.readCustomGameSettings(gameId!!, view)
+            for ((sectionName, effectiveSection) in sections) {
+                if (effectiveSection == null) continue
+                val globalSection = globalSections[sectionName]
+                val priorSection = priorOverrides[sectionName]
+
+                val overrideSection = SettingSection(sectionName)
+                for ((key, effSetting) in effectiveSection.settings) {
+                    if (effSetting == null) continue
+
+                    val globalSetting = globalSection?.getSetting(key)
+                    val hadPrior = priorSection?.getSetting(key) != null
+                    val wasTouched = touchedKeys.contains("$sectionName::$key")
+
+                    // Include key when one of the following is true:
+                    // - value differs from the compiled default (explicit choice),
+                    // - key existed previously in the per-game file (preserve intent),
+                    // - user touched this setting in this session (explicit choice).
+                    if (!isDefaultValue(effSetting) || hadPrior || wasTouched) {
+                        val toWrite: AbstractSetting = if (isDefaultValue(effSetting))
+                            SimpleStringSetting(key, sectionName, "") else effSetting
+                        overrideSection.putSetting(toWrite)
+                    }
+                }
+
+                if (!overrideSection.settings.isEmpty()) {
+                    overrides[sectionName] = overrideSection
+                }
+            }
+
+            view.showToastMessage(
+                CitraApplication.appContext.getString(R.string.ini_saved),
+                false
+            )
+            SettingsFile.saveCustomFile(gameId!!, overrides, view)
+        }
+    }
+
+    private fun isDefaultValue(setting: AbstractSetting): Boolean = when (setting) {
+        is AbstractBooleanSetting -> setting.boolean == setting.defaultValue
+        is AbstractIntSetting -> setting.int == setting.defaultValue
+        is ScaledFloatSetting -> setting.float == setting.defaultValue * setting.scale
+        is FloatSetting -> setting.float == setting.defaultValue
+        is AbstractShortSetting -> setting.short == setting.defaultValue
+        is AbstractStringSetting -> setting.string == setting.defaultValue
+        else -> false
+    }
+
+    private fun areSettingsEqual(a: AbstractSetting, b: AbstractSetting?): Boolean {
+        if (b == null) {
+            // Global missing means it uses compiled default; equal if a is default.
+            return isDefaultValue(a)
+        }
+        return when {
+            a is AbstractBooleanSetting && b is AbstractBooleanSetting -> a.boolean == b.boolean
+            a is AbstractIntSetting && b is AbstractIntSetting -> a.int == b.int
+            a is ScaledFloatSetting && b is ScaledFloatSetting -> a.float == b.float
+            a is FloatSetting && b is FloatSetting -> a.float == b.float
+            a is AbstractShortSetting && b is AbstractShortSetting -> a.short == b.short
+            a is AbstractStringSetting && b is AbstractStringSetting -> a.string == b.string
+            else -> a.valueAsString == b.valueAsString
+        }
+    }
+
+    private data class SimpleStringSetting(
+        override val key: String?,
+        override val section: String?,
+        private val value: String
+    ) : AbstractSetting {
+        override val isRuntimeEditable: Boolean get() = true
+        override val valueAsString: String get() = value
+        override val defaultValue: Any get() = ""
+    }
+
+    fun markTouched(setting: AbstractSetting) {
+        if (setting.section != null && setting.key != null) {
+            touchedKeys.add("${setting.section}::${setting.key}")
         }
     }
 
@@ -245,4 +328,4 @@ class Settings {
                 )
         }
     }
-}
+}

src/android/app/src/main/java/org/citra/citra_emu/features/settings/ui/SettingsActivityPresenter.kt

@@ -29,6 +29,9 @@ class SettingsActivityPresenter(private val activityView: SettingsActivityView)
     fun onCreate(savedInstanceState: Bundle?, menuTag: String, gameId: String) {
         this.menuTag = menuTag
         this.gameId = gameId
+        // Force reload of settings for each entry to avoid leaking values between
+        // global and per-game contexts in the shared Settings instance.
+        settings.isLoaded = false
         if (savedInstanceState != null) {
             shouldSave = savedInstanceState.getBoolean(KEY_SHOULD_SAVE)
         }

src/android/app/src/main/java/org/citra/citra_emu/features/settings/ui/SettingsAdapter.kt

@@ -74,6 +74,7 @@ class SettingsAdapter(
     public val context: Context
 ) : RecyclerView.Adapter<SettingViewHolder?>(), DialogInterface.OnClickListener {
     private var settings: ArrayList<SettingsItem>? = null
+    var isPerGame: Boolean = false
     private var clickedItem: SettingsItem? = null
     private var clickedPosition: Int
     private var dialog: AlertDialog? = null
@@ -531,23 +532,7 @@ class SettingsAdapter(
         MaterialAlertDialogBuilder(context)
             .setMessage(R.string.reset_setting_confirmation)
             .setPositiveButton(android.R.string.ok) { _: DialogInterface, _: Int ->
-                when (setting) {
-                    is AbstractBooleanSetting -> setting.boolean = setting.defaultValue as Boolean
-                    is AbstractFloatSetting -> {
-                        if (setting is ScaledFloatSetting) {
-                            setting.float = setting.defaultValue * setting.scale
-                        } else {
-                            setting.float = setting.defaultValue as Float
-                        }
-                    }
-
-                    is AbstractIntSetting -> setting.int = setting.defaultValue as Int
-                    is AbstractStringSetting -> setting.string = setting.defaultValue as String
-                    is AbstractShortSetting -> setting.short = setting.defaultValue as Short
-                }
-                notifyItemChanged(position)
-                fragmentView.onSettingChanged()
-                fragmentView.loadSettingsList()
+                resetSettingToDefault(setting, position)
             }
             .setNegativeButton(android.R.string.cancel, null)
             .show()
@@ -555,6 +540,35 @@ class SettingsAdapter(
         return true
     }
 
+    fun resetSettingToDefault(setting: AbstractSetting, position: Int) {
+        when (setting) {
+            is AbstractBooleanSetting -> setting.boolean = setting.defaultValue as Boolean
+            is AbstractFloatSetting -> {
+                if (setting is ScaledFloatSetting) {
+                    setting.float = setting.defaultValue * setting.scale
+                } else {
+                    setting.float = setting.defaultValue as Float
+                }
+            }
+            is AbstractIntSetting -> setting.int = setting.defaultValue as Int
+            is AbstractStringSetting -> setting.string = setting.defaultValue as String
+            is AbstractShortSetting -> setting.short = setting.defaultValue as Short
+        }
+        notifyItemChanged(position)
+        fragmentView.onSettingChanged()
+        fragmentView.loadSettingsList()
+    }
+
+    fun isAtCompiledDefault(s: AbstractSetting): Boolean = when (s) {
+        is AbstractBooleanSetting -> s.boolean == s.defaultValue
+        is AbstractIntSetting -> s.int == s.defaultValue
+        is ScaledFloatSetting -> s.float == s.defaultValue * s.scale
+        is AbstractFloatSetting -> s.float == s.defaultValue
+        is AbstractShortSetting -> s.short == s.defaultValue
+        is AbstractStringSetting -> s.string == s.defaultValue
+        else -> false
+    }
+
     fun onClickDisabledSetting(isRuntimeDisabled: Boolean) {
         val titleId = if (isRuntimeDisabled)
             R.string.setting_not_editable

src/android/app/src/main/java/org/citra/citra_emu/features/settings/ui/SettingsFragmentPresenter.kt

@@ -65,6 +65,7 @@ class SettingsFragmentPresenter(private val fragmentView: SettingsFragmentView)
     fun onViewCreated(settingsAdapter: SettingsAdapter) {
         this.settingsAdapter = settingsAdapter
         preferences = PreferenceManager.getDefaultSharedPreferences(CitraApplication.appContext)
+        settingsAdapter.isPerGame = !TextUtils.isEmpty(gameId)
         loadSettingsList()
     }
 
@@ -74,9 +75,9 @@ class SettingsFragmentPresenter(private val fragmentView: SettingsFragmentView)
         }
 
         val section = settings.getSection(setting.section!!)!!
-        if (section.getSetting(setting.key!!) == null) {
-            section.putSetting(setting)
-        }
+        // Update setting and mark as touched so changes persist and save explicitly.
+        section.putSetting(setting)
+        settings.markTouched(setting)
     }
 
     fun loadSettingsList() {

src/android/app/src/main/java/org/citra/citra_emu/features/settings/ui/viewholder/SingleChoiceViewHolder.kt

@@ -36,6 +36,18 @@ class SingleChoiceViewHolder(val binding: ListItemSettingBinding, adapter: Setti
             binding.textSettingDescription.alpha = 0.5f
             binding.textSettingValue.alpha = 0.5f
         }
+
+        // Show "Use default" button in Custom Settings if applicable.
+        val adapterIsPerGame = adapter.isPerGame
+        val showDefault = adapterIsPerGame && setting.setting != null && !adapter.isAtCompiledDefault(setting.setting!!)
+        binding.buttonUseDefault.visibility = if (showDefault) View.VISIBLE else View.GONE
+        if (showDefault) {
+            binding.buttonUseDefault.setOnClickListener {
+                if (setting.setting != null) {
+                    adapter.resetSettingToDefault(setting.setting!!, bindingAdapterPosition)
+                }
+            }
+        }
     }
 
     private fun getTextSetting(): String {

src/android/app/src/main/java/org/citra/citra_emu/features/settings/ui/viewholder/SliderViewHolder.kt

@@ -44,6 +44,18 @@ class SliderViewHolder(val binding: ListItemSettingBinding, adapter: SettingsAda
             binding.textSettingDescription.alpha = 0.5f
             binding.textSettingValue.alpha = 0.5f
         }
+
+        // Show "Use default" button in Custom Settings if applicable.
+        val adapterIsPerGame = adapter.isPerGame
+        val showDefault = adapterIsPerGame && setting.setting != null && !adapter.isAtCompiledDefault(setting.setting!!)
+        binding.buttonUseDefault.visibility = if (showDefault) View.VISIBLE else View.GONE
+        if (showDefault) {
+            binding.buttonUseDefault.setOnClickListener {
+                if (setting.setting != null) {
+                    adapter.resetSettingToDefault(setting.setting!!, bindingAdapterPosition)
+                }
+            }
+        }
     }
 
     override fun onClick(clicked: View) {

src/android/app/src/main/java/org/citra/citra_emu/features/settings/ui/viewholder/StringInputViewHolder.kt

@@ -35,6 +35,18 @@ class StringInputViewHolder(val binding: ListItemSettingBinding, adapter: Settin
             binding.textSettingDescription.alpha = 0.5f
             binding.textSettingValue.alpha = 0.5f
         }
+
+        // Show "Use default" button in Custom Settings if applicable.
+        val adapterIsPerGame = adapter.isPerGame
+        val showDefault = adapterIsPerGame && setting.setting != null && !adapter.isAtCompiledDefault(setting.setting!!)
+        binding.buttonUseDefault.visibility = if (showDefault) View.VISIBLE else View.GONE
+        if (showDefault) {
+            binding.buttonUseDefault.setOnClickListener {
+                if (setting.setting != null) {
+                    adapter.resetSettingToDefault(setting.setting!!, bindingAdapterPosition)
+                }
+            }
+        }
     }
 
     override fun onClick(clicked: View) {

src/android/app/src/main/java/org/citra/citra_emu/features/settings/ui/viewholder/SwitchSettingViewHolder.kt

@@ -38,6 +38,18 @@ class SwitchSettingViewHolder(val binding: ListItemSettingSwitchBinding, adapter
         val textAlpha = if (setting.isActive) 1f else 0.5f
         binding.textSettingName.alpha = textAlpha
         binding.textSettingDescription.alpha = textAlpha
+
+        // Show "Use default" button in Custom Settings if applicable.
+        val adapterIsPerGame = adapter.isPerGame
+        val showDefault = adapterIsPerGame && setting.setting != null && !adapter.isAtCompiledDefault(setting.setting!!)
+        binding.buttonUseDefault.visibility = if (showDefault) View.VISIBLE else View.GONE
+        if (showDefault) {
+            binding.buttonUseDefault.setOnClickListener {
+                if (setting.setting != null) {
+                    adapter.resetSettingToDefault(setting.setting!!, bindingAdapterPosition)
+                }
+            }
+        }
     }
 
     override fun onClick(clicked: View) {

src/android/app/src/main/java/org/citra/citra_emu/features/settings/utils/SettingsFile.kt

@@ -107,7 +107,8 @@ object SettingsFile {
         gameId: String,
         view: SettingsActivityView?
     ): HashMap<String, SettingSection?> {
-        return readFile(getCustomGameSettingsFile(gameId), true, view)
+        val file = findCustomGameSettingsFile(gameId) ?: return SettingsSectionMap()
+        return readFile(file, true, view)
     }
 
     /**
@@ -147,6 +148,28 @@ object SettingsFile {
         }
     }
 
+    fun saveCustomFile(
+        gameId: String,
+        sections: TreeMap<String, SettingSection?>,
+        view: SettingsActivityView
+    ) {
+        val ini = getOrCreateCustomGameSettingsFile(gameId)
+        try {
+            val context: Context = CitraApplication.appContext
+            val outputStream = context.contentResolver.openOutputStream(ini.uri, "wt")
+            val parser = Wini()
+            for ((_, section) in sections) {
+                if (section != null) writeSection(parser, section)
+            }
+            parser.store(outputStream)
+            outputStream!!.flush()
+            outputStream.close()
+        } catch (e: Exception) {
+            Log.error("[SettingsFile] Error saving custom file: config/custom/$gameId.ini: ${e.message}")
+            view.onSettingsFileNotFound()
+        }
+    }
+
     fun saveFile(
         fileName: String,
         setting: AbstractSetting
@@ -189,10 +212,26 @@ object SettingsFile {
         return configDirectory!!.findFile("$fileName.ini")!!
     }
 
-    private fun getCustomGameSettingsFile(gameId: String): DocumentFile {
+    private fun findCustomGameSettingsFile(gameId: String): DocumentFile? {
         val root = DocumentFile.fromTreeUri(CitraApplication.appContext, Uri.parse(userDirectory))
-        val configDirectory = root!!.findFile("GameSettings")
-        return configDirectory!!.findFile("$gameId.ini")!!
+        val configDir = root?.findFile("config") ?: return null
+        val customDir = configDir.findFile("custom") ?: return null
+        return customDir.findFile("$gameId.ini")
+    }
+
+    private fun getOrCreateCustomGameSettingsFile(gameId: String): DocumentFile {
+        val root = DocumentFile.fromTreeUri(CitraApplication.appContext, Uri.parse(userDirectory))!!
+        val configDir = root.findFile("config") ?: root.createDirectory("config")
+        var customDir = configDir?.findFile("custom")
+        if (customDir == null || !customDir.isDirectory) {
+            customDir = configDir?.createDirectory("custom")
+        }
+        var file = customDir!!.findFile("$gameId.ini")
+        if (file == null) {
+            // Use generic MIME to avoid providers appending ".txt" to the name
+            file = customDir.createFile("*/*", "$gameId.ini")
+        }
+        return file!!
     }
 
     private fun sectionFromLine(line: String, isCustomGame: Boolean): SettingSection {

src/android/app/src/main/java/org/citra/citra_emu/fragments/EmulationFragment.kt

@@ -359,6 +359,27 @@ class EmulationFragment : Fragment(), SurfaceHolder.Callback, Choreographer.Fram
                     true
                 }
 
+                R.id.menu_application_settings -> {
+                    val titleId = NativeLibrary.getRunningTitleId()
+                    if (titleId != 0L) {
+                        val gameId = java.lang.String.format("%016X", titleId)
+                        SettingsActivity.launch(
+                            requireContext(),
+                            SettingsFile.FILE_NAME_CONFIG,
+                            gameId
+                        )
+                    } else {
+                        // Fallback: open global settings if title id unknown
+                        SettingsActivity.launch(
+                            requireContext(),
+                            SettingsFile.FILE_NAME_CONFIG,
+                            ""
+                        )
+                    }
+
+                    true
+                }
+
                 R.id.menu_exit -> {
                     emulationState.pause()
                     MaterialAlertDialogBuilder(requireContext())

src/android/app/src/main/jni/config.cpp

@@ -77,7 +77,12 @@ static const std::array<int, Settings::NativeAnalog::NumAnalogs> default_analogs
 
 template <>
 void Config::ReadSetting(const std::string& group, Settings::Setting<std::string>& setting) {
-    std::string setting_value = sdl2_config->Get(group, setting.GetLabel(), setting.GetDefault());
+    std::string setting_value = setting.GetDefault();
+    if (per_game_config && per_game_config->HasValue(group, setting.GetLabel())) {
+        setting_value = per_game_config->Get(group, setting.GetLabel(), setting_value);
+    } else if (sdl2_config) {
+        setting_value = sdl2_config->Get(group, setting.GetLabel(), setting_value);
+    }
     if (setting_value.empty()) {
         setting_value = setting.GetDefault();
     }
@@ -86,16 +91,33 @@ void Config::ReadSetting(const std::string& group, Settings::Setting<std::string
 
 template <>
 void Config::ReadSetting(const std::string& group, Settings::Setting<bool>& setting) {
-    setting = sdl2_config->GetBoolean(group, setting.GetLabel(), setting.GetDefault());
+    bool value = setting.GetDefault();
+    if (per_game_config && per_game_config->HasValue(group, setting.GetLabel())) {
+        value = per_game_config->GetBoolean(group, setting.GetLabel(), value);
+    } else if (sdl2_config) {
+        value = sdl2_config->GetBoolean(group, setting.GetLabel(), value);
+    }
+    setting = value;
 }
 
 template <typename Type, bool ranged>
 void Config::ReadSetting(const std::string& group, Settings::Setting<Type, ranged>& setting) {
     if constexpr (std::is_floating_point_v<Type>) {
-        setting = sdl2_config->GetReal(group, setting.GetLabel(), setting.GetDefault());
+        double value = static_cast<double>(setting.GetDefault());
+        if (per_game_config && per_game_config->HasValue(group, setting.GetLabel())) {
+            value = per_game_config->GetReal(group, setting.GetLabel(), value);
+        } else if (sdl2_config) {
+            value = sdl2_config->GetReal(group, setting.GetLabel(), value);
+        }
+        setting = static_cast<Type>(value);
     } else {
-        setting = static_cast<Type>(sdl2_config->GetInteger(
-            group, setting.GetLabel(), static_cast<long>(setting.GetDefault())));
+        long value = static_cast<long>(setting.GetDefault());
+        if (per_game_config && per_game_config->HasValue(group, setting.GetLabel())) {
+            value = per_game_config->GetInteger(group, setting.GetLabel(), value);
+        } else if (sdl2_config) {
+            value = sdl2_config->GetInteger(group, setting.GetLabel(), value);
+        }
+        setting = static_cast<Type>(value);
     }
 }
 
@@ -320,3 +342,37 @@ void Config::Reload() {
     LoadINI(DefaultINI::sdl2_config_file);
     ReadValues();
 }
+
+void Config::LoadPerGameConfig(u64 title_id, const std::string& fallback_name) {
+    // Determine file name
+    std::string name;
+    if (title_id != 0) {
+        std::ostringstream ss;
+        ss << std::uppercase << std::hex << std::setw(16) << std::setfill('0') << title_id;
+        name = ss.str();
+    } else {
+        name = fallback_name;
+    }
+    if (name.empty()) {
+        per_game_config.reset();
+        per_game_config_loc.clear();
+        return;
+    }
+
+    const auto base = FileUtil::GetUserPath(FileUtil::UserPath::ConfigDir);
+    per_game_config_loc = base + "custom/" + name + ".ini";
+
+    std::string ini_buffer;
+    FileUtil::ReadFileToString(true, per_game_config_loc, ini_buffer);
+    if (!ini_buffer.empty()) {
+        per_game_config = std::make_unique<INIReader>(ini_buffer.c_str(), ini_buffer.size());
+        if (per_game_config->ParseError() < 0) {
+            per_game_config.reset();
+        }
+    } else {
+        per_game_config.reset();
+    }
+
+    // Re-apply values so that per-game overrides (if any) take effect immediately.
+    ReadValues();
+}

src/android/app/src/main/jni/config.h

@@ -14,6 +14,8 @@ class Config {
 private:
     std::unique_ptr<INIReader> sdl2_config;
     std::string sdl2_config_loc;
+    std::unique_ptr<INIReader> per_game_config;
+    std::string per_game_config_loc;
 
     bool LoadINI(const std::string& default_contents = "", bool retry = true);
     void ReadValues();
@@ -23,6 +25,8 @@ public:
     ~Config();
 
     void Reload();
+    // Load a per-game config overlay by title id or fallback name. Does not create files.
+    void LoadPerGameConfig(u64 title_id, const std::string& fallback_name = "");
 
 private:
     /**

src/android/app/src/main/jni/native.cpp

@@ -205,8 +205,8 @@ static Core::System::ResultStatus RunCitra(const std::string& filepath) {
     }
 
     // Forces a config reload on game boot, if the user changed settings in the UI
-    Config{};
-    // Replace with game-specific settings
+    Config global_config{};
+    // Load game-specific settings overlay if available
     u64 program_id{};
     FileUtil::SetCurrentRomPath(filepath);
     auto app_loader = Loader::GetLoader(filepath);
@@ -214,6 +214,10 @@ static Core::System::ResultStatus RunCitra(const std::string& filepath) {
         app_loader->ReadProgramId(program_id);
         system.RegisterAppLoaderEarly(app_loader);
     }
+    // Use filename as fallback if title id is zero (e.g., homebrew)
+    const std::string fallback_name =
+        program_id == 0 ? std::string(FileUtil::GetFilename(filepath)) : std::string{};
+    global_config.LoadPerGameConfig(program_id, fallback_name);
     system.ApplySettings();
     Settings::LogSettings();
 
@@ -726,13 +730,18 @@ void Java_org_citra_citra_1emu_NativeLibrary_logUserDirectory(JNIEnv* env,
 
 void Java_org_citra_citra_1emu_NativeLibrary_reloadSettings([[maybe_unused]] JNIEnv* env,
                                                             [[maybe_unused]] jobject obj) {
-    Config{};
+    Config cfg{};
     Core::System& system{Core::System::GetInstance()};
 
-    // Replace with game-specific settings
+    // Load game-specific settings overlay (if a game is running)
     if (system.IsPoweredOn()) {
         u64 program_id{};
         system.GetAppLoader().ReadProgramId(program_id);
+        // Use the registered ROM path (if any) to derive a fallback name
+        const std::string current_rom_path = FileUtil::GetCurrentRomPath();
+        const std::string fallback_name =
+            program_id == 0 ? std::string(FileUtil::GetFilename(current_rom_path)) : std::string{};
+        cfg.LoadPerGameConfig(program_id, fallback_name);
     }
 
     system.ApplySettings();

src/android/app/src/main/res/layout/dialog_about_game.xml

@@ -179,6 +179,14 @@
                 android:contentDescription="@string/cheats"
                 android:text="@string/cheats" />
 
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/application_settings"
+                style="@style/Widget.Material3.Button.TonalButton.Icon"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginStart="8dp"
+                android:contentDescription="@string/application_settings"
+                android:text="@string/application_settings" />
 
         </LinearLayout>
 

src/android/app/src/main/res/layout/list_item_setting.xml

@@ -62,6 +62,15 @@
                 android:textSize="13sp"
                 tools:text="1x" />
 
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/button_use_default"
+                style="@style/Widget.Material3.Button.TextButton"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="4dp"
+                android:text="@string/use_default"
+                android:visibility="gone" />
+
         </LinearLayout>
 
     </LinearLayout>

src/android/app/src/main/res/layout/list_item_setting_switch.xml

@@ -46,6 +46,15 @@
             android:textAlignment="viewStart"
             tools:text="@string/frame_limit_enable_description" />
 
+        <com.google.android.material.button.MaterialButton
+            android:id="@+id/button_use_default"
+            style="@style/Widget.Material3.Button.TextButton"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="4dp"
+            android:text="@string/use_default"
+            android:visibility="gone" />
+
     </LinearLayout>
 
 </RelativeLayout>

src/android/app/src/main/res/menu/menu_in_game.xml

@@ -57,6 +57,11 @@
         android:icon="@drawable/ic_settings"
         android:title="@string/preferences_settings" />
 
+    <item
+        android:id="@+id/menu_application_settings"
+        android:icon="@drawable/ic_settings"
+        android:title="@string/application_settings" />
+
     <item
         android:id="@+id/menu_exit"
         android:icon="@drawable/ic_exit"

src/android/app/src/main/res/values/strings.xml

@@ -494,6 +494,8 @@
     <string name="menu_emulation_amiibo">Amiibo</string>
     <string name="menu_emulation_amiibo_load">Load</string>
     <string name="menu_emulation_amiibo_remove">Remove</string>
+    <string name="application_settings">Custom Settings</string>
+    <string name="use_default">Use default</string>
     <string name="select_amiibo">Select Amiibo File</string>
     <string name="amiibo_load_error">Error Loading Amiibo</string>
     <string name="amiibo_load_error_message">While loading the specified Amiibo file, an error occurred. Please check that the file is correct.</string>

src/common/file_util.cpp

@@ -884,6 +884,10 @@ void SetCurrentRomPath(const std::string& path) {
     g_currentRomPath = path;
 }
 
+std::string GetCurrentRomPath() {
+    return g_currentRomPath;
+}
+
 bool StringReplace(std::string& haystack, const std::string& a, const std::string& b, bool swap) {
     const auto& needle = swap ? b : a;
     const auto& replacement = swap ? a : b;

src/common/file_util.h

@@ -200,6 +200,7 @@ bool SetCurrentDir(const std::string& directory);
 void SetUserPath(const std::string& path = "");
 
 void SetCurrentRomPath(const std::string& path);
+[[nodiscard]] std::string GetCurrentRomPath();
 
 // Returns a pointer to a string with a Citra data dir in the user's home
 // directory. To be used in "multi-user" mode (that is, installed).
@@ -547,4 +548,4 @@ void OpenFStream(T& fstream, const std::string& filename, std::ios_base::openmod
 }
 
 BOOST_CLASS_EXPORT_KEY(FileUtil::IOFile)
-BOOST_CLASS_EXPORT_KEY(FileUtil::CryptoIOFile)
+BOOST_CLASS_EXPORT_KEY(FileUtil::CryptoIOFile)